JP6777003B2 - Vehicle brake unit - Google Patents

Description

The present invention relates to a vehicle brake unit that is mounted on a vehicle and generates braking force.

Patent Document 1 describes an invention relating to an in-wheel motor drive device. The in-wheel motor is arranged on the inner peripheral portion of the wheel of the vehicle, and by outputting the driving torque, the wheel is directly driven to generate the driving force of the vehicle. In the in-wheel motor described in Patent Document 1, a drive motor, a motor housing for accommodating the drive motor, and a brake unit are arranged on the inner peripheral portion of the wheel of the wheel. The brake unit has a brake disc (brake rotor) attached so as to rotate integrally with the hub of the wheel, and a brake caliper for sandwiching the brake disc. A pressurizing mechanism (brake actuator) that presses the brake pad and presses it against the brake disc is provided inside the brake caliper.

In addition, Patent Document 2 includes a plurality of discs and a plurality of linings arranged alternately, and a plurality of discs and a plurality of linings are brought into frictional contact with each other by a magnetic attraction generated by energizing the coil. A multi-plate electromagnetic braking device that generates power is described. Such a multi-plate type brake can generate a larger braking force as compared with a single plate type brake or a disc brake of the same size.

JP-A-2015-54659 Jikkai Sho 63-11729

An in-wheel motor as described in Patent Document 1 can directly drive a drive wheel without using a differential gear or a drive shaft in a conventional vehicle. Therefore, as compared with the conventional vehicle, the degree of freedom in vehicle body design is high, and the comfortability and loadability of the vehicle can be improved. Further, since the left and right drive wheels can be controlled independently, it is possible to improve the steering stability performance and the turning running performance of the vehicle.

On the other hand, in a vehicle equipped with an in-wheel motor, the unsprung load of the vehicle becomes large, which causes a problem that the riding comfort of the vehicle and the ground contact property of the tire are deteriorated. Therefore, in-wheel motors are required to be as small and lightweight as possible. When a brake unit is provided together with a drive motor as in the in-wheel motor described in Patent Document 1, naturally, the brake unit is also required to be small and lightweight. The same applies not only to in-wheel motors but also to on-board type brake units (that is, in-board brakes) mounted on the vehicle body.

A disc brake as described in Patent Document 1 can be miniaturized by reducing the outer diameter of the brake rotor. However, as a trade-off, the braking force that can be generated by the brake unit also decreases. Therefore, for example, by adopting a multi-plate type braking device as described in Patent Document 2, the braking force can be secured. However, in that case, in order to reduce the size and weight of the brake unit, it is particularly important to make the brake actuator for applying pressing force to a plurality of friction plates as small and lightweight as possible. It becomes an issue.

Furthermore, when the vehicle brake unit is configured, in addition to the function of generating braking torque during normal braking, it also has the function of a parking brake for maintaining the braking force during parking and maintaining the stopped state of the vehicle. It is also required to be.

The present invention has been conceived by paying attention to the above technical problems, and is intended to have a parking brake function and to further reduce the size and weight without causing a decrease in braking force that may occur. It is an object of the present invention to provide a vehicle brake unit capable of the above.

In order to achieve the above object, the present invention comprises a brake actuator that generates braking torque, an input shaft into which the braking torque is input, an axle that rotates integrally with the wheels of the vehicle, and the input shaft and the axle. In a vehicle brake unit which is provided with a first deceleration mechanism for decelerating the number of rotations between the gear and the gear, amplifies the braking torque input to the input shaft and transmits the braking torque to the axle to generate a braking force of the vehicle. The first reduction mechanism includes a planetary gear mechanism having a sun gear, a ring gear, and a carrier, an external tooth gear formed on the outer peripheral portion of the ring gear, a first pinion that meshes with the external tooth gear, and the first pinion. An external gear set having a second pinion arranged on the same rotation axis as the above and rotating integrally with the first pinion, and a pinion shaft rotating integrally with the first pinion and the second pinion, and the sun gear. A center gear arranged on the same rotation axis and rotating integrally with the sun gear, and a counter gear arranged between the center gear and the second pinion and meshing with both the center gear and the second pinion. A sun gear shaft that rotates integrally with the center gear and the sun gear, and a carrier shaft that rotates integrally with the carrier, the pinion shaft serves as the input shaft, and the carrier shaft serves as the axle. The brake actuator has a service brake mechanism that operates by energizing to generate the braking torque by causing frictional contact between predetermined friction materials, and operates by energizing to generate the braking torque and energizes. A parking brake mechanism capable of holding the braking torque in a stopped state is provided, and the parking brake mechanism operates by energizing and outputs a torque, and an output of the braking motor. It is possible to convert the rotary motion by torque into a linear motion to generate an axial force acting in a direction in which the friction materials are brought into frictional contact with each other, and to maintain the axial force in a state where the energization of the braking motor is stopped. It is characterized by including a possible feed screw mechanism and a second reduction gear mechanism that amplifies the output torque of the braking motor and transmits the output torque to the feed screw mechanism.

The second reduction gear mechanism in the vehicle brake unit of the present invention is formed on the second sun gear, the second ring gear, the second planetary gear mechanism having the second carrier, and the outer peripheral portion of the second ring gear. The second external tooth gear, the third pinion that meshes with the second external tooth gear, the fourth pinion that is arranged on the same rotation axis as the third pinion and rotates integrally with the third pinion, and the first pinion. A second external gear set having a third pinion and a second pinion shaft that rotates integrally with the fourth pinion, and a second center that is arranged on the same rotation axis as the second sun gear and rotates integrally with the second sun gear. A second counter gear, which is arranged between the second center gear and the fourth pinion and meshes with both the second center gear and the fourth pinion, and the second center gear and the second sun gear. A second sun gear shaft that rotates integrally with the second sun gear shaft and a second carrier shaft that rotates integrally with the second carrier are provided, and the second sun gear shaft rotates integrally with the rotor shaft of the braking motor, and the first The two-carrier shaft may be configured to rotate integrally with the feed screw of the feed screw mechanism and reduce the number of rotations between the rotor shaft and the feed screw.

Further, the second reduction gear mechanism in the vehicle brake unit of the present invention includes a second planetary gear mechanism having a second sun gear, a first ring gear, and a second carrier, and the second ring gear as the second planetary gear mechanism. An extension internal gear extending in the direction of the rotation axis, a second center gear arranged on the rotation axis together with the second sun gear and rotating integrally with the second sun gear, the second sun gear and the second center. A second sun gear shaft that rotates integrally with the gear, and a second counter gear that is arranged between the second center gear and the extension internal gear and meshes with both the second center gear and the extension internal gear. The second carrier shaft is provided with a second carrier shaft that rotates integrally with the second carrier, the second sun gear shaft rotates integrally with the rotor shaft of the braking motor, and the second carrier shaft is the feed screw mechanism. It can also be configured to rotate integrally with the feed screw and reduce the number of revolutions between the rotor shaft and the feed screw.

Further, the second reduction mechanism in the vehicle brake unit of the present invention includes a second sun gear, a first ring gear, a second planetary gear mechanism having a second carrier, a third sun gear, a third ring gear, and a first. A third planetary gear mechanism having three carriers, a second sun gear shaft that connects the second sun gear and the third sun gear, and rotates integrally with the second sun gear and the third sun gear, and the second carrier. A connecting shaft that connects the third ring gear and the third ring gear, and a ring gear shaft that rotates integrally with the second ring gear are provided, the three carriers are fixed so as not to rotate, and the second sun gear shaft is the braking motor. The second ring gear shaft rotates integrally with the rotor shaft of the rotor shaft, rotates integrally with the feed screw of the feed screw mechanism, and is configured to reduce the rotation speed between the rotor shaft and the feed screw. You can also.

According to the vehicle brake unit of the present invention, the braking torque generated by the brake actuator can be amplified by the first reduction mechanism and transmitted to the axle. That is, a large braking force can be obtained even from a small braking torque. In the first reduction mechanism of the vehicle brake unit of the present invention, an external tooth gear is formed on the outer peripheral portion of the ring gear of the planetary gear mechanism. Then, when the first pinion meshes with the external tooth gear, torque is transmitted between the ring gear and the center gear via the second pinion that rotates integrally with the first pinion and the counter gear that meshes with the second pinion. To do. The center gear is connected to the sun gear of the planetary gear mechanism via the sun gear shaft and rotates integrally with the sun gear. Therefore, when the braking torque is input to the pinion shaft, the torque is transmitted from the second pinion to the ring gear via the pinion shaft and the first pinion. At that time, the first pinion rotates in the same rotation direction as the center gear and the sun gear. As a result, the ring gear rotates in the direction opposite to that of the sun gear and the carrier. Therefore, as compared with a planetary gear mechanism that stops the rotation of the ring gear and decelerates between the sun gear and the carrier, for example, the reduction ratio can be increased by the amount of reverse rotation of the ring gear. Therefore, the first reduction mechanism in the vehicle brake unit of the present invention can significantly increase the reduction ratio between the sun gear and the carrier without causing a particular increase in size as compared with the conventional reduction device. it can. That is, according to the vehicle brake unit of the present invention, the braking torque generated by the brake actuator can be significantly amplified by the first reduction mechanism and transmitted to the axle. Therefore, the brake actuator can be sufficiently miniaturized by the amount that the output braking torque is significantly amplified. As a result, the vehicle brake unit can be significantly reduced in size and weight.

Further, according to the vehicle brake unit of the present invention, the brake actuator is composed of a service brake mechanism and a parking brake mechanism. Therefore, it is possible to configure a vehicle brake unit having a function of a parking brake that maintains a braking force during parking and maintains a stopped state of the vehicle.

According to the vehicle brake unit of the present invention, the parking brake mechanism is composed of a braking motor, a feed screw mechanism, and a second deceleration mechanism. The feed screw mechanism is operated by the output torque of the braking motor. Like the first deceleration mechanism, the second deceleration mechanism is composed of a gear deceleration mechanism using a planetary gear mechanism, and is composed of an output shaft (rotor shaft) of a braking motor and an input shaft (feed screw) of a feed screw mechanism. Decelerate the number of revolutions between and. That is, the second deceleration mechanism amplifies the output torque of the braking motor and transmits it to the feed screw mechanism. Therefore, the braking motor can be downsized by the amount that the output torque is amplified. As a result, the parking brake mechanism can be made smaller and lighter.

Therefore, according to the present invention, it is possible to construct a vehicle brake unit that has a parking brake function and is significantly reduced in size and weight without causing a decrease in braking force that may occur.

It is a figure which shows an example of the vehicle brake unit of this invention, and is the figure for demonstrating the whole structure of the vehicle brake unit. It is a figure which shows an example of the vehicle brake unit of this invention, and in particular, is sectional drawing for demonstrating the structure of the 1st reduction mechanism in the vehicle brake unit. It is a collinear diagram of the planetary gear mechanism used in the 1st deceleration mechanism shown in FIGS. 1 and 2, and is the figure for demonstrating the high deceleration function in the 1st deceleration mechanism. It is sectional drawing for demonstrating the specific structure of the brake actuator in the vehicle brake unit of this invention. It is a figure for demonstrating the structure of the 2nd reduction mechanism in the vehicle brake unit of this invention, and is the figure which shows an example of the 2nd reduction mechanism incorporated in the brake actuator shown in FIG. It is a figure for demonstrating the structure of the 2nd reduction mechanism in the vehicle brake unit of this invention, and is the figure which shows another example of the 2nd reduction mechanism incorporated in the brake actuator shown in FIG. It is a figure for demonstrating the structure of the 2nd reduction mechanism in the vehicle brake unit of this invention, and is the figure which shows another example of the 2nd reduction mechanism incorporated in the brake actuator shown in FIG. It is a figure which shows the example which configured the in-wheel motor with a braking function by applying the vehicle brake unit of this invention.

An outline of a vehicle brake unit to which the present invention is applied is shown in FIG. The vehicle brake unit 1 according to the embodiment of the present invention typically includes a brake actuator 2, an input shaft 3, an axle 4, and a first deceleration mechanism 5. The vehicle brake unit 1 amplifies the braking torque generated by the brake actuator 2 by the first reduction mechanism 5 and transmits it to the axle 4 to brake the axle 4. That is, the braking force of the vehicle is generated.

The brake actuator 2 is, for example, an electromagnetic brake using a magnetic attraction force generated by a coil or an electric brake using a torque generated by a motor, and generates a braking torque for braking the axle 4. The brake actuator 2 according to the embodiment of the present invention operates by energizing the service brake mechanism 2a that generates braking torque by causing frictional contact between predetermined friction materials, and operates by energizing the braking torque. It is provided with a parking brake mechanism 2b capable of generating the braking torque and holding the braking torque in a state where the energization is stopped. Details of the brake actuator 2 will be described later.

For example, a pinion shaft 23 or a counter gear shaft 20, which will be described later, is connected to the input shaft 3. Alternatively, the pinion shaft 23 or the counter gear shaft 20 functions as the input shaft 3. The braking torque generated by the brake actuator 2 is input to the input shaft 3. FIG. 1 shows an example in which two input shafts 3 are provided, and a brake actuator 2 and an actuator 36 described later are connected to the two input shafts 3, respectively.

The axle 4 is connected to a carrier shaft 16 which will be described later. Alternatively, the carrier shaft 16 functions as the axle 4. Wheels 6 of a vehicle (not shown) are connected to the axle 4. Therefore, the axle 4 rotates integrally with the wheel 6.

The first reduction mechanism 5 is composed of a planetary gear mechanism 7, a counter gear set 8, and a circumscribed gear set 9. The first deceleration mechanism 5 decelerates the rotation speed between the input shaft 3 and the axle 4, amplifies the torque input to the input shaft 3, and transmits the torque to the axle 4.

The planetary gear mechanism 7 has a sun gear 10, a ring gear 11, and a carrier 12 as three rotating elements that rotate differentially with each other. It also has a planetary gear 13 that is held by the carrier 12 and meshes with both the sun gear 10 and the ring gear 11. That is, FIG. 1 shows an example of a planetary gear mechanism 7 configured by a single pinion type planetary gear mechanism. In the planetary gear mechanism 7, an external tooth gear 14 that meshes with the first pinion 21 of the external gear set 9, which will be described later, is formed on the outer peripheral portion of the ring gear 11.

The planetary gear mechanism 7 is supported by the sun gear shaft 15 and the carrier shaft 16 in the case 17 of the first reduction gear mechanism 5. The sun gear shaft 15 is a rotation shaft of the sun gear 10, and rotates integrally with the sun gear 10 and the center gear 18 described later. The carrier shaft 16 is a rotation shaft of the carrier 12, and rotates integrally with the carrier 12. The sun gear shaft 15 and the carrier shaft 16 are arranged so as to be relatively rotatable on the same rotation axis.

Although FIG. 1 shows an example in which the planetary gear mechanism 7 is configured by a single pinion type planetary gear mechanism, the planetary gear mechanism 7 in the embodiment of the present invention is configured by a double pinion type planetary gear mechanism. You can also do it.

The counter gear set 8 is composed of a center gear 18 and at least one counter gear 19. FIG. 1 shows a counter gear set 8 composed of a center gear 18 and two counter gears 19. The center gear 18 is attached to the sun gear shaft 15. That is, the center gear 18 is arranged on the same rotation axis as the sun gear 10. The counter gear 19 is attached to the counter gear shaft 20. The counter gear shaft 20 is a rotation shaft of the counter gear 19, and rotates integrally with the counter gear 19. The counter gear 19 is arranged between the center gear 18 and the second pinion 22 of the circumscribed gear set 9 described later, and meshes with both the center gear 18 and the second pinion 22.

The circumscribed gear set 9 is composed of a first pinion 21, a second pinion 22, and a pinion shaft 23. The first pinion 21 is a gear having a diameter smaller than that of the external tooth gear 14 described above, and meshes with the external tooth gear 14. The second pinion 22 is a gear having a small diameter like the first pinion 21, and meshes with the counter gear 19. The first reduction mechanism 5 in the embodiment of the present invention may include at least one set of the above-mentioned circumscribed gear sets 9. FIG. 1 shows two sets of circumscribed gear sets 9. As will be described later, considering that the ring gear 11 is supported by the circumscribed gear set 9, it is preferable to provide at least three sets of circumscribed gear sets 9 at equal intervals in the circumferential direction of the ring gear 11.

In the example shown in FIG. 1, the input shaft 3 is connected to the pinion shaft 23. Alternatively, the pinion shaft 23 functions as the input shaft 3. That is, substantially, the pinion shaft 23 is the input shaft 3 in the vehicle brake unit 1. Further, the axle 4 is connected to the carrier shaft 16. Alternatively, the carrier shaft 16 functions as the axle 4. That is, substantially, the carrier shaft 16 is the axle 4 in the vehicle brake unit 1. In the vehicle brake unit 1 according to the embodiment of the present invention, the input shaft 3 can be connected to the counter gear shaft 20, or the counter gear shaft 20 can function as the input shaft 3. That is, substantially, the counter gear shaft 20 can be used as the input shaft 3 in the vehicle brake unit 1.

The specific configuration of the first deceleration mechanism 5 shown in FIG. 1 is shown in FIG. As described above, the first reduction mechanism 5 is mainly composed of a planetary gear mechanism 7, a counter gear set 8, and a circumscribed gear set 9. In the examples shown in FIGS. 1 and 2, the two pinion shafts 23 are input shafts 3, respectively. Further, the carrier shaft 16 is the axle 4.

The sun gear shaft 15 is rotatably supported by the case 17 by a bearing 24 assembled to the case 17. The carrier shaft 16 is rotatably supported by the case 17 by a bearing 25 assembled to the case 17. A bearing 26 is assembled to the inner end of the case 17 of the carrier shaft 16. The sun gear shaft 15 and the carrier shaft 16 are connected so as to be relatively rotatable via the bearing 26. In the example shown in FIG. 2, the tip 16a of the carrier shaft 16 projects toward the outside of the case 17 (right side in FIG. 2), and the axle 4 is connected to the tip 16a. The axle 4 is rotatably supported by the case 17 by bearings 31 and 32 assembled to the case 17. A flange 33 for fixing the wheel 6 to the axle 4 is formed at the end portion 4a of the axle 4 on the side opposite to the connecting side with the carrier shaft 16 (right side in FIG. 2). A bolt 34 for bolting the axle 4 and the wheel 6 is attached to the flange 33. Further, on the back side (left side in FIG. 2) of the case 17, a bolt 35 for bolting the vehicle brake unit 1 to the vehicle body (not shown) or the suspension mechanism 104 described later is attached. There is.

The planetary gear mechanism 7 is arranged inside the case 17 so as to be in parallel with the counter gear set 8. The sun gear 10 is attached to the sun gear shaft 15 and rotates integrally with the sun gear shaft 15. Therefore, the sun gear 10 and the sun gear shaft 15 are rotatably supported by the case 17 by bearings 24. The carrier 12 is attached to the carrier shaft 16. Alternatively, the carrier 12 and the carrier shaft 16 are integrally formed. The carrier 12 rotates integrally with the carrier shaft 16. Therefore, the carrier 12 and the carrier shaft 16 are rotatably supported by the case 17 by bearings 25. An external tooth gear 14 is formed on the outer peripheral portion of the ring gear 11, and the external tooth gear 14 and the first pinion 21 of the external gear set 9 are in mesh with each other.

As described above, the counter gear set 8 is arranged inside the case 17 in parallel with the planetary gear mechanism 7 so as to face the planetary gear mechanism 7. The center gear 18 is attached to the sun gear shaft 15 and rotates integrally with the sun gear shaft 15. The counter gear 19 is attached to the counter gear shaft 20 and rotates integrally with the counter gear shaft 20. The counter gear shaft 20 is arranged parallel to the sun gear shaft 15 and is rotatably supported by the case 17 by bearings 27 and 28 assembled to the case 17.

The circumscribed gear set 9 is arranged on the outer peripheral side of the planetary gear mechanism 7 and the counter gear set 8. The first pinion 21 is attached to the pinion shaft 23 and rotates integrally with the pinion shaft 23. The first pinion 21 meshes with the external tooth gear 14. Similarly, the second pinion 22 is attached to the pinion shaft 23 and rotates integrally with the pinion shaft 23. Therefore, the first pinion 21 and the second pinion 22 are arranged on the same rotation axis CL2 as shown in FIG. The second pinion 22 meshes with the counter gear 19. The pinion shaft 23 is arranged parallel to the sun gear shaft 15 and is rotatably supported by the case 17 by bearings 29 and 30 assembled to the case 17. Therefore, in the external gear set 9, the first pinion 21, the second pinion 22, and the pinion shaft 23 all rotate integrally, and torque is applied between the external gear 14 and the center gear 18 and the counter gear 19. To convey.

As described above, the circumscribed gear set 9 is provided to transmit torque between the external gear 14 and the center gear 18. Therefore, the first reduction mechanism 5 in the embodiment of the present invention may include at least one set of circumscribed gear sets 9. However, by providing the plurality of circumscribed gear sets 9, the ring gear 11 can be rotatably supported via the first pinion 21. Therefore, by providing three or more sets of circumscribed gear sets 9 at equal intervals in the circumferential direction of the ring gear 11, the ring gear 11 can be supported stably and in a well-balanced manner. The counter gear 19 is provided according to the number of sets of the circumscribed gear sets 9 provided. For example, when four sets of circumscribed gear sets 9 are provided, four counter gears 19 are provided correspondingly. That is, four counter gears 19 are provided that mesh with the four second pinions 22 in the four sets of circumscribed gear sets 9. Further, in FIGS. 1 and 2, two sets of circumscribed gear sets 9 and two corresponding counter gears 19 are shown. As described above, three or more sets of circumscribed gear sets 9 and corresponding circumscribed gear sets 9 are shown. Three or more counter gears 19 can be provided.

In the first reduction mechanism 5 according to the embodiment of the present invention, the counter gear set 8 and the circumscribed gear set 9 are provided as described above, so that torque can be transmitted between the external tooth gear 14 and the center gear 18. That is, the torque input to the center gear 18 can be transmitted to the external tooth gear 14 to drive the ring gear 11. In the examples shown in FIGS. 1 and 2, the sun gear shaft 15 and the input shaft 3 rotate integrally. Therefore, the torque input to the input shaft 3 is directly transmitted from the sun gear shaft 15 to the sun gear 10. At the same time, torque is transmitted between the center gear 18 and the circumscribed gear 14 via the counter gear set 8 and the circumscribed gear set 9. The torque transmitted to the external tooth gear 14 causes the external tooth gear 14, that is, the ring gear 11, to rotate in the direction opposite to the rotation direction of the center gear 18 and the sun gear 10. As a result, due to the differential action of the planetary gear mechanism 7, the rotation speed of the carrier 12 is greatly reduced with respect to the rotation speed of the sun gear 10. That is, the first deceleration mechanism 5 in the embodiment of the present invention has a high deceleration function capable of obtaining an extremely high reduction ratio between the input shaft 3 and the axle 4.

When torque is input to the input shaft 3 and the sun gear shaft 15 to rotate the sun gear 10 as described above, the rotational state of each rotating element in the planetary gear mechanism 7 is shown in the collinear diagram of FIG. As described above, the planetary gear mechanism 7 shown in FIGS. 1 and 2 is a single pinion type planetary gear mechanism, the sun gear shaft 15 is the input shaft 3, and the carrier shaft 16 is the axle 4 (that is, the output shaft). ). Therefore, the sun gear (S) 10 is an input element (IN), and the carrier (C) 12 is an output element (OUT).

Conventionally, a reduction gear is configured by using the single pinion type planetary gear mechanism as described above. For example, as shown by a broken line in the collinear diagram of FIG. 3, the sun gear (S) is used as an input element (IN), the carrier (C) is used as an output element (OUT), and the ring gear (R) is stopped rotating. By fixing, a speed reducer for decelerating the rotation speed of the output element with respect to the rotation speed of the input element is configured. On the other hand, in the first reduction mechanism 5 according to the embodiment of the present invention, the ring gear (R) is used when the sun gear 10 is used as an input element and the carrier 12 is used as an output element, as in the conventional speed reduction device as described above. 11 rotates in a rotation direction opposite to the rotation direction of the sun gear 10 and the carrier 12. That is, when torque is input to the center gear 18 and the sun gear 10 and the sun gear 10 rotates in the "positive" direction in the collinear diagram of FIG. 3 at a predetermined rotation speed, the ring gear 11 has the center gear 18 and the external tooth gear. The torque transmitted to and from the counter gear set 8 and the external gear set 9 causes rotation in the "reverse" direction in the collinear diagram of FIG. In this way, when the sun gear 10 rotates in the "forward" direction, the ring gear 11 rotates in the "reverse" direction, so that the rotation speed of the carrier 12 is lowered, and the rotation speed of the carrier 12 is reduced with respect to the rotation speed of the sun gear 10. The number of revolutions is greatly reduced. The reduction ratio between the input element and the output element is larger than that of the conventional reduction gear shown by the broken line in the collinear diagram of FIG.

Further, in the first reduction mechanism 5 according to the embodiment of the present invention, the ring gear 11 is rotated in the "reverse" direction by transmitting torque to the external tooth gear 14 formed on the ring gear 11 as described above. Therefore, for example, the degree of freedom in setting the gear ratio is greatly increased as compared with an existing compound planetary gear mechanism or a reduction mechanism using a planetary gear mechanism. As a result, the reduction ratio between the input shaft 3 and the axle 4 can be significantly increased.

Generally, when the reduction gear is configured by a single pinion type planetary gear mechanism in which the sun gear is an input element and the carrier is an output element and the ring gear is fixed, the reduction ratio γ is that the number of teeth of the sun gear is Z _s and the ring gear (internal tooth). ) Is Z _r ,
γ = 1 + Z _r / Z _s
Will be. The reduction ratio γ in this case is the ratio of the rotation speed N _IN of the input element to the rotation speed N _OUT of the output element (that is, γ = N _IN / N _OUT ). In such a conventional planetary gear mechanism, the reduction ratio γ that can be realized by itself is said to be about 4 to 10. On the other hand, assuming, for example, a physique having an outer diameter of about 300 mm, the first reduction mechanism 5 in the embodiment of the present invention is not restricted by the number of internal teeth and the inner diameter of the ring gear 11 as described above. Since the degree of freedom in setting the gear ratio is high, theoretically, a very large reduction ratio γ of about 10,000 can be obtained.

As described above, the vehicle brake unit 1 according to the embodiment of the present invention includes the first deceleration mechanism 5 having a high deceleration function capable of setting a considerably large reduction ratio as compared with the conventional configuration. .. As shown in FIGS. 1 and 2, the first reduction mechanism 5 has a configuration in which a set of planetary gear mechanisms 7 and a set of parallel shaft gear pairs, a counter gear set 8, are arranged in parallel. .. Therefore, for example, a first deceleration mechanism 5 having the same physique and a significantly increased reduction ratio as compared with a deceleration device using a conventional compound planetary gear mechanism or a deceleration device using a two-stage gear train is configured. be able to. Alternatively, the first deceleration mechanism 5 having a smaller physique can be configured.

Then, in the vehicle brake unit 1 according to the embodiment of the present invention, the braking torque generated by the brake actuator 2 is significantly amplified and transmitted to the axle 4 by the first deceleration mechanism 5 having the high deceleration function as described above. be able to. Therefore, the brake actuator 2 can be sufficiently miniaturized by the amount that the output braking torque is significantly amplified. As a result, it is possible to configure the vehicle brake unit 1 which is significantly smaller and lighter than the conventional vehicle braking device.

As described above, in the example shown in FIGS. 1 and 2, the vehicle brake unit 1 includes a plurality of pinion shafts 23 and a plurality of input shafts 3 corresponding thereto. Then, in FIGS. 1 and 2, the brake actuator 2 as described above is connected to one of the pinion shafts 23 and the input shaft 3, and the actuator 36 is connected to the other pinion shaft 23 and the input shaft 3. An example is shown. As the actuator 36, for example, a drive actuator that generates a drive torque for driving the axle 4 can be provided. The drive actuator is composed of, for example, a permanent magnet type synchronous motor, an induction motor, or the like. In that case, it is possible to configure a compact vehicle power unit having both a braking function of generating a vehicle braking force by the brake actuator 2 as described above and a driving function of generating a vehicle driving force by a motor.

Further, as the actuator 36, for example, a brake actuator 2 can be provided. That is, a vehicle brake unit 1 including two brake actuators 2 can be configured. In that case, for example, the transmission system of the braking torque generated by one brake actuator 2 can be the main system, and the transmission system of the braking torque generated by the other brake actuator 2 can be the redundant system. That is, a vehicle brake unit 1 having two independent power sources can be configured. Therefore, a compact and highly reliable vehicle brake unit 1 can be configured.

The vehicle brake unit 1 according to the embodiment of the present invention has a function as a main braking device that operates during normal braking and a function as a parking braking device that operates during parking or when the vehicle is stopped to maintain braking force. .. Specifically, the brake actuator 2 in the vehicle brake unit 1 includes a service brake mechanism 2a that operates during normal braking and a parking brake mechanism 2b that operates during parking or stopping to maintain braking force. There is.

FIG. 4 shows a specific configuration of the brake actuator 2. The service brake mechanism 2a is an excitation-operated electromagnetic brake that operates when energized to brake a predetermined rotating member. In the example shown in FIG. 4, the service brake mechanism 2a is composed of a multi-plate electromagnetic brake. Specifically, the service brake mechanism 2a includes a friction plate 41, a pressing plate 42, a coil 43, and an output shaft 44.

The friction plate 41 is a predetermined friction material, and is composed of a plurality of rotating plates 41a and a plurality of fixing plates 41b. In the example shown in FIG. 4, the friction plate 41 is composed of three rotating plates 41a and three fixing plates 41b. The rotating plate 41a is fixed to the output shaft 44 so as to rotate integrally with the output shaft 44. The rotating plate 41a is entirely or at least partially formed of a magnetic material. The fixed plate 41b is incorporated in the case 45 of the brake actuator 2 so that the output shaft 44 can move in the axial direction and cannot rotate in the rotation direction of the output shaft 44. The fixed plate 41b is formed entirely or at least in part by a magnetic material. The plurality of rotating plates 41a and the plurality of fixed plates 41b are alternately arranged in the rotation axis CL2 direction (left-right direction in FIG. 4) to form a multi-plate friction plate 41.

The pressing plate 42 is formed of an annular magnetic material. The pressing plate 42 is incorporated in the case 45 so that it can move in the rotation axis CL2 direction and cannot rotate in the rotation direction of the output shaft 44.

The coil 43 is fixed to the case 45, and a magnetic attraction force is generated by applying a predetermined voltage. The magnetic attraction generated by the coil 43 acts on the friction plate 41 and the pressing plate 42, and attracts the pressing plate 42 to the friction plate 41 side. Therefore, when the coil 43 is energized, the friction plate 41 is pressed by the pressing plate 42, the rotating plate 41a of the friction plate 41 and the fixed plate 41b are frictionally engaged with each other, and braking torque is generated.

As shown in FIG. 2 described above, the output shaft 44 is connected to the input shaft 3 and the pinion shaft 23 of the first reduction gear mechanism 5, and rotates integrally with the input shaft 3 and the pinion shaft 23. Further, as described above, the rotating plate 41a is attached to the output shaft 44 so as to rotate integrally. Therefore, the braking torque generated by the frictional engagement between the rotating plate 41a and the fixed plate 41b is transmitted to the input shaft 3 of the first deceleration mechanism 5 via the output shaft 44.

Therefore, the service brake mechanism 2a attracts the pressing plate 42 to the friction plate 41 side by the magnetic attraction generated by energizing the coil 43. When the pressing plate 42 is sucked, the pressing plate 42 presses the friction plate 41. Then, the pressing force acts on the friction plate 41, so that the rotating plate 41a and the fixing plate 41b are frictionally engaged with each other. Therefore, the service brake mechanism 2a operates so as to frictionally engage the rotating plate 41a and the fixed plate 41b by energizing the coil 43, and generates braking torque. The service brake mechanism 2a does not operate as described above and does not generate the braking torque as described above when the coil 43 is not energized.

The parking brake mechanism 2b is configured to operate by energizing to generate braking torque and to maintain braking torque in a state where energization is stopped. Specifically, the parking brake mechanism 2b includes a braking motor 46, a feed screw mechanism 47, and a second deceleration mechanism 48.

The braking motor 46 is an electric motor that operates by energizing and outputs drive torque. The braking motor 46 has a stator 46a, a rotor 46b, and a rotor shaft 46c that rotates integrally with the rotor 46b. The stator 46a is non-rotatably fixed to the case 45. The rotor shaft 46c is the output shaft of the braking motor 46, and rotates integrally with the input shaft 48a of the second reduction mechanism 48, which will be described later.

The feed screw mechanism 47 converts the rotary motion into a linear motion, presses the pressing plate 42 toward the friction plate 41 side (left side in FIG. 4) in the direction of the rotation axis CL2, and frictions the rotating plate 41a and the fixing plate 41b. Generates axial force to match. At the same time, even when the energization is stopped while the axial force is generated, the rotating plate 41a and the fixed plate 41b can be frictionally engaged to maintain the braking state of the output shaft 44. It is configured as follows. The feed screw mechanism 47 is composed of a pressing member 47a and a feed screw member 47b.

The pressing member 47a is formed of a disk-shaped non-magnetic material. A female screw portion 47c of a feed screw penetrating the pressing member 47a in the plate thickness direction (left-right direction in FIG. 4) is formed in the central portion of the pressing member 47a. Like the pressing plate 42, the pressing member 47a is incorporated in the case 45 so that it can move in the rotation axis CL2 direction and cannot rotate in the rotation direction of the output shaft 44. The pressing member 47a is arranged adjacent to the pressing plate 42 in the direction of the rotation axis CL2. The pressing member 47a has a contact surface 47d that comes into contact with the pressing plate 42 and exerts an axial force (pressing pressure) in the direction of the rotation axis CL2 on the pressing plate 42.

The feed screw member 47b serves as a rotation shaft of the feed screw mechanism 47. The feed screw member 47b has a male screw portion 47e of the feed screw formed on the outer peripheral portion thereof. The feed screw member 47b rotates integrally with the output shaft 48b of the second speed reduction mechanism 48, which will be described later.

The male screw portion 47e of the feed screw member 47b is screwed into the female screw portion 47c of the pressing member 47a, thereby forming the feed screw mechanism 47. The female screw portion 47c and the male screw portion 47e of the lead screw mechanism 47 are formed of, for example, a ball screw, a trapezoidal screw, or a square screw.

The feed screw mechanism 47 rotates the feed screw member 47b in a predetermined rotation direction (forward rotation direction) to bring the pressing member 47a closer to the pressing plate 42 in the rotation axis CL2 direction (left direction in FIG. 4). Axial force is generated. Further, the feed screw mechanism 47 rotates the feed screw member 47b in the direction opposite to the forward rotation direction (reverse direction) to move the pressing member 47a away from the pressing plate 42 in the rotation axis CL2 direction (in FIG. 4). Axial force (to the right) is generated.

The second deceleration mechanism 48 has an input shaft 48a and an output shaft 48b, and decelerates the rotation speed between the input shaft 48a and the output shaft 48b. Therefore, the second deceleration mechanism 48 amplifies the torque input to the input shaft 48a and transmits it to the output shaft 48b. The rotor shaft 46c of the braking motor 46 described above is connected to the input shaft 48a. Alternatively, the input shaft 48a and the rotor shaft 46c are integrally formed. That is, the input shaft 48a rotates integrally with the rotor shaft 46c. The feed screw member 47b of the feed screw mechanism 47 described above is connected to the output shaft 48b. Alternatively, the output shaft 48b and the feed screw member 47b are integrally formed. That is, the output shaft 48b rotates integrally with the feed screw member 47b.

Therefore, in the parking brake mechanism 2b, the output torque of the braking motor 46 is amplified by the second deceleration mechanism 48 and transmitted to the feed screw mechanism 47. Therefore, the braking motor 46 can be downsized by the amount that the output torque is amplified. As a result, the parking brake mechanism 2b can be made smaller and lighter. As a result, the vehicle brake unit 1 that is significantly smaller and lighter can be configured.

The parking brake mechanism 2b can brake the output shaft 44 by frictionally engaging the rotating plate 41a and the fixing plate 41b by applying torque in the forward rotation direction to the feed screw member 47b of the feed screw mechanism 47. .. That is, a braking torque can be applied to the output shaft 44. Further, by applying a torque in the reverse direction to the feed screw member 47b, the braking of the output shaft 44 by the parking brake mechanism 2b can be released. That is, the braking torque of the output shaft 44 can be reduced or set to zero.

Further, the feed screw mechanism 47 in the parking brake mechanism 2b is set so that the reverse efficiency of the feed screw when converting the linear motion into the rotary motion is lower than the positive efficiency of the lead screw when converting the rotary motion into the linear motion. Has been done. That is, the feed screw mechanism 47 moves the pressing member 47a in the backward direction rather than the positive efficiency when the feed screw member 47b is rotated in the forward rotation direction to move the pressing member 47a in the forward direction, and the feed screw member 47b Is configured to have low reverse efficiency when rotating in the reverse direction. Therefore, the feed screw mechanism 47 can press the pressing member 47a and the pressing plate 42 in the forward direction to maintain the braking state of the output shaft 44. Therefore, even when the feed screw mechanism 47 is operated by the braking motor 46 and the energization of the service brake mechanism 2a and the braking motor 46 is stopped while the output shaft 44 is braked, the parking brake mechanism 2b The braking state of the output shaft 44 can be maintained.

The second deceleration mechanism 48 in the parking brake mechanism 2b described above can be configured by, for example, a gear mechanism 51 similar to the first deceleration mechanism 5 described above, as shown in FIG. The gear mechanism 51 shown in FIG. 5 is composed of a planetary gear mechanism 7, a counter gear set 8, and a circumscribed gear set 9, similarly to the first reduction mechanism 5. The gear mechanism 51 is appropriately formed according to a desired reduction ratio and the physique of the brake actuator 2. Therefore, the gear mechanism 51 and the first deceleration mechanism 5 have basically the same configuration, although they have different physiques. Therefore, in FIG. 5, members and parts having the same configuration and function as the first deceleration mechanism 5 shown in FIGS. 1 and 2 are assigned the same reference codes as those used in FIGS. 1 and 2. There is.

In the gear mechanism 51 shown in FIG. 5, the sun gear shaft 15 is the input shaft 48a of the second reduction gear mechanism 48. Further, the carrier shaft 16 is the output shaft 48b in the second speed reduction mechanism 48. The rotor shaft 46c of the braking motor 46 is connected to the input shaft 48a. The feed screw member 47b of the feed screw mechanism 47 is connected to the output shaft 48b. Therefore, the second reduction gear mechanism 48 by the gear mechanism 51 amplifies the output torque of the braking motor 46 and transmits it to the feed screw mechanism 47.

As described above, the second reduction mechanism 48 configured by using the gear mechanism 51 can also set a considerably large reduction ratio as compared with the conventional configuration, like the first reduction mechanism 5. It has a deceleration function. Therefore, the second reduction mechanism 48 can significantly amplify the output torque of the braking motor 46 and transmit it to the feed screw mechanism 47. Therefore, the braking motor 46 can be significantly reduced in size.

Further, the second speed reduction mechanism 48 can also be configured by a gear mechanism 61 as shown in FIG. The gear mechanism 61 shown in FIG. 6 typically includes an input shaft 62, an output shaft 63, a planetary gear mechanism 64, and a counter gear set 65. Then, the gear mechanism 61 decelerates the rotation speed between the input shaft 62 and the output shaft 63, and transmits the torque input to the input shaft 62 to the output shaft 63. That is, the gear mechanism 61 is configured as a reduction mechanism.

The planetary gear mechanism 64 has a sun gear 66, a ring gear 67, and a carrier 68. It also has a planetary gear 69 that is held by the carrier 68 and meshes with both the sun gear 66 and the ring gear 67. The ring gear 67 in the gear mechanism 61 is formed with an extension internal tooth gear 70 in which the ring gear 67 is extended in the rotation axis direction (left-right direction in FIG. 6) of the planetary gear mechanism 64. The extension internal gear 70 is formed with an internal gear, similarly to the meshing portion of the ring gear 67 with the planetary gear 69. The extension internal tooth gear 70 meshes with a counter gear 75, which will be described later.

The planetary gear mechanism 64 is rotatably supported by the sun gear shaft 71 and the carrier shaft 72 by the case 45 of the brake actuator 2 and the case 73 of the parking brake mechanism 2b. The sun gear shaft 71 is a rotation shaft of the sun gear 66, and the sun gear 66 is attached to the sun gear shaft 71. A center gear 74, which will be described later, is attached to the sun gear shaft 71. Therefore, the sun gear shaft 71 rotates integrally with the sun gear 66 and the center gear 74. The carrier shaft 72 is a rotation shaft of the carrier 68, and the carrier 68 is attached to the carrier shaft 72. Alternatively, the carrier 68 and the carrier shaft 72 are integrally formed. Therefore, the carrier shaft 72 rotates integrally with the carrier 68. The sun gear shaft 71 and the carrier shaft 72 are arranged so as to be relatively rotatable on the same rotation axis. In the gear mechanism 61 shown in FIG. 6, the sun gear shaft 71 is the input shaft 62, and the carrier shaft 72 is the output shaft 63.

The counter gear set 65 is arranged in parallel with the planetary gear mechanism 64 on the same rotation axis as the planetary gear mechanism 64. The counter gear set 65 includes a center gear 74 and a counter gear 75. The center gear 74 is attached to the sun gear shaft 71 and rotates integrally with the sun gear shaft 71. That is, the center gear 74 is arranged on the same rotation axis as the sun gear 66. The counter gear 75 is attached to the counter gear shaft 76 and rotates integrally with the counter gear shaft 76. The counter gear shaft 76 is arranged in parallel with the sun gear shaft 71. The counter gear 75 is arranged between the center gear 74 and the extension internal tooth gear 70, and meshes with both the center gear 74 and the extension internal tooth gear 70. Therefore, the counter gear set 65 transmits torque between the center gear 74 and the extension internal tooth gear 70, that is, the ring gear 67.

In the gear mechanism 61 shown in FIG. 6, torque can be transmitted between the center gear 74 and the ring gear 67 by providing the counter gear set 65 together with the planetary gear mechanism 64 as described above. That is, the torque input to the center gear 74 can be transmitted to the extension internal tooth gear 70 to drive the ring gear 67. At the same time, torque is transmitted between the center gear 74 and the extension internal gear 70 via the counter gear 75. The counter gear 75 that meshes with the center gear 74 rotates in a rotation direction opposite to the rotation direction of the center gear 74. Since the extension internal gear 70 that meshes with the counter gear 75 is an internal gear, it rotates in the same rotation direction as the counter gear 75. Therefore, the torque transmitted from the center gear 74 to the extension internal gear 70 causes the extension internal gear 70, that is, the ring gear 67, to rotate in the direction opposite to the rotation direction of the center gear 74 and the sun gear 66. As a result, the rotation speed of the carrier 68 is greatly reduced with respect to the rotation speed of the sun gear 66 due to the differential action of the planetary gear mechanism 64. That is, the second speed reduction mechanism 48 by the gear mechanism 61 shown in FIG. 6 has a high speed reduction function capable of obtaining a considerably high reduction ratio between the input shaft 62 and the output shaft 63.

In the gear mechanism 61 shown in FIG. 6, the sun gear shaft 71, that is, the input shaft 62 is the input shaft 48a in the second reduction gear mechanism 48. Further, the carrier shaft 16, that is, the output shaft 63 is the output shaft 48b in the second speed reduction mechanism 48. The rotor shaft 46c of the braking motor 46 is connected to the input shaft 48a. The feed screw member 47b of the feed screw mechanism 47 is connected to the output shaft 48b. Therefore, the second reduction mechanism 48 by the gear mechanism 61 amplifies the output torque of the braking motor 46 and transmits it to the feed screw mechanism 47.

Therefore, the output torque of the braking motor 46 can be significantly amplified and transmitted to the feed screw mechanism 47 by the second reduction mechanism 48 configured by using the gear mechanism 61. Therefore, the braking motor 46 can be significantly reduced in size.

The gear mechanism 61 described above can also be configured by using two sets of planetary gear mechanisms or a composite planetary gear mechanism. That is, in the gear mechanism 61 shown in FIG. 6, a counter gear set 65 and an extension internal tooth gear 70 of the ring gear 67 are provided in order to transmit torque between the center gear 74 and the ring gear 67. The gear mechanism composed of the counter gear set 65 and the extension internal tooth gear 70 operates in the same manner as a single planetary type planetary gear mechanism in which the carrier is stopped and fixed (carrier fixed). That is, the center gear 74 can be regarded as a sun gear of a single planetary type planetary gear mechanism, the extension internal tooth gear 70 can be regarded as a ring gear, and the counter gear 75 can be regarded as a planetary gear that is held on a rotating carrier by stopping rotation. it can. Therefore, the gear mechanism including the counter gear set 65 and the extension internal tooth gear 70 shown in FIG. 6 can be replaced with a carrier-fixed single planetary type planetary gear mechanism. Therefore, the gear mechanism 61 can be configured by two sets of planetary gear mechanisms in which the sun gears and the ring gears are connected to each other. Alternatively, the gear mechanism 61 can be configured by a compound planetary gear mechanism in which two sun gears are connected and the two sun gears and the two carriers are incorporated into a common ring gear.

Further, the second speed reduction mechanism 48 can also be configured by a gear mechanism 81 as shown in FIG. 7. The gear mechanism 81 shown in FIG. 7 is a so-called Simpson type compound planetary gear mechanism. That is, the gear mechanism 81 typically includes an input shaft 82, an output shaft 83, an input side planetary gear mechanism 84, and an output side planetary gear mechanism 85. Then, the gear mechanism 81 decelerates the rotation speed between the input shaft 82 and the output shaft 83, and transmits the torque input to the input shaft 82 to the output shaft 83. That is, the gear mechanism 81 is configured as a reduction mechanism.

The input-side planetary gear mechanism 84 has a sun gear 86, a ring gear 87, and a carrier 88. Similarly, the output side planetary gear mechanism 85 has a sun gear 89, a ring gear 90, and a carrier 91. The sun gear 86 of the input side planetary gear mechanism 84 and the sun gear 89 of the output side planetary gear mechanism 85 are connected. Further, the ring gear 87 of the input side planetary gear mechanism 84 and the carrier 91 of the output side planetary gear mechanism 85 are connected to each other. Both the sun gear 86 and the sun gear 89 are attached to the sun gear shaft 92, and the sun gear shaft 92 rotates integrally with the sun gear 86 and the sun gear 89. A ring gear shaft 93 is connected to the ring gear 90. Alternatively, the ring gear 90 and the ring gear shaft 93 are integrally formed. Therefore, the ring gear shaft 93 rotates integrally with the ring gear 90. The carrier 88 is non-rotatably fixed to the case 94 of the parking brake mechanism 2b. In the gear mechanism 81 shown in FIG. 7, the sun gear shaft 92 is the input shaft 82, and the ring gear shaft 93 is the output shaft 83.

As described above, in FIG. 7, the gear mechanism 81 is composed of a Simpson type compound planetary gear mechanism in which the carrier 88 on the input side is fixed so as not to rotate. The Simpson type compound planetary gear mechanism is well known. By using the sun gear of one planetary gear mechanism on the carrier fixing side as an input and the ring gear of the other planetary gear mechanism as an output, a reduction mechanism with a high reduction ratio To configure.

In the gear mechanism 81 shown in FIG. 7, the sun gear shaft 92, that is, the input shaft 82 is the input shaft 48a in the second reduction gear mechanism 48. Further, the ring gear shaft 93, that is, the output shaft 83 is the output shaft 48b in the second reduction gear mechanism 48. The rotor shaft 46c of the braking motor 46 is connected to the input shaft 48a. The feed screw member 47b of the feed screw mechanism 47 is connected to the output shaft 48b. Therefore, the second reduction mechanism 48 by the gear mechanism 81 amplifies the output torque of the braking motor 46 and transmits it to the feed screw mechanism 47.

Therefore, the output torque of the braking motor 46 can be significantly amplified and transmitted to the feed screw mechanism 47 by the second reduction mechanism 48 configured by using the gear mechanism 81. Therefore, the braking motor 46 can be significantly reduced in size.

As described above, the vehicle brake unit 1 according to the embodiment of the present invention has the brake actuator 2 and the parking brake mechanism in the brake actuator 2, respectively, due to the high deceleration functions of the first deceleration mechanism 5 and the second deceleration mechanism 48. 2b can be significantly reduced in size and weight. Further, by adopting a multi-plate type friction brake for the service brake mechanism 2a of the brake actuator 2, the brake actuator 2 is made smaller and lighter while ensuring the capacity of the braking torque that can be generated. Further, by adopting an electromagnetic brake for the service brake mechanism 2a, it is possible to omit a hydraulic system generally used in a conventional braking device and a strong member such as a brake caliper that receives a reaction force. Therefore, the structure of the vehicle brake unit 1 can be simplified, and the size and weight can be further reduced.

As described above, the vehicle brake unit 1 according to the embodiment of the present invention can be significantly reduced in size and weight. For example, as shown in FIG. 8, the in-wheel type power unit 100 can be configured by incorporating the vehicle brake unit 1 which has been reduced in size and weight as described above inside the wheel of the wheel 6.

The power unit 100 shown in FIG. 8 is composed of a vehicle brake unit 1 and wheels 6. The vehicle brake unit 1 shown in FIG. 8 has the same configuration as the vehicle brake unit 1 shown in FIGS. 1 and 2 above. In the power unit 100 shown in FIG. 8, a drive actuator 101 is provided as the actuator 36. The drive actuator 101 serves as a drive force source for the vehicle, and is composed of, for example, a permanent magnet type synchronous motor, an induction motor, or the like.

As shown in FIG. 2 described above, in the vehicle brake unit 1, the axle 4 is connected to the carrier shaft 16. The axle 4 is formed with a flange 33 for fixing the wheel 6 to the axle 4. The flange 33 is formed at a position on the tip side (right side in FIGS. 1 and 8) of the axle 4 with respect to the brake actuator 2 and the drive actuator 101 attached to the case 17 in the direction of the rotation axis CL1 of the axle 4. ..

The wheel 6 has a tire 102 that comes into contact with the road surface and a wheel 103 on which the tire 102 is mounted. A vehicle brake unit 1 is arranged on the inner peripheral portion of the wheel 103. That is, the brake actuator 2, the drive actuator 101, the input shaft 3, the axle 4, and the first deceleration mechanism 5 of the vehicle brake unit 1 are arranged on the inner peripheral portion of the wheel 103. Then, the wheel 103 is fastened to the axle 4 by the bolt 34 attached to the flange 33 of the axle 4. As described above, the flange 33 is formed on the tip side of the axle 4 with respect to the brake actuator 2 and the drive actuator 101 in the direction of the rotation axis CL1. Therefore, both the brake actuator 2 and the drive actuator 101 are arranged between the first deceleration mechanism 5 and the wheel 103 in the direction of the rotation axis CL1 in a state of being assembled to the case 17.

The power unit 100 composed of the vehicle brake unit 1 and the wheels 6 as described above is fastened to, for example, the vehicle suspension mechanism 104 by bolts 35 attached to the case 17. That is, the power unit 100 shown in FIG. 8 constitutes an in-wheel motor having a parking brake function in addition to the service brake.

As described above, by configuring the power unit 100 with the vehicle brake unit 1 according to the embodiment of the present invention, it is possible to construct an in-wheel motor that is significantly reduced in size and weight. As a result, the unsprung load of the vehicle equipped with the in-wheel motor can be significantly reduced, and the riding comfort of the vehicle and the ground contact property of the tire can be improved.

1 ... Vehicle brake unit, 2 ... Brake actuator, 2a ... Service brake mechanism, 2b ... Parking brake mechanism, 3 ... Input shaft, 4 ... Axle, 5 ... First deceleration mechanism, 6 ... Wheels, 7 ... Planetary gear mechanism, 8 ... Counter gear set, 9 ... External gear set, 10 ... Sun gear (S), 11 ... Ring gear (R), 12 ... Carrier (C), 13 ... Planetary gear, 14 ... External tooth gear, 15 ... Sun gear shaft, 16 ... Carrier shaft , 17 ... case, 18 ... center gear, 19 ... counter gear, 20 ... counter gear shaft, 21 ... 1st pinion, 22 ... 2nd pinion, 23 ... pinion shaft, 36 ... actuator, 41 ... friction plate, 41a ... rotation Plate, 41b ... Fixed plate, 42 ... Pressing plate, 43 ... Coil, 44 ... Output shaft (of brake actuator), 46 ... Braking motor, 47 ... Feed screw mechanism, 47a ... Pressing member, 47b ... Feed screw member, 48 ... 2nd deceleration mechanism, 48a ... Input shaft (of 2nd deceleration mechanism), 48b ... Output shaft (of 2nd deceleration mechanism), 51, 61, 81 ... Gear mechanism, 100 ... Power unit, 101 ... Drive actuator, 102 ... Tire, 103 ... Wheel, 104 ... Suspension mechanism, CL1 ... (Axle) rotation axis, CL2 ... (Pinion axis) rotation axis.

Claims (1)

A brake actuator that generates braking torque, an input shaft into which the braking torque is input, an axle that rotates integrally with the wheels of the vehicle, and a first deceleration mechanism that reduces the number of rotations between the input shaft and the axle. In a vehicle brake unit that amplifies the braking torque input to the input shaft and transmits the braking torque to the axle to generate the braking force of the vehicle.
The first deceleration mechanism
A planetary gear mechanism with sun gears, ring gears, and carriers,
An external tooth gear formed on the outer peripheral portion of the ring gear and
A first pinion that meshes with the external tooth gear, a second pinion that is arranged on the same rotation axis as the first pinion and rotates integrally with the first pinion, and one with the first pinion and the second pinion. An external gear set with a pinion shaft that rotates to
A center gear that is arranged on the same rotation axis as the sun gear and rotates integrally with the sun gear.
A counter gear that is arranged between the center gear and the second pinion and meshes with both the center gear and the second pinion.
A sun gear shaft that rotates integrally with the center gear and the sun gear,
A carrier shaft that rotates integrally with the carrier is provided.
The pinion shaft serves as the input shaft, and the carrier shaft serves as the axle.
The brake actuator
A service brake mechanism that operates by energizing and generates the braking torque by frictionally contacting predetermined friction materials with each other.
It is equipped with a parking brake mechanism that operates by energizing to generate the braking torque and can hold the braking torque while the energization is stopped.
The parking brake mechanism
A braking motor that operates by energizing and outputs torque,
The rotary motion due to the output torque of the braking motor is converted into a linear motion to generate an axial force acting in a direction in which the friction materials are brought into frictional contact with each other, and the shaft is stopped while energization of the braking motor is stopped. A feed screw mechanism that can hold the force and
A vehicle brake unit including a second deceleration mechanism that amplifies the output torque of the braking motor and transmits the output torque to the feed screw mechanism.

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