JP5768407B2 - One-way clutch and pulley device with one-way clutch - Google Patents

Description

  The present invention relates to a one-way clutch that transmits engine rotational power to an alternator and a pulley device with a one-way clutch.

  FIG. 6 (Patent Document 1) shows an example in which a conventional pulley device with a one-way clutch is attached to an AC generator (alternator).

  This transmits the rotational power of the engine of an automobile to a power generation shaft 111 of an AC generator (alternator) 110 via a pulley device 100 with a belt (not shown) and a one-way clutch, and a field winding 112 together with the power generation shaft 111. A rotating magnetic field is generated by rotating. An AC voltage is generated in the stator winding 113 by this rotating magnetic field, and this AC voltage is rectified to a direct current by the commutator 114. The AC generator 110 includes a regulator 120 that causes an excitation current to flow through the field winding 112, and an AC voltage generated from the stator winding 113 can be controlled by controlling the excitation current.

  As the number of rotations of the power generation shaft 111 increases, a magnetic field is frequently generated, a current flows frequently, and the temperature of the stator winding 113, the field winding 112, and the regulator 120 increases due to frequent control. There is a tendency. When the regulator 120 becomes uncontrollable, the temperature of the stator winding 113 and the field winding 112 rises further, and the AC generator is prevented so that seizure does not occur in the stator winding 113 and the field winding 112. From the viewpoint of protecting 110, heat from the stator winding 113, the field winding 112, and the regulator 120 is transmitted to the one-way clutch 101 through the power generation shaft 111, and the rotation shaft is rotated from the pulley unit 102 by the one-way clutch 101. It is conceivable to block the rotation to 103.

  As an apparatus for interrupting rotation, there is an apparatus as shown in FIG. 7 (Patent Document 2), which moves the spring support 131 in a direction away from the cylindrical roller 132 by the temperature displacement member 130 at a high temperature, and the spring 133. Thus, the force for urging the cylindrical roller 132 is reduced, and the outer ring 135 is rotated freely with respect to the inner ring 134.

Patent No. 4449263 JP 2009-287671 A

When the outer ring 135 is freely rotated, the cylindrical roller 132 moves in the same direction as the rotation direction of the outer ring 135 while rotating, and bites into a wedge space 136 formed between the outer ring 135 and the inner ring 134 so that the inner ring 134 and the outer ring 135 move together. There was a risk of spinning.
The present invention has been made to solve the above-described problems, and the object of the present invention is to rotate the cylindrical roller during free rotation by reliably moving the cylindrical roller to a position where it does not bite into the wedge space at high temperatures. A one-way clutch that reliably cuts off is provided.

  The invention according to claim 1 is a wedge in which the first rotating part and the second rotating part are rotatably supported coaxially with each other, and a space gradually decreases in the circumferential direction between the first rotating part and the second rotating part. In a one-way clutch that forms a space, and an engagement element is inserted into the wedge space, and a spring that biases the engagement element in a direction in which the wedge space gradually decreases, the wedge space gradually increases in the engagement element. A temperature sensitive member is provided that pushes in the direction and increases as the amount of push increases.

  According to this configuration, the engagement element can be reliably moved to a position where the engagement element does not bite into the wedge space at a high temperature, so that the rotation can be reliably blocked between the first rotating part and the second rotating part.

  According to a second aspect of the present invention, in the one-way clutch according to the first aspect, the engagement element is a cylindrical cylindrical roller that rolls in the wedge space, and the temperature-sensitive member has an arcuate shape at a high temperature. A plate-like bimetal that is curved in the axial direction, and the middle in the axial direction of the cylindrical roller is pushed in the middle in the longitudinal direction of the bimetal that is curved in an arcuate shape.

  According to this configuration, since the cylindrical roller is pushed in the middle in the axial direction of the cylindrical roller, the inclination of the cylindrical roller is eliminated, and the rotation can be reliably interrupted between the first rotating portion and the second rotating portion at a high temperature.

  According to a third aspect of the present invention, the one-way clutch according to the first or second aspect is applied to a pulley device.

  According to this structure, rotation can be reliably interrupted | blocked with a pulley apparatus at the time of high temperature.

  According to the present invention, the engagement element (cylindrical roller) can be reliably moved to a position where the wedge space gradually increases at a high temperature, so that the rotation can be reliably interrupted during free rotation.

It is sectional drawing which applied the pulley apparatus with a one-way clutch in embodiment of this invention to the alternator. It is the partially expanded sectional view of FIG. 1 which expanded the pulley apparatus with a one-way clutch in FIG. 1 in embodiment of this invention. It is the DD sectional view taken on the line of FIG. 2 in embodiment of this invention. It is the action | operation figure at the time of the low temperature which expand | deployed the holder | retainer in embodiment of this invention in the circumferential direction. It is the action | operation figure at the time of the high temperature which expand | deployed the holder | retainer in embodiment of this invention in the circumferential direction. It is sectional drawing which applied the conventional pulley apparatus with a one-way clutch to the alternator. It is sectional drawing of the conventional one-way clutch to which the temperature displacement member is applied.

  An embodiment of the present invention will be described with reference to FIGS. 1 is a cross-sectional view in which a pulley device with a one-way clutch is applied to an alternator, FIG. 2 is a partially enlarged cross-sectional view of FIG. 1 in which the pulley device with a one-way clutch in FIG. 1 is enlarged, and FIG. FIG. 4 is an operation diagram at a low temperature when the cage is expanded in the circumferential direction, and FIG. 5 is an operation diagram at a high temperature when the cage is expanded in the circumferential direction.

  An alternating current generator (alternator) 10 as shown in FIG. 1 is attached to an unillustrated engine of an automobile, and a direct current output from the alternating current generator 10 is stored in an unillustrated battery. . A pulley device 50 with a one-way clutch is attached to the AC generator 10, and the rotational power of the engine is transmitted to the AC generator 10 via a belt 90 and a pulley device 50 with a one-way clutch. Yes.

  The AC generator 10 generates DC current using the rotational power of the engine. The AC generator 10 includes a casing 11, a pair of rolling bearings 12 attached to the casing 11, a power generation shaft 13 rotatably supported on the casing 11 via the pair of rolling bearings 12, and the power generation shaft 13. A rotor 14 attached to the stator 11, a stator 15 attached to the casing 11 on the outer peripheral side of the rotor 14, a commutator 16 that rectifies an AC voltage from a stator winding 15a of the stator 15, and the rotation A brush device 17 that is in electrical contact with one end of the power generation shaft 13 so that an excitation current can be supplied to the field winding 14a of the child 14, and a regulator 18 that controls the excitation current supplied to the field winding 14a. It has become.

  The rotor 14 includes a field winding 14a wound in a cylindrical shape around the power generation shaft 13, and a rotor core 14b that holds the field winding 14a. The stator includes a three-phase stator winding 15a disposed at a predetermined interval in the circumferential direction, and a stator core 15b around which the stator winding 15a is wound.

  The regulator 18 controls the excitation current supplied to the field winding 14a, and controls the excitation current so that the output voltage from the AC generator 10 is constant. More specifically, the output voltage of the AC generator 10 tends to increase as the rotational speed of the power generation shaft 13 increases, and the output voltage of the AC generator 10 decreases when an electrical load such as an automobile light decreases. Goes up. When the excitation current is reduced, the output voltage of the AC generator 10 decreases. Therefore, the excitation current is controlled while detecting the output voltage of the AC generator 10.

  The pulley device 50 with one-way clutch is attached to one end of the power generation shaft 13 of the AC generator 10. As shown also in FIG. 2, the pulley device 50 with a one-way clutch includes a rotating shaft 51 screwed to the power generation shaft 13, a roller bearing 52 and a ball bearing 53 disposed on the outer periphery of the rotating shaft 51, and a roller. A pulley portion 54 rotatably supported on the rotary shaft 51 via a bearing 52 and a ball bearing 53, and between the roller bearing 52 and the ball bearing 53 in the axial direction and in the radial direction, the rotary shaft 51 and the pulley portion. It consists of the one-way clutch 60 inserted between 54.

  On the inner periphery of the rotating shaft 51, a screw portion 51a is formed in the middle in the axial direction, and a hexagonal hole 51b is formed at one end. An unillustrated tool such as a hexagon wrench is inserted into the hexagonal hole 51b in order to rotate the rotary shaft 51. A screw portion 13a is formed on the outer periphery of one end of the power generation shaft 13, and the screw portion 51a of the rotary shaft 51 is screwed to the screw portion 13a.

  As shown in FIGS. 3 to 5, the one-way clutch 60 includes a cage 61 having a plurality of windows 61a at equal intervals in the circumferential direction, and a cylindrical shape that is guided by each window 61a so as to be movable in the circumferential direction. A cylindrical roller 62, a coil spring 63 disposed between the window 61 a and the cylindrical roller 62 to urge the cylindrical roller 62 in one circumferential direction, and on the opposite side of the coil spring 63 across the cylindrical roller 62. The temperature sensing member 64 is arranged between the window 61a and the cylindrical roller 62. The pulley portion 54 also serves as an outer ring of the one-way clutch 60, and an outer ring side raceway surface 54 a on which the cylindrical roller 62 rolls is formed on the inner periphery of the pulley portion 54. As shown in FIG. 3, the outer ring side raceway surface 54a has a circular cross section. The rotating shaft 51 also serves as an inner ring of the one-way clutch 60, and the outer periphery of the rotating shaft 51 is on the inner ring side where the cylindrical roller 62 rolls at an axial position corresponding to the one-way clutch 60. A raceway surface 51c is formed. The inner ring side raceway surface 51c is formed in an octagonal cross section. The outer ring side raceway surface 54a and the inner ring side raceway surface 51c form a wedge space 70 in which the radial space gradually decreases in the circumferential direction.

  The retainer 61 has an outer periphery formed in a circular cross section and an inner periphery formed in an octagonal cross section. The cage 61 is fitted to the inner ring side raceway surface 51c of the rotating shaft 51 so as not to be relatively movable in the circumferential direction, and the cage 61 is loosely fitted to the pulley portion 54 so as to be relatively movable in the circumferential direction. ing.

  The temperature sensitive member 64 is a plate-like bimetal. That is, the temperature sensitive member 64 is obtained by bonding two members having different linear expansion coefficients. As shown in FIG. 4, the temperature sensitive member 64 is curved in an arc shape so that both ends thereof are in contact with the cylindrical roller 62 and the middle in the longitudinal direction is in contact with the window 61 a of the cage 61 at a low temperature. As shown in FIG. 5, the temperature sensitive member 64 is curved in an arc shape so that both ends thereof are in contact with the window 61 a of the retainer 61 and the middle in the longitudinal direction is in contact with the cylindrical roller 62 at a high temperature. As the temperature changes from a low temperature to a high temperature, the temperature-sensitive member 64 is less bent, and the temperature-sensitive member 64 is bent in the opposite direction from the low temperature. For this reason, the amount by which the temperature sensitive member 64 pushes the cylindrical roller 62 toward the coil spring 63 decreases, and the amount by which the temperature sensitive member 64 pushes the cylindrical roller 62 toward the coil spring 63 starts to increase.

  The high temperature assumes that the temperature sensitive member 64 itself is about 100 degrees Celsius, and at this temperature, the cylindrical roller 62 cannot bite into the wedge space 70 by the temperature sensitive member 64. The coil spring 63 is pushed to the position. In other words, at a temperature lower than the high temperature, the temperature sensitive member 64 does not hinder the cylindrical roller 62 from getting into the wedge space 70.

  When the cylindrical roller 62 moves in the clockwise direction from the position of the cylindrical roller 62 in FIG. 3, the wedge space 70 gradually decreases in the radial direction. Further, in the wedge space 70, when the cylindrical roller 62 moves counterclockwise from the position of the cylindrical roller 62 in FIG. 3, the radial space increases and gradually decreases from the middle. 3 and 4 are state diagrams of the temperature sensitive member 64 in a low temperature state of -30 degrees Celsius.

  When the pulley portion 54 rotates in the clockwise direction in FIG. 3 in a state where the temperature sensitive member 64 does not reach a high temperature, the cylindrical roller 62 rotates in the clockwise direction with respect to the rotating shaft 51, that is, in the radial direction of the wedge space 70. So that the cylindrical roller 62 bites into the wedge space 70, and the clockwise rotation of the pulley portion 54 is transmitted to the rotating shaft 51 via the cylindrical roller 62. It has become. When the rotating shaft 51 rotates in the clockwise direction in FIG. 4 with the pulley portion 54 stopped, the cylindrical roller 62 overcomes the coil spring 63 and counterclockwise with respect to the rotating shaft 51, that is, in the wedge space 70. The radial space moves in a gradually increasing direction so that the rotation of the rotating shaft 51 is not transmitted to the pulley portion 54.

  As shown in FIG. 2, a first seal portion 71 and a second seal portion 72 are provided between the rotary shaft 51 and the pulley portion 54 on the front side opposite to the AC generator 10. A third seal portion 73 is provided on the rear side on the same side as the generator 10. The first seal portion 71 is fitted and fixed to the outer periphery of the rotating shaft 51 on the inner peripheral side, and is in sliding contact with the pulley portion 54 on the outer peripheral side. The outer peripheral side of the second seal portion 72 is fitted and fixed to the inner periphery of the pulley portion 54, and the inner peripheral side is in sliding contact with the rotating shaft 51. The outer peripheral side of the third seal portion 73 is fitted and fixed to the inner periphery of the pulley portion 54, and the inner peripheral side is in sliding contact with the rotating shaft 51. Between the second seal part 72 and the third seal part 73 in the axial direction, grease is filled between the pulley part 54 and the rotary shaft 51 in the radial direction. A large number of V grooves 54b having a V-shaped cross section are formed at equal intervals in the axial direction on the outer periphery of the pulley portion 54, and a belt 90 is engaged with the V grooves 54b.

Next, the operation will be described based on the above-described configuration.
As shown in FIG. 1, the rotational power of the automobile engine is transmitted to the power generation shaft 13 via a belt 90, a pulley portion 54, a one-way clutch 60, and a rotating shaft 51. At this time, the cylindrical roller 62 of the one-way clutch 60 bites into the wedge space 70, and the rotating shaft 51 rotates together with the pulley portion 54. An exciting current is supplied from the regulator 18 to the field winding 14a, and a rotating magnetic field is generated by rotating the field winding 14a. By this rotating magnetic field, an AC voltage is generated in the stator winding 15a, and this AC voltage is rectified to DC by the commutator 16, and electricity is stored in the battery. The exciting current supplied to the field winding 14a is controlled so that the output voltage of the AC generator 10 is constant.

  As the rotational speed of the power generation shaft 13 increases, the temperatures of the stator winding 15a, the field winding 14a, and the regulator 18 tend to increase. When the regulator 18 becomes uncontrollable, the temperature of the stator winding 15a and the field winding 14a further increases. The heat of the stator winding 15 a, the field winding 14 a, and the regulator 18 is transmitted to the temperature sensitive member 64 through the power generation shaft 13 and the rotation shaft 51. When the temperature sensitive member 64 reaches a high temperature (in this case, 100 degrees Celsius), the temperature sensitive member 64 is bent in the state shown in FIG. 5 and the cylindrical roller 62 is moved to a position where it cannot be caught in the wedge space 70 by the temperature sensitive member 64. It is pushed and moved. The rotation of the pulley portion 54 is interrupted by the one-way clutch 60 and is not transmitted to the rotary shaft 51 and the power generation shaft 13. As described above, since the cylindrical roller is pushed by the temperature sensitive member 64, the rotation of the pulley unit 54 is surely cut off without the cylindrical roller 62 biting into the wedge space 70 due to the rotation of the pulley unit 54. There is a merit that can be done. In addition, since the intermediate portion of the temperature sensitive member 64 in the axial direction of the cylindrical roller 62 in the axial direction contacts and presses the cylindrical roller 62, the cylindrical roller 62 does not tilt when pressed, and the pulley portion 54 rotates. There is a merit that can be shut off reliably.

  The present invention is not limited to these embodiments, and can of course be implemented in various modes without departing from the gist of the present invention.

  In the embodiment described above, an example in which a plate-like bimetal is used as the temperature sensitive member 64 has been described. As another embodiment, a coil spring-shaped shape memory alloy may be used as the temperature sensitive member 64. In this case, when the temperature becomes high, the natural length of the coil spring made of the shape memory alloy is extended, and the cylindrical roller is pushed to a position where it cannot be caught in the wedge space.

  In the above-described embodiment, the wedge space in which the radial space gradually decreases in the circumferential direction has been described. As another embodiment, the present invention can also be applied to a wedge space in which an axial space gradually decreases in the circumferential direction. In this case, side surfaces facing each other are formed on the pulley portion and the rotation shaft, and a cam surface that approaches and separates in the axial direction is formed on one side surface.

50: Pulley device with one-way clutch, 51: Rotating shaft (first rotating part), 54: Pulley part (second rotating part), 60: One-way clutch, 62: Cylindrical roller (engaging element), 63: Coil spring ( Spring), 64: Temperature sensitive member, 70: Wedge space

Claims (3)

A first rotating portion and a second rotating portion are supported so as to be rotatable about the same axis, and a wedge space is formed between the first rotating portion and the second rotating portion so that a space gradually decreases in a circumferential direction. In a one-way clutch that is provided with a spring that inserts an engagement element and biases the engagement element in a direction in which the wedge space gradually decreases, the engagement element is pushed in a direction in which the wedge space gradually increases, and the amount of pushing is high. A one-way clutch comprising a temperature-sensitive member that increases as the The one-way clutch according to claim 1,
The engagement element is a cylindrical cylindrical roller that rolls in the wedge space, and the temperature-sensitive member is a plate-like bimetal that curves in an arc shape at a high temperature, and an axial middle of the cylindrical roller is an arcuate shape. A one-way clutch characterized in that it is pushed in the middle of the longitudinal direction of a bimetal that is curved. A pulley apparatus with a one-way clutch to which the one-way clutch according to claim 1 is applied.

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