JP7035583B2 - Electric oil pump - Google Patents

Description

The present invention relates to an electric oil pump using an electric motor as a drive source.

Conventionally, an electric oil pump using an electric motor as a drive source has been used in various applications such as in-vehicle devices such as transmissions, power steering devices or brake devices, and various mechanical equipments (see, for example, Patent Document 1). ).

The electric oil pump described in Patent Document 1 is pressed against an electric motor, a drive gear driven by the electric motor, a driven gear that rotates by meshing gear teeth with the drive gear, and a drive gear and a gear portion of the driven gear. It is provided with a side plate to be mounted and a pump housing for accommodating a drive gear and a driven gear together with the side plate.

Japanese Unexamined Patent Publication No. 2016-65481

In the electric oil pump configured as described above, if the side plate is worn, for example, due to long-term use, the oil sealing property in the pump housing may be deteriorated and the volumetric efficiency may be lowered. In this case, a sufficient discharge pressure and discharge amount cannot be obtained. Therefore, it is preferable to issue a warning to the user or the like to urge replacement or repair when the life is approaching. However, for example, when the life is determined simply based on the cumulative usage time, the life may be determined even if the sealing property is sufficiently secured, or the volumetric efficiency is significantly reduced due to harsh usage conditions. It may be determined that the life is still ahead. Here, the volumetric efficiency is the ratio of the actual value to the theoretical value of the amount of oil discharged when the drive gear and the driven gear make one rotation, and the amount of oil leakage in the pump housing due to wear of each part or the like. The volumetric efficiency decreases as the amount increases.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electric oil pump capable of determining the life of a pump unit with high accuracy.

In order to achieve the above object, the present invention includes a drive gear and a driven gear having a gear portion provided with a plurality of gear teeth, a pump housing for accommodating the drive gear and the driven gear , and the drive gear and the driven gear. A pump unit having a side plate pressed against the gear unit along the rotation axis direction of the driven gear, an electric motor for rotating the drive gear, and a control unit for controlling the electric motor are provided, and the drive gear and the drive gear are provided. An electric oil pump that sucks and discharges oil into the pump housing by the rotation of the driven gear, and the control unit is a rotation speed and output torque of the electric motor obtained at predetermined intervals and the oil. It stores map information in which the relationship between the temperature and the index value relating to the life of the pump unit is defined, and has a life determination means for determining the life of the pump unit with reference to the map information, and the index value is Provided is an electric oil pump, which is the amount of wear of the side plate per unit time .
Further, in order to achieve the above object, the present invention includes a drive gear and a driven gear having a gear portion provided with a plurality of gear teeth, a pump housing for accommodating the drive gear and the driven gear, and the drive gear and the driven gear. A pump unit having a sliding bearing for supporting the driven gear, an electric motor for rotating the drive gear, and a control unit for controlling the electric motor are provided, and the pump housing is provided by rotation of the drive gear and the driven gear. An electric oil pump that sucks and discharges oil into the pump, and the control unit is an index relating to the rotation speed and output torque of the electric motor obtained at predetermined cycles, the temperature of the oil, and the life of the pump unit. It stores map information in which the relationship with the value is defined, and has a life determination means for determining the life of the pump unit with reference to the map information, and the index value is the index value per unit time of the sliding bearing. Provides an electric oil pump, which is the amount of wear.
Further, in order to achieve the above object, the present invention has a drive gear and a driven gear having a gear portion provided with a plurality of gear teeth, a pump housing for accommodating the drive gear and the driven gear, the drive gear and the above. A side plate pressed against the gear portion along the rotation axis direction of the driven gear, a pump portion having a drive gear and a sliding bearing for supporting the driven gear, an electric motor for rotating the drive gear, and the electric motor. An electric oil pump including a control unit for controlling the pump, which sucks and discharges oil into the pump housing by rotation of the drive gear and the driven gear, and the control unit is obtained at predetermined intervals. It stores map information that defines the relationship between the rotational speed and output torque of the electric motor, the temperature of the oil, and the index value related to the life of the pump unit, and also refers to the map information to store the life of the pump unit. Provided is an electric oil pump having a life determining means for determining the above, wherein the index value is the amount of wear of the side plate per unit time and the amount of wear of the sliding bearing per unit time.

According to the electric oil pump according to the present invention, it is possible to determine the life of the pump unit with high accuracy.

It is sectional drawing which shows the external gear pump which concerns on embodiment of this invention. It is an exploded perspective view which shows the pump part of a circumscribed gear pump. It is explanatory drawing explaining the operating state of a circumscribed gear pump. It is a schematic block diagram which shows the structural example of a control part. It is a graph which shows the specific example of the 1st map information.

[Embodiment]
Embodiments of the present invention will be described with reference to FIGS. 1 to 5. It should be noted that the embodiments described below are shown as suitable specific examples for carrying out the present invention, and there are some parts that specifically exemplify various technically preferable technical matters. , The technical scope of the present invention is not limited to this specific aspect.

(Structure of circumscribed gear pump)
FIG. 1 is a cross-sectional view of an external gear pump according to an embodiment of the present invention. FIG. 2 is an exploded perspective view showing the pump portion of the circumscribed gear pump. FIG. 3 is an explanatory diagram illustrating an operating state of the circumscribed gear pump. This circumscribed gear pump is one aspect of the electric oil pump of the present invention.

The circumscribed gear pump 1 has a pump unit 10, an electric motor 2 for driving the pump unit 10, and a control unit 7 for controlling the electric motor 2. The pump unit 10 includes a drive gear 3 rotated by the torque of the electric motor 2, a driven gear 4 rotated by the rotation of the drive gear 3, first and second side plates 51 and 52, and first and second side plates 51 and 52. A pump housing 6 that houses the cylindrical slide bearings 53 to 56 held by the side plates 51 and 52, and the drive gear 3 and the driven gear 4 together with the first and second side plates 51 and 52 and the slide bearings 53 to 56. And have. The first and second side plates 51 and 52 are made of a material having a hardness lower than that of the drive gear 3 and the driven gear 4. More specifically, the drive gear 3 and the driven gear 4 are made of, for example, iron-based metal, and the first and second side plates 51, 52 are made of, for example, an aluminum alloy or resin.

The circumscribed gear pump 1 is mounted on a vehicle, for example, and sucks and discharges oil for operating an in-vehicle device into the pump housing 6 by rotation of a drive gear 3 and a driven gear 4. Examples of the in-vehicle device include a transmission and a power steering device. In FIG. 3, the rotation directions of the drive gear 3 and the driven gear 4 when the electric motor ₂ rotates in the forward direction are indicated by arrows A1 and _A2 , and the oil suction direction and the oil discharge direction are indicated by white arrows. When the electric motor 2 rotates in the reverse direction, the oil suction direction and the oil discharge direction are opposite to each other.

The electric motor 2 includes a motor housing 20, a motor shaft 21, an annular stator 22 held in the motor housing 20, a rotor 23 arranged inside the stator 22, and a rolling support for the motor shaft 21. It has bearings 24 and 25, and a rotation angle sensor 26 that detects the rotation angle of the motor shaft 21 with respect to the stator 22.

The stator 22 has an iron core 221, an insulator 222 attached to the iron core 221 and a winding 223 wound around the insulator 222. Motor current is supplied to the winding 223 from the control unit 7. The rotor 23 has a core 231 fixed to the motor shaft 21 and a plurality of permanent magnets 232 attached to the outer peripheral surface of the core 231. The rotation angle sensor 26 is fixed to a flange 211 provided at one end of the motor shaft 21, has a permanent magnet 261 having a plurality of magnetic poles, and is fixed to the motor housing 20 to detect the magnetic field of the magnetic poles of the permanent magnet 261. It has a sensor 262. The detection signal of the magnetic sensor 262 is sent to the control unit 7.

The drive gear 3 has a gear portion 32 provided with a plurality of external teeth 31, a first shaft portion 33 protruding axially from the center portion of the gear portion 32, and an axial direction from the center portion of the gear portion 32. It integrally has a second shaft portion 34 protruding to the other side. The tip portion 331 of the first shaft portion 33 is connected to the motor shaft 21 of the electric motor 2 by a coupling (shaft joint) 27. The electric motor 2 receives a motor current from the control unit 7 to generate a torque for rotationally driving the drive gear 3, and rotates the drive gear 3 connected so as to rotate integrally with the motor shaft 21.

Similar to the drive gear 3, the driven gear 4 includes a gear portion 42 provided with a plurality of external teeth 41, a first shaft portion 43 protruding axially from the center portion of the gear portion 42, and a gear portion. It integrally has a second shaft portion 44 projecting from the center portion of the 42 to the other side in the axial direction. The plurality of external teeth 31 of the drive gear 3 and the plurality of external teeth 41 of the driven gear 4 correspond to the gear teeth of the invention according to the claim of the present application, and mesh with each other in the pump chamber 600 of the pump housing 6. The driven gear 4 rotates due to the meshing of the external teeth 31 and 41 with the drive gear 3.

The pump housing 6 has a tubular portion 60 having an inner surface 60a facing the tooth tip surfaces 31a and 41a (see FIG. 3) of the external teeth 31 and 41 of the drive gear 3 and the driven gear 4, and the tubular portion 60 in the central axial direction thereof. It has flat plate-shaped first and second side plate portions 61 and 62 sandwiched between the two. The tubular portion 60, the first and second side plate portions 61, 62, and the motor housing 20 are fastened by a plurality of bolts 63.

The cylinder portion 60 is formed with first and second flow holes 601,602 through which oil flows. When the electric motor 2 rotates in the forward direction, the oil sucked into the pump chamber 600 from the first flow hole 601 is discharged from the second flow hole 602, and when the electric motor 2 rotates in the reverse direction, the second flow hole The oil sucked into the pump chamber 600 from 602 is discharged from the first flow hole 601.

As shown in FIG. 1, the first side plate portion 61 is formed with an insertion hole 611 through which the first shaft portion 33 of the drive gear 3 is inserted, and the inner peripheral surface of the insertion hole 611 and the first one. A seal member 64 is arranged between the shaft portion 33 and the outer peripheral surface of the shaft portion 33. The first side plate 51 is arranged between the gear portions 32 and 42 of the drive gear 3 and the driven gear 4 and the first side plate portion 61, and the second side plate 52 is the drive gear 3 and the driven gear 4. It is arranged between the gear portions 32 and 42 of the above and the second side plate portion 62.

The first side plate 51 is formed with an insertion hole 511 through which the first shaft portion 33 of the drive gear 3 is inserted, and an insertion hole 512 through which the first shaft portion 43 of the driven gear 4 is inserted. A slide bearing 53 that supports the first shaft portion 33 of the drive gear 3 is internally fitted in the insertion hole 511, and a slide bearing 54 that supports the first shaft portion 43 of the driven gear 4 is fitted in the insertion hole 512. It is fitted inside.

A concave groove 513 is formed in the surface of the first side plate 51 facing the first side plate portion 61, and the side seal 65 made of an elastic body such as rubber is compressed in the concave groove 513. It is contained. The first side plate 51 is pressed against the gear portions 32 and 42 along the rotation axis direction of the drive gear 3 and the driven gear 4 by the restoring force of the side seal 65. More specifically, the facing surface 51b of the first side plate 51 facing the gear portions 32 and 42 of the drive gear 3 and the driven gear 4 on the side opposite to the facing surface 51a of the first side plate portion 61. It is pressed against the axial end faces 32a, 42a on the first shaft portions 33, 43 side of the gear portions 32, 42.

The second side plate 52 is formed with an insertion hole 521 through which the second shaft portion 34 of the drive gear 3 is inserted, and an insertion hole 522 through which the second shaft portion 44 of the driven gear 4 is inserted. A slide bearing 55 that supports the second shaft portion 34 of the drive gear 3 is internally fitted in the insertion hole 521, and a slide bearing 56 that supports the second shaft portion 44 of the driven gear 4 is fitted in the insertion hole 522. It is fitted inside.

A concave groove 523 is formed on the surface of the second side plate 52 facing the second side plate portion 62, and the side seal 66 made of an elastic body such as rubber is compressed in the concave groove 523. It is contained. The second side plate 52 is pressed against the gear portions 32 and 42 along the rotation axis direction of the drive gear 3 and the driven gear 4 by the restoring force of the side seal 66. More specifically, the facing surface 52b of the second side plate 51 facing the gear portions 32 and 42 of the drive gear 3 and the driven gear 4 on the side opposite to the facing surface 52a of the second side plate portion 62. It is pressed against the axial end faces 34b, 44b on the second shaft portions 34, 44 side of the gear portions 32, 42.

(Operation of circumscribed gear pump)
In the circumscribed gear pump 1 configured as described above, the drive gear 3 is rotationally driven by the electric motor 2. Further, the driven gear 4 rotates in the direction opposite to that of the drive gear 3 due to the meshing of the outer teeth 41 of the driven gear 4 with the outer teeth 31 of the drive gear 3. An oil chamber C is formed between two external teeth 31 adjacent to each other in the circumferential direction of the drive gear 3 and between two external teeth 41 adjacent to each other in the circumferential direction of the driven gear 4. The oil sucked from the first flow hole 601 or the second flow hole 602 moves from the low pressure chamber side in the pump chamber 600 to the high pressure chamber side by the oil chamber C as the drive gear 3 and the driven gear 4 rotate. do. On the high pressure chamber side, the oil pressure is increased by the volume change due to the meshing of the external teeth 31 of the drive gear 3 and the external teeth 41 of the driven gear 4.

In the present embodiment, the outer diameter and the number of teeth of the drive gear 3 and the driven gear 4 are the same, and the gear portion 32 of the drive gear 3 and the gear portion 42 of the driven gear 4 have 12 external teeth 31, respectively. 41 are provided radially. In the drive gear 3 and the driven gear 4, the tooth surface 31b of at least one of the external teeth 31 and 41 and the tooth surface 41b of the external tooth 41 are in contact with each other, and the contact portion is on the low pressure chamber side. It is a seal portion S that separates the high pressure chamber side.

(Configuration of control unit and control content)
FIG. 4 is a schematic configuration diagram showing a configuration example of the control unit 7. The control unit 7 has a speed control unit 70, a current control unit 71, a two-phase three-phase conversion unit 72, a PWM control unit 73, a phase calculation unit 74, and a three-phase two-phase by executing a program stored in advance by the CPU. It functions as a conversion unit 75, a speed calculation unit 76, an instantaneous wear amount calculation unit 77, a wear amount integration unit 78, and a life determination unit 79. The CPU of the control unit 7 executes each process described later at each predetermined calculation cycle. Further, the control unit 7 has an inverter circuit 81 having a plurality of switching elements, and three current sensors 82 for detecting the U-phase, V-phase, and W-phase phase currents output from the inverter circuit 81, respectively. ing. The instantaneous wear amount calculation unit 77, the wear amount integration unit 78, and the life determination unit 79 correspond to the life determination means of the invention according to the claim of the present application.

The control unit 7 receives the rotation speed command value ω ^* of the electric motor 2 from the host controller in the speed control unit 70, and calculates a current command value which is a target value of the motor current. More specifically, it is proportional to the deviation (ω ^* -ω) between this rotation speed command value ω ^* and the actual rotation speed ω indicating the actual rotation speed of the electric motor 2 calculated by the speed calculation unit 76 described later. By performing the integration calculation (PI calculation), the q-axis current command value Iq ^* , which is the target value of the torque component of the motor current supplied to the electric motor 2, is calculated.

The current control unit 71 calculates a voltage command value, which is a target value of the voltage to be applied to the electric motor 2, based on the q-axis current command value Iq ^* calculated by the speed control unit 70. More specifically, a proportional integral calculation is performed based on the q-axis current command value Iq ^* and the q-axis current detection value Iq and the d-axis current detection value Id calculated by the three-phase two-phase conversion unit 75 described later, and the q-axis is performed. Calculate the voltage command value Vq ^* and the d-axis voltage command value Vd ^* .

The two-phase three-phase conversion unit 72 uses the rotation angle θ calculated by the phase calculation unit 74, which will be described later, to set the q-axis voltage command value Vq ^* and the d-axis voltage command value Vd ^* to the U phase, V phase, and W. Converts to phase voltage command values Vu ^* , Vv ^* , Vw ^* . The PWM control unit 73 generates a duty U-phase PWM control signal, a V-phase PWM control signal, and a W-phase PWM control signal corresponding to each of the three-phase voltage command values Vu ^* , Vv ^* , and Vw ^* , and generates an inverter. It is supplied to the circuit 81. The inverter circuit 81 turns on or off the switching element according to the PWM control signal of each phase, and supplies the electric motor 2 with the three-phase alternating current as the motor current.

The phase calculation unit 74 calculates the rotation angle θ of the motor shaft 21 of the electric motor 2 based on the detection signal of the rotation angle sensor 26 of the electric motor 2. The three-phase two-phase conversion unit 75 uses the rotation angle θ calculated by the phase calculation unit 74 to detect the phase currents of each phase obtained by the three current sensors 82 with the q-axis current detection value Iq and the d-axis current detection. Convert to the value Id. It is also possible to omit one of the three current sensors 82 based on the relationship that the sum of the phase currents of the U phase, V, and W phase becomes zero. The speed calculation unit 76 calculates the actual rotation speed ω of the electric motor 2 for each predetermined calculation cycle based on the difference between the rotation angle θ of the previous calculation cycle and the rotation angle θ of the current calculation cycle.

(Life judgment processing)
The instantaneous wear amount calculation unit 77, the wear amount integration unit 78, and the life determination unit 79 as the life determination means determine the life of the pump unit 10 based on the rotation speed of the electric motor 2 obtained at least every predetermined cycle. do. In the present embodiment, the life of the pump unit 10 is determined in consideration of the output torque of the electric motor 2 and the oil temperature (oil temperature) obtained at predetermined intervals.

The instantaneous wear amount calculation unit 77 obtains the actual rotation speed ω of the electric motor 2 calculated by the speed calculation unit 76 and the q-axis current detection value Iq calculated by the three-phase two-phase conversion unit 75 multiplied by the torque constant Kt. The torque conversion value Tm and the oil temperature to be obtained are acquired at predetermined intervals. The torque conversion value Tm indicates the output torque of the electric motor 2. The oil temperature is, for example, a detected value of an oil temperature gauge provided in an in-vehicle device to which oil is supplied. An oil temperature gauge may be arranged in the hole formed in the pump housing 6 and the detected value of the oil temperature gauge may be acquired as the oil temperature.

The control unit 7 stores map information in which the relationship between the actual rotation speed ω and torque conversion value Tm of the electric motor 2 thus obtained and the oil temperature and the index value related to the life of the pump unit 10 is defined. ing. In the present embodiment, the control unit 7 stores the first map information 771 and the second map information 772. These first and second map information 771,772 are defined based on the results of experiments and simulations, and are recorded in advance in the non-volatile memory.

The index value regarding the life of the pump unit 10 in the first map information 771 is the amount of wear of the first and second side plates 51 and 52 per unit time. In the first and second side plates 51 and 52, the facing surfaces 51b and 52b mainly facing the gear portions 32 and 42 are worn by the rotation of the drive gear 3 and the driven gear 4. When this amount of wear becomes large, the amount of oil leaking from the high pressure chamber side to the low pressure chamber side in the pump chamber 600 increases, and the volumetric efficiency of the pump portion 10 decreases.

The index value regarding the life of the pump unit 10 in the second map information 772 is the amount of wear per unit time of the slide bearings 53 to 56. The inner peripheral surfaces of the slide bearings 53 to 56 that face the outer peripheral surfaces of the first shaft portions 33, 43 and the second shaft portions 34, 44 are worn by the rotation of the drive gear 3 and the driven gear 4. When this amount of wear becomes large, tilting and rattling of the drive gear 3 and the driven gear 4 in the pump chamber 600 are likely to occur, uneven wear of each sliding portion is likely to occur, and the volumetric efficiency of the pump portion 10 is increased. It will drop.

In the first and second map information 771 and 772, the relationship between the rotational speed and output torque of the electric motor 2 and the amount of wear per unit time is defined in the form of a three-dimensional map for each of a plurality of oil temperatures. There is. The predetermined cycle in which the unit time and the instantaneous wear amount calculation unit 77 acquire the actual rotation speed ω and the like may be the same as the above calculation cycle, but may be an integral multiple of the calculation cycle. The plurality of oil temperatures are, for example, a medium temperature region including normal temperature, a high and low temperature region higher than the medium temperature region, and a low temperature region lower than the medium temperature region.

FIG. 5 is a graph showing a specific example of the first map information 771, where (a) is a high temperature region, (b) is a medium temperature region, and (c) is a rotation speed and output torque of the electric motor 2 in a low temperature region. The relationship between the first and second side plates 51 and 52 and the amount of wear per unit time is shown.

As shown in FIG. 5, the amount of wear of the first and second side plates 51 and 52 is smaller as the rotation speed of the electric motor 2 is higher, is larger as the output torque of the electric motor 2 is larger, and is higher as the oil temperature is higher. big. The higher the rotation speed of the electric motor 2, the smaller the amount of wear. When the rotation speed of the drive gear 3 and the driven gear 4 is high, the gear portions 32, 42 and the first and second side plates 51, 52 This is because an oil film is formed between them to promote lubrication by the oil. The larger the output torque of the electric motor 2, the larger the amount of wear, because the drive gear 3 and the driven gear 4 tend to tilt as the discharge pressure increases, and the oil film tends to break. Further, the higher the oil temperature, the larger the amount of wear, because the higher the oil temperature, the lower the viscosity of the oil and the more difficult it is to form an oil film. Although not shown, the second map information 772 also shows similar wear characteristics.

The wear amount integrating unit 78 integrates the wear amounts of the first and second side plates 51 and 52 and the slide bearings 53 to 56 obtained by the instantaneous wear amount calculation unit 77 per unit time, and calculates the integrated value. .. This integrated value is a cumulative value from the beginning of use of the circumscribed gear pump 1, and when the power of the control unit 7 is turned off, the integrated value up to that point is stored in the non-volatile memory in the power down process, and the power is supplied again. When is turned on, the integrated value stored in the non-volatile memory is read out and the integrated value is further accumulated.

The life determination unit 79 determines that the pump unit 10 has reached the end of its life when the integrated value of the wear amount of the first and second side plates 51 and 52 exceeds a predetermined threshold value. Further, the life determination unit 79 determines that the pump unit 10 has reached the end of its life even when the integrated value of the wear amount of the slide bearings 53 to 56 exceeds a predetermined threshold value. That is, when at least one of the integrated value of the wear amount of the first and second side plates 51 and 52 and the integrated value of the wear amount of the slide bearings 53 to 56 exceeds the threshold value, the life determination unit 79 is the pump unit. It is determined that 10 has reached the end of its life. These thresholds are predetermined based on the results of experiments and simulations, and are defined as constants in a program, for example.

When the life determination unit 79 determines that the pump unit 10 has reached the end of its life, the life determination unit 79 outputs an alarm signal, and the alarm device 9 receives this alarm signal and issues an alarm. Various modes of this alarm can be adopted depending on the application target of the circumscribed gear pump 1. For example, when the circumscribed gear pump 1 is mounted on a vehicle, the warning light of the instruments panel is turned on for operation. Can issue an alarm to a person.

(Actions and effects of embodiments)
According to the embodiment of the present invention described above, it is possible to determine the life of the pump unit 10 with high accuracy. This prevents, for example, the continuous use of the circumscribed gear pump 1 in a state where the volumetric efficiency is greatly reduced, and the prompting of replacement even though the volumetric efficiency is not significantly reduced.

(Additional note)
Although the present invention has been described above based on the embodiments, these embodiments do not limit the invention according to the claims. It should also be noted that not all combinations of features described in the embodiments are essential to the means for solving the problems of the invention.

Further, the present invention can be appropriately modified and implemented without departing from the spirit of the present invention. For example, in the above embodiment, the control unit 7 has a life of the pump unit 10 based on the rotation speed of the electric motor 2 (actual rotation speed ω), the output torque of the electric motor 2 (torque conversion value Tm), and the oil temperature. However, the case is not limited to this, and the life of the pump unit 10 may be determined by, for example, the rotational speed and output torque of the electric motor 2, or only by the rotational speed of the electric motor 2.

Further, in the above embodiment, the case where the functions of each part are realized by the CPU of the control unit 7 executing the program has been described, but some or all of the functions of each part are ASICs (integrated circuits for specific applications). ) And other hardware may be used. The mechanical configuration of the circumscribed gear pump 1 shown in FIGS. 1 to 3 is shown as an example. The drive gear is driven by an electric motor, and the driven gear is engaged with the drive gear by engaging the gear teeth with each other. The present invention can be applied to electric gear pumps having various mechanical configurations as long as they have a rotating configuration.

1 ... External gear pump (electric oil pump) 10 ... Pump part 2 ... Electric motor 3 ... Drive gear 31 ... External teeth (gear teeth) 32 ... Gear part 4 ... Driven gear 41 ... External teeth (gear teeth)
42 ... Gear part 51 ... First side plate 52 ... Second side plate 53-56 ... Slide bearing 6 ... Pump housing 7 ... Control unit 77 ... Instantaneous wear amount calculation unit (life determination means) 771 ... First map Information 772 ... Second map information 78 ... Wear amount integrating unit (life determination means)
79 ... Lifespan determination unit (lifespan determination means)

Claims (6)

A drive gear and a driven gear having a gear portion provided with a plurality of gear teeth, a pump housing accommodating the drive gear and the driven gear , and the gear portion along the rotation axis direction of the drive gear and the driven gear. With a pump section that has a side plate that is pressed against
An electric motor that rotates the drive gear and
A control unit that controls the electric motor is provided.
An electric oil pump that sucks and discharges oil into the pump housing by rotation of the drive gear and the driven gear.
The control unit stores map information in which the relationship between the rotational speed and output torque of the electric motor obtained at predetermined cycles, the temperature of the oil, and the index value relating to the life of the pump unit is defined, and the control unit is used. It has a life determination means for determining the life of the pump unit with reference to map information .
The index value is the amount of wear of the side plate per unit time.
Electric oil pump. The life determining means determines that the pump portion has reached the end of its life when the integrated value of the wear amount of the side plate exceeds the threshold value.
The electric oil pump according to claim 1. A drive gear and a driven gear having a gear portion provided with a plurality of gear teeth, a pump housing for accommodating the drive gear and the driven gear, and a pump portion having a slide bearing for supporting the drive gear and the driven gear.
An electric motor that rotates the drive gear and
A control unit that controls the electric motor is provided.
An electric oil pump that sucks and discharges oil into the pump housing by rotation of the drive gear and the driven gear.
The control unit stores map information in which the relationship between the rotational speed and output torque of the electric motor obtained at predetermined cycles, the temperature of the oil, and the index value relating to the life of the pump unit is defined, and the control unit is used. It has a life determination means for determining the life of the pump unit with reference to map information.
The index value is the amount of wear of the slide bearing per unit time.
Electric oil pump. The life determining means determines that the pump portion has reached the end of its life when the integrated value of the wear amount of the slide bearing exceeds the threshold value.
The electric oil pump according to claim 3. A drive gear and a driven gear having a gear portion provided with a plurality of gear teeth, a pump housing accommodating the drive gear and the driven gear, and pressing against the gear portion along the rotation axis direction of the drive gear and the driven gear. A pump portion having a side plate and a slide bearing for supporting the drive gear and the driven gear,
An electric motor that rotates the drive gear and
A control unit that controls the electric motor is provided.
An electric oil pump that sucks and discharges oil into the pump housing by rotation of the drive gear and the driven gear.
The control unit stores map information in which the relationship between the rotational speed and output torque of the electric motor obtained at predetermined cycles, the temperature of the oil, and the index value relating to the life of the pump unit is defined, and the control unit is used. It has a life determination means for determining the life of the pump unit with reference to map information.
The index value is the amount of wear of the side plate per unit time and the amount of wear of the slide bearing per unit time.
Electric oil pump. The life determining means determines that the pump portion has reached the end of its life when at least one of the integrated value of the wear amount of the side plate and the integrated value of the wear amount of the slide bearing exceeds the threshold value.
The electric oil pump according to claim 5.

Images