JP2018152944A - Lubrication device of motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve lubricity by increasing the temperature of lubricant at the time of low temperature.SOLUTION: In a front motor 2 housing a rotor 12 and a stator 13 in a housing 10, and having an oil pan 19 for reserving lubricant in the lower part of the housing 10, and cooling the rotor with lubricant supplied into the housing 10 by a hydraulic pump 6, an air bag 31 is provided in the oil pan 19, the air bag 31 is inflated by supplying high pressure air by means of an air compressor 32, and the oil level is increased until the rotor 12 is immersed in the lubricant, so that the lubricant is introduced between the rotor 12 and the stator 13 by rotation of the rotor 12, and the oil temperature is raised by frictional heat generated by rotation of the rotor 12.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a lubrication technique in an electric motor.

In an electric motor such as an electric motor or a generator used in a vehicle such as a hybrid vehicle, a cooling device for cooling the electric motor with a coolant has been developed.
For example, Patent Document 1 discloses a device that houses a motor for driving a vehicle in a housing and supplies oil to the housing to cool the motor. In patent document 1, it is the structure which cools oil with driving | running | working wind in the oil tank provided in the housing.

  In addition, in an electric motor such as a motor that can be cooled using oil as in Patent Document 1, not only the cooling performance of the electric motor can be obtained by supplying lubricating oil (oil) into the electric motor, but also a bearing in the electric motor or the like. The lubricating performance can be improved by supplying lubricating oil to the sliding portion. In addition, when the lubricating oil is circulated by a pump between the electric motor and an external heat exchanger, the supply amount of the lubricating oil can be increased, and the cooling and lubricating performance can be improved.

JP, 2006-178822, A

However, in the electric motor equipped with the cooling device configured to circulate the lubricating oil as described above, when the lubricating oil becomes low temperature, the lubricating oil cannot be sufficiently discharged by the circulation pump, and it is difficult to lubricate the electric motor. There is a risk of becoming.
The present invention has been made to solve such problems, and an object of the present invention is to provide a lubricating device for an electric motor that improves the lubrication performance by rapidly increasing the oil temperature when the oil temperature is lowered. It is in.

  In order to achieve the above object, an electric motor lubrication device according to the present invention has a reservoir and a stator stored in a casing, and a reservoir for storing lubricating oil in a lower portion of the casing. A lubricating device for an electric motor that supplies lubricating oil from a portion to a sliding portion in the casing and circulates the lubricating oil, and supplies fluid to the bag body provided in the storage portion and the bag body. And a fluid supply part for inflating the bag body.

In addition, preferably, it has a partition member that partitions the storage section into a first space and a second space, and the bag body is disposed in the first space, A discharge port for discharging the lubricating oil to the hydraulic pump may be provided.
Preferably, the central axis of the rotor is arranged above the second space.

  Preferably, the communication path includes a communication path that allows the discharge port and the second space to communicate with each other, and the communication path extends from the second space below the rotor in a tangential direction at a lower end portion of the rotor, The opening on the second space side may open toward the rear side in the rotational direction of the rotor.

  According to the lubricating device for an electric motor of the present invention, the oil level of the lubricating oil in the reservoir can be raised by supplying fluid to the bag body by the fluid supply section and inflating the bag body. And by raising the lubricating oil until it contacts the rotor, the temperature of the lubricating oil can be raised by the friction between the lubricating oil and the rotor. In this way, it becomes possible to raise the temperature of the lubricating oil with a simple configuration using the rotation of the rotor, and the temperature of the lubricating oil in the low temperature state can be easily raised to improve the circulation of the lubricating oil by the hydraulic pump early. Thus, the lubricating performance of the lubricating oil can be improved.

It is a block diagram of the lubricating device of the electric motor which concerns on embodiment of this invention. It is a figure which shows the schematic structure of the front motor and the structure of an oil level raising apparatus in this embodiment. It is a longitudinal cross-sectional view which shows the state in a front motor at the time of an air bag contraction. It is a longitudinal cross-sectional view which shows the state in a front motor at the time of an air bag expansion | swelling. It is a cross-sectional view showing the structure in the oil pan. It is a flowchart which shows the operation control point of the oil level raising apparatus in a control unit. It is a graph which shows an example of transition of the oil temperature in this embodiment, pressure, and operation of an air compressor.

Hereinafter, an embodiment of a lubricating device for an electric motor embodying the present invention will be described.
FIG. 1 is a configuration diagram of a motor lubrication device 1 according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a schematic structure of the front motor 2 and a configuration of the oil level raising device 30 in the present embodiment. FIG. 2 shows a longitudinal section of the front motor 2. FIG. 3 is a longitudinal sectional view showing a state in the front motor 2 when the air bag contracts. FIG. 4 is a longitudinal sectional view showing a state in the front motor 2 when the air bag is inflated. FIG. 5 is a cross-sectional view showing the structure inside the oil pan. 3 and 4, the two-dot chain line indicates the main flow path of the lubricating oil in the front motor 2.

  The lubrication apparatus 1 of the present embodiment is employed in a hybrid vehicle (hereinafter referred to as a vehicle) that can be driven by a front motor 2 and can be driven by an engine (not shown). The lubricating device 1 serves as an oil-cooled cooling device that lubricates the motor of the vehicle with lubricating oil and cools the motor. The electric motors to be lubricated and cooled are the front motor 2 that drives the front wheels of the vehicle and the generator 4 that is driven by the engine to generate electric power.

  As shown in FIG. 1, the lubricating device 1 of the present embodiment includes a lubricating oil circulation path 5 in which a front motor 2 and a generator 4 are connected in parallel. The circulation path 5 is provided with an electric hydraulic pump 6 and a heat exchanger 7 in order in the flow direction of the lubricating oil. The circulation path 5 branches downstream of the heat exchanger 7, and the front motor 2 is provided in one branch path 5a, and the generator 4 is provided in the other branch path 5b.

Further, an oil tank 8 is provided downstream of the front motor 2 and the generator 4, and a circulation path 5 is configured so as to return from the oil tank 8 to the hydraulic pump 6.
With such a configuration, the lubricating oil circulates in the circulation path 5 by operating the hydraulic pump 6, and the lubricating oil cooled by the heat exchanger 7 is supplied to the front motor 2 and the generator 4. The generator 4 is cooled. The lubricating oil that has cooled the front motor 2 and the generator 4 is collected in the oil tank 8 and supplied to the hydraulic pump 6.

The front motor 2, the generator 4, and the oil tank 8 are provided with temperature sensors 21, 22, and 23 (oil temperature detectors) that detect the temperature of the lubricating oil, respectively.
As shown in FIG. 2, the front motor 2 includes a housing 10 (casing), a motor shaft 11, a rotor 12, and a stator 13.
The housing 10 is formed in a substantially cylindrical shape with both ends closed by, for example, an aluminum alloy.

The motor shaft 11 is rotatably supported by the housing 10 by a front bearing 15 (sliding portion) and a rear bearing 16 (sliding portion) provided at both ends of the housing 10. One end of the motor shaft 11 protrudes from the end of the housing 10 and is connected to a rotationally driven object such as a drive shaft of a vehicle as an output shaft of the front motor 2.
The rotor 12 is a columnar magnet fixed to the motor shaft 11 and is disposed in the housing 10.

The stator 13 is disposed in the housing 10 so as to surround the periphery of the rotor 12, and is configured by winding a plurality of coils around the stator core.
When a current is supplied to the coils of the stator 13, a magnetic field is generated in the stator 13, and the rotor 12 made of a magnet is driven to rotate by receiving electromagnetic force in the magnetic field.
A resolver 17 that detects the rotation angle of the motor shaft 11 is provided at the other end of the motor shaft 11.

  Further, an oil supply port 18 through which lubricating oil is supplied from the heat exchanger 7 via the branch path 5a is provided in the upper part of the housing 10 of the front motor 2. As shown by the arrow in FIG. 2, the lubricating oil supplied into the housing 10 from the oil supply port 18 moves downward while contacting the rotor 12 and the stator 13, cooling the rotor 12 and the stator 13, Alternatively, the lubricant is supplied to the front bearing 15 and the rear bearing 16 for lubrication. These lubricating oils fall into a lower oil pan 19 (storage part) in the housing 10.

An oil discharge port 20 (discharge port) for discharging the lubricating oil from the oil pan 19 is provided in the lower part of the housing 10, and the lubricating oil is supplied from the oil discharge port 20 to the oil tank 8 through the branch path 5a. Discharged.
Further, the front motor 2 of the present embodiment is provided with an oil level raising device 30.
The oil level raising device 30 includes an air bag 31 (bag body) provided in the front motor 2 and an air compressor 32 (fluid supply unit).

The air bag 31 is installed in the oil pan 19 below the front motor 2.
The air compressor 32 is connected to the air bag 31 via the air pipe 33 and has a function of supplying compressed air (fluid) to the air bag 31. The air compressor 32 includes an electromagnetic control type pressure valve 34. The pressure valve 34 is a normally closed valve, and has a function of discharging the compressed air in the air bag 31 to the atmosphere via the air pipe 33 by opening the valve.

  As shown in FIGS. 3-5, in this embodiment, the partition member 40 which divides the space in the oil pan 19 into two is provided. The partition member 40 is positioned below the rotor 12, extends in parallel with the motor shaft 11, and is arranged offset in the lateral direction that is a direction perpendicular to the motor shaft 11. For example, as shown in FIG. 3, in a motor in which the rotor 12 rotates clockwise by normal rotation, the partition member 40 is disposed on the left side of the central axis CL of the rotor 12.

The air bag 31 is disposed in the first space 41 on the left side that is the front side in the rotational direction in the tangential direction at the lower end of the rotor 12 in the space in the oil pan 19 partitioned by the partition member 40. On the other hand, the air bag 31 is not installed in the second space 42 on the right side.
Further, the oil pan 19 is provided with a discharge pipe 43 (communication passage) that allows the oil discharge port 20 and the second space 42 to communicate with each other, and the lubricating oil is discharged from the second space 42. Has been.

The discharge pipe 43 extends from the opening 44 on the second space 42 side toward the front side in the rotational direction of the tangential direction at the lower end of the rotor 12, that is, toward the left side in FIG. 3, and then in the first space 41. Is bent at a right angle and extends in the axial direction of the rotor 12 toward the oil discharge port 20.
The opening 44 on the second space 42 side of the discharge pipe 43 opens toward the rear side in the rotational direction in the tangential direction at the lower end of the rotor 12, that is, toward the right in FIG. 3.

A temperature sensor 21 that detects the temperature of the lubricating oil stored in the second space 42 of the oil pan 19 is provided at the lower portion of the housing 10. The air bag 31 is provided with a pressure sensor 35 that detects the pressure in the air bag 31.
Further, the vehicle is provided with a control unit 36 (control unit) that controls the operation of the oil level raising device 30.

As shown in FIG. 3, the air bag 31 contracts by opening the pressure valve 34 of the air compressor 32. When the air bag 31 contracts, the oil level of the lubricating oil in the oil pan 19 decreases, but the oil amount is set so that the oil level at this time is lower than the rotor 12. Moreover, the height of the partition member 40 is set lower than the oil level of the lubricating oil when the air bladder 31 contracts.
As shown in FIG. 4, when compressed air is supplied into the air bag 31 by operating the air compressor 32 with the pressure valve 34 closed, the air bag 31 expands in the first space 41. At this time, the capacity of the air bladder 31 is set so that the oil level in the front motor 2 is above the lower end of the rotor 12.

The control unit 36 includes an input / output device, a storage device (ROM, RAM, nonvolatile RAM, etc.), a central processing unit (CPU), and the like. The control unit 36 inputs the oil temperature T from the temperature sensor 21 and also inputs the pressure P in the air bladder 31 from the pressure sensor 35 to control the operation of the air compressor 32.
FIG. 6 is a flowchart showing an operation control procedure of the oil level raising device 30 in the control unit 36. FIG. 7 is a graph showing an example of the transition of the oil temperature T, the pressure P, and the operation of the air compressor 32 in the present embodiment.

The control unit 36 executes the control shown in FIG. 6 when the vehicle power is turned on. When the vehicle power is off, the air compressor 32 is stopped and the pressure valve 34 is closed.
As shown in FIG. 6, first, in step S <b> 10, the oil temperature T in the oil pan 19 is detected by the temperature sensor 21, and it is determined whether or not the oil temperature T is lower than a predetermined temperature Ta. The predetermined temperature Ta is a target temperature of the oil temperature in the oil pan 19 and may be set as appropriate near the lower limit value of the temperature at which the viscosity is such that the lubricating oil can be sufficiently discharged by the hydraulic pump 6. When the oil temperature T is lower than the predetermined temperature Ta, the process proceeds to step S20. When the oil temperature T is equal to or higher than the predetermined temperature Ta, the process proceeds to step S50.

In step S <b> 20, the air compressor 32 is operated to supply compressed air to the air bag 31. Thereby, the inside of the air bag 31 is pressurized and expanded. Then, the process proceeds to step S30.
In step S30, the pressure sensor 35 detects the pressure P in the air bladder and determines whether or not the pressure P is greater than a predetermined value Pa. The predetermined value Pa may be set to a pressure at which the air bag 31 expands in the oil pan 19 as shown in FIG. If the pressure P is greater than the predetermined value Pa, the process proceeds to step S40. If the pressure P is less than or equal to the predetermined value Pa, the process returns to step S20.

In step S40, the operation of the air compressor 32 is stopped. Then, the process proceeds to S50.
In step S50, the oil temperature T in the oil pan 19 is detected by the temperature sensor 21, and it is determined whether or not the oil temperature T is higher than a predetermined temperature Ta + α. α may be set to about 2 to 3 degrees, for example. When the oil temperature T is higher than the predetermined temperature Ta + α, the process proceeds to step S60. If the oil temperature T is equal to or lower than the predetermined temperature Ta + α, the process returns to step S10.

In step S60, the pressure valve 34 is opened. The opening time of the pressure valve 34 may be set until the pressure P in the air bag 31 actually decreases to near zero, or may be set to a time at which the pressure P decreases to near zero. Then, the process proceeds to step S70.
In step S70, it is determined whether or not the ignition is off (IG-OFF), that is, the vehicle is powered off. If the ignition is off, this routine is terminated. If the ignition is on, the process returns to step S10.

By the above control, as shown in FIG. 7, for example, when the oil temperature T is lower than the predetermined temperature Ta when the power is turned on, the air compressor 32 is operated (a in FIG. 7). At this time, since the pressure valve 34 is closed, the pressure P increases by the operation of the air compressor 32, and when the pressure P reaches a predetermined value Pa, the air compressor 32 stops (b in FIG. 7). .
As described above, when the air compressor 32 is operated until the pressure P reaches the predetermined value Pa with the pressure valve 34 closed, the air bag 31 is inflated as shown in FIG. The oil level rises and the lower part of the rotor 12 is immersed in the lubricating oil. When the rotor 12 rotates in such a state, the lubricating oil is scraped up by the rotor 12 and pushed between the rotor 12 and the stator 13, and the temperature of the lubricating oil rapidly rises due to frictional heat generated by the rotation of the rotor 12. (B → c in FIG. 7).
When the oil temperature T becomes equal to or higher than the predetermined temperature Ta + α, the pressure valve 34 is opened. Therefore, as shown in FIG. 3, the air bladder 31 contracts and the oil level is lowered to the extent that the rotor 12 is not immersed in the rotor 12. When the oil temperature T is equal to or higher than the predetermined temperature Ta + α, the viscosity of the lubricating oil is lowered, and the lubricating oil is circulated favorably by the hydraulic pump 6 and supplied from the oil supply port 18 at the upper part of the front motor 2. The lubricated oil flows downward while contacting the rotor 12 and the stator 13, and the rotor 12 and the stator 13 can be sufficiently cooled, and the lubricating oil is supplied to the front bearing 15 and the rear bearing 16 to be sufficiently lubricated. can do. Further, when the oil temperature T becomes equal to or higher than the predetermined temperature Ta + α, the oil level of the lubricating oil does not contact the rotor 12, so that the rotational resistance of the rotor 12 can be suppressed and the output reduction of the rotor 12 can be suppressed.

When the pressure P becomes 0, the pressure valve 34 is closed (d in FIG. 7).
As described above, in the present embodiment, the air bag 31 is provided in the oil pan 19, and the oil surface of the lubricating oil in the oil pan 19 can be easily made by supplying high-pressure air to the air bag 31 to inflate it. Can be raised. Then, by raising the lubricating oil until it contacts the rotor 12, the temperature of the lubricating oil can be increased by friction between the lubricating oil and the rotor 12, and the rotation of the rotor 12 can be used to achieve a simple and compact configuration. The temperature of the lubricating oil can be increased.

Therefore, even when the lubricating oil is in a low temperature state, for example, when the engine is started, the lubricating oil can be circulated by the hydraulic pump 6 at an early stage to improve the lubricating performance of the front motor 2 by the lubricating oil. it can.
In the present embodiment, the partition member 40 is provided in the oil pan 19 of the front motor 2, and the oil pan 19 is partitioned into two spaces, a first space 41 and a second space 42. An air bag 31 is disposed in one space 41. Even if the air bag 31 is inflated, the partition member 40 prevents the air bag 31 from entering the second space 42.

  Since the partition member 40 is arranged so that the central axis CL of the rotor 12 is positioned above the second space 42, most of the lubricant that falls from the rotor 12 falls into the second space 42. Further, most of the lubricating oil flowing in from the oil supply port 18 contacts the rotor 12 that rotates clockwise, passes through the right side of the rotor 12, and falls downward. Therefore, more lubricating oil that falls from the rotor 12 falls into the second space 42.

Thereby, most of the lubricating oil supplied from the oil supply port 18 falls to the rotor 12, passes through the right side of the rotor 12, and is discharged from the oil discharge port 20 via the second space 42 and the discharge pipe 43. The
And since the air bag 31 is arrange | positioned in the 1st space 41 as mentioned above, even if the air bag 31 expand | swells, since it penetrates into the 2nd space 42 by the partition member 40, the rotor 12 And the flow of the lubricating oil discharged from the oil discharge port 20 via the second space 42 is not disturbed.

Accordingly, the lubricating oil heated to the rotor 12 due to friction or the like can be discharged preferentially, and the lubricating oil supplied to the hydraulic pump 6 can be quickly heated.
Further, the discharge pipe 43 that guides the lubricating oil from the second space 42 to the oil discharge port 20 has an opening 44 on the second space 42 side facing the right side, and is tangential to the lower end of the rotor 12. Among these, it extends toward the front side in the rotation direction. As a result, the lubricating oil that falls downward in the rotational direction toward the lower side of the rotor 12 along with the rotation of the rotor 12 smoothly flows into the discharge pipe 43 and passes through the discharge pipe 43, and the lubricating oil whose temperature is increased is discharged into the oil discharge port. 20 can be quickly discharged.

  The description of the embodiment is finished as above, but the aspect of the present invention is not limited to the above embodiment. For example, the shape of the air bladder 31 may be appropriately changed according to the shape of the oil pan 19. Further, the presence / absence, position, and height of the partition member 40 may be set as appropriate. For example, the height of the partition member 40 may be made as high as possible so that the lower portion of the first space 41 and the lower portion of the second space 42 communicate with each other through a small-diameter communication path.

  In the above embodiment, the present invention is applied to the front motor 2, but may be applied to the generator 4. When applied to the generator 4, for example, as with the oil level raising device 30, an air bag 31 is provided in the oil pan of the generator 4, and the oil temperature in the oil pan of the generator 4 is set as shown in FIG. An oil temperature sensor 22 to detect and a pressure sensor 35 to detect the pressure of the air bag in the oil pan of the generator 4 are provided, and the control unit 36, based on the oil temperature and pressure, etc. What is necessary is just to control operation | movement of.

Further, as shown in FIG. 1, a temperature sensor 23 is provided in the oil tank 8, and if the detected temperature is equal to or lower than a predetermined temperature Ta, high pressure air is introduced into the air bags of both the front motor 2 and the generator 4 for lubrication. You may make it raise the oil level of oil.
Further, the oil level raising device 30 may have a configuration other than the air bag 31. The present invention can be widely applied to an electric motor that performs lubrication with lubricating oil stored in a case.

1 Lubricator 2 Front motor (electric motor)
4 Generator (electric motor)
10 Housing (casing)
12 Rotor 13 Stator 19 Oil pan (reservoir)
30 Oil level raising device 31 Air bag (bag)
32 Air compressor (fluid supply part)
40 partition member 41 first space 42 second space 43 discharge pipe (communication path)
44 opening

Claims (4)

While storing a rotor and a stator in a casing, it has a storage part which stores lubricating oil in the lower part in the casing,
A lubricating device for an electric motor that supplies lubricating oil from the storage part to the sliding part in the casing by a hydraulic pump and circulates the lubricating oil,
A bag provided in the storage section;
A fluid supply unit for supplying fluid to the bag body and inflating the bag body;
An electric motor lubrication device comprising: A partition member that partitions the storage section into a first space and a second space;
The bag is disposed in the first space,
The motor lubrication device according to claim 1, further comprising a discharge port that discharges the lubricating oil from the second space to the hydraulic pump.   The motor lubrication device according to claim 2, wherein a central axis of the rotor is disposed above the second space. A communication path for communicating the discharge port and the second space;
The communication path extends from the second space below the rotor in a tangential direction at the lower end of the rotor, and the opening on the second space side opens toward the rear side in the rotation direction of the rotor. The lubricating device for an electric motor according to claim 3.

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