CN118128889A - Electric drive motor unit - Google Patents

Abstract

The invention relates to the technical field of electric automobiles, in particular to an electric drive motor unit, which mainly comprises a motor shaft, an intermediate shaft and a differential shaft which extend in parallel along the horizontal direction, wherein the extending direction of a connecting line of the motor shaft and the differential shaft is the horizontal direction or is close to the horizontal direction, the intermediate shaft is positioned above the connecting line of the motor shaft and the differential shaft, a main liquid storage area and an independent liquid storage area for storing lubricating liquid are formed in an area below the motor shaft and the differential shaft in a housing space, the independent liquid storage area and the main liquid storage area are mutually separated through a division bar and are communicated through an opening formed in the division bar, the independent liquid storage area is positioned below the differential, a pump is arranged in the main liquid storage area, and the pump supplies the lubricating liquid in the main liquid storage area to a drive motor, a speed reducer and the independent liquid storage area through a lubricating liquid pipeline. The stirring of the intermediate shaft gear to the lubricating liquid is avoided, the energy loss of the motor unit is reduced, the size of the motor unit in the vertical direction is reduced, and the arrangement of the motor unit on the whole vehicle is facilitated.

Description

Electric drive motor unit

Technical Field

The present invention relates to the technical field of electric vehicles, and in particular to an electric drive motor unit.

Background technique

The motor unit used in electric vehicles is mainly composed of two parts: the motor and the reduction gearbox. The motor and the reduction gearbox share a lubricating coolant (hereinafter referred to as lubricant). The stator and rotor of the motor are directly cooled by the lubricant of the reduction gearbox, which can significantly improve the cooling efficiency and reduce the operating temperature of the motor. This technology has been widely used in recent years.

The motor unit used in electric vehicles should have a small size and should have the smallest possible energy loss during power transmission. A large part of the energy loss of the motor unit comes from the agitation of the lubricant when the gearbox rotates. For motors that use lubricants to directly cool the stator and rotor, if a large amount of lubricant enters the air gap between the rotor and stator during operation, the rotor will also cause a large energy loss due to the violent agitation of the lubricant by the rotor.

The invention patent application with publication number CN109563920A discloses a motor unit, which comprises: a motor having a rotor rotating around the motor axis; a reduction gear connected to the motor and having an intermediate gear rotating around the intermediate axis; a differential device connected to the reduction gear and having a ring gear rotating around the differential axis; a housing having a storage space for storing the motor and the differential device; oil accumulated in an area below the storage space in the vertical direction; and an oil passage, which guides the oil from the area below the storage space in the vertical direction and supplies the oil to the motor, and the ring gear to the A small portion is located below the level of the oil accumulated in the area below the vertical direction of the storage space, the motor axis, the intermediate axis and the differential axis extend in parallel with each other in the horizontal direction, the intermediate axis and the differential axis are located below the motor axis, and when viewed along the axial direction of the motor axis, when the line segment connecting the motor axis and the intermediate axis is assumed to be the first line segment, the line segment connecting the intermediate axis and the differential axis is assumed to be the second line segment, and the line segment connecting the motor axis and the differential axis is assumed to be the third line segment, the first line segment extends in a substantially vertical direction, and the second line segment extends in a substantially horizontal direction. The motor unit is characterized in that the input shaft of the reduction gear (reduction gear) and the rotor shaft of the motor (motor) are on the same straight line and are located above the line connecting the differential shaft (differential axis) and the intermediate shaft (intermediate axis). The advantage of this arrangement is that the lubricating liquid level in the motor unit is lower than the lowest position of the air gap between the stator and the rotor of the motor, thereby preventing the lubricating liquid from entering the air gap between the stator and the rotor of the motor. However, this arrangement causes the intermediate shaft to be located slightly below the reduction gearbox, so that the large gear on the intermediate shaft is immersed deeper in the lubricating fluid. Since the intermediate shaft rotates at a high speed, the stirring of the lubricating fluid by the intermediate shaft will cause a large energy loss. Although the motor unit is provided with a liquid storage area above the reduction gearbox, part of the lubricating fluid is stirred up by the gears and enters the liquid storage area, thereby reducing the height of the lubricating fluid in the reduction gearbox. However, this method can only reduce the height of the lubricating fluid to a limited extent and cannot completely eliminate the energy loss caused by the stirring of the oil by the intermediate shaft gears. At the same time, because the motor axis is located much higher than the differential axis, the motor unit is relatively large in the vertical direction, which is not conducive to the arrangement of the motor unit on the vehicle.

Summary of the invention

In view of the above-mentioned defects in the prior art, the technical problem to be solved by the present invention is to provide an electric drive motor unit that can reduce energy loss and facilitate the arrangement of the motor unit on the entire vehicle.

In order to solve the above technical problems, the present invention adopts the following technical solutions:

The present invention provides an electric drive motor unit, comprising: a drive motor, having a motor shaft for outputting torque; a reducer, having an intermediate shaft for transmitting torque, the intermediate shaft and the motor shaft being connected by gear transmission; a differential, having a differential shaft for transmitting torque, the differential shaft and the intermediate shaft being connected by gear transmission; a housing, having a storage space for storing the drive motor, the reducer and the differential; the motor shaft, the intermediate shaft and the differential shaft extending in parallel with each other in a horizontal direction; the extending direction of the line connecting the motor shaft and the differential shaft is a horizontal direction or a direction close to a horizontal direction, the intermediate shaft is located above the line connecting the motor shaft and the differential shaft, the housing space of the housing is located below the motor shaft and the differential shaft and is constituted of a main liquid storage area and a separate liquid storage area for storing lubricating liquid, the separate liquid storage area and the main liquid storage area are separated from each other by a partition bar and are connected through an opening provided on the partition bar, the separate liquid storage area is located below the differential, a pump is provided in the main liquid storage area, and the pump supplies the lubricating liquid in the main liquid storage area to the drive motor, the reducer and the separate liquid storage area through a lubricating liquid pipeline.

Preferably, the differential has a differential gear arranged on the differential shaft, and the spacer bar is arranged below the differential gear.

Preferably, one end of the partition bar is connected to the bottom of the housing, and the other end extends upward, and the partition bar and a portion of the housing located below the differential gear together form a separate liquid storage area between the differential gear.

Preferably, the spacer bar is in the shape of an arc extending along the outer circumference of the differential gear.

Preferably, the pump is arranged at the lower part of the main liquid storage area.

Compared with the prior art, the present invention has significant improvements:

The electric drive motor unit of the present invention sets the extension direction of the line connecting the motor shaft and the differential shaft to be horizontal or nearly horizontal, thereby reducing the size of the motor unit in the vertical direction and facilitating the arrangement of the motor unit on the vehicle; the intermediate shaft is located above the line connecting the motor shaft and the differential shaft, and the main liquid storage area and the separate liquid storage area are both located below the motor shaft and the differential shaft, thereby avoiding the stirring of the lubricating fluid by the intermediate shaft gear, thereby reducing the energy loss of the motor unit; a pump is arranged in the main liquid storage area, and the pump directionally delivers the lubricating fluid to the cooling and lubrication positions of the drive motor and the reducer, thereby greatly reducing the total amount of lubricating fluid required by the motor unit; the bearings at both ends of the differential can be lubricated by the oil stirring method in which the differential gear rotates to stir up the lubricating fluid in the separate liquid storage area, thereby simplifying the design of the lubricating fluid flow channel in the motor unit housing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a horizontal arrangement of an electric drive motor unit according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of the lubricating liquid level when the electric drive motor unit is arranged horizontally according to an embodiment of the present invention.

3 is a schematic diagram of the lubricating fluid level of the electric drive motor unit when the motor shaft axis is lower than the differential shaft axis of the electric drive motor unit according to the embodiment of the present invention.

4 is a schematic diagram of the lubricating fluid level of the electric drive motor unit when the motor shaft axis is higher than the differential shaft axis of the electric drive motor unit according to the embodiment of the present invention.

The reference numerals are described as follows:

1. Drive motor

10 Motor shaft

2 Reducer

20 Intermediate shaft

3 Differential

30 Differential shaft

31 Differential gear

4 Housing

40 Storage Space

5 Main liquid storage area

6 Separate liquid storage area

7 Spacers

8 Opening

9 Pumps

Detailed ways

The specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. These embodiments are only used to illustrate the present invention, but not to limit the present invention.

In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Furthermore, in the description of the present invention, unless otherwise specified, “plurality” means two or more.

As shown in FIG. 1 to FIG. 4 , an embodiment of the electric drive motor unit of the present invention is shown.

1 and 2 , the electric drive motor unit of this embodiment includes a drive motor 1 , a reducer 2 , a differential 3 and a housing 4 .

Among them, the drive motor 1 has a motor shaft 10 for outputting torque. The drive motor 1 also has a motor rotor fixedly connected to the motor shaft 10 and a motor stator located on the outer peripheral side of the motor rotor. When the drive motor 1 is working, the motor rotor rotates relative to the motor stator to drive the motor shaft 10 to rotate and output a rotational torque.

The reducer 2 has an intermediate shaft 20 for transmitting torque. The intermediate shaft 20 is connected to the motor shaft 10 through a gear transmission. Specifically, the reducer input shaft is coaxially fixed to the motor shaft 10, and a first gear is provided on the reducer input shaft. The first gear is meshed with a second gear fixed on the intermediate shaft 20, forming a first-stage gear transmission of the reducer 2.

The differential 3 has a differential shaft 30 for transmitting torque, and the differential shaft 30 is connected to the intermediate shaft 20 through gear transmission. Specifically, the differential 3 has a differential gear 31 fixed on the differential shaft 30, and a third gear is also fixed on the intermediate shaft 20 of the reducer 2. The third gear is meshed with the differential gear 31 to form the second-stage gear transmission of the reducer 2. Therefore, the reducer 2 transmits the torque output by the motor shaft 10 of the drive motor 1 to the differential 3, and the differential shaft 30 of the differential 3 further transmits the torque to the wheels of the vehicle.

The housing 4 has a storage space 40 for accommodating the drive motor 1, the reducer 2 and the differential 3. The drive motor 1, the reducer 2 and the differential 3 are all accommodated in the storage space 40 of the housing 4. The motor shaft 10, the intermediate shaft 20 and the differential shaft 30 extend parallel to each other in the horizontal direction.

In the electric drive motor unit of this embodiment, the extending direction of the line connecting the motor shaft 10 and the differential shaft 30 is horizontal or close to horizontal, wherein close to horizontal means having a small angle with the horizontal direction, preferably a direction within ±10° relative to the horizontal direction. The intermediate shaft 20 is located above the line connecting the motor shaft 10 and the differential shaft 30.

The storage space 40 of the housing 4 is located below the motor shaft 10 and the differential shaft 30 and is composed of a main liquid storage area 5 and a separate liquid storage area 6. Both the main liquid storage area 5 and the separate liquid storage area 6 are used to store lubricating liquid, which is not limited to oil. The separate liquid storage area 6 is separated from the main liquid storage area 5 by a partition bar 7, and an opening 8 is provided on the partition bar 7, so that the separate liquid storage area 6 is connected to the main liquid storage area 5 through the opening 8 provided on the partition bar 7.

The separate liquid storage area 6 is located below the differential 3 , so that the lower portion of the differential gear 31 of the differential 3 can be immersed in the lubricating fluid stored in the separate liquid storage area 6 .

Preferably, the partition bar 7 is arranged below the differential gear 31. Furthermore, one end of the partition bar 7 is connected to the bottom of the shell 4, and the other end of the partition bar 7 extends upward. The partition bar 7 and the part of the shell 4 located below the differential gear 31 together form a separate liquid storage area 6 between the differential gear 31, thereby forming a separate liquid storage area 6 separated from the main liquid storage area 5 below the differential 3, and ensuring that the lower part of the differential gear 31 can be immersed in the lubricating fluid stored in the separate liquid storage area 6.

Preferably, the partition bar 7 is in the shape of an arc extending along the outer periphery of the differential gear 31. The partition bar 7 extends in the shape of an arc around the outer periphery of the differential gear 31 to form a separate liquid storage area 6 surrounding the differential gear 31, further ensuring that the lower part of the differential gear 31 is immersed in the lubricating fluid stored in the separate liquid storage area 6.

A pump 9 is provided in the main liquid storage area 5, preferably, the pump 9 is provided at the lower part of the main liquid storage area 5. The pump 9 supplies the lubricating liquid accumulated in the main liquid storage area 5 to the drive motor 1, the reducer 2 and the separate liquid storage area 6 through the lubricating liquid pipeline.

In the electric drive motor unit of this embodiment, the pump 9 sucks the lubricating liquid accumulated in the main liquid storage area 5, and delivers the lubricating liquid to the motor stator and motor rotor of the drive motor 1, the bearings at both ends of the input shaft of the reducer 2, the bearings at both ends of the intermediate shaft 20, the first-stage gear meshing area (the meshing area between the first gear and the second gear), the second-stage gear meshing area (the meshing area between the third gear and the differential gear 31), and the separate liquid storage area 6 through the lubricating liquid pipeline arranged in the housing 4. After passing through the above-mentioned cooling and lubricating areas, the lubricating liquid naturally flows back to the main liquid storage area 5 and the separate liquid storage area 6 by gravity. The bearings at both ends of the differential shaft 30 are lubricated by the lubricating liquid in the separate liquid storage area 6 stirred up by the rotation of the differential gear 31. After passing through the bearings at both ends of the differential shaft 30, the stirred up lubricating liquid naturally flows back to the main liquid storage area 5 and the separate liquid storage area 6 by gravity.

2 , when the electric drive motor unit of this embodiment is arranged horizontally, the lubricating liquid level in the main liquid storage area 5 and the lubricating liquid level in the separate liquid storage area 6 are flush with each other due to the connection effect of the opening 8 on the partition bar 7, and both are located on the lubricating liquid level a.

When the vehicle is on a slope, the connection line between the motor shaft 10 and the differential shaft 30 will be inclined.

Referring to FIG. 3 , when the axis of the motor shaft 10 is lower than the axis of the differential shaft 30, after the lubricating liquid in the main liquid storage area 5 is sucked by the pump 9, the remaining lubricating liquid level b is lower than the lowest height of the air gap between the motor stator and the motor rotor. At the same time, due to the effect of the spacer 7, the lubricating liquid level c in the separate liquid storage area 6 is higher than the lubricating liquid level b in the main liquid storage area 5. At this time, the differential gear 31 can still stir up enough lubricating liquid to lubricate the bearings at both ends of the differential shaft 30.

Referring to FIG. 4 , when the axis of the motor shaft 10 is higher than the axis of the differential shaft 30 , due to the effect of gravity, after the lubricating liquid in the main liquid storage area 5 is sucked by the pump 9 , the remaining lubricating liquid level d can also be lower than the lowest height of the air gap between the motor stator and the motor rotor, and is lower than the state when the axis of the motor shaft 10 is lower than the axis of the differential shaft 30 . At this time, the lubricating liquid level d in the main liquid storage area 5 should be higher than the height of the suction port of the pump 9 to ensure that the pump 9 can continuously and reliably suck the lubricating liquid in the main liquid storage area 5 and avoid noise caused by empty suction. At the same time, the lubricating liquid in the separate liquid storage area 6 can flow into the main liquid storage area 5 through the opening 8 on the partition bar 7 to avoid the lubricating liquid level in the main liquid storage area 5 being too low to cause empty suction of the pump 9 . In this state, the lubricating liquid level e in the separate liquid storage area 6 is relatively high, but because the rotation speed of the differential gear 31 is much lower than the intermediate shaft 20 , the energy loss of stirring oil caused by the angle of the lubricating liquid level is not obvious.

In summary, the electric drive motor unit of this embodiment has the following advantages:

(1) The extension direction of the line connecting the motor shaft 10 and the differential shaft 30 is horizontal or close to horizontal, which reduces the size of the motor unit in the vertical direction and is beneficial to the arrangement of the motor unit on the vehicle.

(2) The intermediate shaft 20 is located above the line connecting the motor shaft 10 and the differential shaft 30, and the main liquid storage area 5 and the separate liquid storage area 6 are both located below the motor shaft 10 and the differential shaft 30, thereby avoiding the stirring of the lubricating fluid by the intermediate shaft gears, thereby reducing the energy loss of the motor unit.

(3) A pump 9 is provided in the main liquid storage area 5, and the pump 9 delivers lubricating liquid to the motor stator, the motor rotor, the bearings at both ends of the input shaft of the reducer, the bearings at both ends of the intermediate shaft 20, and the meshing area of the two-stage gears, thereby greatly reducing the total amount of lubricating liquid required by the motor unit.

(4) When the motor unit is in different tilt directions and tilt angles, in the working state, the lubricating liquid level in the main liquid storage area 5 is lower than the lowest position of the air gap between the motor stator and the motor rotor, thereby avoiding energy loss caused by the motor rotor stirring the lubricating liquid.

(5) When the motor unit is tilted in different directions and at different angles, the lubricating liquid level in the separate liquid storage area 6 can always meet the lubricating liquid level required for normal oil stirring lubrication of the bearings at both ends of the differential shaft 30.

(6) The bearings at both ends of the differential shaft 30 are lubricated by stirring oil, which can simplify the design of the lubricating fluid flow path in the motor unit housing 4.

The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims (5)

1. An electric drive motor unit, comprising: A drive motor (1) having a motor shaft (10) for outputting torque; A reducer (2) having an intermediate shaft (20) for transmitting torque, wherein the intermediate shaft (20) is connected to the motor shaft (10) via a gear transmission; A differential (3) having a differential shaft (30) for transmitting torque, wherein the differential shaft (30) is connected to the intermediate shaft (20) via a gear transmission; A housing (4) having a storage space (40) for storing the drive motor (1), the reducer (2) and the differential (3); The motor shaft (10), the intermediate shaft (20) and the differential shaft (30) extend in parallel with each other in a horizontal direction; characterized in that: The extending direction of the line connecting the motor shaft (10) and the differential shaft (30) is horizontal or nearly horizontal. The intermediate shaft (20) is located above the line connecting the motor shaft (10) and the differential shaft (30). The storage space (40) of the housing (4) is located below the motor shaft (10) and the differential shaft (30), and is composed of a main liquid storage area (5) and a separate liquid storage area (6) for storing lubricating liquid. The separate liquid storage area (6) and the main liquid storage area (5) are separated from each other by a partition bar (7) and are connected through an opening (8) provided on the partition bar (7). The separate liquid storage area (6) is located below the differential (3). A pump (9) is provided in the main liquid storage area (5). The pump (9) supplies the lubricating liquid in the main liquid storage area (5) to the drive motor (1), the reducer (2) and the separate liquid storage area (6) through a lubricating liquid pipeline. 2. The electric drive motor unit according to claim 1 is characterized in that the differential (3) has a differential gear (31) arranged on the differential shaft (30), and the spacer (7) is arranged below the differential gear (31). 3. The electric drive motor unit according to claim 2 is characterized in that one end of the partition bar (7) is connected to the bottom of the shell (4), and the other end extends upward, and the partition bar (7) and the part of the shell (4) located below the differential gear (31) together form the separate liquid storage area (6) between the differential gear (31). 4. The electric drive motor unit according to claim 2 or 3, characterized in that the spacer bar (7) is in the shape of an arc extending along the outer circumference of the differential gear (31). 5. The electric drive motor unit according to claim 1, characterized in that the pump (9) is arranged at the lower part of the main liquid storage area (5).