JP2022168660A - Rotary electric machine cooling structure - Google Patents

Abstract

To provide a rotary electric machine cooling structure capable of suppressing the flow of a cooling oil into an air gap.SOLUTION: In a rotary electric machine cooling structure for supplying a cooling oil to an end plate installed on a side surface of a rotor core from the inside toward the outside in a radial direction of the rotor to cool the rotor, the end plate is formed by bending the end plate at an outside position in the radial direction. The cooling structure has a shield wall for suppressing a flow of the cooling oil into an air gap between a stator disposed on an outer circumferential side of the rotor and the rotor.SELECTED DRAWING: Figure 1

Description

The present invention relates to a rotating electric machine cooling structure.

Patent Literature 1 discloses a motor cooling structure in which cooling oil is supplied from the inner side to the outer side in the radial direction of the rotor to an end plate provided on the side surface of the rotor core.

The cooling oil supplied to the end plates is further supplied to a stator provided on the outer peripheral side of the rotor core.

JP-A-2003-9467

An air gap is provided between the stator and rotor core of a motor (rotating electric machine). In the motor cooling structure described above, cooling oil tends to flow into the air gap when flowing from the end plate to the stator.

Here, since the air gap is set to be narrow, if the cooling oil flows into the air gap, there is a risk that the operating efficiency of the motor (rotating electric machine) will decrease due to the shear resistance of the cooling oil.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a rotating electrical machine cooling structure capable of suppressing cooling oil from flowing into an air gap.

According to one aspect of the present invention, there is provided a rotary electric machine cooling structure that cools the rotor by supplying cooling oil from the inner side to the outer side in the radial direction of the rotor to an end plate provided on the side surface of the rotor core, The end plate is formed by bending the end plate at an outer position in the radial direction, and the cooling oil flows into an air gap between the rotor and a stator arranged on the outer peripheral side of the rotor. A rotating electric machine cooling structure is provided that has a shield wall that suppresses the

According to this, the cooling oil that has reached the end plate is discharged from the inside of the shield wall to the outside at a position away from the air gap by the shield wall. Therefore, it is possible to suppress the cooling oil from flowing into the air gap.

1 is a schematic configuration diagram of a hybrid vehicle including a rotating electrical machine to which a rotating electrical machine cooling structure according to an embodiment of the invention is applied; FIG. It is the figure which looked at an intermediate cover, a pipe, and a chain from the rotary electric machine side. It is the perspective view which looked at the housing from the intermediate cover side. It is the figure which looked at the housing and the rotation sensor from the inside of the housing. 1 is a cross-sectional view of a rotating electrical machine; FIG.

A hybrid vehicle (hereinafter simply referred to as "vehicle") 100 including a rotating electrical machine 40 to which a rotating electrical machine cooling structure according to an embodiment of the present invention is applied will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram of a vehicle 100. As shown in FIG. As shown in FIG. 1 , a vehicle 100 includes an engine 1 and a power transmission device 10 provided in a power transmission path connecting the engine 1 and drive wheels 5 .

In this embodiment, the power transmission device 10 is a transmission and includes a variator 20 , a forward/reverse switching mechanism 30 , and a rotating electric machine 40 .

Rotating electric machine 40 is provided between variator 20 and engine 1 in the power transmission path.

The rotary electric machine 40 includes a housing 41, a cover 42 provided at an opening of the housing 41 on the engine 1 side, a stator 43 provided on the inner periphery of the housing 41, a rotating shaft 44, and a rotating shaft 44 on the outer periphery of the rotating shaft 44. and a clutch 48 that connects and disconnects the rotor 80 and the input shaft 11 . The rotor 80 includes a rotor frame 81 and a rotor core 82 provided on the outer circumference of the rotor frame 81 .

A rotation sensor 47 that detects the rotation state of the rotor 80 is provided inside the housing 41 . Specifically, the rotation sensor 47 detects at least one of the rotational speed and angle (phase) of the rotor 80 .

The rotary electric machine 40 is fixed to the power transmission device 10 by fastening the cover 42 to the case 12 of the power transmission device 10 with bolts (not shown).

The input shaft 11 is rotatably supported by the cover 42 via a bearing 50 and receives the output rotation of the engine 1 . The rotary shaft 44 is rotatably supported by the housing 41 via bearings 51 .

The clutch 48 is a normally open hydraulic clutch. Engagement and disengagement of the clutch 48 are controlled by hydraulic pressure regulated by a hydraulic control valve unit 70 provided in the lower portion of the power transmission device 10 . In this embodiment, the clutch 48 is a wet multi-plate clutch, but other clutches may be used.

When the clutch 48 is engaged, the input shaft 11 and the rotor 80 are directly connected. That is, the input shaft 11 and the rotating shaft 44 are directly connected and rotate at the same speed.

The rotor core 82 has an end plate 83 provided on the side surface on the housing 41 side and an end plate 84 provided on the side surface on the cover 42 side. The end plate 83 has a cylindrical shielding wall 83a on the outer side in the radial direction. A detected portion 52 of the rotation sensor 47 is provided on the inner periphery of the shielding wall 83a. The shielding wall 83a will be described later in detail.

The rotation sensor 47 can be, for example, a Hall sensor. When the rotation sensor 47 is a Hall sensor, the detected portion 52 is a magnet, specifically a permanent magnet, an electromagnet, or the like. The magnet is attached to the shielding wall 83a by caulking, press-fitting, or the like. When an electromagnet is used as the magnet, a current may be supplied to the electromagnet using a slip ring or the like.

Also, the rotation sensor 47 can be, for example, a proximity sensor. When the rotation sensor 47 is a proximity sensor, the detected portion 52 is an uneven portion. The concave-convex portion may be formed integrally with the shielding wall 83a, or may be formed by attaching a separate part to the shielding wall 83a. Further, the rotation sensor 47 may be a sensor that detects rotation speed or another sensor that detects an angle.

The rotating electric machine 40 can operate as an electric motor that is rotationally driven by being supplied with power from a battery (not shown). In addition, when the rotor 80 receives rotational energy from the driving wheels 5, the rotating electric machine 40 functions as a generator and can charge the battery. The configuration of rotating electric machine 40 will be described later in detail.

The variator 20 has a primary pulley 2 and a secondary pulley 3 arranged so that the V grooves are aligned, and a belt 4 that is stretched over the V grooves of the pulleys 2 and 3 .

An engine 1 is arranged coaxially with the primary pulley 2, and between the engine 1 and the primary pulley 2, a rotating electric machine 40 and a forward/reverse switching mechanism 30 are provided in order from the engine 1 side.

The forward/rearward movement switching mechanism 30 has a double pinion planetary gear set 30a as a main component, the sun gear of which is coupled to the rotary shaft 44 of the rotating electric machine 40, and the carrier of which is coupled to the primary pulley 2 of the variator 20. As shown in FIG. The forward/reverse switching mechanism 30 further includes a forward clutch 30b that directly connects the sun gear and the carrier of the double pinion planetary gear set 30a, and a reverse brake 30c that fixes the ring gear. When the forward clutch 30b is engaged, the input rotation from the rotating shaft 44 is transmitted to the primary pulley 2 in the same rotational direction. is transmitted to

The forward clutch 30b is engaged by supplying clutch pressure from the hydraulic control valve unit 70 when the forward travel mode is selected as the travel mode of the vehicle 100 . The reverse brake 30c is engaged by supplying brake pressure from the hydraulic control valve unit 70 when the reverse travel mode is selected as the travel mode of the vehicle 100 .

Rotation of the primary pulley 2 is transmitted to the secondary pulley 3 via the belt 4 , and rotation of the secondary pulley 3 is transmitted to the driving wheels 5 via the output shaft 8 , gear set 9 and differential gear device 15 .

In order to change the gear ratio between the primary pulley 2 and the secondary pulley 3 during the above power transmission, one of the conical plates forming the V grooves of the primary pulley 2 and the secondary pulley 3 is fixed as a fixed conical plate 2a, 3a. and the other are movable conical plates 2b and 3b that can be displaced in the axial direction.

These movable conical plates 2b, 3b are biased toward the fixed conical plates 2a, 3a by supplying the primary pulley pressure and the secondary pulley pressure from the hydraulic control valve unit 70, thereby causing the belt 4 to frictionally engage the conical plates. Power is transmitted between the primary pulley 2 and the secondary pulley 3 by combining them.

At the time of shifting, the width of the V groove of both pulleys 2 and 3 is changed by the differential pressure between the primary pulley pressure and the secondary pulley pressure generated corresponding to the target gear ratio, and the belt 4 is wound around the pulleys 2 and 3. The target gear ratio is achieved by continuously changing the arc diameter.

Between the rotating electrical machine 40 and the forward/reverse switching mechanism 30, an arc-shaped pipe 53 and an intermediate cover covering the rotating electrical machine 40 side of the forward/reverse switching mechanism 30 and axially facing the rotating electrical machine 40 via the pipe 53 are provided. 31 and are provided.

A sprocket 55 is rotatably supported by the intermediate cover 31 via a bush 54 . The sprocket 55 is connected to the rotating shaft 44 of the rotary electric machine 40 via a connecting member 56 , and is further connected to the sprocket 6 b provided on the input shaft 6 a of the oil pump 6 with a chain 57 . Accordingly, when the rotary electric machine 40 rotates, the oil pump 6 is driven and oil is supplied to the hydraulic control valve unit 70 . The hydraulic control valve unit 70 supplies oil to each part of the power transmission device 10 .

FIG. 2 is a diagram of the intermediate cover 31, the pipe 53, and the chain 57 viewed from the rotating electrical machine 40 side. FIG. 3 is a perspective view of the housing 41 viewed from the intermediate cover 31 side. FIG. 4 is a diagram of the housing 41 and the rotation sensor 47 viewed from the inside of the housing 41. FIG. 2 to 4 indicate the direction of gravity.

As shown in FIGS. 2 and 3, the pipe 53 extends along the circumferential direction of the rotary electric machine 40 in an upwardly convex curved shape, and has a notch 53b at the bottom. As shown in FIG. 2, a plurality of holes 53a are provided in the side surface of the pipe 53 on the rotating electric machine 40 side. Note that the shape of the pipe 53 may be a curved line that protrudes upward, and may be, for example, an arc shape or an elliptical arc shape.

A plurality of clamps 34 are attached to the pipe 53 . The pipe 53 is fixed to the case 12 by fastening these clamps 34 together with the intermediate cover 31 .

The pipe 53 is connected to an oil passage provided inside the intermediate cover 31 via the intermediate member 32, and is arranged to eject the oil supplied from the intermediate cover 31 toward the rotary electric machine 40 through a plurality of holes 53a. It has become. Note that the intermediate member 32 is omitted in FIG. 3 .

As shown in FIG. 3, the surface of the housing 41 facing the intermediate cover 31 is formed with a plurality of holes 41c along the circumferential direction, and the oil jetted out from the plurality of holes 53a of the pipe 53 is distributed through a plurality of holes 41c. It is directly blown onto the coils of the stator 43 through the holes 41c. As a result, the oil can be supplied to the rotating electrical machine 40 from above, and the rotating electrical machine 40 can be efficiently cooled. Note that the shape and number of the holes 41c can be changed as appropriate.

In this embodiment, the bushing 54, the sprocket 55, and the chain 57 are provided at positions radially overlapping the pipe 53, as shown in FIG. It is arranged to extend from the inner peripheral side of the pipe 53 to the outer peripheral side of the pipe 53 through the notch 53b of the pipe 53 . "Radially overlapping" means being arranged so as to overlap at least partially when viewed from the radial direction.

The intermediate cover 31 has arc-shaped ribs 31a provided along the pipe 53 as shown in FIG. 2, and the housing 41 has arc-shaped ribs 41d provided along the pipe 53 as shown in FIG. have.

The rib 31 a of the intermediate cover 31 and the rib 41 d of the housing 41 are arranged such that the rib 31 a fits inside the rib 41 d when the rotary electric machine 40 is assembled to the case 12 . Thus, the rib 31a and the rib 41d form a partition wall that surrounds the chain 57 and separates the pipe 53 and the chain 57 from each other. This prevents the oil flowing down from the pipe 53 and the housing 41 from adhering to the chain 57 .

As shown in FIGS. 3 and 4, the rotation sensor 47 is housed inside the housing 41 and fixed to the housing 41 with bolts.

More specifically, the rotation sensor 47 has an arc shape and is fixed to the housing 41 so as to straddle a communicating hole 41e formed in the housing 41 in the circumferential direction. That is, the rotation sensor 47 is arranged so as to partially cover the communication hole 41e. The communication hole 41e is a discharge hole for discharging the oil that cools the rotary electric machine 40 from the inside of the housing 41 to the outside.

A detection signal of the rotation sensor 47 is transmitted to a rotating electric machine controller (not shown) via wiring 47a. As shown in FIG. 3, the wiring 47a is connected to the rotation sensor 47 at a portion of the rotation sensor 47 exposed in the communication hole 41e.

The vehicle 100 is configured as described above, and has an EV mode in which the rotating electric machine 40 is driven by electric power supplied from the battery and runs only by the driving force of the rotating electric machine 40, and a driving mode in which the vehicle runs only by the driving force of the engine 1. and an HEV mode in which the vehicle is driven by the driving force of the engine 1 and the driving force of the rotary electric machine 40 .

In the EV mode, the vehicle 100 runs with the clutch 48 released and one of the forward clutch 30b and the reverse brake 30c engaged, driving only the electric rotating machine 40 with electric power from the battery.

In the engine running mode, the vehicle 100 runs by driving only the engine 1 with the clutch 48 and either one of the forward clutch 30b and the reverse brake 30c engaged.

In the HEV mode, the vehicle 100 runs by driving the engine 1 and the rotating electric machine 40 with the clutch 48 and either one of the forward clutch 30b and the reverse brake 30c engaged.

Next, the configuration of the rotating electric machine 40 will be described in detail with reference to FIG. 5 . FIG. 5 is a cross-sectional view of rotating electrical machine 40. As shown in FIG. A solid arrow G in FIG. 5 indicates the direction of gravity.

The housing 41 includes a tubular portion 41a provided on the outer peripheral side, a tubular portion 41b provided on the inner peripheral side and extending toward the inside of the housing 41, a plurality of holes 41c (see FIG. 3), and ribs 41d. (see FIG. 3) and a communication hole 41e.

A stator 43 is fixed to the inner circumference of the cylindrical portion 41a. The tubular portion 41b rotatably supports the rotating shaft 44 via the bearing 51. As shown in FIG.

The outer peripheral side of the cover 42 is fixed to the case 12 of the power transmission device 10 . Further, the cover 42 has a tubular portion 42a provided on the inner peripheral side and extending toward the housing 41 side. The cylindrical portion 42a rotatably supports the input shaft 11 via a bearing 50. As shown in FIG.

A seal member 59 is provided between the cylindrical portion 42a and the input shaft 11 to prevent oil from leaking to the outside.

The rotary shaft 44 is inserted into the input shaft 11 on the engine 1 side. A needle bearing 60 that receives an axial load and a needle bearing 61 that receives a radial load are provided between the input shaft 11 and the rotary shaft 44 .

An oil passage 44 a is formed inside the rotating shaft 44 to supply oil (cooling oil) to the inside of the housing 41 . White arrows in FIG. 5 indicate the main flow of the oil supplied from the oil passage 44a. The oil supplied from the oil passage 44 a lubricates each part and cools the rotating electric machine 40 .

A clutch hub 62 is welded to the end of the input shaft 11 on the forward/reverse switching mechanism 30 side. The clutch hub 62 has a cylindrical portion 62a provided on the outer peripheral side and extending toward the engine 1 side. A plurality of drive plates 48a of the clutch 48 are attached to the outer periphery of the cylindrical portion 62a by spline connection so as to be slidable in the axial direction.

A rotor frame 81 is fixed to the outer circumference of the rotating shaft 44 by welding. The rotor frame 81 has a tubular portion 81a provided on the outer peripheral side. A rotor core 82 is fixed to the outer circumference of the cylindrical portion 81a.

A plurality of driven plates 48b of the clutch 48 are attached to the inner periphery of the tubular portion 81a by spline connection so as to be slidable in the axial direction. The retainer plate 63 is interposed between the driven plate 48b arranged at the end opposite to the piston arm 64 and the ring 65 fixed to the groove on the inner circumference of the cylindrical portion 81a. The retainer plate 63 is thicker in the axial direction than the driven plate 48b and prevents the drive plate 48a and the driven plate 48b from falling.

When the engagement pressure is supplied from the hydraulic control valve unit 70 to the piston oil chamber 66, the piston 67 compresses the return spring 68 and moves toward the engine 1 side. The clutch 48 is engaged by the pressing force transmitted from the piston 67 via the needle bearing 69 and the piston arm 64 . The needle bearing 69 prevents the piston 67 from rotating with the rotation of the piston arm 64 .

The rotor core 82 has an end plate 83 provided on the side surface on the housing 41 side and an end plate 84 provided on the side surface on the cover 42 side. The end plate 83 has a cylindrical shielding wall 83a on the outer side in the radial direction. The shield wall 83 a is formed by bending the end plate 83 toward the housing 41 side and extends in a direction away from the air gap A between the stator 43 and the rotor 80 .

The oil supplied to the rotary electric machine 40 from the oil passage 44a is supplied to the end plate 83 as indicated by the white arrow. Thereby, the heat of the rotor core 82 is transferred from the end plate 83 to the oil. In other words, the oil supplied to the rotary electric machine 40 from the oil passage 44 a mainly cools the rotor 80 .

The oil that has reached the end plate 83 is discharged from the inside of the shielding wall 83a to the outside at the position of the open end of the shielding wall 83a, that is, the position away from the air gap A. As a result, the oil is prevented from flowing into the air gap A.

That is, the shielding wall 83a prevents the oil that has flowed to the lower end side of the rotor 80 due to gravity and the oil that has flowed to the outer peripheral side of the rotor 80 due to the centrifugal force acting when the rotor 80 rotates. prevents flow into the air gap A between

Since the air gap A is set narrow, when oil flows into the air gap A, there is a risk that the operating efficiency of the rotating electric machine 40 will decrease due to the shear resistance of the oil. In contrast, in the present embodiment, the end plate 83 has the shield wall 83a, so that the oil can be prevented from flowing into the air gap A. As shown in FIG. Therefore, it is possible to suppress a decrease in the operation efficiency of the rotating electric machine 40 .

A detected portion 52 of the rotation sensor 47 is provided on the inner periphery of the shielding wall 83a.

The rotation sensor 47 is arranged radially facing the detected portion 52 in a space whose outer peripheral side is surrounded by the shielding wall 83a.

In this way, by arranging the rotation sensor 47 that detects the rotation of the rotor 80 using the space inside the shielding wall 83a, the size of the rotating electric machine 40 can be suppressed.

Main effects of the cooling structure for the rotating electrical machine 40 according to the embodiment of the present invention will be collectively described below.

(1) In the cooling structure of the rotary electric machine 40 in which the rotor 80 is cooled by supplying oil from the inner side to the outer side in the radial direction of the rotor 80 to the end plate 83 provided on the side surface of the rotor core 82, the end plate 83 is: A shielding wall formed by bending the end plate 83 at a radially outer position to prevent oil from flowing into the air gap A between the stator 43 arranged on the outer peripheral side of the rotor 80 and the rotor 80. 83a.

According to this, the oil reaching the end plate 83 is discharged from the inside of the shielding wall 83a to the outside at a position away from the air gap A by the shielding wall 83a. Therefore, the oil can be prevented from flowing into the air gap A.

(2) The detected part 52 of the rotation sensor 47 for detecting the rotation of the rotor 80 is provided on the inner periphery of the shield wall 83a. are arranged radially opposite to each other.

According to this, since the rotation sensor 47 that detects the rotation of the rotor 80 is arranged using the space inside the shielding wall 83a, the size of the rotating electric machine 40 can be suppressed.

Although the embodiments of the present invention have been described above, the above embodiments merely show one application example of the present invention, and the technical scope of the present invention is limited to the specific configurations of the above embodiments. is not.

For example, in the above embodiment, the rotating electric machine 40 has a function as an electric motor and a function as a generator. However, the present invention can be applied even when the rotary electric machine has only one of the functions of an electric motor and a generator.

Further, in the above-described embodiment, the case where the shape of the rotation sensor 47 is arcuate has been described. However, various other shapes can be adopted as the shape of the rotation sensor 47 . For example, the rotation sensor 47 may be an annular sensor arranged coaxially with the rotation axis 44 .

40 rotary electric machine 43 stator 47 rotation sensor 52 part to be detected 80 rotor 82 rotor core 83 end plate 83a shielding wall A air gap

Claims (2)

A rotary electric machine cooling structure that cools the rotor by supplying cooling oil from the inner side to the outer side in the radial direction of the rotor to end plates provided on the side surface of the rotor core,
The end plate is formed by bending the end plate at an outer position in the radial direction, and the cooling oil flows into an air gap between the rotor and a stator arranged on the outer peripheral side of the rotor. having a shielding wall that suppresses
Rotating electric machine cooling structure. The rotating electric machine cooling structure according to claim 1,
A detected part of a rotation sensor for detecting rotation of the rotor is provided on the inner circumference of the shielding wall,
The rotation sensor is arranged in a space surrounded by the shielding wall on the outer peripheral side thereof so as to face the detected part in the radial direction.
Rotating electric machine cooling structure.

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