Rotating electrical machine cooling structure

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

[Technical field]

[0001] The present invention relates to a cooling structure for a rotating electrical machine. [Background technology]

[0002] Patent Document 1 discloses a motor cooling structure in which cooling oil is supplied to end plates provided on the sides of a rotor core from the inside toward the outside in the radial direction of the rotor.

[0003] The cooling oil supplied to the end plates is further supplied to a stator provided on the outer periphery of the rotor core. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2003-9467 A Summary of the Invention [Problem to be solved by the invention]

[0005] An air gap is provided between the stator and rotor core of a motor (rotating electric machine). In the above motor cooling structure, when cooling oil flows from the end plates to the stator, the cooling oil tends to flow into the air gap.

[0006] Here, since the air gap is set narrow, if the cooling oil flows into the air gap, the shear resistance of the cooling oil may reduce the operating efficiency of the motor (rotating electric machine).

[0007] The present invention has been made in consideration of such technical problems, and has an object to provide a rotating electrical machine cooling structure capable of suppressing the inflow of cooling oil into the air gap. [Means for solving the problem]

[0008] According to one aspect of the present invention, there is provided a rotating electrical machine cooling structure in which cooling oil is supplied to an end plate provided on a side surface of a rotor core from the inside to the outside in a radial direction of the rotor to cool the rotor, the end plate being formed by bending the end plate to an outer position in the radial direction and having a shielding wall that prevents the cooling oil from flowing into an air gap between the rotor and a stator disposed on the outer periphery of the rotor. a detection target portion of a rotation sensor that detects rotation of the rotor is provided on an inner periphery of the shielding wall, and the rotation sensor is disposed in a space whose outer periphery is surrounded by the shielding wall so as to face the detection target portion in the radial direction. A rotating electrical machine cooling structure is provided. Effect of the Invention

[0009] According to this, the cooling oil that has reached the end plate is discharged from the inside to the outside of the shielding wall at a position away from the air gap by the shielding wall, thereby making it possible to prevent the cooling oil from flowing into the air gap. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram of a hybrid vehicle including a rotating electric machine to which a rotating electric machine cooling structure according to an embodiment of the present invention is applied; [Diagram 2] 4 is a view of the intermediate cover, the pipe, and the chain as viewed from the rotating electric machine side. [Diagram 3] FIG. 4 is a perspective view of the housing as viewed from the intermediate cover side. [Figure 4] FIG. 4 is a view of the housing and the rotation sensor as seen from inside the housing. [Diagram 5] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, a hybrid vehicle (hereinafter simply referred to as "vehicle") 100 including a rotating electric machine 40 to which a rotating electric machine cooling structure according to an embodiment of the present invention is applied will be described with reference to the accompanying drawings.

[0012] Fig. 1 is a schematic configuration diagram of a vehicle 100. As shown in Fig. 1, the 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.

[0013] 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.

[0014] The rotating electric machine 40 is provided between the variator 20 and the engine 1 in the power transmission path.

[0015] The rotating 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, a rotor 80 provided 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 periphery of the rotor frame 81.

[0016] 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 rotation speed and angle (phase) of the rotor 80.

[0017] The rotating 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).

[0018] 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 rotating shaft 44 is rotatably supported by the housing 41 via a bearing 51.

[0019] The clutch 48 is a normally open hydraulic clutch. The engagement and disengagement of the clutch 48 is controlled by hydraulic pressure adjusted by a hydraulic control valve unit 70 provided at the bottom of the power transmission device 10. In this embodiment, the clutch 48 is a wet multi-plate clutch, but other clutches may be used.

[0020] When the clutch 48 is engaged, the input shaft 11 is directly connected to the rotor 80. That is, the input shaft 11 and the rotating shaft 44 are directly connected to each other and rotate at the same speed.

[0021] The rotor core 82 has an end plate 83 provided on a side surface facing the housing 41, and an end plate 84 provided on a side surface facing the cover 42. The end plate 83 has a cylindrical shielding wall 83a at a radially outer position. The 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 in detail later.

[0022] The rotation sensor 47 may be, for example, a Hall sensor. When the rotation sensor 47 is a Hall sensor, the detected part 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.

[0023] Furthermore, the rotation sensor 47 may be, for example, a proximity sensor. When the rotation sensor 47 is a proximity sensor, the detected portion 52 is an uneven portion. The uneven portion may be formed integrally with the shielding wall 83a, or may be formed by attaching a separate part to the shielding wall 83a. Furthermore, the rotation sensor 47 may be another sensor that detects the rotation speed or another sensor that detects the angle.

[0024] The rotating electric machine 40 can operate as an electric motor that is rotationally driven by receiving power from a battery (not shown). When the rotor 80 receives rotational energy from the drive wheels 5, the rotating electric machine 40 functions as a generator and can charge the battery. The configuration of the rotating electric machine 40 will be described in detail later.

[0025] The variator 20 has a primary pulley 2 and a secondary pulley 3 arranged so that their V-grooves are aligned, and a belt 4 stretched over the V-grooves of the pulleys 2 and 3.

[0026] An engine 1 is disposed coaxially with a primary pulley 2, and a rotating electric machine 40 and a forward / reverse switching mechanism 30 are provided between the engine 1 and the primary pulley 2 in this order from the engine 1 side.

[0027] The forward / reverse switching mechanism 30 has as its main component a double pinion planetary gear set 30a, whose sun gear is coupled to a rotating shaft 44 of the rotating electric machine 40 and whose carrier is coupled to the primary pulley 2 of the variator 20. The forward / reverse switching mechanism 30 further includes a forward clutch 30b that directly connects the sun gear and 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, and when the reverse brake 30c is engaged, the input rotation from the rotating shaft 44 is reversed and transmitted to the primary pulley 2.

[0028] The forward clutch 30b is engaged by being supplied with clutch pressure from the hydraulic control valve unit 70 when the forward driving mode is selected as the driving mode of the vehicle 100. The reverse brake 30c is engaged by being supplied with brake pressure from the hydraulic control valve unit 70 when the reverse driving mode is selected as the driving mode of the vehicle 100.

[0029] The rotation of the primary pulley 2 is transmitted to the secondary pulley 3 via a belt 4, and the rotation of the secondary pulley 3 is transmitted to the drive wheels 5 via an output shaft 8, a gear set 9 and a differential gear device 15.

[0030] In order to make it possible to change the gear ratio between the primary pulley 2 and the secondary pulley 3 during the above-mentioned power transmission, one of the conical plates forming the V-grooves of the primary pulley 2 and the secondary pulley 3 is a fixed conical plate 2a, 3a, and the other is a movable conical plate 2b, 3b that can be displaced in the axial direction.

[0031] These movable conical plates 2b, 3b are urged toward the fixed conical plates 2a, 3a by supplying primary pulley pressure and secondary pulley pressure from the hydraulic control valve unit 70, thereby causing the belt 4 to frictionally engage with the conical plates, transmitting power between the primary pulley 2 and the secondary pulley 3.

[0032] When changing gears, the width of the V-grooves of both pulleys 2, 3 is changed by the differential pressure between the primary pulley pressure and the secondary pulley pressure generated in accordance with the target gear ratio, and the target gear ratio is realized by continuously changing the wrapping arc diameter of the belt 4 around the pulleys 2, 3.

[0033] Between the rotating electric machine 40 and the forward / reverse switching mechanism 30, there are provided an arc-shaped pipe 53 and an intermediate cover 31 which covers the rotating electric machine 40 side of the forward / reverse switching mechanism 30 and faces the rotating electric machine 40 in the axial direction via the pipe 53.

[0034] A sprocket 55 is rotatably supported on the intermediate cover 31 via a bush 54. The sprocket 55 is connected to the rotating shaft 44 of the rotating electric machine 40 via a connecting member 56, and the sprocket 55 is further connected to a sprocket 6b provided on the input shaft 6a of the oil pump 6 by a chain 57. As a result, when the rotating 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 portion of the power transmission device 10.

[0035] Fig. 2 is a view of the intermediate cover 31, the pipe 53, and the chain 57 as viewed from the rotating electric machine 40 side. Fig. 3 is a perspective view of the housing 41 as viewed from the intermediate cover 31 side. Fig. 4 is a view of the housing 41 and the rotation sensor 47 as viewed from inside the housing 41. Note that the solid arrow G in Figs. 2 to 4 indicates the direction of gravity.

[0036] 2 and 3, pipe 53 extends in the circumferential direction of rotating electric machine 40 in an upwardly convex curved shape, and has notched portions 53b on the downward side. As shown in Fig. 2, a plurality of holes 53a are provided in the side surface of pipe 53 facing rotating electric machine 40. Note that the shape of pipe 53 may be any shape as long as it is an upwardly convex curved shape, and may be, for example, a circular arc shape, an elliptical arc shape, or the like.

[0037] A plurality of clamps 34 are attached to the pipe 53. The pipe 53 is fixed to the case 12 by fastening the plurality of clamps 34 together with the intermediate cover 31.

[0038] The pipe 53 is connected to an oil passage provided inside the intermediate cover 31 via the intermediate member 32, and the oil supplied from the intermediate cover 31 is sprayed from the multiple holes 53a toward the rotating electric machine 40. Note that the intermediate member 32 is omitted from FIG. 3.

[0039] 3, a plurality of holes 41c are formed in the circumferential direction on the surface of the housing 41 facing the intermediate cover 31, and the oil ejected from the plurality of holes 53a of the pipe 53 is directly sprayed onto the coil of the stator 43 through the plurality of holes 41c. This allows the oil to be supplied to the rotating electric machine 40 from above, and the rotating electric machine 40 can be efficiently cooled. The shape and number of the holes 41c can be changed as appropriate.

[0040] In this embodiment, the bushing 54, the sprocket 55, and the chain 57 are provided at positions that overlap with the pipe 53 in the radial direction as shown in Fig. 1, and the chain 57 is arranged so as to extend from the inner periphery side of the arc-shaped pipe 53 through the cutout portion 53b of the pipe 53 to the outer periphery side of the pipe 53 as shown in Fig. 2. "Overlapping in the radial direction" means that they are arranged so as to overlap at least partially when viewed from the radial direction.

[0041] The intermediate cover 31 has an arc-shaped rib 31a provided along the pipe 53 as shown in FIG. 2, and the housing 41 has an arc-shaped rib 41d provided along the pipe 53 as shown in FIG.

[0042] The rib 31a of the intermediate cover 31 and the rib 41d of the housing 41 are arranged so that the rib 31a fits inside the rib 41d when the rotating electric machine 40 is assembled to the case 12. As a result, the rib 31a and the rib 41d form a partition wall that surrounds the chain 57 and separates the pipe 53 from the chain 57. This makes it possible to prevent oil that flows down from the pipe 53 or the housing 41 from adhering to the chain 57.

[0043] As shown in FIGS. 3 and 4, the rotation sensor 47 is housed inside the housing 41 and is fixed to the housing 41 with bolts.

[0044] More specifically, the rotation sensor 47 has an arc shape and is fixed to the housing 41 so as to straddle a communication hole 41e formed in the housing 41 in the circumferential direction. In other words, the rotation sensor 47 is disposed so as to cover a part of the communication hole 41e. The communication hole 41e is a discharge hole that discharges oil that cools the rotating electric machine 40 from the inside of the housing 41 to the outside.

[0045] A detection signal of the rotation sensor 47 is transmitted to a rotating electric machine controller (not shown) via a wire 47a. As shown in Fig. 3, the wire 47a is connected to the rotation sensor 47 at a portion of the rotation sensor 47 exposed in the communication hole 41e.

[0046] Vehicle 100 is configured as described above, and has driving modes including an EV mode in which the rotating electric machine 40 is driven by power supplied from the battery and the vehicle runs on the driving force of the rotating electric machine 40 alone, an engine driving mode in which the vehicle runs on the driving force of the engine 1 alone, and an HEV mode in which the vehicle runs on the driving force of both engine 1 and rotating electric machine 40.

[0047] In the EV mode, the vehicle 100 runs with only the rotating electric machine 40 driven by electric power from the battery, with the clutch 48 released and either the forward clutch 30b or the reverse brake 30c engaged.

[0048] In the engine running mode, the vehicle 100 runs by driving only the engine 1 with the clutch 48 and either the forward clutch 30b or the reverse brake 30c engaged.

[0049] 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 the forward clutch 30b or the reverse brake 30c being engaged.

[0050] 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 the rotating electric machine 40. Note that a solid arrow G in Fig. 5 indicates the direction of gravity.

[0051] Housing 41 has a cylindrical portion 41a provided on the outer periphery, a cylindrical portion 41b provided on the inner periphery and extending toward the inside of housing 41, a plurality of holes 41c (see Figure 3), a rib 41d (see Figure 3), and a communicating hole 41e.

[0052] A stator 43 is fixed to the inner periphery of the cylindrical portion 41a. The cylindrical portion 41b supports a rotating shaft 44 via a bearing 51 so as to be freely rotatable.

[0053] The cover 42 has an outer circumferential side fixed to the case 12 of the power transmission device 10. The cover 42 also has a cylindrical portion 42a provided on the inner circumferential side and extending toward the housing 41. The cylindrical portion 42a rotatably supports the input shaft 11 via a bearing 50.

[0054] A seal member 59 is provided between the cylindrical portion 42a and the input shaft 11 to prevent oil from leaking to the outside.

[0055] The rotating shaft 44 is inserted into the input shaft 11 on the engine 1 side. Between the input shaft 11 and the rotating shaft 44, a needle bearing 60 for receiving an axial load and a needle bearing 61 for receiving a radial load are provided.

[0056] An oil passage 44a is formed inside the rotating shaft 44 to supply oil (cooling oil) to the inside of the housing 41. The 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 44a lubricates each component and cools the rotating electric machine 40.

[0057] A clutch hub 62 is fixed by welding 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 that is provided on the outer periphery and extends toward the engine 1. 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.

[0058] A rotor frame 81 is fixed by welding to the outer periphery of the rotating shaft 44. The rotor frame 81 has a cylindrical portion 81a provided on the outer periphery side. A rotor core 82 is fixed to the outer periphery of the cylindrical portion 81a.

[0059] A plurality of driven plates 48b of the clutch 48 are attached to the inner periphery of the cylindrical 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 a ring 65 fixed to a groove on the inner periphery of the cylindrical portion 81a. The retainer plate 63 has a thickness in the axial direction that is thicker than that of the driven plate 48b, and prevents the drive plate 48a and the driven plate 48b from falling over.

[0060] When an engagement pressure is supplied from the hydraulic control valve unit 70 to the piston oil chamber 66, the piston 67 moves toward the engine 1 while compressing the return spring 68. The clutch 48 is brought into an engaged state by a pressing force transmitted from the piston 67 via a needle bearing 69 and the piston arm 64. The needle bearing 69 prevents the piston 67 from rotating in association with the rotation of the piston arm 64.

[0061] The rotor core 82 has an end plate 83 provided on a side surface facing the housing 41, and an end plate 84 provided on a side surface facing the cover 42. The end plate 83 has a cylindrical shielding wall 83a at a radially outer position. The shielding wall 83a is formed by bending the end plate 83 toward the housing 41, and extends in a direction away from the air gap A between the stator 43 and the rotor 80.

[0062] The oil supplied from oil passage 44a to rotary electric machine 40 is supplied to end plate 83 as indicated by the white arrow. This causes heat from rotor core 82 to be transferred from end plate 83 to the oil. In other words, the oil supplied from oil passage 44a to rotary electric machine 40 mainly cools rotor 80.

[0063] The oil that has reached the end plate 83 is discharged from the inside to the outside of the shielding wall 83a at the position of the open end of the shielding wall 83a, that is, at a position away from the air gap A. This prevents the oil from flowing into the air gap A.

[0064] In other words, the shielding wall 83a prevents oil that has flowed toward the lower end of the rotor 80 due to gravity, or oil that has flowed toward the outer periphery of the rotor 80 due to the centrifugal force acting as the rotor 80 rotates, from flowing into the air gap A between the stator 43 and the rotor 80.

[0065] Because air gap A is set to be narrow, if oil flows into air gap A, the shear resistance of the oil may reduce the operating efficiency of the rotating electric machine 40. In contrast, in this embodiment, the end plate 83 has the shielding wall 83a, which can prevent oil from flowing into the air gap A. Therefore, the operating efficiency of the rotating electric machine 40 can be prevented from decreasing.

[0066] The detected portion 52 of the rotation sensor 47 is provided on the inner periphery of the shielding wall 83a.

[0067] The rotation sensor 47 is disposed radially opposite the detected portion 52 in a space surrounded on the outer periphery by the shielding wall 83a.

[0068] In this manner, by utilizing the space inside the shielding wall 83a to dispose the rotation sensor 47 that detects the rotation of the rotor 80, the size of the rotating electrical machine 40 can be reduced.

[0069] Hereinafter, the main functions and effects of the cooling structure of the rotating electrical machine 40 according to the embodiment of the present invention will be described together.

[0070] (1) In the cooling structure of a rotating electric machine 40 in which oil is supplied from the inside to the outside in the radial direction of the rotor 80 to an end plate 83 provided on a side of a rotor core 82 to cool the rotor 80, the end plate 83 is formed by bending the end plate 83 at a radially outer position and has a shielding wall 83a that prevents oil from flowing into an air gap A between the rotor 80 and a stator 43 arranged on the outer periphery of the rotor 80.

[0071] According to this, the oil that has reached the end plate 83 is discharged by the shielding wall 83a from the inside to the outside of the shielding wall 83a at a position away from the air gap A. Therefore, the oil can be prevented from flowing into the air gap A.

[0072] (2) A detectable portion 52 of a rotation sensor 47 that detects the rotation of the rotor 80 is provided on the inner circumference of the shielding wall 83a, and the rotation sensor 47 is arranged radially opposite the detectable portion 52 in a space whose outer circumference is surrounded by the shielding wall 83a.

[0073] According to this, the space inside the shielding wall 83a is utilized to place the rotation sensor 47 that detects the rotation of the rotor 80, so that the size of the rotating electrical machine 40 can be reduced.

[0074] An embodiment of the present invention has been described above, but the above embodiment merely illustrates one application example of the present invention, and is not intended to limit the technical scope of the present invention to the specific configuration of the above embodiment.

[0075] 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 also be applied to a case where the rotating electric machine has only one of the functions of an electric motor and a generator.

[0076] In the above embodiment, the rotation sensor 47 has an arc-shaped configuration. However, various other shapes may be used as the shape of the rotation sensor 47. For example, the rotation sensor 47 may be an annular sensor arranged coaxially with the rotation shaft 44. [Explanation of symbols]

[0077] 40 Rotating Electric Machine 43 Stator 47 Rotation Sensor 52 Detected part 80 rotors 82 Rotor core 83 End Plate 83a Shielding wall A Air Gap

Claims

[Claim 1] A rotating electrical machine cooling structure that cools a rotor by supplying cooling oil from an inner side to an outer side in a radial direction of the rotor to an end plate provided on a side surface of a rotor core, the end plate has a shielding wall formed by bending the end plate at an outer position in the radial direction and preventing the cooling oil from flowing into an air gap between the rotor and a stator disposed on an outer circumferential side of the rotor, a detection target portion of a rotation sensor that detects rotation of the rotor is provided on an inner periphery of the shielding wall, The rotation sensor is disposed in a space whose outer circumferential side is surrounded by the shielding wall, and is opposed to the detection target in the radial direction. Rotating electrical machine cooling structure.

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