JP5952204B2 - Power transmission device - Google Patents

Description

  The present invention relates to a power transmission device including a motor generator.

  2. Description of the Related Art Conventionally, a structure including a motor and a stator cooling oil flow passage disposed above the motor and cooling the stator by discharging cooling oil from the stator cooling oil flow passage is known (for example, a patent). Reference 1).

  In Patent Document 1, cooling oil is also applied to the coil end portion of the stator, and heat is recovered when the cooling oil flows down.

JP 2008-178243 A

  However, in Patent Document 1 described above, the cooling oil supplied from the stator cooling oil flow passage to the coil end portion flows into the coil gap of the coil end portion or flows to the end surface of the coil end portion in the axial direction of the motor. Therefore, it is difficult to supply cooling oil evenly to the coil end portion. That is, it is difficult to sufficiently cool a portion far from the stator cooling oil flow passage in the coil end portion.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a power transmission device capable of improving the cooling performance for the coil end portion.

A power transmission device according to the present invention includes a motor generator including a stator and a rotor, and a case for housing the motor generator. The stator includes a stator core formed in a cylindrical shape and a coil wound around a tooth portion formed inside the stator core. The coil has a coil end portion that protrudes from the stator core in the rotation axis direction of the motor generator. A support portion that supports the outer peripheral surface of the stator core is formed in the case so as to extend along the rotation axis direction. And the support part is comprised so that the oil which flows along the outer peripheral surface of a stator core may be guided to a coil end part. In the power transmission device, a breather is provided on the opposite side of the support portion from the upper end portion of the stator core.

By configuring in this way, the oil on the outer peripheral surface of the stator core can be supplied to the coil end portion by the support portion, so that the cooling performance for the coil end portion can be improved. Furthermore, since the oil can be blocked by the support portion, it is possible to suppress the oil from entering the breather.

  The power transmission device may further include a cooling pipe that is disposed above the motor generator and supplies oil to the outer peripheral surface of the stator core.

  If comprised in this way, the oil supplied to a stator core from a cooling pipe can be guided to a coil end part by a support part.

  In the power transmission device, a power line drawn from the coil end portion may be disposed in the vicinity of the support portion.

  If comprised in this way, since the oil guided to a coil end part by a support part can be applied to a power line, cooling of the power line which tends to become high temperature can be accelerated | stimulated.

  According to the power transmission device of the present invention, it is possible to improve the cooling performance for the coil end portion.

It is the block diagram which showed the outline of the power transmission device by one Embodiment of this invention. It is the figure which looked at the power transmission device of FIG. 1 from the rotating shaft direction. FIG. 2 is a schematic plan view for explaining the flow of oil in the power transmission device of FIG. 1.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, with reference to FIG. 1 and FIG. 2, the power transmission device 100 by one Embodiment of this invention is demonstrated.

  As shown in FIG. 1, the power transmission device 100 includes a motor generator 1, a cooling pipe 2 for cooling the motor generator 1, and a case 3 for housing the motor generator 1 and the cooling pipe 2. The power transmission device 100 is mounted on, for example, an electric vehicle, and is configured to transmit power from the motor generator 1 to drive wheels (not shown). Hereinafter, a direction along the rotation axis of the motor generator 1 is referred to as a rotation axis direction (X direction), and a direction orthogonal to the rotation axis of the motor generator 1 is referred to as a radial direction.

  The motor generator 1 mainly functions as an electric motor, and also functions as a generator depending on the situation. The motor generator 1 is an AC synchronous motor, for example, and is connected to a battery via an inverter (not shown). The inverter converts the direct current supplied from the battery into an alternating current to drive the motor generator 1 (powering control), and converts the alternating current generated by the motor generator 1 into a direct current and outputs it to the battery ( Regenerative control) is possible.

  The motor generator 1 includes a stator 11 formed in a cylindrical shape (annular shape) and a rotor 12 arranged inside the stator 11. The stator 11 is fixed to the case 3, and the rotor 12 is connected to a shaft 4 that is rotatably supported by the case 3.

  The stator 11 includes a stator core 111 formed in a cylindrical shape, and a coil 112 wound around the stator core 111.

  Stator core 111 is made of, for example, a plurality of electromagnetic steel plates stacked in the direction of the rotation axis. The stator core 111 includes a cylindrical yoke portion 111a, a teeth portion 111b formed inside the yoke portion 111a, and a protruding portion 111c (see FIG. 2) formed outside the yoke portion 111a.

  The teeth portion 111b is formed so as to protrude in the radial direction (rotor 12 side) from the inner peripheral surface of the yoke portion 111a and to extend in the rotation axis direction. A plurality of teeth 111b are formed at a predetermined interval in the circumferential direction on the inner peripheral surface of the yoke 111a.

  As shown in FIG. 2, the protruding portion 111 c is formed so as to protrude from the yoke portion 111 a in the radial direction (on the side opposite to the rotor 12) and to extend in the rotation axis direction. A bolt insertion hole is formed in the protruding portion 111c so as to extend in the rotation axis direction, and a plurality of electromagnetic steel plates are fastened by attaching a bolt 113 to the bolt insertion hole.

  As shown in FIG. 1, the coil 112 is wound around a tooth portion 111 b and has a coil end portion 112 a that protrudes from the stator core 111 in the rotation axis direction. The coil end portions 112a are respectively formed at both ends of the stator core 111 in the rotation axis direction, and are formed in an annular shape when viewed from the rotation axis direction. Further, the outer peripheral surface of the coil end portion 112 a is disposed on the inner side of the outer peripheral surface of the stator core 111.

  The coil 112 includes a U-phase coil, a V-phase coil, and a W-phase coil. One end of each phase coil is connected to a neutral point, and the other end of each phase coil is connected to a power line 114 (see FIG. 2). It is connected. The power line 114 is drawn from one of the coil end portions 112a and is provided to electrically connect the coil 112 and the inverter.

  The rotor 12 includes a rotor core 121 connected to the shaft 4 and a permanent magnet 122 embedded in the rotor core 121. The rotor core 121 is constituted by, for example, a plurality of electromagnetic steel plates stacked in the rotation axis direction. A plurality of permanent magnets 122 are arranged at a predetermined interval in the circumferential direction of the rotor core 121.

  The cooling pipe 2 is arranged above the motor generator 1 and is provided for flowing oil for cooling the motor generator 1 to the motor generator 1. Specifically, cooling pipe 2 is arranged in parallel with the rotation axis of motor generator 1 and is formed to extend in the rotation axis direction. The cooling pipe 2 has an oil discharge hole 21 disposed at a position corresponding to the stator core 111 and an oil discharge hole 22 disposed at a position corresponding to the coil end portion 112a. In addition, an oil pump (not shown) is connected to the cooling pipe 2, and oil supplied from the oil pump is discharged from the oil discharge holes 21 and 22. The flow of oil discharged from the cooling pipe 2 will be described later in detail.

  As shown in FIG. 2, the case 3 is provided with a support portion 31 that supports the motor generator 1 housed therein and a breather 32 for adjusting the internal pressure of the case 3.

  The support part 31 is formed so as to extend along the rotation axis direction. The support portion 31 is configured to contact the outer peripheral surface of the stator core 111 over the entire length of the stator core 111 in the rotation axis direction. Support portion 31 is formed so as to protrude obliquely downward from the inside of case 3, and the contact position between support portion 31 and stator core 111 is above the rotational axis of motor generator 1, and the stator core It is below the upper end of 111. Specifically, the contact position between support portion 31 and stator core 111 is a position inclined at a predetermined angle (for example, about 45 degrees) from the upper end portion of stator core 111 around the rotation axis of motor generator 1.

  Further, in the vicinity of the support portion 31, a power line 114a located at the uppermost position among the power lines 114 drawn from the coil end portion 112a is disposed. Specifically, a portion of the power line 114a is disposed adjacent to the support portion 31 in the rotation axis direction.

  The breather 32 has a breather hole that communicates the inside and the outside of the case 3, and is configured to eliminate the pressure difference between the inside and the outside of the case 3. The breather 32 is disposed in the vicinity of the support portion 31 and is disposed on the side opposite to the cooling pipe 2 (the upper end portion of the stator core 111) with respect to the support portion 31. In other words, the breather 32 is disposed on the outer side (downstream side of the oil flow) than the support portion 31 when viewed from the rotation axis direction. It is preferable to provide a gap between the breather 32 and the support portion 31.

  Next, the flow of oil in the power transmission device 100 according to the present embodiment will be described with reference to FIGS. 2 and 3. 2 and 3, the oil flow is indicated by arrows.

  First, oil for cooling the motor generator 1 is supplied to the cooling pipe 2 by the oil pump. Thereby, as shown in FIGS. 2 and 3, the oil is discharged from the oil discharge holes 21 and 22 of the cooling pipe 2.

  The oil discharged from the oil discharge hole 22 flows down along the outer peripheral surface of the coil end portion 112a. At this time, the oil flows into the gap between the coil end portions 112a, or the oil flows down to the end surfaces of the coil end portions 112a in the rotation axis direction.

  Further, the oil discharged from the oil discharge hole 21 flows down along the outer peripheral surface of the stator core 111. The oil flowing on the outer peripheral surface of the stator core 111 is blocked by the support portion 31, and the oil is guided along the support portion 31 to the coil end portion 112 a. That is, the support portion 31 has a function of collecting oil on the outer peripheral surface of the stator core 111 and supplying it to the coil end portion 112a. As a result, oil can be supplied to the coil end portion 112 a by the support portion 31 on the downstream side of the oil supply position from the oil discharge hole 22. In addition, since the power line 114a is arrange | positioned in the vicinity of the support part 31, the oil guided by the support part 31 is supplied to the coil end part 112a via a part of power line 114a.

  Thus, the motor generator 1 is cooled by recovering heat when the oil flowing from the cooling pipe 2 to the motor generator 1 flows down. The oil that has flowed down from the motor generator 1 is returned to the oil pump.

-Effect-
In the present embodiment, as described above, by providing the support portion 31 in contact with the outer peripheral surface of the stator core 111 in the case 3, the oil on the outer peripheral surface of the stator core 111 can be supplied to the coil end portion 112 a by the support portion 31. Therefore, the amount of oil supplied to the coil end portion 112a can be increased. Further, by setting the oil supply position to the coil end portion 112a by the support portion 31 downstream of the oil supply position from the oil discharge hole 22, the oil is evenly distributed to the outer peripheral surface of the coil end portion 112a. Can be supplied. That is, the oil discharged from the oil discharge hole 22 flows into the gap of the coil end portion 112a or flows down to the end surface of the coil end portion 112a in the rotation axis direction, so that the oil on the outer peripheral surface of the coil end portion 112a is reduced. Since the oil can be supplied by the support portion 31 on the downstream side that decreases, the coil end portion 112a can be cooled to a location far from the cooling pipe 2. As a result, the cooling performance for the coil end portion 112a can be improved.

  Moreover, in this embodiment, since the power line 114a is arranged in the vicinity of the support part 31, the oil guided to the coil end part 112a by the support part 31 can be applied to the power line 114a, so that the temperature easily rises. Cooling of the power line 114a can be promoted.

  Further, in the present embodiment, by arranging the breather 32 on the side opposite to the cooling pipe 2 with respect to the support portion 31, the oil can be blocked by the support portion 31, so that the oil can be prevented from entering the breather 32. can do. Thereby, the breather performance can be ensured. Furthermore, since the breather 32 can be disposed below the cooling pipe 2, the power transmission device 100 can be downsized while ensuring the breather performance.

-Other embodiments-
In addition, embodiment disclosed this time is an illustration in all the points, Comprising: It does not become a basis of limited interpretation. Therefore, the technical scope of the present invention is not interpreted only by the above-described embodiments, but is defined based on the description of the scope of claims. Further, the technical scope of the present invention includes all modifications within the meaning and scope equivalent to the scope of the claims.

  For example, in the present embodiment, an example in which the present invention is applied to the power transmission device 100 mounted on an electric vehicle has been described. However, the present invention is not limited thereto, and the present invention is applied to a power transmission device mounted on a hybrid vehicle. Also good. In this case, the power of the engine (not shown) may be input to the power transmission device, and the power transmission device may transmit the power to the drive wheels.

  Further, in the present embodiment, an example in which the cooling pipe 2 for flowing oil to the motor generator 1 is shown. However, the present invention is not limited to this, and is scraped by a gear (not shown) accommodated in the power transmission device. The received oil may be received by an oil catch tank (not shown), and the oil may be poured from the oil catch tank to the motor generator.

  In the present embodiment, an example in which one support portion 31 is provided in the case 3 has been described. However, the present invention is not limited thereto, and a plurality of support portions may be provided in the case.

  In the present embodiment, the oil supplied from the oil pump to the cooling pipe 2 may be cooled using an oil cooler (not shown).

  Moreover, in the breather 32 of this embodiment, the valve body etc. for suppressing the outflow of the oil from a breather hole may be provided.

  The present invention can be used in a power transmission device including a motor generator, and more specifically, can be effectively used in a power transmission device that cools the motor generator by flowing oil.

DESCRIPTION OF SYMBOLS 1 Motor generator 2 Cooling pipe 3 Case 11 Stator 12 Rotor 31 Support part 32 Breather 100 Power transmission device 111 Stator core 111b Teeth part 112 Coil 112a Coil end part 114a Power line

Claims (3)

A motor generator including a stator and a rotor;
A power transmission device comprising a case for housing the motor generator,
The stator includes a stator core formed in a cylindrical shape, and a coil wound around a tooth portion formed inside the stator core,
The coil has a coil end portion protruding from the stator core in the rotation axis direction of the motor generator,
In the case, a support portion that supports an outer peripheral surface of the stator core is formed so as to extend along the rotation axis direction,
The support portion is configured to guide oil flowing along the outer peripheral surface of the stator core to the coil end portion ,
A power transmission device , wherein a breather is provided on a side opposite to an upper end portion of the stator core with respect to the support portion . The power transmission device according to claim 1,
The power transmission device further comprising a cooling pipe that is disposed above the motor generator and supplies oil to an outer peripheral surface of the stator core. In the power transmission device according to claim 1 or 2,
A power transmission device characterized in that a power line drawn from the coil end portion is disposed in the vicinity of the support portion.

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