JP2009247085A - Rotary electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water channel structure that prevent the degradation in cooling efficiency due to stagnation of cooling water that occurs in proximity to a cooling liquid discharge port. <P>SOLUTION: A rotary electric machine includes a stator 3 and a rotor 4 rotatably held in the stator 3 with a predetermined gap in-between. A cooling liquid passage 15 is positioned on the outer circumferential surface of the stator 3 and is formed in a band shape in the circumferential direction by a bracket. The cooling liquid passage 15 includes: a boundary wall 131; a cooling liquid feed port 111 provided on one side of the boundary wall 131; and a cooling liquid discharge port 112 provided on the other side. The boundary wall 131 is so formed that the distance between the boundary wall 131 and the cooling liquid discharge port 112 is shorter than the distance between the boundary wall 131 and the cooling liquid feed port 111. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rotating electrical machine.

  Electric / electronic devices used in automobiles are required to be smaller and have higher output. In rotating electrical machines, forced cooling with cooling water or oil is used to cool the heat generated in the stator conductor due to an increase in the amount of current. It is becoming essential.

  As a water-cooled rotating electrical machine, there is known a water-cooled rotating electrical machine having a belt-like water channel structure in which a coolant introduction port and a discharge port are provided close to each other and divided between them by a boundary wall (for example, see Patent Document 1). ). Further, there is known a structure in which a housing has a partition parallel to the axial direction, a folded flow path is provided in a bracket at the housing opening, and the water channel is meandered (for example, see Patent Document 2).

JP 2004-364429 A JP 2007-20333 A

  In the vicinity of the coolant discharge port, stagnation occurs due to the flow of the liquid, and the cooling efficiency of the stagnation portion decreases. Moreover, when the water channel structure is complicated, it is difficult to keep the pressure loss in the water channel low. The prior art has not fully considered these problems.

  An object of the present invention is to provide a cooling structure for a rotating electrical machine having a higher cooling effect.

  The present invention is located on the outer periphery of the stator, the coolant passage formed in a belt shape in the circumferential direction by the bracket, the boundary wall formed in the cooling passage, and the coolant introduction provided on one side across the boundary wall A rotating electrical machine having a mouth and a coolant discharge port provided on the other side, wherein the distance between the boundary wall and the coolant discharge port is smaller than the distance between the boundary wall and the coolant introduction port .

  ADVANTAGE OF THE INVENTION According to this invention, the cooling structure of the rotary electric machine with a higher cooling effect is obtained.

  Hereinafter, an embodiment of the present invention will be described using rotating electricity used in a hybrid vehicle. The rotating electrical machine of the present embodiment has a function of a motor that drives the wheels of the vehicle and a function of a generator that generates power using regeneration, and switches between these functions according to the traveling state of the vehicle. used.

  FIG. 1 is a side sectional view of an induction type rotating electrical machine that constitutes an embodiment of the present invention. 2 is a front sectional view of FIG. 1, FIG. 3 is a perspective view of the center bracket of FIG. 1, and FIG. 4 is a schematic view of the coolant passage of FIG.

  It has a container-shaped rear bracket 11 with one end opened in the axial direction, and a front bracket 12 that closes the opening. A coolant introduction port 111 and a coolant discharge port 112 are provided at a rear portion in the axial direction of the rear bracket 11 so as to be separated from each other by about L = 30 mm to 50 mm. Have. The center bracket 13 is sandwiched between the rear bracket 11 and the front bracket 12 at the front part in the axial direction, and is fixed together by a plurality of bolts. The coolant passage 15 is located on the outer periphery of the stator 3, sandwiched between the center bracket 13 and the rear bracket 11, and formed in a belt shape in the circumferential direction of the rotating electrical machine 100.

  As shown in FIG. 3, the center bracket 13 has a boundary wall 131 that is a protrusion having a width of about 2 mm to 5 mm, and the boundary wall 131 is positioned between the coolant introduction port 111 and the coolant discharge port 112. As shown in FIG. 2, the rear bracket 11 is combined with the coolant introduction port 111 or the coolant discharge port 112. The center bracket 13 includes a stator 3 that is fixed by shrink fitting or press fitting, and a rotor 4 that is rotatably held inside the center bracket 13. Further, a rotation detection sensor 51 such as a resolver is attached to the rear bracket 11 and the shaft 44.

  The stator 3 is formed by winding a stator coil 32 around a plurality of slots 33 provided in a stator core 31 formed by laminating electromagnetic steel plates with insulating paper therebetween.

  The rotor 4 has a plurality of conductor bars 42 inserted into a plurality of slots 45 provided in a rotor core 41 formed by laminating electromagnetic steel plates, and a short-circuit ring 43 connecting them in front and rear in the axial direction. The rotor core 41 is fastened to the shaft 44 by shrink fitting or press-fitting. The shaft 44 is rotatably held via bearings provided on the rear bracket 11 and the front bracket 12, and receives power from a portion protruding from the front bracket 12. Tell.

  The rotating electrical machine having the above-described configuration is installed in an engine room of a vehicle (not shown) and transmits driving force via a belt. Further, it is connected to a control device such as an inverter by a three-phase power cable, and drive and power generation are controlled.

  As shown in FIG. 4, the boundary wall 131 is provided such that the distance D from the coolant discharge port 112 is 0 mm <D <(L / 2). Therefore, the distance between the boundary wall 131 and the coolant discharge port 112 is smaller than the distance between the boundary wall 131 and the coolant introduction port 111. The region where the coolant stagnates is reduced on the coolant discharge port 112 side of the boundary wall 131. Conversely, on the coolant introduction port 111 side, the coolant flowing from the coolant introduction port 111 flows so as to turn to the vicinity of the boundary wall 131, so that cooling in the region between the coolant introduction port 111 and the coolant discharge port 112 is performed. Efficiency is improved. In addition, stagnation is reduced and the flow of coolant discharge is smoothed, so that pressure loss is reduced.

  Furthermore, since the boundary wall 131 can be integrally formed with the center bracket 13 by casting such as die casting, the boundary wall 131 does not need to be provided as a separate part, so that the number of parts can be reduced and the cost can be reduced. In addition, since the coolant passage 15 is configured by using the two parts of the rear bracket 11 and the center bracket 13, it is easier to cast and prolong the mold life as compared with the case where a water channel is formed by providing a deep groove in the housing. I can do it.

  A second embodiment will be described with reference to FIG. However, the description of the same parts as in the first embodiment is omitted.

  In this embodiment, the boundary wall 131 is not a straight line but is substantially V-shaped, and the flow path is narrowed toward the cooling liquid discharge port 112 along the flow of the cooling liquid so that the cooling liquid stagnates on the cooling liquid discharge port 112 side. It is a structure that can eliminate cooling and increase cooling efficiency.

  A third embodiment will be described with reference to FIG. However, the description of the same parts as in the first embodiment is omitted.

  In the present embodiment, the boundary wall 131 is formed in a curved shape and arranged so as to surround the coolant discharge port 112. As a result, the discharged coolant is guided to the coolant discharge port 112 without stagnation, and the cooling temperature can be further improved by widening the region where the coolant having a low temperature flowing from the introduction port 111 is circulated. it can.

  A fourth embodiment will be described with reference to FIG. However, the description of the same parts as in the first embodiment is omitted.

  FIG. 7 is an enlarged view of the boundary wall 131 portion of the water channel structure in which a gap is provided in the boundary wall 131 so that the coolant can intentionally flow from the coolant introduction port 111 side to the coolant discharge port 112 side. It is. By adjusting the height of the boundary wall 131 between the rear bracket 11 and the boundary bracket 131 provided in the center bracket 13, a clearance of about 0.1 mm to 1 mm is provided in all or part of the channel width.

  According to this embodiment, since the coolant on the inlet side having a relatively low temperature is mixed with the coolant on the outlet side having a relatively high temperature, the temperature difference between both sides of the boundary wall 131 is reduced. And the stator coil can be cooled more uniformly. In addition, since the fitting between the rear bracket 11 and the boundary wall 131 is a gap, it is not necessary to process the upper part of the boundary wall 131 when manufacturing the center bracket 13, so that the number of manufacturing steps can be reduced.

  Further, when the boundary wall 131 is provided above the rotating electrical machine and the gap is arranged in the vicinity of the coolant discharge port 112, it is easy to remove air remaining in the vicinity of the coolant introduction port 111, and the cooling efficiency can be improved. .

  A fifth embodiment will be described with reference to FIG. However, the description of the same parts as in the first embodiment is omitted.

  In this embodiment, the boundary wall 131 is formed at the center of the coolant passage 15, and gaps of about 0.5 mm to 2 mm are provided at both ends of the coolant passage 15 so that the coolant can move. The boundary wall 131 is preferably bent so as to surround the coolant discharge port 112 and has a shape in which the coolant can easily flow toward the gaps on both sides. According to this embodiment, since the coolant on the inlet side having a relatively low temperature is mixed with the coolant on the outlet side having a relatively high temperature, the temperature difference between both sides of the boundary wall 131 is reduced. And the stator coil can be cooled more uniformly. In addition, since the coolant can flow to the end of the coolant passage 15 where it is difficult for the coolant to flow, the cooling effect in the axial direction of the rotating electrical machine is enhanced.

  According to the above embodiment, without increasing the pressure loss, there is no stagnation in the vicinity of the coolant discharge port, and a partial temperature rise in the coolant passage can be prevented. Is more uniform and the cooling efficiency is improved.

The side sectional view of the induction type rotating electrical machine which makes one example of the present invention is shown. FIG. 2 is a front sectional view of FIG. 1. The perspective view of the center bracket of FIG. 1 is shown. The schematic diagram of the cooling fluid channel | path of FIG. 1 is shown. The schematic diagram of the cooling fluid path | route which makes one Example of this invention is shown. The schematic diagram of the cooling fluid path | route which makes one Example of this invention is shown. 1 is a cross-sectional view of a coolant passage that constitutes an embodiment of the present invention. The schematic diagram of the cooling fluid path | route which makes one Example of this invention is shown. The schematic diagram of the cooling fluid path | route which makes one Example of this invention is shown.

Explanation of symbols

3 Stator 4 Rotor 11 Rear bracket 12 Front bracket 13 Center bracket 15 Coolant passage 111 Cooling water inlet 112 Cooling water outlet 131 Boundary wall

Claims (6)

A stator,
A rotor held rotatably inside the stator through a predetermined gap;
A coolant passage located on the outer periphery of the stator and formed in a band shape in the circumferential direction by a bracket;
A boundary wall formed in the cooling passage;
A coolant inlet provided on one side of the boundary wall;
A coolant outlet provided on the other side,
A rotating electrical machine in which a distance between the boundary wall and the coolant discharge port is smaller than a distance between the boundary wall and the coolant introduction port. The rotating electrical machine according to claim 1,
A center bracket on the outer periphery of the stator, a rear bracket on the coolant introduction port or the coolant discharge port side of the center bracket, a front bracket on the opposite side of the center bracket,
The cooling fluid passage is a rotating electrical machine formed between the center bracket and the rear bracket. The rotating electrical machine according to claim 2,
The rotating electric machine is a rotating electric machine in which the boundary wall is a protrusion that forms a part of the center bracket. The rotating electrical machine according to claim 1,
The rotating electrical machine is formed such that the boundary wall is bent so as to surround the coolant discharge port. The rotating electrical machine according to claim 1,
The boundary wall is a rotating electrical machine having a gap through which a coolant can move from the coolant introduction port side to the coolant discharge port side. The rotating electrical machine according to claim 5,
The casing is a rotating electrical machine in which a gap is formed in the boundary wall portion by two brackets on the inner side and the outer side.

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