JP2013090454A - Cooling device for vehicle use rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device for vehicle use rotary electric machines which, although in a simple structure, can secure cooling performance depending on the situation even when the vehicle runs down an inclined road.SOLUTION: A cooling device 28 includes coolant piping 30 with a dual piping structure which is installed at the top of a rotary electric machine 10, and in which a coolant flows. Inner piping 32 has an inner discharge hole 36 through which the cooling flowing in the piping is discharged toward the inside of outer piping 34, and is disposed so that its position relative to the rotary electric machine 10 will be constant. The outer piping 34 has a plurality of outer discharge holes 40 through which the coolant discharged from the inner discharge hole 36 is discharged toward the rotary electric machine 10, varying in their bore diameters in a rotation axis direction 20, and is disposed in such a way that its position relative to the inner piping 32 in the lengthwise direction of the piping can move depending on the inclination of the vehicle.

Description

  The present invention relates to a cooling device for a vehicular rotating electrical machine mounted on a vehicle, and more particularly to an improvement in a cooling structure for cooling the rotating electrical machine with a refrigerant.

  The rotating electrical machine includes a rotatable rotor and a stator disposed around the rotor. The stator has a coil, and a rotating magnetic field is generated when a current flows through the coil. The rotor is rotated by an electromagnetic action acting between the rotating magnetic field and the rotor.

  Generally, a rotating electrical machine generates heat by driving the rotating electrical machine. When the rotating electrical machine generates heat and the temperature rises, the operating efficiency of the rotating electrical machine decreases. Therefore, there is an example in which the rotating electrical machine is cooled by the refrigerant.

  The following Patent Document 1 describes a cooling device for a rotating electrical machine having a cooling oil pipe disposed along the rotation axis direction of the rotating electrical machine and an oil pump for supplying cooling oil to the cooling oil pipe. ing. A cooling oil pipe has a discharge hole formed so that it may be located in the upper part of the coil end of a rotary electric machine, and the cooling oil discharged from this discharge hole is supplied to a coil end, and a rotary electric machine is cooled.

  Patent Document 2 listed below describes a rotating electrical machine cooling structure having a refrigerant passage disposed in an upper part of the rotating electrical machine. The refrigerant passage has a discharge hole formed so as to be positioned above the stator coil, and the refrigerant discharged from the discharge hole is supplied to the stator coil to cool the rotating electrical machine. The refrigerant passage has a throttle portion that restricts the cross section of the passage upstream from the discharge hole. Since the throttle portion increases the speed of the refrigerant flowing through the refrigerant passage, inertia force is generated in the foreign matter passing through the throttle portion. This inertial force prevents foreign matter from flowing through the discharge hole to the downstream side and being discharged from the discharge hole.

JP 2006-115650 A JP 2011-91956 A

  In a conventional cooling device for a rotating electric machine, a refrigerant pipe through which a refrigerant flows is provided at the upper part of the rotating electric machine, and the refrigerant discharged from the hole of the refrigerant pipe is supplied to a heat generating area of the rotating electric machine, for example, a coil end to rotate. The electric machine is cooled. However, in such a configuration, when the vehicle on which the rotating electrical machine is mounted travels on an inclined road, there is a problem that the cooling performance is not stable because the flow rate of the refrigerant discharged from the hole of the refrigerant pipe changes. Further, when traveling on an uphill road, the load on the rotating electrical machine increases and heat generation also increases, so that the rotating electrical machine cannot be sufficiently cooled with the amount of refrigerant discharged from the hole of the refrigerant pipe during traveling on flat ground. There is a problem.

  An object of the present invention is to provide a cooling device for a rotating electrical machine for a vehicle that can ensure cooling performance according to the situation even when the vehicle travels on a sloping road with a simple structure. is there.

  The present invention relates to a cooling device for a rotating electrical machine for a vehicle that cools a rotating electrical machine including a rotatable rotor and a stator disposed around the rotor with a refrigerant, and is provided at an upper portion of the rotating electrical machine and flows through the refrigerant. Piping is provided, and the refrigerant pipe has a double pipe structure composed of an inner pipe and an outer pipe, and the inner pipe has an inner discharge hole for discharging the refrigerant flowing in the pipe toward the outer pipe and rotates. The outer pipe has a plurality of outer discharge holes that discharge the refrigerant discharged from the inner discharge holes toward the rotating electric machine so that the diameters are different along the rotation axis direction. In addition, a relative position with the inner pipe in the pipe length direction is provided so as to move according to the inclination of the vehicle.

  Further, as the inclination of the vehicle with the vehicle front facing upward increases, the outer pipe can move relative to the inner pipe so that the refrigerant is discharged from the outer discharge hole having a larger diameter toward the rotating electrical machine.

  Moreover, it is preferable that the inner pipe has a throttle portion that restricts a refrigerant flow area of the pipe on the upstream side of the inner discharge hole.

  According to the cooling device for a rotating electrical machine for a vehicle of the present invention, even when the vehicle travels on a sloping road with a simple structure, cooling performance can be ensured according to the situation.

It is sectional drawing which shows the structure of the cooling device of the rotary electric machine for vehicles which concerns on this embodiment. It is a figure which shows the principal part of FIG. 1 when a vehicle inclines by uphill running.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a cooling apparatus for a rotating electrical machine for a vehicle according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view illustrating a configuration of a cooling device for a rotating electrical machine for a vehicle according to the present embodiment, and illustrates a state in which the vehicle is not tilted. FIG. 2 is a diagram illustrating a main part of FIG. 1 when the vehicle is inclined by traveling uphill. In these figures, the left side is the front of the vehicle, and the right side is the rear of the vehicle. In these drawings, the vertical direction A is the vertical direction, and the upper side is the upper side of the vehicle.

  A vehicular rotating electrical machine (hereinafter simply referred to as a “rotating electrical machine”) 10 is a prime mover of a vehicle. The rotating electrical machine 10 includes a rotor 14 fixed to the rotor shaft 12 and a stator 16 disposed so as to surround the rotor 14. The rotating electrical machine 10 is accommodated in the case 18.

  The rotor 14 is a cylindrical magnetic body concentric with the rotor shaft 12, and is configured by, for example, laminating laminated steel plates in the rotation axis direction 20. A hole extending in the direction of the rotation axis is formed in the laminated steel sheet, and the permanent magnet 22 is disposed in this hole. In addition, the permanent magnet 22 can also be arrange | positioned not on the inside of a laminated steel plate but on the outer periphery of a laminated steel plate.

  The rotor shaft 12 is rotatably supported by a bearing 24 provided in the case 18. The rotor shaft 12 is an output shaft that transmits the output of the rotating electrical machine 10 to drive wheels (not shown) of the vehicle. Further, the power of the rotor shaft 12 may be transmitted to a pump (not shown) that circulates a refrigerant described later.

  The stator 16 is disposed with a gap around the rotor 14. The stator 16 has magnetic poles (not shown) that protrude toward the inner peripheral side of the stator 16 and are arranged at a predetermined interval in the circumferential direction. In a slot (not shown) which is a space between the magnetic poles, a coil 26 formed by winding a conductive wire around the magnetic poles is disposed. FIG. 1 shows a coil 26, that is, a coil end, that bridges between the slots at both ends of the stator 16. When the coil 26 is energized, a rotating magnetic field is generated in the stator 16, and a force attracted by the rotating magnetic field is generated in the rotor 14 having the permanent magnet 22, so that the rotor 14 rotates.

  Generally, a rotating electrical machine generates heat by driving the rotating electrical machine. When the rotating electrical machine is a permanent magnet type rotating electrical machine, the permanent magnets provided in the starter coil and the rotor generate heat. When these generate heat and the temperature rises, the operating efficiency of the rotating electrical machine decreases. In order to prevent this reduction in operating efficiency, the vehicle of the present embodiment is provided with a cooling device 28 that cools the rotating electrical machine 10 with a refrigerant, for example, lubricating oil (ATF). The cooling device 28 will be described below.

  The case 18 accommodates a pump (not shown) for circulating the refrigerant. This pump is configured to rotate in synchronization with the rotation of the rotor shaft 12. In addition, this invention is not limited to this structure, The electric pump which a pump drives with a dedicated motor may be sufficient.

  The cooling device 28 has a refrigerant pipe 30 through which the refrigerant flows. The refrigerant pipe 30 is accommodated in the case 18 and is disposed on the rotating electrical machine 10. The refrigerant pipe 30 has a double pipe structure including an inner pipe 32 and an outer pipe 34. In the present embodiment, the refrigerant pipe 30 is disposed so as to extend along the rotation axis direction 20.

  The inner pipe 32 is inserted into the outer pipe 34 and is disposed so that the relative position with the rotating electrical machine 10 is fixed. One end (not shown) of the inner pipe 32 is connected to the pump, and the other end 32a is closed. In addition, this invention is not limited to this structure, The other end 32a may be open | released.

  The inner pipe 32 has an inner discharge hole 36 for discharging the refrigerant flowing in the pipe toward the outer pipe 34. The inner discharge hole 36 of the present embodiment is formed so as to be positioned above the coil end 26 in the vertical direction A, as shown in FIG. The present invention is not limited to this configuration, and the inner discharge hole 36 may be formed so as to be positioned above another heat generating region of the rotating electrical machine 10.

  Further, the inner pipe 32 has a throttle portion 38 that restricts the refrigerant flow area of the pipe on the upstream side of the inner discharge hole 36. Since the throttle portion 38 increases the speed of the refrigerant flowing through the inner pipe 32, inertia force is generated in the foreign matter contained in the refrigerant passing through the throttle portion 38. Due to this inertial force, the foreign matter passes through the inner discharge hole 36 formed on the downstream side of the throttle portion 38 without being discharged, and further flows to the downstream side of the inner pipe 32. That is, the provision of the throttle portion 38 prevents foreign matter from being discharged from the inner discharge hole 36. Such a foreign matter outflow prevention structure can prevent foreign matter from being supplied to the rotating electrical machine 10 and damaging the rotating electrical machine 10.

  The outer pipe 34 has a plurality of outer discharge holes 40 that discharge the refrigerant discharged from the inner discharge holes 36 toward the rotating electrical machine 10 so that the diameters are different along the rotation axis direction 20. In the present embodiment, as shown in FIG. 1, three outer discharge holes 40a, 40b, and 40c are arranged in order so that the diameter gradually increases from the front to the rear of the vehicle. These outer discharge holes 40 are formed so as to be positioned above the rotating electrical machine 10 in the vertical direction A, as shown in FIG. In addition, this invention is not limited to the number 3 of the outer discharge holes 40, The hole of 2 or 4 or more different diameters may be located in order. Further, the present invention is not limited to the arrangement of the outer discharge holes 40, that is, the arrangement in which the diameter gradually increases from the front to the rear of the vehicle, and the plurality of outer discharge holes 40 are gradually increased from the front to the rear of the vehicle. You may arrange | position so that an aperture may become small.

  Further, the outer pipe 34 of the present embodiment is provided such that the relative position with the inner pipe 32 in the pipe length direction is movable according to the inclination of the vehicle. The movable part that moves the outer pipe 34 can be a known technique, for example, an actuator, and the actuator moves the outer pipe 34 based on a sensor that detects the inclination of the vehicle. As the outer pipe 34 moves in this manner, the outer discharge hole 40 through which the refrigerant discharged from the inner discharge hole 36 passes can be changed. That is, by operating one of the outer discharge holes 40 below the inner discharge hole 36 by the operation of the outer pipe 34, it can be set as the outer discharge hole 40 through which the refrigerant passes. Thus, by making it possible to change the outer discharge hole 40 through which the refrigerant passes, the flow rate of the refrigerant discharged therefrom can also be adjusted. As a result, based on the inclination of the vehicle, the refrigerant flow rate can be adjusted optimally, and the rotating electrical machine 10 can be effectively cooled.

  Specifically, the outer pipe 34 is connected to the inner pipe 32 so that the refrigerant is discharged from the outer discharge hole 40 having a larger diameter toward the rotating electrical machine 10 as the inclination of the vehicle with the vehicle front facing upward increases. Moving. FIG. 2 is a diagram illustrating a state of the outer pipe 34 that has moved when the vehicle is inclined by running uphill. In this way, when traveling uphill, the outer pipe 34 moves to the vehicle rear side based on the inclination of the vehicle, so that the refrigerant is discharged toward the rotating electrical machine 10 from the outer discharge hole 40c having a larger diameter. With such an operation, when the load on the rotating electrical machine 10 increases and heat generation also increases during traveling on an uphill road, the flow rate of the refrigerant supplied to the rotating electrical machine 10 is the opening of the outer discharge hole 40 through which the coolant passes. Since the area increases as the area increases, the rotating electrical machine 10 can be sufficiently cooled.

  At this time, it is preferable to move the outer pipe 34 so that the outer discharge hole 40c and the inner discharge hole 36 are aligned in the vertical direction A. Accordingly, the refrigerant discharged from the inner discharge hole 36 stays in the outer pipe 34 and flows efficiently toward the rotating electrical machine 10 without flowing downstream, so that the cooling performance of the rotating electrical machine 10 can be ensured. it can.

  On the other hand, as the inclination of the vehicle becomes smaller, the outer pipe 34 moves relative to the inner pipe 32 so that the refrigerant is discharged from the outer discharge hole 40 having a smaller diameter toward the rotating electrical machine 10. For example, when the vehicle changes from climbing to flat travel, the outer pipe 34 moves to the front side of the vehicle based on the inclination of the vehicle, so that the refrigerant flows from the outer discharge hole 40a having a smaller diameter to the rotating electrical machine 10. It is exhaled toward. By such an operation, when traveling on flat ground, the flow rate of the refrigerant supplied to the rotating electrical machine 10 can be reduced by reducing the opening area of the outer discharge hole 40 through which the refrigerant passes, and the surplus amount is reduced by the outer pipe. It flows downstream of 40 and returns to the pump again.

  According to the cooling device 28 of the present embodiment, when the vehicle travels on a sloping road, the flow rate of the refrigerant supplied to the rotating electrical machine 10 increases, so that the cooling performance for the rotating electrical machine 10 that generates more heat is stabilized. Can be achieved.

  In the present embodiment, the case where the rotating electrical machine 10 is a permanent magnet type motor has been described. However, the present invention is not limited to this configuration, and the rotating electrical machine 10 may be of another type, for example, an induction winding type or a reluctance type. May be.

  DESCRIPTION OF SYMBOLS 10 Rotating electrical machine for vehicles, 12 Rotor shaft, 14 Rotor, 16 Stator, 18 Case, 20 Rotational axis direction, 22 Permanent magnet, 24 Bearing, 26 Coil (coil end), 28 Cooling device, 30 Refrigerant piping, 32 Inner piping, 34 Outer piping, 36 Inner discharge holes, 38 Restricted portion, 40 Outer discharge holes.

Claims (3)

A rotatable rotor,
A stator arranged around the rotor;
In a cooling device for a vehicular rotating electrical machine that cools the rotating electrical machine with a refrigerant,
Provided at the top of the rotating electrical machine, provided with a refrigerant pipe through which the refrigerant flows,
The refrigerant pipe has a double pipe structure consisting of an inner pipe and an outer pipe,
The inner pipe has an inner discharge hole for discharging the refrigerant flowing in the pipe toward the outer pipe, and is provided so that the relative position with the rotating electrical machine is fixed,
The outer pipe has a plurality of outer discharge holes that discharge the refrigerant discharged from the inner discharge holes toward the rotating electrical machine so that the diameters are different along the rotation axis direction, and the relative position to the inner pipe in the pipe length direction is , Provided to move according to the inclination of the vehicle,
A cooling device for a vehicular rotating electrical machine. The cooling apparatus for a rotating electrical machine for a vehicle according to claim 1,
As the inclination of the vehicle with the vehicle front facing upward increases, the outer pipe moves relative to the inner pipe so that the refrigerant is discharged from the outer discharge hole having a larger diameter toward the rotating electrical machine.
A cooling device for a vehicular rotating electrical machine. The cooling apparatus for a rotating electrical machine for a vehicle according to claim 1 or 2,
The inner pipe has a throttle portion that restricts the refrigerant flow area of the pipe on the upstream side of the inner discharge hole.
A cooling device for a vehicular rotating electrical machine.

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