JPH09154258A - Forcible oil cooled motor or cooling structure of motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize effective cooling by forming the inside of the rotating shaft of the rotor as the tapered hollow portion and setting the output side or the motor or drive side of the generator in the larger diameter side of the tapered hole. SOLUTION: Cooling oil 2 supplied with pressure from an external oil source 1 enters a cooling oil sending port 4 provided to a motor 3. The cooling oil 2 enters a tapered hollow portion (TP) 7 formed inside the rotating shaft 6 of rotor. The output axis 12 side of TP7 is set in the larger diameter hole side of tapered portion. A plurality of cooling oil spray small holes 9b, 9a are respectively formed in the same diameter at the large and small diameter sides in the diagonal direction to the axial center 8 of the rotor shaft from TP7. When the rotor shaft 6 is rotating, a centrifugal, force is applied to the cooling oil 2 at the internal circumference of TP7. This centrifugal force becomes larger in the small hole 9b of the larger diameter side than that of the small hole 9a in the small diameter side. Therefore, when the small hole 9b is far from the small hole 9a, the same amount of cooling oil flows out of the small holes 9b, 9a. Accordingly, the oil 10 collides with the stator coil 10 to absorb the heat.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling oil passage structure for a rotor rotating shaft of an electric motor or generator, which is used in an electrically driven vehicle or the like to achieve a high output by a forced oil cooling system.

[0002]

2. Description of the Related Art In a conventional oil-cooled generator or electric motor, as shown in FIG.
7 is machined and a plurality of small holes 09 are formed on the side surface of the rotor rotation shaft.
(09a, 09b) are opened, and these small holes are used as holes for flowing cooling oil. In this structure, after the cooling oil is pressure-fed to the hollow hole 09, the cooling oil is radially discharged from the small holes 09 to the outside by the centrifugal force caused by the rotation of the rotor rotation shaft 012 from the plurality of small holes 09, and The structure is such that it strikes the coil 010 and takes away the heat generated in the coil.

[0003]

However, in the conventional example,
The cooling oil is discharged by the centrifugal force caused by the rotation of the generator or the electric motor, but the amount of cooling oil discharged from the small holes 09 is not uniform and is discharged from the small holes 09b far from the pressure feed port 04. The amount of oil that is discharged is smaller than the amount of oil that is discharged from the small hole 09a near the pressure feed port 04, and the cooling of the coil 010 is uneven.

Since the hollow hole 07 is machined parallel to the rotary shaft core 08, the cooling oil 02 flowing from the pressure feed port 04 is concentrated and discharged to the small holes 09a near the pressure feed port 04, and is distant. This is because a small amount of the remaining cooling oil is discharged from the small hole 09b.

Therefore, in order to supply a sufficient amount of oil to the small hole 09b located far from the pressure feed port 04, for example, a method of increasing the amount of oil supplied from the external hydraulic power source 01 is conceivable.
This method further requires another measure for increasing the amount of supplied oil, and since the amount of oil also increases, it also increases the oil agitation resistance loss inside the generator or the electric motor, which is not a good measure. However, in the past, this method was often used.

As another means for achieving the above object, the hole diameter of the small hole 09b is made larger than the hole diameter of the small hole 09a, or the number of small holes on the 09b side is made larger than the number of small holes on the 09a side. There is also a method to properly distribute the amount of oil,
It is not preferable to make a large-diameter horizontal hole or to make a large number of holes in the rotor shaft that transmits power, because it reduces the strength of the rotor shaft (however, this method is often used in the past. Was often used).

An object of the present invention is to efficiently and evenly remove the heat generated in the coil inside the electric motor or generator over the entire surface of the coil from the load shaft to the anti-load side.

[0008]

In the cooling structure for a generator or an electric motor according to the present invention, the inside of the rotor rotating shaft is hollow, and cooling oil is pressure-fed from the outside to the forcible hydraulic cooling. The inside of the rotor shaft is hollow and has a tapered shape, and the output side of the electric motor or the driving side of the generator is the large diameter side of the taper hole.

In the conventional example, the cooling hollow hole inside the rotor rotary shaft was machined parallel to the rotary shaft core, but in the present invention, as shown in FIG. 1, the cooling hydraulic pressure feed port 4 side has a small diameter. Since the taper-shaped hollow hole 7 having a large diameter on the load shaft side is provided, uniform cooling oil can be obtained from the small holes at either position of the small holes 9a and 9b by the action of the centrifugal force acting on the cooling oil. It will be scattered to the coil, and the coil can be efficiently and uniformly cooled.

[0010]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to FIG. Since the forced oil cooling type motor cooling hydraulic pressure supply port 4 side of the present invention has a small diameter and the load shaft side has a large diameter taper-shaped hollow hole, it is in any position due to the influence of the centrifugal force acting on the cooling oil. Even cooling oil is scattered from the small holes 9a and 9b to the coil, so that the coil can be efficiently cooled.

FIG. 1 shows an embodiment applied to the permanent magnet type brushless motor of the first embodiment according to the present invention as described above. In the following description, it is assumed that the electric motor is rotating. The cooling oil 2 pressure-fed from the external hydraulic power source 1 flows into the cooling hydraulic pressure feed port 4 provided in the electric motor 3. An oil seal 5 is arranged near the pressure feed port 4,
Cooling oil is prevented from leaking inside the motor. The cooling oil 2 that has flowed in from the outside flows into the taper-shaped hollow hole 7 formed inside the rotor rotation shaft 6. The taper-shaped hollow hole 7
The output shaft 12 side is the large diameter hole side of the taper.

A plurality of cooling oil spraying small holes 9b, 9a are formed in the large diameter and small diameter sides in the direction perpendicular to the axis 8 of the rotor rotation shaft from the hollow hole 7 so as to have the same diameter. B
When the rotary shaft 6 is rotating, a centrifugal force acts on the cooling oil 2 on the inner circumference of the tapered hollow hole 7. Since this centrifugal force is larger in the small hole 9b on the large diameter side than in the small hole 9a on the small diameter side, an equal amount of cooling oil flows out from the small holes 9b, 9a even if the position of the small hole 9b is farther than the small hole 9a.

As described above, an equal amount of cooling oil flows out from the small holes 9a and 9b, scatters and collides with the starter coil 10 to carry away heat, and the starter coil 10 can be cooled uniformly. . Then, the cooling oil 2 that has cooled the stator coil 10 gathers by the action of gravity at the case drain port 11 below the electric motor, passes through the oil pipe, and returns to the external hydraulic power source 1 for circulation.

As described above, the direction of the taper when the taper-shaped hollow hole 7 is formed in the rotor shaft 6 is such that the cooling hydraulic pressure supply port 4 side, that is, the opposite output side of the electric motor is the smaller diameter side. The output shaft 12 side of the electric motor is the large diameter side. In the case of taper processing, the output shaft 12 and the rotor rotation shaft 6 need to be separate parts because the diameter starts from the large diameter side and starts from the small diameter side. Therefore, after the taper processing is applied to the inside of the rotor rotation shaft 6, the output shaft 12
The rotor rotating shaft 6 and the rotor rotating shaft 6 may be integrally connected by, for example, electron beam welding.

The above is an example of application of the present invention to an electric motor. However, when the present invention is applied to a generator, the same cooling can be performed if the hollow taper hole of the rotor rotating shaft has a large diameter on the driving side. Means can be adopted.

[0016]

According to the present invention, a taper-shaped hollow hole is formed in the rotor rotating shaft and cooling oil is poured into the hole, whereby heat generated in the coil inside the electric motor or generator is removed. , It is possible to take away efficiently and evenly over the entire surface of the stator coil.

[Brief description of the drawings]

FIG. 1 is a cooling structure diagram applied to a permanent magnet type brushless electric motor according to a first embodiment of the present invention.

FIG. 2 is a diagram corresponding to FIG. 1 of a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... External hydraulic power source, 2 ... Cooling oil, 3 ... Electric motor, 4 ... Cooling hydraulic pressure supply port, 5 ... Oil seal, 6 ... Rotor rotating shaft, 7 ... Tapered hollow hole, 8 ... Rotor Rotating shaft core, 9a, 9b ... Small hole, 10 ... Steer coil, 11 ... Case drain port, 1
2 ... Output shaft, 01 ... External hydraulic power source, 02 ... Cooling oil, 04 ...
Pressure feed port, 07 ... Hollow hole, 08 ... Rotating shaft core, 09a, 09
b ... small hole, 010 ... coil, 012 ... rotor rotation axis.

Claims (1)

[Claims] 1. A rotor rotating shaft is hollow, and cooling oil is pressure-fed from the outside to centrifugally disperse the cooling oil to forcibly hydraulically cool the rotor rotating shaft. A cooling structure for a forced oil-cooled electric motor or generator, characterized in that it has a taper shape and the output side of the electric motor or the drive side of the electric generator is the large diameter side of the taper hole.