JP2885294B2 - Motor cooling structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor cooling structure, and more particularly to a cooling structure for improving cooling efficiency.

[0002]

2. Description of the Related Art As a conventional cooling structure for a motor, for example, a structure described in Japanese Patent Application Laid-Open No. 56-123765 is known. In this cooling structure, a gap is formed between a stator and a rotor in a motor case, and cooling fins are provided facing the gap. Then, the cooling fins are rotated to flow air through the gap, and the air flowing through the gap cools the windings of the stator.

[0003]

However, in the above-described conventional motor cooling structure, both the rotor and the stator must be cooled by the air flowing through the gap between the rotor and the stator. However, there is a problem that it is difficult to effectively cool the electric motor, particularly, to effectively cool the rotor. The present invention has been made in view of the above problems,
An object of the present invention is to provide a cooling structure that can effectively cool an electric motor, particularly a rotor.

[0004]

In order to achieve the above object, a cooling structure for an electric motor according to the present invention has a structure in which a rotor is rotatably accommodated in a motor case, and a stator is mounted on an inner wall of the motor case at a position radially outside the rotor. In the electric motor, which is fixed and forms a refrigerant passage in the motor case and cools at least one of the rotor and the stator with a cooling medium flowing through the refrigerant passage, a first medium is provided between the stator and the rotor. A first refrigerant passage is formed inside the rotor, a second refrigerant passage is formed in the rotor axis direction, and the first refrigerant passage and the second refrigerant passage are communicated on one side in the rotation axis direction. The cooling medium is made to flow continuously through the passage and the second refrigerant passage.

[0005]

In the cooling structure for an electric motor according to the present invention, a first refrigerant passage is formed between a stator and a rotor, and a second refrigerant passage is formed inside the rotor. As a result, the stator and the like can be effectively cooled, and in particular, the rotor can be effectively cooled from inside and outside in the radial direction.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a cooling structure for an electric motor according to a first embodiment of the present invention. In the figure, reference numeral 11 denotes a cylindrical case main body having both ends opened. The case body 11 and the end covers 11 and 12 constitute the motor case 10.

In the motor case 10, a rotor 16 is rotatably arranged at the center in the radial direction on the right and left sides in the figure, and a stator 18 is fixed to the inner wall of the case body 11 radially outward of the rotor 16. A cylindrical space 21 is formed in the motor case 10 on the right side of the end plate 12 in the drawing, and an annular gap is formed as a first refrigerant passage 20 between the rotor 16 and the stator 18. The first refrigerant passage 20 has a right end in the figure open to the outside through a vent hole 13a formed in the end plate 13, and has a left end through a space 21 and a second refrigerant in the rotor 16 as described later. Communicate with passage.

The rotor 16 has a second refrigerant passage 22 therein.
The magnet 16b is formed on the outer periphery of the cylindrical tubular member 16a on which
Is fixed. The right end of the cylindrical member 16a in the figure is rotatably supported on the end cover 13 by a bearing 17, and the output shaft 14 is fitted to the left end and connected to the output shaft 14 so as to be integrally rotatable. The right end of the second refrigerant passage 22 in the cylindrical member 16a in the drawing is open to the outside, and the left end communicates with the first refrigerant passage 20 via the space 21.

The output shaft 14 is rotatably penetrated through a central portion of the end plate 12 through a bearing 15, a left end in the drawing projects outward, and a large diameter flange portion 14 a is formed at a right end. A plurality of notches 19 are formed on the outer periphery of the flange portion 14a so as to be spaced apart from each other in the circumferential direction. Form. The communication hole 19 opens into the space 21 to communicate the second refrigerant passage 22 of the cylindrical member 16 a with the first refrigerant passage 20.

The stator 18 has a coil 1 mounted on a yoke 18a.
8b is wound, and the yoke 18a is
1 is fixed to the inner wall surface. As is well known, the coil 18b of the stator 18 is connected to a drive circuit (not shown) or the like. In addition,
In the figure, reference numeral 27 denotes a wind guide member fixed to the inner surface of the end cover 12.

In such a motor cooling structure,
As shown by the arrow in the figure, the cooling air flows into the motor case 10 from the right end of the second refrigerant passage 22, and the cooling air flows from the ventilation hole to the outside through the space 21 and the first refrigerant passage 20. For this reason, the rotor 16 is connected to the refrigerant passages 20 and 22.
And the stator 18 can be cooled by the cooling air flowing through the refrigerant passage 20.

FIG. 2 shows a motor cooling structure according to a second embodiment of the present invention, and is a sectional view of the motor. In the second embodiment and third and fourth embodiments to be described later, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

In this embodiment, the yoke 18 of the stator 18 is used.
A plurality of notches 30 are formed on the outer periphery of a, and a plurality of refrigerant passages 30 (same numbers as the notches) are separated between the notches 30 and the inner wall surface of the case body 11.

In the second embodiment, the cooling air flows from the refrigerant passage 22 to the refrigerant passages 20 and 30 as indicated by arrows in the figure.
And the cooling air flowing through the refrigerant passages 20 and 30 cools the stator 18 from inside and outside in the radial direction. For this reason,
The cooling of the stator 18 can also be performed effectively.

FIG. 3 shows a third embodiment of the present invention and is a longitudinal sectional view of an electric motor. In the third embodiment, a holder 40 is provided at the right end of the rotor 16, and a switch element 42 such as an FET constituting a drive circuit is attached to the holder 40. The holder 40 has a cylindrical shape, an inner peripheral surface of which is rotatably engaged with the cylindrical member 16 a of the rotor 16 via the bearing 17, and an outer peripheral surface of which is separated from the case body 11 by a partition member 41. In the holder 40, a passage 40a for opening the second refrigerant passage 22 to the outside is formed, and the first refrigerant passage 2
A ventilation passage 43 that opens 0 to the outside is formed. 90 is a radiation fin.

In the third embodiment, the cooling air flows as indicated by the arrow in the figure, and after cooling the switch element 42, the rotor 16 and the stator 18 are cooled. For this reason,
Even if the drive circuit is assembled in the motor case 10 of the motor, the cooling performance of the drive circuit is not impaired, and the overall size of the drive circuit and the motor can be reduced.

FIG. 4 shows a fourth embodiment of the present invention and is a longitudinal sectional view of an electric motor. In the fourth embodiment, fins 50 are provided in the rotor 16 at a portion where the fins 50 are connected to the output shaft 14, and the rotor 16 is forcibly cooled. This allows for more effective cooling,
The fins 50 can reduce the size and weight without increasing the size as a whole.

[0018]

As described above, according to the electric motor cooling structure of the present invention, the first refrigerant passage is formed between the stator and the rotor, and the rotor is formed into a hollow shape to form the inside of the rotor. Since the second refrigerant passage is formed, the components such as the stator and the like, particularly the rotor, can be effectively cooled, and the cooling fan can be incorporated in the rotor to reduce the size. Can be

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a cooling structure for an electric motor according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a motor cooling structure according to a second embodiment of the present invention;

FIG. 3 is a longitudinal sectional view of a motor cooling structure according to a third embodiment of the present invention;

FIG. 4 is a longitudinal sectional view of a motor cooling structure according to a fourth embodiment of the present invention;

[Explanation of symbols]

11 ... case body, 12, 13 ... end cover, 14 ...
Motor case, 15 ... rotating shaft, 16 ... rotor,
18 ... stator, 20 ... first refrigerant passage, 21 ...
Space, 22 ... second refrigerant passage.

Continuation of the front page (56) References JP-A-3-82356 (JP, A) JP-A-2-231939 (JP, A) JP-A-50-121705 (JP, A) (58) Fields investigated (Int) .Cl. ⁶ , DB name) H02K 9/00-9/28

Claims (1)

(57) [Claims] A rotor is rotatably accommodated in a motor case, a stator is fixed to an inner wall of the motor case radially outward of the rotor, a coolant passage is formed in the motor case, and the coolant flows through the coolant passage. An electric motor configured to cool at least one of a rotor and a stator with a cooling medium, wherein a first refrigerant passage is formed between the stator and the rotor, and a second refrigerant passage is provided inside the rotor in a rotation axis direction. Is formed, the first refrigerant passage and the second refrigerant passage communicate with each other on one side in the rotation axis direction, and the cooling medium continuously flows through the first refrigerant passage and the second refrigerant passage. A motor cooling structure characterized by the following.