JPH0297252A - Commutator - Google Patents

Abstract

PURPOSE:To improve the cooling efficiency of a commutator by arranging a through-path departing gradually from a rotary shaft toward a discharge port at a supporting member section. CONSTITUTION:A commutator chip 1 is held around a rotary shaft 2 by means of a supporting member 3 and a through-path 7 departing gradually from the rotary shaft 2 toward a discharge port 6 is made through the supporting member 3. Centrifugal component of cooling air in the through-path 7 directs in the discharging direction 8 and the magnitude thereof increases gradually. Consequently, the cooling air is discharged forcibly from the through-path 7 and temperature rise of the supporting member which causes unstable sliding of brush can be suppressed efficiently. When the supporting member 3 is made of metal, temperature rise of the rotary shaft 2 which causes damage at the bearing section can also be suppressed.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a commutator.

BACKGROUND ART Conventionally, as shown in FIG. 3, a plurality of commutator pieces 1 arranged in a cylindrical shape are fixed to the outer periphery of a rotating shaft 2 with a support member 3, and the rotating shaft 2 is attached to a portion of the supporting member 3. A through passage 4 for cooling the commutator was provided parallel to the commutator.

Problems to be Solved by the Invention In such a conventional configuration, the expected commutator cooling effect could not be obtained because the cooling air in the through passage 4 was insufficiently exhausted. Therefore, if the support member 3 is made of a material such as resin that has poor thermal conductivity and is weak against heat, a temperature rise in the support member 3 portion becomes a problem, and the resulting decrease in strength promotes deterioration of the roundness of the commutator surface. This prevented the brush from sliding securely.

Furthermore, if the support member 3 is made of a material with good thermal conductivity and resistance to heat, such as metal, the temperature of the rotating shaft 2 will rise more than that of the support member 3, causing damage to the bearing part due to poor lubrication. was there.

The present invention is intended to solve such problems, and aims to obtain a sufficient commutator cooling effect by increasing the exhaust efficiency of cooling air.

Means for Solving the Problems The commutator of the present invention has a through passage that gradually moves away from the rotation shaft from the suction port toward the discharge port in the support member portion that fixes the commutator pieces arranged in a cylindrical shape around the rotation shaft. It has been established.

Function: In the commutator of the present invention, the through passage is provided so that it gradually moves away from the rotating shaft from the suction port toward the discharge port, and centrifugal force always exerts a force on the cooling air in the through passage in the discharge direction. This, combined with the fact that the centrifugal force increases as it advances in the discharge direction, allows the cooling air in the through passage to be forcibly exhausted by rotational force, increasing the amount of heat dissipated from the support member. High commutator cooling efficiency can be obtained.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIG.

The figure shows the case where the support member is made of resin. In the figure, 1 is a commutator piece, which is held around the rotating shaft 2 by the support member 3, and the support member 3 has an inlet port 5 and an outlet port 5. A through passage 7 that gradually moves away from the rotating shaft 2 toward the rotary shaft 2 is bored.

In the above configuration, the component of the centrifugal force acting on the cooling air in the through passage 7 always points in the exhaust direction 8, and its magnitude gradually increases as it advances in the exhaust direction 8.Therefore, the cooling air flows through the through passage 7. As a result, it is possible to more efficiently suppress the temperature rise of the support member 3, which would make the sliding movement of the brush unstable.

Note that when the support member 3 is made of metal, it is possible to suppress a temperature rise of not only the support member 3 but also the rotating shaft 2 that would cause damage to the bearing portion.

In the above embodiment, the through passage 7 is linear, but the present invention is not limited to this (as shown in FIG. The goal is to achieve the following.

Effects of the Invention According to the present invention, the cooling efficiency of the commutator can be improved by providing the support member with a through passage that gradually moves away from the rotating shaft from the suction port toward the discharge port. When the support member is made of a material such as resin that has poor thermal conductivity and is weak against heat, stable sliding of the brush can be realized while suppressing a decrease in strength due to a temperature rise in that part. In addition, if the support member is made of a material with good thermal conductivity and resistance to heat, such as metal, it will be effective to suppress the temperature rise of the rotating shaft, and it will be possible to prevent poor lubrication of the bearing part due to the temperature rise of the rotating shaft. can.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a commutator according to an embodiment of the present invention, FIG. 2 is a vertical cross-sectional view of a commutator according to another embodiment of the present invention, and FIG. 3 is a vertical cross-sectional view of a conventional commutator. . 1... Commutator piece, 3... Support member, 5
...Intake port, 6...Outlet port, 7,9.
...Passway.

Claims (1)

[Claims] A commutator in which commutator pieces are held in a cylindrical shape around a rotating shaft by a supporting member, characterized in that the supporting member portion has a through passage that gradually moves away from the rotating shaft from the suction port toward the discharge port. Commutator.