JPS6391985A - Slip ring for rotary electric machine - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a slip ring for a rotating electric machine, and more particularly to a slip ring structure for an AC power generator for a vehicle.

Prior Art and Problems Fig. 2 shows an axial cross-sectional view of a general vehicle AC power generator in which the ITIJ slip ring structure of the present invention is used. By supplying and receiving current to the rotating slip ring and energizing the rotor coil 4, the rotor 5 becomes an electromagnet, and the rotor rotates within the stator 6, thereby operating as a generator.

Since the slip ring 3 and the brush 1, which is mainly made of carbon, rotate with a certain amount of surface pressure applied by the spring, it is inevitable that they will wear out against each other.
Although much effort has been made to extend its durable life, contact voltage drop is also required to be small due to its influence on the output performance of the generator.

Normally, slip rings for AC power generators for vehicles are often made of copper (Cu) in order to minimize contact voltage drop, but copper has a high resistance to oils such as engine oil and grease. If it were to become wavy during rotation, it would cause significant wear and significantly shorten its life as a slip ring. On the other hand, stainless steel slip rings are often used to increase resistance to these oils, but in this case, the contact voltage drop becomes large, causing excessive stress! Each had its own advantages and disadvantages, such as the difficulty in allowing current to flow and reducing the output performance of the generator itself.

Means for Solving the Problems The present invention provides a multi-layered slip ring using different metal materials such as copper and stainless steel, which have electrically and mechanically complementary performance. It includes a double structure in which a first metal member with a small contact voltage drop is provided on an oil-resistant second metal member.

Function: According to the above-mentioned multilayer structure, the upper first metal member acts as a slip ring when used under normal environment.
Contact voltage drop can be reduced, output performance can be greatly increased, and even if the first metal member wears out due to oil bunkering, etc., the second
The metal member is exposed to prevent wear, and it is possible to avoid power generation stoppage due to slip ring wear.

Embodiment FIG. 1 shows an axial sectional view of an embodiment of a slip ring for a vehicle alternator according to the present invention. The slip ring 13 has a two-layer structure, and generally the contact voltage drop with the carbon brush 1 is a metal layer 7 forming a first metal member with a small
Typically, a copper layer is arranged on the surface side, and a wear-resistant metal layer 8, which forms a second metal member that is generally resistant to oil etc., and typically a stainless steel layer is placed on the inside. Allocate. Stainless steel is preferable because it has water resistance in addition to oil resistance. 9 is a supporting mold resin, and 10 is a shaft. The copper layer is provided on the stainless steel layer by plating,
The thickness is set to 40 to 60 microns, which is about the amount of wear during the average life of a normal copper slip ring. In addition, a metal that is resistant to petroleum products such as engine oil, grease, oil, gasoline, etc. is selected as the second metal member that serves as the base, and a metal that is resistant to petroleum products such as engine oil, grease, oil, gasoline, etc. is selected, and as the first metal member that forms a thin layer on the surface of the base metal, Select a metal with low contact voltage drop. In this way, under normal operating conditions (no oil, etc.), the copper layer 7 will be in contact with the brush, so there will be less voltage drop and it will be possible to extract a large output from the RA generator. However, in the unlikely event that oil gets too hot and the copper layer wears out, the stainless steel and brush will come into contact with each other.
Even if the generator life is reached if there is only a copper layer,
It does not shorten the service life, but can improve environmental resistance.

Although the above embodiment shows a two-layer structure consisting of a copper layer and a stainless steel layer, it is also possible to have a multi-layer structure including other metals if necessary. It is clear that this can also be applied to Ai.

Effects Generally speaking, a first metal member made of carbon that has a small contact voltage drop with the brush is used as the surface layer, and a wear-resistant second metal member layer is placed below it to form a slip ring with a multilayer structure. Therefore, it can be used in a normal usage environment without reducing the rotational output or life, and even if the surface layer is worn out due to usage in an environment where abrasive oils such as petroleum products adhere, the bottom side will not deteriorate. The metal layer functions as a brush and can complete the intended life.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view in the axial direction of the rotor showing a slip ring portion according to an embodiment of the present invention, and FIG. 2 is a sectional view in the axial direction showing the general structure of an alternator for a vehicle.

Claims (1)

[Claims] A slip ring for a rotating electric machine, which has a multi-layer structure in which a first metal member with a small contact voltage drop with a brush is provided on an oil-resistant second metal member.