JPS58110637A - Sliding contact material - Google Patents

Abstract

PURPOSE:To enhance the lubricity and wear resistance of an Ag-In alloy with superior sulfurization resistance as a sliding contact material and to reduce the contact resistance by adding a specified amount of at least >=1 kinds among Th, W, Ce, Mo, Nb, Sn, Se and As to the alloy or by further adding an Fe group metal. CONSTITUTION:A material for the contact chips 1a of the commutator 1 of a small-sized motor is obtd. by adding 0.5-5wt% in total of at least >=1 kinds among Th, W, Ce, Mo, Nb, Sr, Se and As to an Ag-In alloy with superior sulfurization resistance contg. 1-10wt% In or by further adding 0.01-0.5% Fe group metal. Oxide of said added metal formed during sliding is softer than In oxide and acts as a lubricant to enhance the wear resistance. By adding the Fe group metal, the grains are made fine to further enhance the wear resistance, and the contact resistance to the wire rods 2 of brushes is reduced, so ununiformity in the number of revolutions of the commutator 1 is considerably reduced.

Description

[Detailed description of the invention] The present invention relates to improvements in sliding contact materials.

Conventionally, A has excellent sulfidation resistance as one of the sliding contact materials.
Although g-In alloy has been used, since Ag-In alloy has low lubricity and poor wear resistance, if this Ag-In alloy is used to make contact pieces around the commutator of a small motor. Abrasion powder is produced by contact with the brush contacts, causing noise, and the contact resistance with the brush contacts changes, making the rotational speed of the commutator widely variable and unstable.

The present invention was made in order to eliminate these drawbacks, and it improves the lubricity of the Ag In alloy, improves the wear resistance, lowers and stabilizes the contact resistance, and reduces and stabilizes the variation in the commutator rotation speed. The present invention aims to provide a sliding contact material.

One of the sliding contact materials of the present invention has a weight ratio of I in Ag.
n1~10% and Th, W, Ce, Mo, Nb
, Sr, Se+As in a total of 0.1
It is made by adding ~2%.

Another of the sliding contact materials of the present invention contains 1 to 10% In and Th, W, Ce, and M in a weight ratio of Ag.

, Nb, Sr, Se, and As in a total of 0.
1 to 2%, and 0.01 to 0.5% of the Fe group.

In the sliding contact material of the present invention, in Ag, 1 to
The reason why 10% In is added is to improve the sulfidation resistance of Ag. If it is less than 1%, the effect will not appear, and if it exceeds 10%, the amount of oxide generated will increase, resulting in high contact resistance and instability. It is something that becomes. Also Th.

The reason why at least one of W, Ce, Mo, Nb, Sr, Se, and Aa is added in a total amount of 0.1 to 2% is because the oxides of these elements generated during sliding are stronger than the oxides of In. This is because it acts as a soft lubricant and improves wear resistance. If the droplet is 0.1%, the wear resistance of Ag-In will not improve, and if it exceeds 2%, the amount of oxide will increase and the contact resistance will increase. is high and unstable. Furthermore, the Fe group was added to 0. The reason why 1 to 0.5% of O is added is to refine the crystal grains and improve wear resistance. If it is less than 0.01%, the grains cannot be refined, and 0.5% is added.
If it exceeds %, alloying will not occur, and it will precipitate as a single large lump in Ag, resulting in high contact resistance and large variations, resulting in instability.

Next, a contact piece for a commutator of a small motor made of a sliding contact material according to the present invention and a conventional sliding contact material will be explained.

The sliding contact material according to the embodiment of the present invention and the conventional sliding contact material having the component compositions shown in the right column of the table below have a thickness of 0.2
A commutator 1 with a diameter of 6 mm and a length of 9 m is provided with three contact pieces on the outer periphery as shown in the drawing. 0.25
m, a brush contact 3 having three brush wires 2 with a length of 10 m
A commutator 10 rotation test was performed under the test conditions described below, with the contacts facing each other in sliding contact, and the amount of wear on the contact piece 1a and the variation in the number of 10 rotations of the commutator were measured. The results shown are obtained.

Test conditions Voltage: 12V Current: DC60mA Commutator rotation speed: 2800rpm Commutator rotation time: 5
00 hours Contact force of brush contact = 5g/3 pieces As is clear from the table above, the amount of wear of the conventional contact piece is 3
6μ, whereas the amount of wear of the contact piece of the example was significantly reduced by 2 to 3μ, indicating that it has excellent wear resistance. Further, the variation in the rotation speed of the commutator with the contact piece of the conventional example was 7 to 10%, while the variation of the rotation speed of the commutator with the contact piece of the example was 2.5 to 4.
It can be seen that there is a significant decrease at 5%.

As detailed above, the sliding contact material of the present invention has high wettability and excellent wear resistance, so the contact pieces of the commutator of a small motor made using this material are abrasion particles when sliding with the brush contacts. There is no occurrence of Therefore, since no noise is generated and the contact resistance is low and stable, there are excellent effects such as significantly reducing variations in the rotation speed of the commutator of a small motor.

[Brief explanation of drawings]

The figure is a perspective view showing the state of contact between the commutator and brush contacts of a small motor. 1-・- Commutator, la・--- Contact piece, 2--
-・Brush wire, 3-...-Brush contact.

Claims (2)

[Claims] (1) 1 to 10% In and Th by weight in Ag. A sliding contact material containing a total of 0.5 to 5% of at least one of W, Ce, Mo, Nb, Sr, Se, and As. (2) 1 to 10% In and Th by weight in Ag. A total of 0.5 to 5% of at least one of W, Ce, Mo, Nb, Sr, Se, and As and 0.01 to 0.5% of Fe group.
Sliding contact material made of additives.