JPS58110636A - Sliding contact material - Google Patents

Abstract

PURPOSE:To reduce and stabilize the contact resistance of an Ag-Sn alloy with superior sulfurization resistance as a sliding contact material by adding a specified amount of V 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 0.5-2wt% V to an Ag-Sn alloy with superior sulfurization resistance contg. 1-10wt% Sn or by further adding 0.05- 0.5wt% Fe group metal. By adding V, oxide formed during sliding in the Ag-Sn alloy as a sliding contact material with superior sulfurization resistance is converted into stable oxide having higher electric conductivity and lower contact resistance than Sn oxide to reduce the contact resistance to the wire rods 2 of brushes, so ununiformity inthe number of revolutions of the commutator 1 is considerably reduced. By adding the Fe group metal, the grains are made fine to enhance the wear resistance of the sliding contact chips 1a.

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.
The Ag-8m alloy has been used, but since the Ag-8m alloy is easily oxidized, the contact resistance is high when the outer circumferential contact piece of the commutator of a small motor is made from the Ag-Sn alloy. Since it is unstable, the contact resistance with the brush contact changes, and the rotation speed of the commutator varies widely and becomes unstable.

The present invention has been made to eliminate such drawbacks.
It is an object of the present invention to provide a sliding contact material that suppresses oxidation of a kgsm alloy, has a low and stable contact resistance, and reduces and stabilizes variations in the rotational speed of a commutator.

One of the sliding contact materials of the present invention contains 1 to 1 Sn in Ag.
It is composed of 0 weight i1t% and 05 to 55 to 5 weight of V.

Another sliding contact material of the present invention is Sn in Ag.
x-t o weight- and V 0.5-2iEii%, F
It is made by adding 0.05 to 0.5 times tS of group e. In the sliding contact material of the present invention, 1 to 10
The purpose of adding t% of Sn is to improve the sulfidation resistance of ViAg, and if it is less than 1 t%, the effect will not appear, and l
When O weight *S is exceeded, the amount of oxide produced increases, resulting in high contact resistance and instability. Also, the reason why vO25~2-layer caps are added is that the oxides generated during sliding have better conductivity than Sn oxides, and the contact resistance can be kept low and stable.
If it is less than 0.5 weight, the effect will not be sufficient, and if it exceeds 2 weight, the amount of oxide will be large and the contact resistance will be high and unstable. Furthermore, KFe group is 0.01~0.5
The purpose of adding weight is to refine the crystal grains and improve wear resistance. If the weight is less than 0.01 weight, the crystal grains cannot be refined, and if it exceeds 0.5 weight, the alloy will not form. It precipitates as a single large lump in the inside, and the contact resistance is high and unstable due to large variations.

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
As shown in the drawing, three contact pieces were made on the outer circumferential surface of a commutator i with a diameter of 6 m and a length of 9 mm, made of Au-Ag-Cu-Pt. Diameter 0
．． Brush contacts 3 having three brush wires 2 of 25 m and length l (1 m) were brought into sliding contact so as to face each other, and a rotation test was conducted on the commutator l under the test conditions described below. When we measured the amount of wear and variations in the rotational speed of the commutator 1, we obtained the results shown in the right column of the table in the report.

Voltage: 12v Current: DC69mA Commutator rotation speed: 2800rpm Commutator rotation time: SOO time Time contact contact crab 5f/3 pieces As is clear from the table above, the wear amount of the conventional contact piece Fi
In contrast, the wear amount of the contact piece of the example was 2 to 25μ, which was significantly reduced, and it can be seen that the wear resistance was excellent. In addition, the rotational speed of the commutator with the contact piece of the conventional example was OK, which was 8 to 11-, while the rotational speed of the commutator with the contact piece of the embodiment varied F13 to 4-.
It can be seen that there is a significant decrease in

UJ″″11i1: Lffi, IJ) 23% “0”01
1.1 It has excellent wear resistance, suppresses oxidation, and has low and stable contact resistance, so it has excellent effects such as greatly reducing variations in the rotation speed of the commutator of small motors.

[Brief explanation of the drawing]

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 (1)

[Claims] 1) In Ag, 8nl to 10wt- and ■0.5 to 2
Weight - Sliding contact material made of additives. 2) A sliding contact material made by adding 8n1-10 by weight, 0.5 to 2 weight % of V, and 0.05 to 0.5 weight % of Fe group to Ag.