JPH0123908B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a brush vibration isolator for a DC motor in which a damper material is welded to the brush. [Prior Art] Conventionally, in this type of brush vibration isolator, a rubber material was attached to the brush as a damper material using double-sided adhesive tape. Therefore, automation is difficult. Adhesive tape becomes sticky in the summer, making it difficult to work with. Since rubber material is used, sulfide gas is emitted which has a negative effect on the commutator. There were problems such as the adhesive tape sagging when used at high temperatures and the brush pressure changing. [Object of the Invention] In view of the above-mentioned problems, the present invention improves the damper material so that it is possible to automate the pasting on brushes with a machine, thereby improving productivity, extending the life of brushes, commutators, etc., and improving the vibration-proofing effect. The purpose of this invention is to propose an improved brush vibration isolator for a DC motor. [Structure of the Invention] The present invention provides a direct current motor in which a damper is provided on a brush that comes into sliding contact with a commutator.
The damper material mixed with a tackifier is integrally attached to the brush by heat welding or ultrasonic welding. [Example] The present invention will be described below with reference to an illustrated example. In Fig. 1, a DC motor M has a stator 2 made of an annular permanent magnet fitted on the inner circumferential surface of a stator case 1 having a bottomed cylindrical shape, and a rotor 3 is inserted into the stator 2 through a small gap. The rotor 3 is provided with a plurality of slots (not shown) and a driving coil 4 is wound therein, and a rotating shaft 5 is mounted at the center of the rotor 3.
A commutator 6 is arranged and fixed in parallel on the rotating shaft 5, and the tips of a pair of brushes 9, 9, each having one end attached to a side plate 7 via an insulating plate 8, are in sliding contact with the circumferential surface of the commutator 6. As shown in FIG. 2, a damper material 10 is integrally welded and fixed to the brushes 9, 9 to constitute a brush vibration isolator. The side plate 7 is made of a flat iron plate, and has a recess 7a formed in the center, and one of the bearings 11 is placed in the recess 7a.
The rotary shaft 5 is supported by a bearing (not shown) provided in the stator case 1. Further, a thrust seat plate 12 is provided at the bottom of the recess 7a, and the tip of the rotary shaft 5 is brought into contact with the thrust seat plate 12 to form a thrust bearing. The damper material 10 has a styrene elastomer (for example, trade name AR-740B) as its main component, and contains a tackifier, an adjuvant carbon black, an anti-aging agent, and a weathering agent as shown in Table 1. It is then mixed and molded. As the tackifier, one or more of the following may be used. (i) Aliphatic hydrocarbons (e.g. trade name Escorets 1315), (ii) aliphatic/alicyclic hydrocarbons, (iii) aliphatic/aromatic hydrocarbons (e.g. trade name Escorets 2200), (iv) ) aromatic hydrocarbons (e.g. trade name Tatsuki Fire 101), (v) hydrogenated alicyclic hydrocarbons (e.g. trade name Quinton U-185), (vi) alicyclic hydrocarbons

〔Effect of the invention〕

As mentioned above, the present invention improves productivity by improving the damper material and making it possible to automate pasting it onto the brush by machine.The damper material eliminates the generation of sulfide gas caused by conventional rubber materials, so there is no risk of contact failure. It is possible to provide a brush vibration isolating device for a DC motor that has excellent practical effects, such as eliminating sagging of the adhesive tape at high temperatures, extending the life of the brush, and improving the vibration isolating effect.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which Fig. 1 is a cross-sectional side view of a brush vibration isolator for a DC motor, Fig. 2 is an external perspective view of a damper material fixed to a brush, and Fig. 3 is a brush and damper material. FIG. 4 is a plan view of the brush and damper material. M...DC motor, 6...Commutator, 9...Brush, 10...Damper material.

Claims (1)

[Claims] 1. In a DC motor in which a damper is provided on the brush that slides on the commutator, a damper material whose main component is a styrene elastomer and 5 to 50 parts of a tackifier mixed into this elastomer is thermally welded or ultrasonically applied to the brush. A DC motor brush vibration isolator characterized by being integrally installed by welding.