JP2523847Y2 - Slip ring - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. INDUSTRIAL APPLICATION FIELD The present invention relates to a slip ring used for passing a current through a rotating body.

B. Summary of the Invention In the present invention, in a slip ring, a support ring having a thermal expansion coefficient substantially equal to that of a slip ring body made of copper or a copper alloy and having a higher rigidity is fixed, and the support ring is slipped. By tightening and fixing to the rotating body together with the ring main body, a large fastening force to the rotating body is obtained by the support ring.

C. Conventional technology For example, a slip ring is fitted to the shaft end of a winding type rotor of an induction motor, and a brush supported on a casing side of the motor is slid into contact with the slip ring.
A current is supplied to the rotor.

FIG. 3 is a view of the slip ring mounting portion, wherein FIG. 3 (a) is a transverse sectional view and FIG. 3 (b) is a longitudinal sectional view. As shown in FIG. 3, a ring core is attached to the end of the rotor shaft 11.
12 is fixed, and this ring core is
Three slip rings 14 corresponding to the u, v, and w phases are tightly fixed to the outer periphery of the outer ring 12 by shrink fitting or the like at intervals. A lead wire 15 is connected to each slip ring 14, and each lead wire 15 is a hole 16 formed in a flange portion of the ring core 12.
Are connected to a rotor winding (not shown). Thus, an electric current is supplied to the rotor winding from a brush (not shown) that slides on the outer peripheral surface of each slip ring 14.

As the material of the slip ring 14, copper or an alloy containing a large amount of copper is frequently used in view of the relationship with the temperature, compatibility with the brush, and the like.

D. Problems to be Solved by the Invention During operation, heat is generated in the slip ring 14 by a voltage drop or friction between the slip ring 14 and the brush, and the heat causes the slip ring 14 to expand. This slip ring 14
The expansion of the ring reduces the interference in the interference fit, and weakens the fastening force of the slip ring 14 to the ring core 12.

However, copper and copper alloys have a small allowable stress and a narrow elastic limit range. If a large interference is given in advance by shrink fitting, permanent deformation may occur. Therefore, the interference must be limited to some extent. For this reason, as described above, when the slip ring 14 thermally expands during operation, the fastening force becomes insufficient, and particularly when the angular velocity of the rotor fluctuates (such as torsional vibration), the slip ring 14 There was a problem that it would rotate in the circumferential direction. As a result, a load is applied to the lead wire 15 and the like connected to the slip ring 14, which may lead to a short circuit accident or the like. This is remarkable when used for a machine with a large load variation, for example, a mixer, a mill, a crusher, a cutter, or the like.

The present invention solves such a problem.
It is an object of the present invention to provide a slip ring that can have a large interference so that a sufficient fastening force can be obtained with a simple configuration.

E. Means for Solving the Problems In order to achieve the above object, in the slip ring according to the present invention, in a slip ring which is fixedly fitted to a rotating body, a slip ring body made of copper or a copper alloy and slidingly in contact with a brush. Having a thermal expansion coefficient equivalent to that of the slip ring main body and having a higher rigidity than the slip ring main body, and being integrally fixed to the slip ring main body and tightly fixed to the rotating body together with the slip ring main body. And a support ring.

F. Action Even when the interference is reduced due to thermal expansion, the firm fixing of the slip ring is maintained by the tightening force of the support ring. Further, since the thermal expansion coefficients are substantially equal, relative displacement between the slip ring main body and the support ring does not occur due to thermal deformation, and generation of internal stress is prevented.

G. Embodiment Hereinafter, an embodiment of the present invention will be described specifically with reference to the drawings.

FIG. 1 is a longitudinal sectional view of one embodiment of the present invention. As shown in FIG. 1, the present slip ring 21 includes a slip ring main body 22 whose circumferential surface is in sliding contact with a brush (not shown), and a support fixed to the slip ring main body 22 and fixed to the ring core 12 together therewith. It has a ring 23. The slip ring body 22 is conventionally made of copper or an alloy containing a large amount of copper. On the other hand, the support ring 23 has a thermal expansion coefficient equivalent to that of the slip ring body 22 and a material having higher rigidity than the slip ring body 22, for example,
It is made of SUS306, SUS316, etc. In this embodiment, the support ring 23 has a shape whose inner diameter is equal to the inner diameter of the slip ring main body 22 and whose outer diameter is smaller than the outer diameter of the slip ring main body 22. And they are integrally fixed by a plurality of bolts 24.

Thus, the slip ring body fixed integrally to each other
The support ring 22 and the support ring 23 are tightly fitted together on the outer peripheral portion of the ring core 12 with an appropriate interference by shrink fitting or the like.

In such a slip ring 21, even when the interference in the interference fit fixing portion is reduced due to thermal expansion due to heat generated during operation, the rotational force of the slip ring 21 is increased by the tightening force of the rigid support ring 23. Strong fastening to 11 is maintained. Therefore, even when the angular velocity of the rotating shaft 11 fluctuates, the slip ring 21 does not rotate with respect to the rotating shaft 11. On the other hand, since the thermal expansion coefficients of the slip ring main body 22 and the support ring 23 are substantially equal, the slip ring main body 22 and the support ring 23 are thermally deformed.
And no internal stress is generated.

FIG. 2 is a longitudinal sectional view of a second embodiment of the present invention. In this embodiment, a concave portion is provided on the side surface of the slip ring main body 22, and the support ring 23 is fitted into the concave portion. In this way, the support ring 23
Is not protruded from the side surface of the slip ring main body 22, which is suitable when the slip ring 21 is arranged adjacent to a narrow space.

In the present invention, the shapes of the slip ring main body 22 and the support ring 23 are not limited to those of the above-described embodiment, and the support ring 23 may be provided only on one side surface of the slip ring main body 22. Well, in addition to this, for example, forming a concave portion on the inner peripheral surface of the slip ring main body 22,
The support ring 23 may be fitted therein.
Further, the means for fixing the slip ring main body 22 and the support ring 23 is not limited to the bolt 24, but may be, for example, brazing.

H. Effects of the Invention As described above in detail with reference to the embodiments, according to the present invention, a slip ring body made of copper or a copper alloy has a thermal expansion coefficient substantially equal to that of the slip ring body and a higher rigidity. The support ring is fixed integrally, and the support ring is fitted to the rotating body together with the slip ring body, so that the slip ring is large due to the support ring tightening even with a small amount of slip ring body. It is possible to obtain a tightening force, and it is possible to effectively prevent the slip ring from idling even with a rapid angular velocity fluctuation of the rotating body. Further, since no relative displacement occurs between the slip ring main body and the support ring due to the thermal deformation, no internal stress is generated.

[Brief description of the drawings]

1 and 2 are longitudinal sectional views of an embodiment of the present invention, respectively, and FIG. 3 is a sectional view of a conventional example. In the drawings, 11 is a rotating shaft, 12 is a ring core, 21 is a slip ring, 22 is a slip ring main body, and 23 is a support ring.

Claims (1)

(57) [Scope of request for utility model registration] 1. A slip ring which is fixedly fitted to a rotating body by means of a slip ring made of copper or a copper alloy and slidably in contact with a brush, said slip ring having a coefficient of thermal expansion equivalent to that of said slip ring body. A slip ring comprising: a support ring having higher rigidity than the main body, being integrally fixed to the slip ring main body, and being fixedly fitted to the rotating body together with the slip ring main body.