JPH0363307B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides improvements to an armature, particularly an armature having a structure in which an armature winding and a commutator connected to the terminals of the winding are cast in resin and fixed together, and a method for manufacturing the same. It is related to.

SUMMARY OF THE INVENTION An object of the present invention is to provide an armature and a method for manufacturing the same in which resin does not leak or adhere to the surface of a commutator when the armature is cast with resin.

The armature of the present invention is an armature in which an armature winding and a commutator connected thereto are integrally fixed with resin, and the commutator 2 has a terminal end of the armature winding on its outer periphery. A groove 24 for inserting an O-ring having a rectangular cross section is formed radially inward from the outer periphery at a portion in contact with the riser portion 2d to be connected, and the bottom surface of this groove 24 is a cut-up groove formed on the side surface of the riser portion. It is characterized by being in contact with the bottom surface of the undercut groove 2e of the commutator 2 which is continuous with the undercut groove 2f.

The method for manufacturing an armature of the present invention is to form a groove 24 for inserting an O-ring radially inward in the outer circumferential portion of the commutator 2 in contact with the riser portion 2d that connects the end of the armature winding. forming the undercut groove 2e of the commutator 2 so as to be in contact with the bottom surface of the undercut groove 2e that is continuous with the cut-up groove formed on the side surface of the riser part;
The armature winding and the commutator 2 are placed in the upper mold 11 of the mold.
and inserting the O-ring 19 into the lower mold 12 between the O-ring insertion groove 24 of the commutator 2 and the side surface of the lower mold 12 facing the O-ring 19, and inserting the resin into the mold. It is characterized by comprising a filling step.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of a conventional armature and an armature of the present invention will be described below with reference to the drawings.

Figures 1a and b show the appearance of a flat armature cast with resin 1-1, 1-2, 1-3...1-n
2 is a plurality of flat armature windings, 2 is a commutator connected to these windings, 3 is a rotor shaft to which this commutator 2 is fixed, and 4 is a resin that integrally fixes these.

In the flat armature shown in Figures 1a and b, a plurality of flat armature windings are arranged in a circular plate shape around the rotor axis. Since there is no core to direct the armature winding, it is common to form the armature winding into a flat disk shape by casting it integrally with the commutator using resin.The main part of the manufacturing process is shown in Figure 2a. , b and FIGS. 3a and 3b.

Figures 2a and b show a plurality of flat-wound armature windings 1-1, 1-2...1-n arranged in a disc shape with some of them overlapping around the axis. The wires are temporarily fixed with adhesive, and the terminal 1c of each winding is connected to the commutator 2.
The figure shows the state in which the wires have been connected to each segment and the wiring has been completed. Figures 3a and 3b show the assembled armature winding and commutator mounted in a mold for casting with resin, 11 is the upper mold of the mold, 12 is the lower mold of the mold, 13 14 is a resin injection hole provided in the upper mold 11;
15 is the cavity formed by the upper mold and the lower mold, 15 is the dowel pin between the upper mold and the lower mold, and 16 is the assembled armature winding and the commutator 2 when the commutator 2 is cast with resin. A guide pin for determining the center position, 17 is a commutator positioning pin, 18 is an armature winding alignment mark provided on the edge of the lower die 12, and 2b is a small hole for positioning provided on the end face of the commutator. It is.

Figures 4a and 4b are a plan view and a side view of a conventional commutator, where 2s is a segment of the commutator 2, 2d is a riser part connecting the ends of the armature windings, and 2e is an insulating part between segments 2s. This is an undercut groove formed by excavating this part so that it does not protrude beyond the outer periphery of the segment.

In the conventional armature, as shown in Fig. 5, when the assembled armature winding and commutator are cast in resin and fixed together, an O-ring 19 is fitted around the outer circumference of the commutator 2. The commutator 2 is inserted into the central lower cavity 12-2 of the lower die 12 shown in FIG. After fitting and aligning the commutator 2 with the position of the lower mold 12, the lower surface of the O-ring 19 fitted on the commutator is inserted into the stepped portion 1 provided in the middle part of the lower mold 12.
2-1, then align the position of one armature winding with the mark 18 provided on the edge of the lower mold, and then press the upper mold 11.
Align and attach with dowel pins 15 and tighten the upper and lower molds.

As a result, the neck of the commutator 2 (cylindrical part extending upward from the top of the commutator 2 along the pin 16)
is pressed, and the O-ring 19 is pressed between the riser part 2d of the commutator and the stepped part 12-1 of the lower mold, and the lower cavity 12 of the lower mold into which the commutator 2 is inserted from inside the cavity 14 of the mold. The flow of resin to -2 is cut off.

That is, the undercut groove 2e is the segment 2s.
This undercut groove 2e is formed in the insulating part so that the insulating part between the segments does not protrude beyond the outer periphery of the segment, and this undercut groove 2e is usually made by cutting with a rotating cutter.
At the same time, a cut-up groove 2f is formed in a portion corresponding to the upper insulating portion on the side surface of d. Therefore, even if the conventional O-ring 19 shown in FIG. 5 is used, the cut-up groove 2f portion is formed further on the outer periphery of the O-ring 19, so that the resin injected into the cavity 14 will flow into the cut-up groove 2f portion. It often leaked through the undercut groove 2e to the outer circumferential surface of the commutator, rendering the completed armature unusable.

In order to prevent the commutator from being contaminated by leaked resin and becoming unusable, liquid paraffin or silicone rubber is applied to the outer periphery and undercut grooves of the commutator to ensure that the surface of the commutator is not directly exposed to the resin. If the commutator is wrapped to prevent contact, it will be possible to prevent the commutator from being contaminated by resin that leaks when it is attached to the mold and cast, but it is important to remove paraffin or silicone rubber that has adhered to the surface of the commutator after casting. This was not a sufficient countermeasure, as it required a lot of time and effort to remove the paraffin, silicone rubber, etc. that had entered the undercut grooves, and it became unusable unless the paraffin, silicone rubber, etc. that had entered the undercut grooves were completely removed.

The present invention eliminates the drawbacks of the prior art as described above, and
This invention provides an armature that can prevent commutator contamination with a simple configuration and a method for manufacturing the same. Examples thereof are shown in FIGS. 6a and 7b and 7a and 7b.

In the present invention, as shown in FIG. 6a, the commutator 2
A groove 24 having an appropriate width and depth is provided along the outer periphery of the groove s at a portion connected to the riser portion 2d. FIG. 6b is an enlarged view of this groove 24. The width W of the groove 24 is a width suitable for the O-ring 19 that fits into this groove, and the depth d is such that the lower surface of the groove 24 is continuous with the cut-up groove 2f. The size is such that it touches the bottom surface of the undercut groove 2e.

In addition, in FIG. 6a, the stepped portion formed on the side surface of the riser portion 2d opposite to the cut-up groove 2f is the commutator 2.
This is the hub part used to tighten and assemble the segments of the

In the armature of the present invention, the groove 24 is provided on the outer periphery of the commutator 2 as described above, and the O-ring 19 is inserted into the groove 24, so that the undercut groove 2e and the side surface of the riser portion 2d are formed. The grooves 2f are discontinuous. Therefore, Fig. 7 a, b
When the completed wire assembly is attached to the mold as shown in
It is pushed by the inner surface of the upper mold 11 through the neck of the commutator 2, and the side surface of the riser part 2d and the stepped part 12 of the lower mold 12 are pressed.
-1 is sandwiched between and pressed into close contact with the cavity 14
The resin is applied to the surface of the commutator 2 and the undercut groove 2.
The injected resin flows only to the armature winding, commutator neck, and outer periphery of the riser, and the resin flows into the surface of the commutator 2 and the undercut groove 2e. There is no longer any need to apply paraffin or silicone rubber to the surface of the commutator as in the past.
There is no need to remove paraffin or silicone rubber, which shortens the process, eliminates the use of auxiliary materials such as paraffin or silicone rubber, and prevents contamination of the commutator due to resin leakage during casting, improving product yield. There are great industrial benefits, such as the ability to significantly improve

[Brief explanation of drawings]

Figures 1a and b are a partially sectional plan view and side view of a conventional flat armature, and Figures 2a and b are a plan view and a side view of a completed wire assembly consisting of an armature winding and a commutator. A front view, FIGS. 3a and 3b are a sectional view showing the completed mold and wire assembly, and a plan view of the lower mold. FIGS. 4a and 4b are a plan view and a side view of a conventional armature commutator, and Fig. 5 is a detailed view showing a conventional armature casting method, Fig. 6 a, b is a side view and an enlarged view of a part of the commutator of the armature of the present invention, and Fig. 7 a, b is a mold and a FIG. 1 is a cross-sectional view showing a completed wire assembly of the armature of the present invention, and an enlarged cross-sectional view of a part thereof. 1-1, 1-2, 1-3 to 1-n... Armature winding, 2... Commutator, 2b... Small hole, 2s... Segment, 2d... Riser section, 2e... Undercut groove , 3...Rotor shaft, 4...Resin, 11...Upper mold, 12...Lower mold, 12-1...Step part, 12-2
... Lower cavity, 13 ... Injection hole, 14 ... Cavity,
15... Dowel pin, 16... Center pin, 17...
...Positioning pin, 18...Positioning mark, 19
...O-ring, 24...groove.

Claims (1)

[Claims] 1. In an armature formed by integrally fixing an armature winding and a commutator connected thereto with a resin, the commutator 2 has a terminal end of the armature winding on its outer periphery. A groove 24 for inserting an O-ring having a rectangular cross section is formed radially inward from the outer periphery in a portion in contact with the riser portion 2d that connects the riser portion 2d, and the bottom surface of this groove 24 is a cut-up groove formed on the side surface of the riser portion. An armature that is in contact with the bottom surface of the undercut groove 2e of the commutator 2 that is continuous with the groove 2f. 2. A groove 24 for inserting an O-ring is formed radially inward in the outer peripheral part of the commutator 2 in contact with the riser part 2d to which the end of the armature winding is connected. A step of forming the commutator 2 so as to be in contact with the bottom surface of the undercut groove 2e that is continuous with the groove, and inserting the armature winding and the commutator 2 into the upper mold 11 and the lower mold 12 of the mold. It is characterized by comprising the steps of inserting the O-ring 19 between the O-ring insertion groove 24 of the commutator 2 and the opposing side surface of the lower mold 12, and filling the mold with resin. A method of manufacturing an armature.