JPS6024657B2 - armature - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an armature whose shaft is double insulated.

Conventional techniques for fixing the armature shaft and the laminated core (rotor core) include providing a protrusion on the shaft, providing a groove on the surface of the center hole of the laminated core, wrapping an insulating sleeve around the shaft, or There are configurations in which the shaft is placed between the shaft and the surface of the central hole of the laminated core and are press-fitted, and configurations in which the shaft is directly inserted into the central hole in the laminated core and fixed with adhesive.

However, in these configurations, since the insulating layer is only an insulating sleeve or an adhesive layer, any dielectric breakdown that occurs in a part of that layer will easily spread to the entire scrap, and cause damage between the shaft and the laminated core. The insulation may be destroyed.

Furthermore, in the first conventional technique, the fixation between the shaft and the laminated core depends on the hardness of the protrusion on the shaft, the insulating sleeve, and the groove in the laminated core, and in the second conventional technique, it depends on the hardness of the adhesive. Because of this, high torque, vibration, and shock often cause dielectric breakdown due to the stress created between the shaft and the laminated core. Furthermore, in the first conventional technique, the shaft, the center hole of the laminated core, and the insulating sleeve must be machined, which increases manufacturing costs and requires strict tolerances for the dimensional accuracy of the machining process. Furthermore, in the second prior art, when providing uneven portions on the surface of the sea bream to prevent slippage or slippage between the shaft and the laminated iron core, it is also necessary to process the surface of the sea bream. Since such machining requires consumable tools, there is a risk that finishing accuracy will change in the case of repeated machining in mass production. In a configuration in which an unprocessed shaft is simply wrapped with an insulating sleeve and inserted directly into the center hole of the laminated core, the problem of slippage between the shaft and the laminated core and resulting dielectric breakdown occurs. The purpose of the present invention is to eliminate the difficulties of these conventional techniques and the extra costs associated with them, and to provide a new electrical appliance that makes dielectric breakdown less likely to occur between the armature shaft and the laminated core, and that improves the insulation effect. It is to provide a child.

Its purpose and features will become apparent by reference to the following description of the embodiments with reference to the accompanying drawings.

In the drawings, the illustrated armature 10 designed for a general-purpose electric motor includes a laminated iron core 11 having a plurality of windings 13, 13, . It consists of a shaft 17 that is fixed and extends outward on both sides of the laminated core 11 in the direction of the bag.

Each of the windings 13 is formed by winding an insulated wire into a plurality of grooves 12, 12, . . . formed in the laminated core 11 using a conventional method.

An insulating sleeve 18 made of an insulating material such as glass is inserted between the laminated core 11 and the shaft 17.
It is insulated from

The insulating sleeve 18 has a dimension that is greater than or equal to the length of the laminated core 11 in the ball direction and shorter than the length of the shaft 17, and is located between the laminated core 11 and the shaft 17 on its left and right sides. Both ends of the laminated core 11 are arranged to extend outwardly on both left and right sides in the axial direction of the laminated core 11, and this arrangement not only provides an insulation effect between the laminated core 11 and the shaft 17, but also improves the insulation effect between the laminated core 11 and the shaft 17. It is also intended to improve the insulation effect between the winding portion protruding from the iron core 11 in all directions of the shaft and the shaft 17. The longer the portion of the insulating sleeve 18 that extends outward on both left and right sides in all directions of the axis of the laminated core 11, the more reliable the insulating effect becomes. Between the shaft 17 and the self-insulating sleeve 18, an insulating adhesive such as room temperature curing silicone rubber is injected over the entire axial length of the insulating sleeve 18 to form a first insulating adhesive layer 19. The first insulating adhesive layer 19 fixes the shaft 17 and the insulating sleeve 18 together.

Further, an insulating adhesive such as room temperature curing silicone rubber is injected between the laminated core 11 and the insulating sleeve 18 over the entire axial length of the laminated core 11 to form a second insulating adhesive layer 20. The laminated core 11 and the insulating sleeve 18 are fixed together through the second insulating adhesive layer 201.
Therefore, the laminated core 11 and the shaft 17 are fixed to each other by the first and second insulating adhesive layers 19 and 20 with the insulating sleeve 18 interposed therebetween. Note that the first and second insulating adhesive layers 19 and 20 are attached to the laminated core 1.
1 and the insulating sleeve 18 and between the insulating sleeve 18 and the shaft 17. A commutator 15 is fixed to one side of the shaft 17 fixed to the laminated iron core 11, and each segment 14, 14, .
・Connect each of the above-mentioned windings 13 to respectively.

The commutator 15 is fixed to the shaft 17 with its side surface in contact with one end of the insulating sleeve 18. As a result, the shaft 17 on the side to which the commutator 15 is fixed
In this case, there is no exposed portion of the rattan 17 between the laminated core 11 and the commutator 15, and the insulation effect between the laminated core 11 and the shaft 17 is further improved. Therefore, in use, the laminated core 11 is rotated by the electromagnetic torque applied to each of the windings 13, and the other end of the shaft 17 fixed in the central hole 16 of the laminated core 11 is rotated. Power is extracted. A particularly significant advantage of the present invention is that it provides a more effective insulating layer than conventional structures.

Particularly when providing a single layer of conventional construction, it is now the case that dielectric breakdown within the material caused by certain causes can easily spread throughout the thickness of the material.
This is due to the fact that the source of the initial dielectric breakdown continues to affect the same material in the same way. However, in the structure according to the present invention, the laminated core 11 and the shaft 1
Due to the arrangement of two different materials in the three insulating layers 18, 19, 20 between 7 and 7, the possibility of dielectric breakdown is eliminated. In this way, a cause of dielectric breakdown in one of the three insulating layers has no effect on the adjacent insulating layer of different material. For example, if a dielectric breakdown of the polymeric insulating adhesive layer occurs due to deterioration in either of the insulating adhesive layers, it may spread rapidly throughout its thickness; The breakdown will not propagate through the insulating sleeve 18 as it is a different material and is not affected by the same conditions. On the other hand, the insulation sleeve 1
Even if a crack occurs in the insulation layer 8, the first and second insulating adhesive layers 19 and 20 are relatively elastic materials and can withstand breaking stress. This does not affect the adhesive layers 19, 20'. As mentioned above, the three-layer structure of the insulating sleeve and the insulating adhesive layer of the present invention and its effects are achieved by simply combining a plurality of insulating sleeves and insulating adhesive layers with mutual features. It brings about a qualitative change in insulation properties in terms of not only an increase in insulation properties, but also a guarantee of safety against dielectric breakdown due to the synergistic effect of the three-layer structure.

In a preferred embodiment, the insulating sleeve 18 is made of glass and the insulating adhesive is a rubber that cures at room temperature. An interesting fact in this particular example is that the dielectric strength of the glass itself is very high, for example under the Underwriters Laboratories' insulation requirements (UL).
Standards) etc. are more than met by the glass cylinder alone, and the insulating effect provided by the rubber is in fact only additional. A possible difficulty with this embodiment is the possibility that the glass may break. According to the invention, this difficulty is overcome by providing sufficiently thick and sufficiently elastic insulating adhesive layers 19, 20 on both sides of the insulating sleeve 18, so that the laminated core 11 and the shaft 17 Any stress that may occur between the two and which may break the glass is resolved by being absorbed by each insulating adhesive layer 19,20. For example, these stresses may be thermal due to the difference in the expansion value during heating of the glass cylinder compared to the value of expansion during heating between the metal laminated core 11 and the shaft 17, or 11 and the rattan 17 mentioned above. Another embodiment of the invention which also produces the aforementioned effects is where the insulating sleeve 18 is made of paper having sufficient thickness and dielectric strength to meet the electrical insulation requirements.

In that embodiment, the insulating sleeve was broken and surprised;
Since the bonding conditions need only be sufficient to bond the parts together, greater tolerances can be provided during manufacturing. In this way, the insulating sleeve
The insulating adhesive can be placed fairly loosely around 7 and injected with enough pressure to ensure that it fills all of the space within the two annular holes. Of course, other insulating materials may be selected as required. It may be desirable to vary the properties of these materials to meet specific requirements. For example, by applying a certain value of elastic energy to the insulating adhesive, it is possible to cause a certain amount of relative rotation between the laminated core 11 and the shaft 17 while the laminated core 11 is locked. . This can be used to reduce strain that can destroy gears in the output of tools and other equipment using electric motors. In still other embodiments, the insulating sleeve 18 may be paper or cardboard having a thickness sufficient to provide the required dielectric strength.

In this case, the insulating adhesive need only be sufficient to bond together the three parts of the armature structure. Regardless of the material chosen, the insulating sleeve 18 of the present invention is preferably a continuous cylinder.

Although several embodiments of the invention have been described and illustrated, it will be apparent to those skilled in the art that many changes and modifications can be made without departing from the scope of the invention.

[Brief explanation of drawings]

FIG. 1 is a plan view including a partial sectional view of an armature according to the present invention. 10... Armature, 11... Laminated core (
rotor core), 13...winding, 16...
- Central hole, 17... shaft, 18... insulating sleeve, 19... first insulating adhesive layer, 20...
...Second insulating adhesive layer.

Claims (1)

[Claims] 1. Consists of a laminated iron core having a plurality of windings and one central hole, and a shaft inserted and fixed into the central hole and extending outward on both sides in the axial direction of the laminated iron core. In the armature of the electric motor, an insulating sleeve made of an insulating material having a dimension greater than or equal to the axial length of the laminated core and shorter than the length of the shaft is inserted between the laminated core and the shaft; A first insulating adhesive layer is formed between the shaft and the insulating sleeve by arranging the left and right ends of the insulating sleeve so as to extend outwardly on both left and right sides in the axial direction of the laminated core, and forming a first insulating adhesive layer between the shaft and the insulating sleeve. A first insulating adhesive layer fixes the shaft and the insulating sleeve, a second insulating adhesive layer is formed between the laminated core and the insulating sleeve, and the second insulating adhesive layer connects the laminated An armature characterized in that an iron core and the above-mentioned insulating sleeve are firmly fixed. 2. The armature according to claim 1, wherein the insulating sleeve is a continuous cylindrical body. 3. The armature according to claims 1 and 2, wherein the insulating sleeve is made of a glass cylinder. 4. The armature according to claims 1 and 2, wherein the insulating sleeve is made of a paper cylinder.