JPS5840756Y2 - rotating electric machine - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a rotating electric machine having a frame in which a stator is molded from plastic.

This type of small electric motor as a rotating electric machine is used in household electrical equipment that requires moisture resistance, such as bathroom ventilation fans.

Incidentally, in this type of electric motor, a method is generally adopted in which the bearing bracket is fixed to the frame by press-fitting.

At this time, in order to ensure that the bearing bracket did not come off, a plurality of locking claws were formed on the periphery of the bracket, and these were designed to make elastic contact by biting into the inside of the end of the frame.
There were the following problems.

That is, when the bearing bracket was press-fitted, the inner surface of the frame was scraped, and the scraps fell into the frame.

The inner surface of the frame is scraped off, causing the bearing bracket to become misaligned, which in turn causes the rotor to become misaligned with respect to the stator.

In addition, the locking claws of the bearing bracket are formed by cutting and bending, but it is difficult to obtain high elastic deformation by increasing the length of the cut due to the strength of the material. The followability is low, and therefore, at high temperatures, the coefficient of linear expansion of the synthetic resin frame is greater than that of the bearing bracket, so the contact force of the locking pawl of the bearing bracket, which is in elastic contact with the inside edge of the frame, decreases. However, there was a problem in that the bearing bracket easily fell off the frame.

The present invention was developed in view of the above circumstances, and its purpose is to prevent the shavings from falling directly into the frame even if the frame is scraped by inserting the bearing bracket, and to prevent the bearing bracket from being misaligned. There is no risk of this occurring, and the bearing bracket can be reliably prevented from coming off even at high temperatures.

Provides rotating electric machines.

An embodiment in which the present invention is applied to an electric motor will be described below based on the drawings.

1 is a stator consisting of a winding 3 wound around an iron core 2, which is molded with plastic such as unsaturated polyester resin mixed with calcium carbonate, glass fiber, etc.
This constitutes a frame 4.

An annular groove 5 is formed on both end surfaces of the frame 4, and the inner peripheral surface 5a on the outer edge side is used for centering, and the inner peripheral surface 5b on the inner edge side is used for preventing removal.

6 is a rotor disposed within the frame 4, which is connected to the iron core 7.
The rotary shaft 8 is fixed by press-fitting.

Reference numerals 9 and 10 denote bearing brackets attached to both ends of the frame 4, which are formed of a steel plate or the like into a substantially disc shape and have buttons, and their outer peripheral edges are curved into a substantially U-shape.

The corner portion curved into a substantially U-shape is used as a centering portion 11 that is fitted into the inner circumferential surface 5a on the outer edge side of the annular groove 5, and the portion folded inward from this centering portion 11 is a split groove. 12, a plurality of locking pawls 13 are formed in sections, and these are used as a retaining portion 14 that is fitted into the inner circumferential surface 5b on the inner edge side of the annular groove 5.

Therefore, the retaining portion 14 is formed continuously on the centering portion 11 by bending.

The inner diameter of the retaining portion 14 is the inner circumferential surface 5 on the inner edge side of the annular groove 5.
It is set slightly smaller than the outer diameter dimension of b.

Reference numerals 15 and 15 designate caps, each of which has a plurality of claw pieces 15a formed on its peripheral edge, and through-holes 9a and 10a corresponding to the claw pieces 15a are formed in the bearing platen 9 and 10.

And each cap 15.15 each bearing platen) 9t
Each cap 15.15 is attached to each bearing bracket 9.15 by bending inward the claw pieces 15a, 15a protruding from the through holes 9a, 10a against the lO. It is installed on io.

16 is each bearing platen) 9, 10 has a holding plate spring 17
18 is an oil-retaining member housed around the bearing 16, and 19 and 20 are collars and oil draining members fitted onto the rotating shaft 8.

Then, the rotor 6 is placed in the frame 4, the rotating shaft 8 is inserted and supported in the bearing 16, and the bearing platen 9 is installed.
, 10 are arranged at both ends of the frame 40, and their outer peripheral edge portions are press-fitted into the annular groove 5.

During this press-fitting process, the locking pawl 13 of each bearing bracket 9, 10 slides on the inner circumferential surface 5b of the annular groove 5 on the inner edge side while elastically deforming so that the tip 3a is oriented in the anti-insertion direction. The insertion is completed when it reaches a dead end.

In this way, the tip 13a of the locking pawl 13 elastically contacts the inner peripheral surface 5b on the inner edge side of the annular groove 5 in a state oriented in the anti-insertion direction, so that the bearing bracket 9, 100
It is prevented from coming out.

That is, when a force is applied to the bearing platen (9, 10) in the direction opposite to insertion, the tip 13 of the locking pawl 13 responds to the force.
Since the portion a strongly bites into the inner peripheral surface 5b of the annular groove 5, it is possible to reliably prevent the bearing brackets 9, 100 from coming off.

Furthermore, even if the frame 4 and bearing brackets 9 and 10 are heated to high temperatures due to Joule heat generated from eddy currents generated by the motor during operation, the coefficient of linear expansion of the frame 4 is greater than that of the bearing platen. Therefore, since the outer diameter of the inner circumferential surface 5b of the annular groove 5 that is in contact with the inner edge side of the annular groove 5 is larger than that of the inner diameter of the retaining part 14, the tip 13a of the locking claw 13 is It bites more strongly into the inner circumferential surface 5b on the inner edge side, and the degree of engagement between the two becomes firmer, thereby making it even more reliable to prevent the bearing platen (9, 10) from coming out.

Now, in the process of press-fitting the bearing platen 9, 10 into the frame 4, the tip 13a of the locking pawl 13 is
is inserted by sliding on the inner circumferential surface 5b on the inner edge side of the annular groove 5, so the inner circumferential surface 5b on the inner edge side may be scraped by the tip 13a of the locking pawl 13; The debris remains within the annular groove 5 and does not fall into the frame 4.

Therefore, the shavings in the annular groove 5 can be easily removed by suctioning with a vacuum suction device or the like.

On the other hand, the positions of the bearing brackets 9 and 10 are determined by the fitting between the inner circumferential surface 5a on the outer edge side of the annular groove 5 and the centering part 11, so that Even if the surface 5b is shaved, the bearing platen) 9, 10
There is no deviation at all in the 0 position, therefore, the rotor 6 is connected to the stator 1.
It can be supported at an accurate centering position.

Note that the present invention is not limited to the above-mentioned embodiments, but can be applied to rotating electric machines in general.

As explained above, the present invention has an annular groove partially formed on the end face of the frame, and a centering part that fits on the inner circumferential surface on the outer edge side of the annular groove on the bearing bracket, and a centering part that fits on the inner circumferential surface on the inner edge side of the annular groove in the anti-insertion direction. Since the structure is such that the locking pawl is provided to make elastic contact with the bearing bracket, even if the inner peripheral surface of the annular groove is scraped by the locking pawl that slides elastically on the annular groove when the bearing bracket is installed, the bearing There is no risk of misalignment of the bunocket, and since the shavings remain in the annular groove, they can be reliably prevented from falling into the frame, and the temperature of the rotating electric machine will rise due to the heat generated during operation. However, since the frame has a larger coefficient of linear expansion than the bearing bracket, the large elongation of the frame causes the locking pawl to bite into the inner peripheral surface of the annular groove more strongly, preventing the bearing bracket from coming out. The effect can be achieved more reliably.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which FIG. 1 is an overall vertical sectional view of the electric motor, and FIG. 2 is an enlarged perspective view of the main part with a portion cut away. In the drawing, 1 is a stator, 4 is a frame, 5 is an annular groove, and 5a
5b is an inner peripheral surface on the outer edge side, 9 and 10 are bearing brackets, 11 is a centering portion, 12 is a split groove, 13 is a locking pawl, 14 is a retaining portion, and 15 is a cap.

Claims (1)

[Scope of utility model registration request] A frame comprising a stator molded from plastic and a bearing bracket for supporting a rotor inserted from an end of the frame, wherein an annular groove is formed at the end of the frame. Along with forming
A centering part that is inserted into the annular groove of the bracket and fits on the inner circumferential surface on the outer edge side of the annular groove, and a centering part that is continuously formed in this centering part and has a tip on the inner circumferential surface on the inner edge side of the annular groove. A rotating electric machine characterized by forming a retaining portion having a plurality of locking claws that come into elastic contact while oriented in a counter-insertion direction.