JPH036146Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field of the Invention The present invention relates to a reverse rotation prevention structure for a small electric motor.

Conventional technology In an inductor type small electric motor without shearing, the direction of rotation is not determined, so it is necessary to restrict rotation in one direction. As a rotation restriction method, there is a method of restricting the rotation by tooth profile, a method of regulating the rotor or stator poles, etc. Although various methods are well known, such as methods for regulating the amount of water, the method of regulating using a mechanical lever is particularly widely adopted because the regulation is reliable and the mechanism is simple.

As shown in FIG. 1, this lever-type regulation system is based on a stopper 3 that is integrally provided on the shaft of a rotor 2 that is rotatably incorporated into a case frame 1.
, a rotating body that meshes with the pinion of the rotor 2, that is, a reverse rotation preventive body, that is, a reverse rotation prevention lever 6, which is frictionally and slidably coupled to the shaft of the first wheel 4, and a stopper wall that is formed protruding from the case frame 1. 7 as the main members.

According to this regulation system, when the rotor 2 rotates forward clockwise, the anti-reverse lever 6 is frictionally interlocked with the first wheel 4 and rotates counterclockwise, and the tip of the anti-reverse lever 6 rotates counterclockwise. The lever 6a is locked to the stopper wall 7. Therefore, there is no contact interference between the reverse rotation prevention lever 6 and the stopper member 3, and the rotor 2 continues to rotate in the normal rotation direction.

On the other hand, when the rotor 2 starts to reverse, the stopper 3 rotates counterclockwise and the anti-reverse lever 6 rotates clockwise, so that the stopper piece 3a of the stopper 3 contacts the contact portion 6b of the anti-reverse lever 6. The rotation of the rotor 2 is corrected in the forward and reverse directions due to the impact reaction.

However, when starting rotor 2,
Since the direction of the stopper piece 3a of the stopper 3 is not regulated in a constant manner and the stopper piece 3a faces in an arbitrary direction, the stopper piece 3a does not always meet the contact portion 6b initially due to the rotation of the rotor 2. As shown in FIG. 2, the shoulder 6c of the reversal prevention lever 6 may come into sliding contact with the base outer circumference 3b of the stopper 3, or as shown in FIG. 3, the tip of the stopper piece 3a may is the shoulder part 6 of the reverse prevention lever 6
A case may occur in which the aforementioned stopper piece 3a and the abutment portion 6b first come into contact after sliding contact with the side end surface of the stopper piece 3a.

At this time, a large load is applied to the rotor 2 due to the sliding contact between the stopper 3 and the anti-reverse lever 6.
In extreme cases, there is a problem that the rotation of the rotor 2 stops during this sliding contact, resulting in a problem that the margin for the rotor torque is reduced.

Purpose of the invention Therefore, the purpose of the present invention is to provide a reverse rotation prevention structure for a small electric motor that can reliably correct forward rotation of the rotor without applying an excessive load to the rotor when the rotor is started in reverse rotation. Our goal is to provide the following.

Summary of the invention Therefore, the present invention forms a stopper piece on the stopper, for example, in a tapered shape, and forms a notch relief part on the end face of the stopper side of the reversal prevention lever as a reversal prevention body, so that the stopper piece and the reversal prevention lever can be connected to each other. This reduces sliding contact and interference between the rotor and the rotor, making it possible to reliably correct normal rotation of the rotor.

Configuration of the invention Hereinafter, the configuration of the invention will be specifically explained based on the drawings.

As shown in FIG. 4, the reversal prevention structure of the present invention, like the conventional structure, includes a stopper 3 integrally fixed to the rotor 2 and a first wheel 4 as a rotating body.
A reversal prevention lever 6 as a reversal prevention body, which is frictionally and slidably coupled to the reversal prevention lever 6, etc., is provided, and the same members as those in the conventional structure are given the same reference numerals and their explanations will be omitted.

In FIG. 4, a holding member 8 is formed to protrude from the case frame 1 within the rotation area of the anti-reverse lever 6. As shown in FIG. The tip position of this holding member 8 is the fifth
As shown in the figure, when the tip lever portion 6a of the reverse prevention lever 6 is in contact with the tip portion of the holding member 8,
The stopper 3 is set at a position where a clearance c is formed between the base outer peripheral portion 3b and the shoulder portion 6c of the anti-reverse lever. The stopper piece 3a is formed, for example, in a tapered shape, and the stopper side end surface of the reverse prevention lever 6 has, for example, a substantially semicircular notch relief part in order to avoid interference with the stopper piece 3a. 9 is formed. The radius of curvature of this cutout relief portion 9 is determined by considering the rotational speed of the stopper 3 and the reverse prevention lever 6, even when the stopper piece 3a is rotating along the end surface of the stopper side of the reverse prevention lever 6. , the stopper piece 3a is designed to a value such that it does not come into contact with the end surface on the stopper side.

Function of the invention Next, the function of the reversal prevention structure of the invention will be explained.

First, when the rotor 2 starts rotating in the forward direction, the rotor 2 rotates at the stopper 3 as in the case of the conventional structure.
It continues to rotate smoothly without being subjected to sliding contact load.

On the other hand, when the rotor 2 starts to reverse, the stopper 3 rotates counterclockwise and the anti-reverse lever 6 rotates clockwise, and the tip lever portion 6a of the anti-reverse lever 6 is locked with the holding member 8. , rotation of the reverse rotation prevention lever 6 is prevented. At this time,,
As shown in FIG. 5, the base outer peripheral portion 3b of the stopper 3
and a clearance c between the shoulder 6c of the reverse prevention lever 6.
When the anti-reverse lever 6 is in a state where it is waiting for collision with the stopper piece 3a, there is no sliding contact between the stopper 3 and the anti-reverse lever 6, and the collision occurs directly with the stopper piece 3a. Collision with the contact portion 6b occurs, and the forward rotation of the rotor 2 is corrected in a state where no frictional load is applied.

Further, as shown in FIG. 4, when the rotor 2 is started in reverse rotation, the tip of the stopper piece 3a is connected to the reverse rotation prevention lever 6 due to the relationship with the starting position of the stopper piece 3a.
When facing the side end surface of the reverse prevention lever 6
Since the notch relief portion 9 is formed in the stopper piece 3a, the stopper piece 3a rotates without slidingly contacting the side end surface of the reverse prevention lever 6. Thereafter, when the rotor 2 rotates approximately one revolution, the stopper piece 3a and the contact portion 6b immediately come into contact with each other. As a result, the rotation of the rotor 2 is caused by the rotation of the rotor 2 and the reverse rotation prevention lever 6.
The rotation will be corrected in the forward direction without any contact load.

Although instantaneous contact between the stopper piece 3a and the shoulder 6c is unavoidable, the pole arrangement is such that the motor torque in the positive direction is large in that phase of rotation. This frictional load does not pose a practical problem, and the probability of this occurring is extremely low.

Modified Example of the Invention In the above-described embodiment, the stopper 3 is provided integrally with the rotor 2, and the reversal prevention lever 6 is provided on the first wheel 4, but this is not necessarily the case. For example, the stopper 3 It is also possible to provide the lever integrally with a desired gear of the wheel train disposed between the rotor 2 and the motor output shaft, and to provide the reverse rotation preventive lever with the gear one stage subsequent thereto.

Effects of the invention In the reversal prevention structure of the present invention, a cutout relief part is provided on the end face of the stopper side of the reversal prevention body, and when the rotor is reversed, the stopper piece remains in contact until the collision part and the stopper piece collide. The stopper piece is configured to be able to rotate through the notch relief portion without contacting the inside, and the stopper piece is formed to gradually taper from the outer circumferential side of the stopper, so that when the rotor starts to rotate in reverse, the contact portion of the reverse rotation preventive body Until the stopper piece collides with the stopper piece, for example, even if the end face of the anti-reverse body and the stopper piece face each other, the stopper piece rotates and passes through the notch relief portion without coming into contact with the anti-reverse body. Torque loss due to frictional sliding contact between the anti-reverse body and the stopper can be effectively avoided, and adverse effects due to an increase in the torque load on the rotor caused by this frictional sliding contact can be reliably prevented.

[Brief explanation of the drawing]

Figure 1 is a plan view of essential parts showing the conventional reversal prevention structure of a small electric motor, Figures 2 and 3 are plan views showing the operation of Figure 1, and Figure 4 is the reversal prevention structure of the small electric motor of the present invention. 5 is a plan view of the main part showing the 4th
FIG. 3 is a plan view showing a locked state of the anti-reverse lever and the holding member in the structure shown in FIG. DESCRIPTION OF SYMBOLS 1... Case frame body, 2... Rotor, 3... Stopper, 3a... Stopper piece, 4... Number one wheel, 6... Reversal prevention lever, 6b... Collision part, 9... Notch escape part.

Claims (1)

[Scope of utility model registration request] a stopper that rotates with the rotation of the rotor and has a stopper piece formed protruding from the outer periphery of the stopper; a rotating body that rotates in response to the rotation of the rotor; A reverse rotation preventive body is provided, which moves out of the rotation locus of the stopper piece during normal rotation, and enters into the rotation locus of the stopper piece when the rotor rotates in reverse, and collides with the stopper piece at its collision portion. , the stopper piece is formed to be tapered gradually from the outer circumferential side of the stopper, and is provided with a cutout relief part on the end face of the stopper side of the reversal prevention body, so that when the rotor reverses rotation, the contact part and the stopper piece are formed. A reverse rotation prevention structure for a small electric motor, characterized in that the stopper piece can rotate and pass through the notch relief portion without contacting the inside of the cutout relief portion until the two collide with each other.