JPH0227539B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a rotation transmission device for a small electric appliance such as a rotary cooker.

Conventional Structure and Problems In general, a small rotary cooker, such as an electric ice shaver, is equipped with a motor 2 inside a main body 1, as shown in FIG. 4, 5, the ice is transmitted to the output shaft 7 via the driven gear 6 to rotate the ice press plate 8.

Since this type of equipment is small, the drive source, motor 2, is a small permanent magnet rotor type synchronous motor, which has a simple structure, is small, and is inexpensive, as shown in Figure 2. This small permanent magnet rotor type synchronous motor 2 includes a stator 10, a drive coil 11 attached to the stator 10, and magnetic pole parts 12, 12.
A permanent magnet rotor 13 rotatably provided between
and a reversal prevention device (not shown).
The small permanent magnet rotor type synchronous motor 2 has magnetic pole parts 12,
By generating an alternating magnetic field in 12, the permanent magnet rotor 13
The machine starts itself by vibrating the rotor and increasing the vibration, but at the time of starting, the magnetic poles of the permanent magnet rotor 13 are opposed to the magnetic poles 12 of the stator 10, and the rotor is at a dead center position where no torque is generated. Because of this, the engine cannot be started even when a slight load is applied. Therefore, in conventional equipment that uses a small permanent magnet synchronous motor 2 as a drive source, consideration is given to ensuring a sufficiently large backlash between reduction gears so that no load is applied while the permanent magnet rotor 13 is near the dead center at the time of startup. However, when the engine is repeatedly stopped and started while applying a load, there is a problem that the load is compressed by the load, resulting in poor starting.

OBJECTS OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems and provide a rotation transmission device that does not cause starting failures.

Configuration of the Invention In order to achieve the above object, the rotation transmission device of the present invention has a rotation shaft supported movably along a guide groove between a drive gear and a driven gear that are rotatably supported within the device body. An elastic body is provided that biases the intermediate gear in a direction along the guide groove away from the driving gear and the driven gear, and during rotation transmission, the intermediate gear is biased by the force acting on each other between the gears. The gear moves along the guide groove to a position where it meshes with the drive gear and the driven gear on a pitch circle, and during non-rotational transmission, the intermediate gear moves along the guide groove with the urging force of the elastic body. It is constructed so that it can be moved to a position away from the engine within a range that does not disengage from the engine, which prevents the load from tightening the lock when the drive is stopped, and ensures reliable starting.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 3 to 5. In the figure, 14 is a drive gear, 1
Reference numeral 5 denotes a driven gear, and rotating shafts 16 and 17 are supported by the main body A of the apparatus by bearings 18 and 19, respectively. Reference numeral 20 denotes an intermediate gear, and both ends of its rotating shaft 21 are movably supported along guide grooves 22 provided in the main body A of the apparatus. The guide groove 22 is the intermediate gear 2
0 is the closest to the driving gear 14 and the driven gear 15 (on the right side in Figure 3), these gears mesh on a pitch circle, and even when the intermediate gear 20 is at the most distant position (on the left side in Figure 3), these gears mesh. These gears are arranged so that they do not mesh with each other. 23 is a coil spring interposed between the device main body A and both ends of the rotation shaft 21 of the intermediate gear 20, and the coil spring 23 moves the intermediate gear 20 along the guide groove 22 to the driving gear 14 and the driven gear 1.
5 (leftward in FIG. 3). Furthermore, the arrangement and rotation direction of each gear are determined by the forces F ₁ , F ₂ , F ₃ ,
The resultant force F of _F4 moves the rotating shaft 21 of the intermediate gear 20 to the third
In the figure, it is set to pull to the right.

Next, the operation of the above configuration will be explained. The direction of rotation is direction A, and when the rotation is transmitted, the above-mentioned resultant force F acts in the right direction, and the rotating shaft 21 moves to the right end of the guide groove 22 against the bias of the coil spring 23. Since the gears are provided so that they mesh with each other in pitch circles when they approach each other, rotation can be transmitted at the proper meshing position.

Furthermore, when the small permanent magnet synchronous motor that is the drive source stops, since it has a salient pole stator, the process until the magnet rotor stops with its magnetic poles facing the stator magnetic poles becomes vibratory. The rotating shaft 21 is moved to the left end of the guide groove 22 by the bias of the coil spring 23. Therefore, each gear 1
4, 15, and 20 are engaged on a pitch circle, and even if the backlash is tightened from the load side, the backlash is prevented by shifting to the left end of the guide groove 22 due to the bias of the coil spring 23 when the intermediate gear 20 stops rotating. This prevents the small permanent magnet synchronous motor from being loaded again at the dead center when restarting, and furthermore, as mentioned above, the guide grooves 22 are set to prevent the gears from disengaging even in this position. Can be restarted.

Effects of the Invention As explained above, according to the present invention, it is possible to prevent starting failures of a small permanent magnet synchronous motor, and also to make each gear take an appropriate meshing position when driving a load, thereby eliminating the conventional problem of simple backlash. It does not generate vibrations like a larger rotation transmission device.

[Brief explanation of drawings]

Figure 1 is a sectional view of an ice scraper equipped with a conventional rotation transmission device, Figure 2 is a plan view of the drive motor, and Figure 3 is a cross-sectional view of an ice scraper equipped with a conventional rotation transmission device.
Figures 5 through 5 show one embodiment of the present invention;
The figure is a plan view showing the operating principle of the rotation transmission device.
The figure is a sectional view of the rotation transmission device, and FIG. 5 is a sectional view of the main part of the guide groove. 14... Drive gear, 15... Driven gear, 20...
...Intermediate gear, 21... Rotating shaft, 22... Guide groove,
23...Coil spring (elastic body), A...Device main body,
F ₁ , F ₂ , F ₃ , F ₄ ... Forces acting on the gears.

Claims (1)

[Claims] 1. An intermediate gear whose rotating shaft is movably supported along a guide groove is interposed between a drive gear and a driven gear that are rotatably supported within the device body, and the intermediate gear is inserted into the guide groove. An elastic body is provided along the guide groove to urge it away from the driving gear and the driven gear, and during rotation transmission, the intermediate gear is moved along the guide groove into a pitch circle with the driving gear and the driven gear by the force acting between the gears. During non-rotational transmission, the intermediate gear is moved along the guide groove by the biasing force of the elastic body to a position where it is distanced from the driving gear and the driven gear within a range that does not disengage the gear. transmission device.