JPS5820218B2 - synchronous motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a synchronous motor, and more particularly to a so-called inductor-type small synchronous motor that uses a single-phase coil as an excitation coil.

In recent years, in this type of synchronous motor, an elastic member consisting of a stopper, a gear, a spring, etc. is inserted from above into the shaft provided on the magnetic pole plate, and a bearing plate is attached to the shaft from above the elastic member to prevent reverse rotation. Attempts are being made to automatically assemble the mechanical parts.

However, with the above-mentioned configuration, automatic assembly is easy, but when a force pushes the gear upward against the pushing force of the elastic member, the gear separates from the stopper, causing the stopper to rotate. Otherwise, the reverse rotation prevention function may be lost.

In particular, synchronous motors have the disadvantage that since the rotor moves upward during startup, the gear tends to move away from the stopper due to this movement.

It is an object of the present invention to address the above-mentioned drawbacks and to
To provide a synchronous motor which can reliably maintain a reverse rotation prevention function and which is easy to assemble automatically.

The gist of the present invention is that the gear and the stopper are provided with protrusions that maintain the engagement of the gear and the stopper even when the gear moves on the shaft.Hereinafter, one embodiment of the present invention will be described. will be described based on the drawings. A first magnetic pole plate 1 made of a steel plate is formed with a flat bottom plate 2 and upright side plates 3 and 4 facing each other so that the cross-sectional shape has a mouth shape.

The bottom plate 2 of the first magnetic pole plate 1 includes magnetic poles 5, 5a, 5b, 5c.
is formed.

The magnetic poles 5, 5a, 5b, and 5c are formed by cutting and raising the substantially central portion of the bottom plate 2.

A metal shaft 6 is installed at the center of the portion of the bottom plate 2 surrounded by the magnetic poles 5.5a, 5b, and 5c.

A bobbin 8 wound with a single-phase excitation coil 7 is fixed to the outer periphery of the magnetic poles 5.5a, sb, and 5c.

A thrust washer 9 is fitted onto the shaft 6.

The rotor 10 is formed from a cylindrical powder solidified magnetic material, for example, barum ferrite.

On the outer peripheral surface of the rotor 10, N magnetic poles and S magnetic poles are alternately magnetized at equal intervals.

A cam 11 and a first output pinion 12, which serve as a locking part for preventing reverse rotation, are provided on the upper center surface of the rotor 10.

The cam 11 and the first output pinion 12 are integrally molded from synthetic resin.

The second magnetic pole plate 13 provided above the bobbin 8 has a flat surface 1
4 and side plates 14a and 14b.

The second magnetic pole plate 13 includes magnetic poles 15 and 15a. 15b,
15c is formed by cutting and raising a part of the flat surface 14.

A shaft 16, 17, 18 is mounted on the flat surface 14.

The side plates 3 and 4 of the first magnetic pole plate 1 have a protrusion 19.1 in the middle part.
9a, 19b, 19c, and a stepped portion 20.20a at the end.
, 20b, 20c and caulking steps 21.21a, 2
1b and 21c are formed.

These protrusions 19, 19a, 19b, 19c and the stepped portion 20.2
After placing the second magnetic pole plate 13 on 0a, 20b, and 20c, the stepped portions 21 and 21a are crimped.

By crimping the portions 21b and 21c, the first magnetic pole plate 1 and the second magnetic pole plate 13 are integrated.

The excitation coil 7 and the bobbin 8 are connected to the side plate 3. of the first magnetic pole plate 1.
4. It is surrounded by the side plates 14a and 14b of the second magnetic pole plate 13, the flat bottom plate 2 of the first magnetic pole plate 1, and the flat surface 14 of the second magnetic pole plate 13, and is almost sealed.

When the first magnetic pole plate 1 and the second magnetic pole plate 13 are integrated,
Between magnetic poles 5.5a, sb, and 5c, magnetic pole 15.15
a, 15b, and 15c are located.

A hole 15d into which the rotor 10 can be inserted is formed inside the magnetic poles 15, 15a, 15b, and 15c.

If the first output pinion 12, cam 11 and rotor 10 are inserted from the upper end of the shaft 6, the rotor 10 will have magnetic poles 5, 5a, 5.
b, 5c and rotatably supported inside the magnetic poles 15.15a, 15b, 15c.

In a state where the rotor 10 is supported on the shaft 6, the cam 11
The height dimension of the rotor 10, the height dimension of the side plates 14a and 14b of the second magnetic pole plate 13, and the magnetic pole 5 are arranged so that the first output pinion 12 is located above the second magnetic pole plate 13.
, 5a.

5 b t 5 c dimensions, magnetic poles 15, 15a, 15b
.

Dimensions of 15c, protrusions 19, 19a, 19b, 1
The position of 9c and the positions of step portions 20, 20a, 20b, and 20c are determined.

A stopper 22 for preventing the rotor 10 from reversing is provided on the shaft 16.
A first gear 24 that meshes with the first output pinion 12 and a coiled push spring 28 are attached.

A protrusion 23 that engages with the cam 11 is integrally formed on the stopper 22 .

A second output pinion 25 is integrally formed with the first gear 24 .

The upper end of the second output pinion 25 has the second output pinion 2
A cylinder 27 having a diameter D2φ smaller than the root diameter D1φ of No. 5 is integrally formed.

A second gear 26 that meshes with the second output pinion 25 is located above the first output pinion 12 and is rotatably supported by the shaft 6.

A third output pinion 29 is integrally formed with the second gear 26 .

A third gear 30 that meshes with the third output pinion 29 is rotatably supported on the shaft 17.

A fourth output pinion 30a is integrally formed with the third gear 30.

A fourth gear 31 that meshes with the fourth output pinion 30a is rotatably supported on the shaft 18.

The fourth gear 31 has a shaft portion 31a and a fifth output pinion 31.
b is integrally formed.

A flat bearing plate 32 fixed to the upper ends of the side plates 3 and 4 of the first magnetic pole plate 1 has a bearing hole 34 for the shaft portion 31a, and a bearing hole 34 for the shaft portion 31a,
Bearing holes 35 and 36 for 6 and 17.

37 and a synthetic resin member 33 forming the shaft 39 of the output gear 38 are molded.
It is designed to mesh with the fifth output pinion.

When the bearing plate 32 is fixed to the first magnetic pole plate 1, the push spring 28
As a result, the first gear 24 and the stopper 22 are connected to the second magnetic pole plate 1.
3 so that it is pressed on top.

The stopper 22 rotates following the rotation of the first gear 24, and the magnetic pole 15 of the cam 11 or the second magnetic pole plate 13,
It locks onto the formed surfaces of 15a, 15b, and 15c.

In order for the stopper 22 to reliably rotate following the rotation of the first gear 24, the friction coefficient of the contact surface between the first gear 24 and the stopper 22 is determined by adjusting the friction coefficient between the stopper 22 and the stationary second magnetic pole plate. The coefficient of friction is made larger than that of the contact surface with 13.

In this embodiment, a washer 40 made of a material with a small coefficient of friction is interposed between the stopper 22 and the second magnetic pole plate 13.

This washer 40 has a size that is large enough to cover the uneven portion 41 that occurs when fixing (caulking) the shaft 16 to the second magnetic pole plate 13.

The outer diameter H2φ of the washer 40 is much smaller than the outer diameter H1φ of the stopper 22 (thereby, the outermost part of the contact area between the first gear 24 and the stopper 22 is
The distance from the center of the stopper 22 is set to be greater than the outermost portion of the contact portion between the stopper 22 and the second magnetic pole plate 13 .

The upper end of the shaft 39 is supported by a boss 43 formed on a device 42 such as a timer.

First output pinion 12, first gear 24, second output pinion 25, second gear 26, third output pinion 29, third gear 30, fourth output pinion 30a, fourth gear 3
The reduction gear group consisting of the first and fifth output pinions 31b and the output gear 38 and the stopper 22 are made of synthetic resin.

Terminals 44 and 45 for the excitation coil 7 are attached to the side plate 14a of the second magnetic pole plate 13.

The first gear 24, the second gear 26, the third gear 30, and the fourth gear 31 can move very slightly (up and down) in the axial direction of the shafts 6, 16, 17, and 18.

As shown in FIG. 4, the second gear 26 is configured to be movable on the shaft 6 by a gap 01.

As shown in FIGS. 6 and 7, the lower surface of the first gear 24 has protrusions 24a, 24b, and 24c, and the upper surface of the stopper 22 has a protrusion 22a.

22b and 22c are provided, respectively.

Protrusions 22a, 22b, 22c and protrusions 24a, 2
4b.

The height H of 24c is set to be larger than the gap G. The slopes of the protrusions 22a, 22b, 22c are gentler on the normal rotation direction side of the No. 1 gear 24 and steeper on the reverse rotation direction side, and the protrusions 24a, 24b.

The slope 24c is steep on the normal rotation direction side of the first gear 24 and gentle on the reverse rotation direction side.

Protrusions 22 a + 22 b, 22 c and protrusions 24
a.

The outermost parts of 24b and 24c are protrusions 22a and 22b located outward from the outer periphery of washer 40.

22c and the radial dimensions of the protrusions 24a, 24b, and 24c are set.

In the example shown in FIG. 7, the protrusion 22 extends to the outer peripheral end of the stopper 22.
a, 22b.

22c is extended.

Protrusions 22a, 22b, 22c and protrusions 24a, 24b
, 24c are at the same height. In the above configuration, terminals 44 and 45 are connected by an external power supply.
When the exciting coil 7 is excited through the magnetic poles 5, 5a, 5
b, 5c and magnetic poles 15, 15a.

15b and 15c are magnetized to the north pole or the south pole, and rotational force is applied to the rotor 10.

For example, when the rotor 10 rotates in the direction of arrow P in FIG. 3, the first gear 24 rotates in the direction of arrow Q in FIG. 3, and the stopper 22 rotates in the direction of arrow R in FIG. , the engagement with the cam 11 is lost.

Therefore, the rotor 10 continues to rotate in the direction of arrow P,
Transmits rotation to the reduction gear group.

In this case, after the stopper 22 is disengaged from the cam 11, it hits a portion of the second magnetic pole plate 13 and remains stationary.

However, since the direction of rotation of the rotor 10 is determined by the positive and negative waveforms of the current applied at the time of startup, the rotor 10 may rotate in the opposite direction to the direction of arrow P in FIG. 3.

In this case as well, the stopper 22 follows the first gear 24 and rotates in the direction opposite to the direction of the arrow Q in FIG.

Therefore, the rotor 10 is prevented from rotating in the direction opposite to the direction of arrow P in FIG.
It is returned in the direction of arrow P in the figure.

In this way, the rotor 10 always rotates in one direction, and the rotation is transmitted to the output gear 38 via the first gear 24, the second gear 26, the third gear 30, and the fourth gear 31. 0 When the rotor 10 is started, it moves by a distance corresponding to the gap G, and as a result of this movement, the second gear 26 and this second gear 26
The No. 1 gear 24 that is engaged with also moves.

Therefore, the stopper 22 moves in the direction away from the first gear 24, but the protrusion 22 a >
22b, 22c and protrusions 24a224b, 24
Since the height H of c is larger than the moving distance (gap G) of the No. 1 gear, the protrusions 22a and 22b are always
, 22c is a protrusion 24a.

24b and 24c, the first gear 24
The engaged state of the stopper 22 is maintained.

Therefore, even if the first gear 24 moves up and down, the first gear 24 and the stopper 22 are always held together, and the reverse rotation prevention function can be reliably achieved.

In this embodiment, as described above, the first gear 24 rotates while vibrating up and down, so even if a foreign object gets caught in the teeth of the second gear 26 and the third pinion 29, the Because it rotates while constantly removing foreign matter, there are almost no breakdowns.

Furthermore, in this embodiment, the protrusions 22a and 22b.

22c or the outermost part of the protrusions 24a, 24b, 24c is set to be located outward from the outer periphery of the thrust washer 40, so that the friction torque between the first gear 24 and the stopper 22 is But stopper 2
However, the friction torque between the first gear 24 and the second magnetic pole plate 13 is larger than that of the second magnetic pole plate 13, so that the stopper 22 follows the rotation of the first gear 24 and rotates more reliably and more smoothly.

Furthermore, in this embodiment, all the parts can be stacked in order on the first magnetic pole plate 1, and the frictional force between the first gear 24 and the stopper 22 can be easily and constantly maintained by the push spring 28. As a result, it is possible to realize a phase-moving assembly with extremely low G, with very low occurrence of defective products.

In this embodiment, the stopper 22 and the thrust washer 40 are separate, but they may be integrated as shown in FIG. 11.

In this case, it is preferable that the material of the stopper 22 has a small surface friction coefficient and does not become large under any usage conditions.

As described above, according to the present invention, it is possible to replace a synchronous motor that can reliably maintain the reverse rotation prevention function and that can be easily automatically assembled.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing an embodiment of the present invention, Fig. 2 is a partially sectional side view showing an embodiment of the invention during assembly, and Fig. 3 is an exploded perspective view showing an embodiment of the invention. A top view of the embodiment with the bearing plate removed; FIG. 4 is a detailed explanatory diagram of the present invention;
5 is an enlarged sectional view of the main part of FIG. 1, FIGS. 6 and 7 are enlarged perspective views of the main part of FIG. 1, and FIGS. 8 to 10 are schematic diagrams showing the operation of the main part of the present invention, FIG. 11 is a sectional view of a main part showing the true flow side of the present invention. 1...First magnetic pole plate, 7...Exciting coil, 10...Rotor, 11...Cam, 1
3...Second magnetic pole plate, 22...Stopper, 23...Protrusion, 24...First gear, 22a, 22b, 22cm protrusion, 24a,
24b, 24c...Protrusion, 28...
Push spring, 40... Thrust washer.

Claims (1)

[Claims] 1. A single-phase excitation coil, a first magnetic pole plate having a magnetic pole magnetically coupled to one end surface of the coil, and a magnetic pole magnetically coupled to the other end surface of the coil. a second magnetic pole plate having a rotor, a rotor that is rotated by the magnetic field of the respective magnetic poles, a group of reduction gears that decelerates the rotation of the rotor and outputs it to the outside, and a rotor that rotates the rotor in only one direction. A stopper for preventing reverse rotation, and a cam that is engaged with the stopper and moves together with the rotor, and one gear of the reduction gear group and the stopper are connected to the second magnetic pole plate by an elastic member. The rotor is configured to rotate until the stopper engages with a locking portion provided on the cam in accordance with the rotation of the gear, when the rotor rotates. and the reduction gear group is allowed to move upward, and a plurality of protrusions are provided on both surfaces where the gear and the stopper come into contact, and the height of the protrusions is adjusted to the height of the rotor and the reduction gear group. A synchronous motor characterized by being set larger than the travel distance. 2. The synchronous motor according to claim 1, wherein the protrusion provided on the stopper extends in a radial direction of the stopper to an outer peripheral end of the stopper. 3. The outermost part of the stopper that contacts the gear is set to be further away from the center of the stopper than the outermost part of the stopper that contacts the second magnetic pole plate. Synchronous motor 04 according to claim 1, characterized in that a plurality of protrusions are provided on both surfaces in contact with the gear and the stopper, and the slope of the protrusion provided on the gear side is set to The normal rotation direction side of the gear is loose and the reverse rotation direction side is steep, and the slope of the protrusion provided on the stopper side is configured to have a steep slope on the normal rotation direction side of the gear and a gentle slope on the reverse rotation direction side. A synchronous motor according to claim 1, characterized in that: