JPS6111974Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a synchronous motor, and more particularly to an improvement in the bearing structure of a rotor rotating shaft.

In a conventional synchronous motor, a rotor rotating shaft is supported by a bearing member fitted into a stator member. The outline of a conventional synchronous motor can be explained with reference to Fig. 1.
A housing member 1 is formed of a magnetic material such as iron into a cylindrical shape with a bottom, and a plurality of first stators 2 formed by cutting a part of the housing member 1 long in the radial direction are located on the same circumference. It is erected. A bearing member 3 molded from a synthetic resin material is fitted into the center of the housing member 1 . Further, a plate member 4 formed of a magnetic material and having a substantially disk shape is assembled into the opening of the housing member 1. The plate member 4 has a plurality of second stators 5 cut and raised on the same circumference as the first stator 2 and located between them. A bearing member 6 is fitted into the center of the plate member 4 with its axis aligned with the bearing member 3. An electromagnetic coil 7 is disposed inside the housing member 1, and the first stator 2 and the second stator 5 pass through the center hole of a coil bobbin 8 formed of synthetic resin of the electromagnetic coil 7. A rotor 9 is disposed in an internal space made up of a group of stators. The rotor 9 is constructed by fixing a magnet 12 around a mounting member 11 made of synthetic resin into which a rotating shaft 10 is insert-molded. The magnet 12 is formed into a ring shape, and a large number of north and south poles are alternately magnetized around the circumference. The rotating shaft 10 is supported at its lower end by a bearing member 3 and by its upper end by a bearing member 6, respectively. According to the conventional synchronous motor configured in this way, parts of the bearing members 3 and 6 are exposed to the outside from the housing member 1 and the plate member 4, respectively. Care must be taken when handling, and consideration must also be given to preventing them from falling off. Furthermore, when assembling the motor, not only is it necessary to be very careful when fitting the motor, but poor fitting can also cause damage to the rotating shaft.
0 is eccentric, which causes problems such as noise and inability to rotate. Furthermore, under high temperature conditions, cracks may occur in the gate or weld portion of the bearing member, or dimensional changes may occur. Furthermore, due to contraction of the bearing member, rotation occurs only between the bearing member and the housing member, which places a load on the rotor and causes the motor to stop.

In view of these circumstances, the present invention provides a synchronous motor that reduces the number of bearing parts and assembly processes, eliminates protrusions from the housing, makes the entire motor thinner, and is highly reliable even under high-temperature conditions. . A synchronous motor according to the present invention that achieves this purpose has a coil bobbin of an electromagnetic coil formed with a bottom that closes one of its center holes, and a shaft hole that supports one end of the rotating shaft of the rotor at the center of the bottom wall. It is characterized by the provision of.

Hereinafter, the present invention will be explained in detail with reference to embodiments shown in the drawings. FIGS. 2 and 3 show an embodiment of the synchronous motor according to the present invention, and the same parts as those of the conventional synchronous motor shown in FIG. 1 are given the same reference numerals and their explanations will be omitted.

The housing member 20 of the synchronous motor shown as an example is formed of a magnetic material such as iron into a cylindrical shape with a bottom, as in the conventional case, and a plurality of pieces are formed by cutting a part of the bottom part long in the radial direction. the first stator 21 of
are placed upright on the same circumference. However, at the center of the bottom of the housing member 20, there is no hole for inserting the bearing member. The electromagnetic coil 30 built into the housing member 20 includes a coil bobbin 31 and a coil 32 made of synthetic resin.
The coil bobbin 31 is molded from a synthetic resin having wear-resistant and heat-resistant properties, and includes a bottomed cylindrical body 33, a disk-shaped flange 34 integrally formed on the top and bottom of the body 33, 35 and a terminal mounting portion 36 connected to a part of the periphery of the lower flange portion 35 via a thin connection portion. Terminal mounting part 3
6 is provided with terminals 37 to which both ends of the coil 32 are respectively connected. Further, a bottom wall 38 is provided on the lower flange portion 35 side of the coil bobbin 31 to close the bottom of the center hole of the body portion 33, and around this bottom wall, which is slightly thicker than the flange portion, , a plurality of guide holes are opened, through which the first stator 5 and the second stator 21 pass, respectively. Further, a blind shaft hole 39 that opens into the center hole is provided in the bottom wall 38 at the center of these guide hole groups, and this shaft hole 39
When the constituent members are assembled, the axis of the shaft hole of the bearing member 6 inserted into the plate 4 coincides with its axis, and the diameter of the hole is slightly larger than the shaft diameter of the rotating shaft 10 of the rotor 9. However, the rotor rotating shaft 10
is supported at its lower end by the shaft hole 39 and by the bearing member 6 at its upper end. It goes without saying that the plate 4 and rotor 9 are the same as those used in the prior art.

According to the synchronous motor configured as above,
Since the bottom wall 38 that supports the lower end of the rotor rotating shaft 10 is formed integrally with the coil bobbin of the electromagnetic coil 30, the conventional step of fitting the bearing member to the housing member 20 is not necessary. Although a process of fitting the bearing member 6 onto the plate 4 is necessary, since the plate 4 is simply disk-shaped, the process is simple and can be fitted with great precision.

As explained in detail above, according to the present invention, the number of bearing members is reduced by one compared to conventional synchronous motors, and the process of attaching a bearing member to a housing member with a relatively complicated shape is also unnecessary. , a reduction in the number of parts and assembly process is achieved. Further, since the process of attaching a bearing member to a housing member having a relatively complicated shape is eliminated, problems such as poor fitting or eccentricity of the shaft are eliminated, and a highly reliable synchronous motor can be obtained. Furthermore, unlike conventional synchronous motors, the end face of the bearing member is not exposed from the bottom of the housing member, allowing the motor to be made thinner, and also easing the specification conditions of equipment to which this motor is attached. . Furthermore, as with conventional synchronous motors, under high temperature conditions, the shape of the bearing member may change, causing problems in supporting the rotating shaft or causing the bearing member itself to rotate. The practical effects are extremely large, such as completely eradicating other inconveniences.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a conventional synchronous motor, FIG. 2 is a longitudinal sectional view showing an embodiment of the synchronous motor according to the present invention, and FIG. 3 is an exploded perspective view thereof. 1, 20... Housing member, 2, 21... First stator, 3... Bearing member, 4... Plate,
5... Second stator, 6... Bearing member, 7, 30
... Electromagnetic coil, 8, 31 ... Coil bobbin, 9
... Rotor, 10 ... Rotating shaft, 11 ... Magnet mounting member, 12 ... Magnet, 32 ... Coil, 33 ... Body part, 34, 35 ... Flange part,
36...Terminal mounting portion, 37...Terminal, 38...Bottom wall, 39...Shaft hole.

Claims (1)

[Scope of utility model registration request] It is formed from a magnetic material such as iron into a cylindrical shape with a bottom,
A housing member in which a plurality of first stators are erected on the same circumference, and a magnetic body in which a plurality of second stators are fixed to an opening of the housing member and are located between the first stators. a plate member, an electromagnetic coil assembled into a housing member such that the first and second stator groups pass through a center hole, and a rotor that rotates in the internal space of the first and second stator groups. In the synchronous motor, one of the center holes of the coil bobbin of the electromagnetic coil is closed by a bottom wall, and the bottom wall has a plurality of guide holes through which the first and second stator groups pass. A shaft hole is provided at the center of these guide holes and is located on the same circumference, and the rotating shaft of the rotor is supported by this shaft hole and a bearing member fitted to the plate member. A synchronous motor characterized by: