JPH028521Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Field of Application) The present invention relates to a flat electric motor, and for example, to a support structure for a bearing that supports a rotor of a thin hybrid stepping motor.

(Prior Art) As shown in FIG. 1, in a conventional electric motor such as a thin hybrid stepping motor, bearings 3, 3, which rotatably support a rotating shaft 2 of a rotor 1, sandwich a stator 4 between them. A structure in which it was held by frames 5, 5 was adopted. A stepped shaft member is used on the rotating shaft 2 of the rotor 1 in order to position the bearings 3, 3. Further, for example, as described in Japanese Patent Publication No. 50-31245, a structure was adopted in which a spacer was fitted to the rotating shaft of the rotor in order to position a bearing.

(Problems to be solved by the invention) The conventional structure using a stepped shaft member for the rotating shaft requires processing time and is expensive, and the structure in which a spacer is fitted requires a large number of parts and is expensive. Along with this, the thickness of the rotating shaft in the axial direction increased, causing problems in flattening the shaft.

The present invention was developed in view of the above-mentioned problems, and does not use a stepped shaft member or a spacer on the rotating shaft of the rotor. The present invention provides a flat electric motor such as a hybrid stepping motor that uses a shaft and is flat and inexpensive.

[Structure of the idea]

(Means for Solving the Problems) The flat electric motor of the present invention includes a stator, a rotor rotatably disposed within the stator and having a rotating shaft, and a rotor that holds the stator and has a rotating shaft. A frame is provided with a pair of bearings spaced apart from each other to rotatably support the rotating shaft, the rotating shaft is formed to have the same diameter over its entire length, and each of the pair of bearings has an inner ring and a frame connected to the inner ring via a ball. Consists of a fitted outer ring,
The rotor is characterized in that an annular protrusion is formed at the center of both sides of the rotor at a position recessed from the outer peripheral edge of the rotor and has an abutment surface for the end surface of the inner ring of each bearing.

(Function) When assembling the flat electric motor of the present invention,
When the bearing is fitted onto the rotating shaft of the rotor, the end surface of the inner ring comes into contact with the abutment surface of the annular projection formed at a position recessed from the outer peripheral edge of the rotor, forming a positioning step on the rotating shaft. There is no need for such machining of the rotating shaft, and there is no need to use other parts such as spacers, and the bearings are individually positioned and configured to be flat overall.

(Embodiment) The configuration of an embodiment of the present invention will be explained with reference to FIG.

10 is a rotor, which includes a disk-shaped permanent magnet 11 and a disk-shaped rotor core 1 sandwiching the permanent magnet 11.
A rotary shaft 13 is fixed through the center of the permanent magnet 11 and the rotor cores 12, 12. The rotating shaft 13 is formed to have the same diameter over its entire length. Further, a plurality of toothed surfaces 14 are formed on the outer peripheral surfaces of the rotor cores 12, 12 to determine the step angle.

Next, 15 is a stator, an annular stator core 16
and a coil (not shown) wound around a plurality of slots formed in the stator core 16. A pole is formed with teeth corresponding to the tooth pitch of the toothed surfaces 14 of the rotor cores 12, 12 of the child 10.

Next, reference numerals 17 and 17 denote a pair of frames, and engagement step portions 18 and 18 for engaging and holding the stator 15 are formed on opposing outer peripheral edges of both frames 17 and 17. 17 is adapted to engage the outer circumferential edge of the stator 15 with the engagement step portions 18, 18 to clamp the stator 15 therebetween. The frames 17, 17 are then connected together using screws (not shown) or the like.

Furthermore, fitting portions 20, 20 are formed in the centers of both frames 17, 17, respectively, for fitting and holding bearings 19, 19 consisting of an inner ring and an outer ring fitted to the inner ring via balls. .

And rotor cores 12, 12 of the rotor 10
There is a recessed part 2 in the center of the outer surface of the
1 and 21 are formed, and the bearing 1 is located in the center of the recessed portions 21 and 21 at a position recessed from the outer peripheral edge side.
an abutting surface 22 that comes into contact with the end surface of the inner ring 9, 19;
Annular protrusions 23, 23 having 22 are formed. Note that the rotor cores 12, 12 are formed by sintering.

Next, the operation of this embodiment will be explained.

During assembly, the end surfaces of the inner rings of the bearings 19, 19 fitted to the rotating shaft 13 of the rotor 10 are fitted with an annular protrusion 23 formed at a position recessed from the outer peripheral edge of the rotor cores 12, 12 of the rotor 10. . is maintained.

[Effect of idea]

According to the present invention, the rotating shaft is formed to have the same diameter over its entire length, and each pair of bearings consists of an inner ring and an outer ring fitted to the inner ring via balls, and the rotor has a rotating shaft at the center of both sides. Since the annular protrusion having the abutting surface of the end face of the inner ring of each bearing is formed at a position recessed from the outer peripheral edge side of the child, there is no need to process the rotating shaft to form a positioning step on the rotating shaft. In addition, there is no need to use other parts such as spacers, and even if the rotating shaft has a simple shape and the same diameter over the entire length, the bearings are positioned individually, and there is no need to use special bearings, so it can be used generally. By using bearings, etc., the electric motor can be made thin and flat as a whole, reducing costs and providing a flat electric motor such as a high-quality hybrid stepping motor.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of a conventional electric motor, FIG. 2 is a longitudinal sectional front view of an electric motor showing an embodiment of the present invention, and FIG. 3 is a perspective view of a rotor core of the same rotor. 10... Rotor, 13... Rotating shaft, 15... Stator, 17... Frame, 19... Bearing, 22...
...Abutting surface, 23...Annular protrusion.

Claims (1)

[Claims for Utility Model Registration] A stator, a rotor rotatably disposed within the stator and having a rotating shaft, and a pair of bearings that hold the stator and rotatably support the rotating shaft. the rotating shafts are formed to have the same diameter over the entire length, and each of the pair of bearings includes an inner ring and an outer ring fitted to the inner ring via a ball, 1. A flat type electric motor characterized in that an annular protrusion having an abutting surface for an end face of an inner ring of each bearing is formed at a central portion of both surfaces of the rotor at a position recessed from the outer peripheral edge side of the rotor.