JPS61173642A - Synchronous motor - Google Patents

Abstract

PURPOSE:To obtain spigots at both ends of a stator without providing terminal boards at both ends of the stator by clamping a core laminated structure with rivets passing its thick portion. CONSTITUTION:A synchronous motor has a rotor 11, which is rotatably supported through bearings 12, 13 to a pair of housings 14, 15. The housings 14, 15 hold a stator 16 for forming part of the sheath of a motor in an axial direction. The stator 16 is held by a bolt 17 engaged with the other housing 15 through the stator 16 from one housing 14 side. The stator 16 has a laminated structure of many thin plates or core 18 made of electromagnetic plates.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a synchronous motor, and particularly to a stator structure of a synchronous motor suitable for a small AC servo motor.

[Conventional technology and problems]

Conventionally, as a method for downsizing a synchronous motor, a structure has been adopted in which the stator itself, which is provided with windings, forms part of the outer sheath of the motor. FIG. 8 shows the structure of such a conventional synchronous motor. Referring to FIG. 8, the synchronous motor includes a rotor 1, a pair of housings 2 and 3 that rotatably support the rotor 1 via bearings, and a stator 4 that is held between the housings 2.3 in the axial direction. The stator 4 is provided with a winding 5.

The stator 4, which has a substantially cylindrical hole on the inside, has a substantially quadrangular prism-like outer shape with chamfered corners on the outer surface.

Generally, the stator 4 has a structure in which a large number of thin plates or cores 6 made of electromagnetic steel plates are laminated in the axial direction.
In order to make the stator 4, which forms part of the outer jacket of the electric motor, strong, it is necessary to firmly fix the cores 6 to each other.

Conventionally, the method of firmly fixing the cores 6 to each other has been to weld the outer periphery of the stator 4 in the axial direction. In order to prevent thermal deformation of the stator 4, it is necessary to weld the thick portions of the stator 4, that is, the corner portions. However, at the corners of both ends of the stator 4,
It is necessary to form a part of the spigot for alignment with the housing 2.3. Therefore, when welding is used, the end plates 7 and 8 are provided at both ends of the stator 4, and the welding at the corners of the stator core 6 is extended to the middle of the end plates 7 and 8, and the end plates 7 and 8 are attached to the stator 4. and the end plate 7
, 8 is widely adopted. This arrangement has the drawback of requiring a pair of relatively thick end plates, which increases the weight and length of the motor. Furthermore, in the case of a stator assembly method using welding, the work process is complicated, making it difficult to automate the stator assembly.

Another method for firmly assembling a stator with a core laminated structure is to pass bolts through holes provided near the corners of the stator core and fasten the stator core in the axial direction with the bolts and nuts. In this method, the end plate can be omitted.

However, the corner portions at both ends of the stator need to be part of the spigot for centering the housing. Therefore, it is necessary to determine the outer diameter of the stator so that the bolt heads and nuts do not protrude sideways from the corners of the stator, but since the bolt heads and nuts have a relatively large outer diameter, There is a drawback that the outer diameter of the stator becomes larger.

Therefore, there is a need for a stator assembly structure suitable for small synchronous motors.

[Means for solving problems]

As a means for solving the above problems, the present invention includes a pair of housings that rotatably support a rotor via bearings, and a stator that is held between the housings in the axial direction, and the stator is made of a thin plate. The present invention provides a synchronous motor having a laminated structure, wherein the thin plates of the stator are fastened together by a plurality of rivets passing through the thick portion of the stator in the axial direction.

[For production]

According to the above means, since the stator of the core laminated structure is fastened with a rivet passing through the thick part thereof, a part of the spigot can be secured at both ends of the stator without providing end plates at both ends of the stator. It becomes like this. Additionally, since the heads at both ends of the rivet can be made smaller than the heads of bolts and nuts, there is no need to increase the outer diameter of the stator.Therefore, it is possible to downsize the synchronous motor. Furthermore, since the stator is fastened by caulking rivets, automation of stator assembly can be easily realized.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention.

Referring to FIG. 1, the synchronous motor includes a rotor 11 rotatably supported by a pair of housings 14.15 via bearings 12.13.

Housing 14.15 is! A stator 16, which constitutes a part of the outer sheath of the motive device, is sandwiched in the axial direction. Stator 16
On the other hand, the clamping of .

This is done by a bolt 17 that passes through the stator 16 from the housing 14 side of the housing 14 and is screwed into the other housing 16.

As shown in FIGS. 1 and 2, the stator 16 has a laminated structure of a large number of thin plates or cores 18 made of electromagnetic steel plates. As shown in FIG. 3, a substantially cylindrical hole is provided inside the stator 16, and a plurality of grooves 20 for passing the windings are spaced apart in the circumferential direction on the inside of the stator 16. It is provided. The stator 16 has an approximately square prism shape with chamfered corners on its outer surface.

Therefore, in this stator 16, the four corner portions (chamfered portions) 19 on the outer surface thereof are thick.

As shown in FIGS. 2 and 3, the core 1 of the stator 16
8 is fastened by two pipe-shaped rivets 21 passing through the thick part of the stator IG. In the thick part of the stator 16, the core 18 is provided with two holes 22 for passing the rivet 21 and two holes 23 for passing the bolt 17 described above.
3 are arranged diagonally. Rivet 21
After being inserted into the hole 22 of the stator 16, both ends thereof are caulked to expand the diameter outward in the radial direction. The stator 16 is fastened in the axial direction by the heads at both ends of the rivet 21 formed in this manner.

As shown in FIGS. 4 to 7, the housing 14.1
5 is provided with holes 24 and 25 for passing the bolt 17, and recesses 26 and 27 for receiving the heads of the rivets 21 at both ends. The outer end face of the housing 14, 15 has a recess 26, respectively, with holes 28, 29 for external mounting.
．． It is provided at a position coaxial with 27.

In the synchronous motor having the above configuration, the chamfered portion 19 on the outer surface of the stator 16 is formed so as to form a part of a common cylindrical surface centered on the central axis of the stator 16, and constitutes a part of the spigot.

The housing 14.15 has a spigot part 30.31 which fits into these chamfers 19. Due to the fit between the chamfered portion 19 and the pilot part 30.31, the housing 14.
15 is centered with respect to the stator 16.

In order to make the chamfered part 19 of the stator 16 a part of the inlet,
It is necessary to set the outer diameter of the stator 16 so that the heads at both ends of the rivet 21 do not protrude laterally from the chamfered portion 19. In this case, since the heads at both ends of the rivet 21 can have a smaller external shape than the head of the bolt or the nut, the outer diameter of the stator 16 can be reduced.

In the above embodiment, since the rivet 21 is pipe-shaped, the weight of the electric motor can be reduced.

Although one embodiment has been described above, the present invention is not limited to Mr. Li of the above embodiment, and various changes can be made to the constituent elements within the scope of the invention described in the claims. be able to. For example, pipe-shaped rivets 2 are provided in each of the four thick parts of the stator 16.
1 and fastens the stator 16 with the rivet 21, and the stator 16 and the housing 14.1 are inserted into the rivet 21.
5 may be configured to pass through a bolt 17 for fastening.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the stator of the core laminated structure is fastened by the rivet penetrating the thick part of the stator. You will be able to secure a portion of the intro.

Furthermore, since the heads at both ends of the rivet can be made smaller than the head of the bolt or the NAND, there is no need to increase the outer diameter of the stator. Therefore, it is possible to provide a small and lightweight synchronous motor. In addition, since the stator is fastened by caulking rivets,
This makes it possible to easily automate the assembly of the stator.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional plan view of a small synchronous motor according to an embodiment of the present invention, FIG. 2 is a side view of the stator in the motor shown in FIG. 1, and FIG. 3 is a right end surface of the stator shown in FIG. 2. Figure 4 is an inner end view of one of the housings in the electric motor shown in Figure 1, Figure 5 is a cross-sectional view of the housing shown in Figure 4, taken along line ■-V in Figure 4, and Figure 6 is a cross-sectional view of the housing shown in Figure 4. Fig. 7 is a cross-sectional view of the housing shown in Fig. 6 taken along the line ■-■ in Fig. 6; Fig. 8 is the structure of a conventional synchronous motor. FIG. 11...Rotor, 14.15...Housing, 16
... Stator, 17... Bolt, 18... Core,
19... Chamfered part, 21...'IJ bed.

Claims (1)

[Claims] 1. A pair of housings rotatably supporting a rotor via bearings, and a stator that is held between the housings in the axial direction and constitutes a part of the outer sheath of the electric motor, and the stator A synchronous motor having a laminated structure of thin plates, wherein the thin plates of the stator are fastened by a plurality of rivets passing through a thick portion of the stator in an axial direction. 2. The synchronous motor according to claim 1, wherein the rivet has a pipe shape.