JPH09289752A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor which can conduct centering of a rotor easily and with high accuracy and improve the manufacturing efficiency of the motor. SOLUTION: This motor is provided with a rotor 1, a stator 2 for storing the rotor 1 so as to rotate, a cylindrical case 3 where the stator 2 with the rotor 1 stored is fitted, and a mounting plate 4 which covers the opening of a case 3 with the stator 2 stored and where a bearing 18 for supporting the rotor 1 so as to rotate is fitted. At the opening of the case 3 of this motor, a flange 30 where the bearing 18 of the mounting plate 4 is fitted is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor that can be easily and highly accurately assembled with a rotor in a casing.

[0002]

2. Description of the Related Art FIG. 1 shows a stepping motor which is a kind of conventional motor. This stepping motor includes a rotor 1 and the rotor 1 with a gap inside.
And a metal case 3 for accommodating the stator 2 accommodating the rotor 1 therein.
And a mounting plate 4 that closes the opening of a bottomed cylindrical case 3 that houses the stator 2 therein. Here, the rotor 1 is a cylindrical rotationally symmetric body having a shaft 5 in the center, a permanent magnet 6 is integrally fixed to the periphery, and the outer peripheral surface 6a of the permanent magnet 6 is further fixed.
Is magnetized so as to have different polarities alternately in the circumferential direction.

The stator 2 is composed of two sets of yokes 1.
A bobbin 10 made of a synthetic resin is integrally formed on the outer circumference of the bobbin 1, and a coil 9 is wound around the outer circumference of the bobbin 10. A plurality of pole teeth 11 are formed on the inner peripheral surface of each yoke 11.
a are alternately arranged at equal intervals. Here, the outer diameter of the yoke 11 is set so that the outer peripheral surface of the yoke 11 and the inner peripheral surface of the case 3 are in close contact with each other, and when the stator 2 is housed in the case 3, 11 contacts the inner peripheral surface of the case 3, and a magnetic circuit is formed between the yoke 11 and the case 3.

The case 3 is formed in a cylindrical shape with a bottom, and one bearing 17 for pivotally supporting the shaft 5 of the rotor 1 is fixed to the center of the bottom of the case 3. On the other hand, in the center of the mounting plate 4, the rotor 1
The other bearing 18 that pivotally supports the shaft 5 is fixed, and a positioning fitting hole that fits with a positioning fitting projection (not shown) formed on the opening edge of the stator 2 is provided on the peripheral surface of the mounting plate 4. Has been drilled. Reference numerals 19a and 19b in the drawing are plug terminals for supplying a current from an external power source to the stator 2 housed inside the case 3.

In assembling the stepping motor having the above structure, the gap between the outer peripheral surface 6a of the permanent magnet 6 of the rotor 1 and the inner peripheral surface of the stator 2 where the pole teeth 11a are formed is made uniform. is important. Therefore, case 3
Stator 2 that is housed in a close-fitting state and is integrated
On the other hand, it is necessary to align the rotor 1 accurately. At this time, since the one bearing 17 that pivotally supports the shaft 5 of the rotor 1 is integrally fixed to the bottom portion of the case 3, the mounting accuracy is ensured. On the other hand, since the other bearing 18 is fixed to the mounting plate 4, when the mounting plate 4 is fixed to the case 3, the position of the bearing 18 is adjusted to accurately center the shaft 5. It becomes important to do.

Therefore, in order to attach such a mounting plate 4 to the case 3, the stator 2 is housed in the case 3 and then the jig 20 is housed in the stator 2 as shown in FIG. The tool 20 is used to perform temporary positioning of the mounting plate 4. As shown in FIG. 3, the jig 20 includes a shaft portion 21a at the center of one end of a cylindrical body 21.
Is a member having a shape of coaxially protruding. The diameter of the cylindrical main body 21 is set so that the main body 21 comes into close contact with the inside of the stator 2. The length of the main body 21 is such that when the mounting plate 4 closes the opening of the case 3, The size is set so as to contact the bearing 17 and the other bearing 18. The shaft portion 21a has the same shape and size as the shaft 5 of the rotor 1.

In mounting the mounting plate 4, first, the jig 20 is placed in the stator 2 housed and fixed in the case 3.
Insert Then, the cylindrical body 2 of the inserted jig 20
Since 1 is in close contact with the inner peripheral surface of the stator 2, the axis of the shaft portion 21a and the axis of the stator 2 coincide with each other. Insert the bearing 18 of the mounting plate 4 into the shaft portion 21a,
The mounting plate 4 is arranged at the mounting position of the case 3, and the positioning fitting projection (not shown) formed on the opening edge of the case 3 and the positioning fitting hole of the mounting plate 4 are temporarily fitted. And
After removing the one-end mounting plate 4 and the jig 20 and inserting one end of the shaft 5 of the rotor 1 into the bearing 17 at the bottom of the case 3, the mounting plate 4 is attached to the bearing 18 of the shaft 5 of the rotor 1.
The fixing of the mounting plate 4 is completed by arranging the mounting plate 4 in the above-mentioned caulking position while fitting it in.

[0008]

In the above-mentioned conventional motor, when the mounting plate 4 that influences the axial center position of the rotor 1 is mounted, the jig 20 is once housed in the stator 2 as described above. , The mounting plate 4 using the jig 20
Since it is necessary to remove the jig 20 from the stator 2 after the temporary positioning is performed, a plurality of steps including attachment and removal of the jig 20 are required until the attachment plate 4 is completely attached. This has been a cause of inefficiency in manufacturing the motor. In addition, in the centering using the jig 20, it is necessary to take out the jig 20 and assemble the rotor 1 once. Therefore, when the mounting plate 4 is finally fixed to the case 3, there is an error in the centering accuracy. Sometimes occurred.

The present invention has been made in order to effectively solve the problems of the conventional motors described above. It is possible to center the rotor easily and with high accuracy, and to improve the motor manufacturing efficiency. It is an object of the present invention to provide a motor capable of

[0010]

According to a first aspect of the present invention, a motor is fitted with a rotor, a stator that rotatably accommodates the rotor therein with a gap therebetween, and a stator that accommodates the rotor. A cylindrical case to be fitted, and a mounting plate to which a bearing for closing the opening of the case accommodating the stator and supporting the rotor rotatably is mounted. In the opening of
A bent portion into which the bearing of the mounting plate fits is formed. Here, in the invention described in claim 2, the bent portion according to claim 1 is extended from the inner peripheral surface of the opening of the case toward the center, and the fitting portion with the bearing is of the stator. It is characterized in that it is constituted by a portion bent parallel to the central axis.

In the motor described in claim 1,
Since the bending part for fitting the bearing is formed on the mounting plate that closes the opening of the cylindrical case into which the stator is fitted,
By preliminarily matching the axis of the bent portion, which is the fitting portion of the mounting plate with the bearing, with the axis of the stator, the bearing can be fitted directly to the mounting plate when the mounting plate is assembled to the stator. In this case, the axis line of the bearing and the stator can be aligned, so high assembly accuracy can be obtained without using a jig, and the work of removing the jig is unnecessary, so the number of assembly steps is small. Moreover, the efficiency of the assembling work can be improved without requiring skill in assembling. Particularly, according to the motor of the second aspect, since the area of the inner peripheral surface of the bent portion that abuts on the bearing is increased, the assembly accuracy can be further improved.

[0012]

FIG. 4 shows an embodiment of the motor of the present invention. The same components as those of the conventional motor shown in FIGS. 1 and 2 are designated by the same reference numerals and their description is simplified. Turn into. In FIG. 4, the motor of the present embodiment is characterized in that the mounting plate 4 that closes the opening of the case 3 is formed with a bent portion 31 into which the bearing of the mounting plate 4 fits. The bent portion 31 is bent in the center direction of the stator 2 in parallel to the central axis of the stator 2, and the inner peripheral surface 31 a of the bent portion 31 has an outer peripheral surface of the bearing 18 fixed to the mounting plate 4. It is fitted to 18a.

In order to assemble the motor having the above structure, the stator 2 is first fitted and fixed in the case 3,
Next, the rotor 1 is housed in the stator 2. In this state, one end of the shaft 5 of the rotor 1 penetrates the bearing 17 at the bottom of the case 3. Next, the mounting plate 4 case is fitted to the inner peripheral surface of the opening of the case 3 while inserting the shaft 15 into the bearing 18. In this case, since the mounting plate 4 is fixed in close contact with the inner peripheral surface of the case 3 having high processing accuracy, the core between the bearing 17 at the bottom of the case 3 and the bearing 18 fitted to this mounting plate 4. The alignment is easy and reliable. As a result, the bearing 17 at the bottom of the case 3 and the bearing 18 of the mounting plate 4 can be easily aligned with high accuracy. In this state, the mounting plate 4 is caulked to the upper part of the case 3. At this time, the opening edge of the case 3 is formed with a groove portion to which the tongue portion 30 protruding from the mounting plate 4 engages, and the tongue portion 30 of the mounting plate 4 is fitted into the groove portion. As a result, the mounting plate 4 is fixed to the case 3 without being displaced from the optimum fixing position.

In the above embodiment, the mounting plate 4
The outer diameter of the bearing 18 fixed to the rotor 1 is set to be larger than the outer diameter of the rotor 1, and the inner diameter of the inner peripheral surface 31a of the bent portion 31 of the mounting plate 4 is increased accordingly. After mounting 4 to the case 3, the stator 2 may be housed in the case 3 and then the bearing 18 may be fitted into the bent portion 31 of the mounting plate 4 in an assembly sequence. By assembling in this order, the load on the rotor 1 and the bearing 17 during assembly can be reduced.

Further, in the above embodiment, the length of the bearing 18 fixed to the mounting plate 4 is increased to increase the area of the outer peripheral surface 18a thereof, and accordingly, the length of the bent portion 31 is also increased. If the length is increased, the contact area between the bearing 18 and the bent portion 31 can be increased, and the alignment accuracy can be further improved.

[0016]

As described above, in the motor according to the present invention, the bending portion in the opening of the case assists the centering of the bearing with respect to the case during assembly and maintains the assembly accuracy after assembly. However, since it is fixed,
When assembling the mounting plate to the stator, the work can be performed without using a jig, the number of assembling steps is small, no skill is required for the assembly, and the efficiency of the assembling work can be improved. In addition, the bent portion can ensure the centering of the mounting plate with respect to the stator and the maintenance of the assembly accuracy after assembly.

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration diagram showing an example of a conventional motor.

FIG. 2 is a cross-sectional configuration diagram of a conventional motor in an assembly process.

FIG. 3 is a perspective view of a jig used for assembling a conventional motor.

FIG. 4 is a cross-sectional configuration diagram of an embodiment of a motor of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 rotor 2 stator 3 case 4 mounting plate 5 shafts 17, 18 bearing 18a bearing outer peripheral surface 31 mounting plate bent portion 31a inner peripheral surface of bent portion

Claims (2)

[Claims] 1. A rotor, a stator rotatably housing the rotor therein with a gap therebetween, a cylindrical case into which the stator housing the rotor is fitted, and a case housing the stator inside. While closing the opening of
In a motor having a mounting plate on which a bearing for rotatably supporting the rotor is mounted, a bent portion into which the bearing of the mounting plate fits is formed in an opening of the mounting plate. The motor to drive. 2. The bent portion extends from the inner peripheral surface of the opening of the case toward the center, and the fitting portion with the bearing is formed by a portion bent parallel to the central axis of the stator. The motor according to claim 1, wherein the motor is provided.