JPS63253849A - Motor assembly method - Google Patents

Abstract

PURPOSE:To arrange bearings concentrically and prevent a rotor from generating faulty rotation, by positioning two sets of assembling parts, which constitute a stator, in reference to the rotary shaft of the rotor to secure them with each other. CONSTITUTION:The fore end part 31a of the rotary shaft 31 of a rotor is inserted into the bearing bush 15 of the fore half part 10 of a stator while the aft end part 31b of the rotary shaft 31 is inserted into the bearing bush 25 of the aft half 20 of the stator. The aft part 31a of the rotary shaft 31 is inserted into the positioning shaft hole 44b of the bottom force 44 of a jig 40. Next, a top force holder 45 is descended and the aft end part 31b of the rotary shaft 31 is inserted relatively into the positioning shaft hole 45b of the top force 45. In this stage, the fore half 10 of the stator is not secured to the aft part 20 but the positioning in the axial direction is being effected in reference to the rotary shaft 31, therefore, the positionings in rotating direction and axial direction are effected under this condition as it is, then, the welding of the contacting part of these assembling parts is effected after finishing the positioning to secure them.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of assembling, for example, a multi-stage variable reluctance stepping motor.

(Prior Art) First, the prior art will be explained with reference to FIG. 1 J3 and FIG. 2 showing one embodiment of the present invention. This example is a two-phase variable reluctance stepping motor, with a stator half and eight
1110 and the stator rear half 20 in the axial direction, a rotor 30 is housed concentrically within the stator, and both ends of the rotating shaft 31 of the rotor 30 are connected to the stator front half 10 and the stator rear half. It has a structure in which it is inserted into and supported by the bearing bushes 15 and 25 of No. 20.

The stator front half 10 houses a coil 13 in a doughnut-shaped yoke made by combining yoke parts 11 and 12, and fixes these yoke parts 11 and 12 by plasma spot welding or the like, and attaches the coil 13 to the front of the yoke part 11. The flange 14 is fixed by welding, and a bearing bush 15 is attached to the center hole of the front 7 flange 14. When assembling the stator front half 10 integrally, the respective parts are positioned so that their centers are aligned.

The stator rear half 20 also has almost the same configuration as the front half 10, with a coil 23 housed in a yoke made up of yoke parts 21 and 22, and these yoke parts 21 and 22 being welded together.
A rear flannon 24 is welded to the back surface of the yoke component 21, and a bearing bushing 25 is attached to the center hole of the rear flange 24. The stator rear half 20 is assembled so that the centers of these components are aligned.

Three assembly parts, the stake 11α half 10, the stator rear half 20, and the rotor 30, are finally combined to form an integral motor. In other words, the rotating shaft 3 of the rotor 30
1 into the bearing bush 15 of the front 7 flange 1/1, and insert the rear end portion 31b of the rotating shaft 31 into the bearing bush 15 of the front 7 flange 1/1.
into the bearing bushing 25 of the rear flange 24. Then, the stator front half 10 and the stator rear half 20 are mutually positioned and connected. This completes an integrated motor.

In this final assembly, conventionally, the stator front half 10
and the stator rear half 20 are the respective yoke parts 11.
12J> and 21.22, or the engagement part between the notch and the claw, and this fitting part or engagement part also serves as a temporary fixing means for both parts. was. Both parts are finally welded together.

(Problems to be Solved by the Invention) In the conventional assembly method described above, there was a high incidence of defective products in which the rotor 30 did not rotate silently with a light force. rotor 30
The cause of the rotation failure is that the axes of the bearing bushes 15 and 25 do not match accurately, and the rotating shaft 31 is forcibly inserted there.
This is due to the fact that the friction becomes extremely large.

Why is the concentricity of bearing bushes 15 and 25 disturbed? This is because the first half 10 and the second half 20 of the stator are positioned by the concave-convex fitting portion or the notch/claw engagement portion during final assembly. In this case, there is a positioning error between the stator front half 10 and the stator rear half 20, a positioning error between the yoke component 11 and the front flange 14, and a positioning error between the front flange 14 and the bearing bush 1.
Positioning error with 5, yoke part 21 and rear flange 24
The positioning errors of the rear flange 24 and the bearing bush 25 are all accumulated, and the positioning errors of the rear flange 24 and the bearing bush 25 are accumulated.
This results in a concentricity error of 5. With conventional assembly methods, this error becomes extremely large.

The present invention was made in view of the above-mentioned conventional problems, and an object thereof is to provide a method for assembling a motor that can eliminate rotor rotation failures caused by concentricity errors between two bearings. There is a particular thing.

(Means for solving the problem) Therefore, in this invention, a stator is constructed by connecting two assembly parts A and 8 in the axial direction, a rotor is housed concentrically within this stator, and the rotor rotates. When assembling a motor with a structure in which both ends of the shaft are inserted and supported by the bearings of assembly parts A and B, respectively, assembly parts A, ! :B
Temporarily assemble assembly parts A and 8 and the rotor without connecting them, keep the rotation axis accurately in a straight line, and in that state, adjust the radial direction of assembly parts A and 8 with respect to the rotation axis. In this state, both parts A and 8 are positioned in the axial direction without applying any force in the radial direction to the assembled parts A and 8, and in this state, both parts A and 8 are connected and fixed to each other. did.

(Function) The state in which the rotating shaft is inserted into the bearing and no unreasonable force is applied to the rotating shaft in the radial direction is a state in which the rotor can rotate extremely smoothly. The rotating shaft in this state serves as a positioning reference when assembling parts A and 8. Therefore, the assembly parts A and 8 are finally connected and fixed while the I coater rotates smoothly.

(Example) Since FIG. 1 has already been explained in detail, a redundant explanation will not be given here. In the present invention, unlike the conventional art, no concave-convex fitting part or notch/projection engaging part for mutually positioning the stator front half 10 and the stator rear half 20 is provided, and the stator front half 10 and the stator rear half 20 are not provided. 20 and the second
While positioning and fixing with a jig 40 (not shown), both parts are fixed by plasma welding or the like.

The jig 40 shown in FIG. 2 is a die set of a press, and 41 is a lower die holder, 42 is a guide post erected perpendicularly to the lower die holder 41, and 43 is a guide post 42.
This is an upper mold holder that slides up and down along the A lower mold 44 is fixed to the lower mold holder 41, and an upper mold 45 is fixed to the upper mold holder 43, respectively.

The lower mold 44 has a horizontal upper surface, and has four parts 44 in the center thereof.
a, and a positioning shaft hole 44b is vertically formed in the center thereof. Similarly, the upper mold 45 has a horizontal lower surface, has a recess 45a in its center, and has a positioning shaft hole 45b vertically formed in the center. The positioning shaft holes 44b and 45b are holes with inner diameter dimensions into which the rotating shaft 31 of the rotor 30 is tightly fitted, and the upper and lower positioning shaft holes 44
b and 45b are concentric with sufficiently high accuracy.

In other words, when fixing the lower die 44 and the upper die 45 to the jig 40, the concentricity ↑1 of the positioning shaft holes 44b and 45b is strictly measured, and the lower die is confirmed to be within a predetermined accuracy. 44 and an upper mold 45 are fixed.

The assembly method of the present invention using the jig 40 described above is executed in the following steps.

The front end portion 31a of the rotor rotating shaft 31 is inserted into the bearing bush 15 of the stator front half 10, and the rotating shaft 31
The rear end portion 31b is inserted into the bearing bush 25 of the stator rear half 20. Then, the stator front half and the stator rear half 20 are combined to enclose the rotor 30.

However, there is no means for positioning and temporarily fixing the stator front half 10 and the stator rear half 20 to each other, and the two parts are simply in contact with each other.

The three parts in this temporarily assembled state are set on a jig 40 as shown in FIG. That is, with the upper die holder 43 sufficiently pulled up, the rear end portion 31b of the rotary shaft 31 is inserted into the positioning shaft hole 44b of the lower die 44, and the front flange 14 is placed on the upper surface of the lower die 44. Next, lower the upper mold holder 43.
The rear end portion 31b of the rotating shaft 31 is relatively inserted into the positioning shaft hole 45b of the lower die 45, and the lower surface of the upper die 45 presses the rear flange 24 from above to below.

In the above state, the rotating shaft 31 with both ends inserted into the positioning shaft holes 44b and 45b is in the shaft hole 44b.

45b as a reference, it is supported in a straight state with no force applied in the radial direction. Further, at this stage, the stator front half 10 and the stator rear half 20 are not yet fixed, so these two parts are each positioned in the radial direction with respect to the rotating shaft 31. In this state, the stator front half 10 and the rear half 20 are positioned in the rotational direction and the axial direction, and once this is completed, the contact portion between the stator half 10 and the rear half 20 is fixed by plasma welding. After this welding is completed, the upper die 45 is raised, and the motor assembled in one piece is not removed from the jig 40.

(Effects of the Invention) As explained in detail above, according to the motor assembly method according to the present invention, the two assembly parts constituting the stator are positioned in the radial direction with reference to the rotation axis of the rotor, and in that state. Since both parts are fixed to each other, the two bearings supporting the rotating shaft are correctly concentric 4f with respect to the rotating shaft, ensuring smooth rotation of the rotor. Therefore, the rotor Q caused by the disturbance of the n1 centricity of the two bearings does not occur.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing three parts immediately before assembly according to an embodiment of the present invention, and FIG. 2 is a sectional view showing a motor being assembled by a method according to an embodiment of the present invention. 10... Stator front half (assembly part Δ) 11.
12...Yoke parts 13...Coil 14...Front 7
Lunge 15... Bearing bushing 20... Stator rear half (assembly part B) 21.
22...Yoke parts 23...Coil 24...Rear 7
Lunge 25...Bearing bushing 30...
・Rotor 31... Rotating shaft 40...
...Jig, 44...Lower mold 45...
... Upper mold 44b, 45b ... Positioning shaft hole Patent applicant: Fuji Electrochemical Co., Ltd.
Patent Attorney - Sodo Iroha
Patent Attorney Masatoshi Matsumoto Figure 1

Claims (1)

[Claims] (1) A stator is constructed by connecting two assembly parts A and B in the axial direction, and a rotor is housed concentrically within this stator, and both ends of the rotating shaft of this rotor bear the bearings of assembly parts A and B, respectively. When assembling a motor with a structure that is inserted into and supported by the rotor, temporarily assemble assembly parts A and B with the rotor without connecting assembly parts A and B, and keep the rotation axis accurately in a straight line. In that state, position the assembly parts A and B in the radial direction with reference to the rotation axis, and in that state, position both parts A and B in the axial direction without applying any force in the radial direction to the assembly parts A and B. and, in this state, both parts A and B are connected and fixed to each other.