JPS62193534A - Assembling of miniaturized rotary electric machine - Google Patents

Abstract

PURPOSE:To ensure a uniform space easily between a stator and a rotor by performing the shop assembly and checking the center and alignment with a spacer interposed, then by removing the spacer. CONSTITUTION:A spacer 7 made of thermocontracting material is interposed to grooves 2a formed at both ends of the outside circumference of a rotor 2. After a uniform space 6 is made up in the whole surrounding area between a stator 1 and a rotor 2, the spacer 7 is temporarily fitted. Then a brush 9 made of rubber is interposed to the clearance 8 between a bracket 4 and bearings 5, where a hardening filler 10 is filled to fix the space between the bracket 4 and an outer ring 5a of the bearings 5. After the hardening filler 10 is hardened enough, the whole motor is heated to remove the spacer 7 by thermocontraction. As it is possible to check the center and alignment completely before the hardening filler 10 is filled, the accuracy in assembly gets improved.

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

The present invention relates to a method for assembling a small rotating electric machine such as a stamping motor or a micro motor.

[Prior art and its problems]

First, FIG. 4 shows the one-touch structure of the above-mentioned motor, which is an object of the present invention. In the figure, 1 is a stator, 2 is a rotor, 3 is a rotating shaft that supports the rotor, 4 is a bearing support bracket connected to both left and right sides of the stator 1, and 5 is mounted on the shaft and is placed between the bracket 4. The bracket 4 is fitted onto the outer periphery of the stator 1 and fixed with screws or adhesive, and the bearing 5 is fitted into a bearing mounting hole opened at the center of the bracket 4 and coupled. has been done. Such motors increase efficiency by reducing motor no-load losses. In order to increase the output per unit volume of the motor, the gap dimension g of the gap 6 between the stator l and rotor 2 should be set as narrow as possible; It is required that the gap 6 has a uniform gap size g over its entire circumferential area. In other words, if the air gap 6 is not uniform around the circumference, problems such as decreased motor performance due to torque pulsation caused by magnetic imbalance, generation of vibration and noise, and mechanical contact between the stator and rotor may occur. Occur. Therefore, high assembly precision is required when assembling rotating electric machines, and in particular, small precision motors such as stamping motors are designed with the above-mentioned air gap value of about 0.1 to 0.211111I, and the tolerance is extremely narrow. Extremely high assembly precision is required. In order to meet such demands for assembly accuracy, the required assembly accuracy has conventionally been achieved by increasing the machining accuracy of each component of the motor, and the dimensional accuracy of each component is entirely dependent on the machining accuracy of the processing machine. The current situation is that it depends on However, in order to obtain high machining dimensional accuracy for individual parts, expensive precision machining equipment is required, which increases the manufacturing cost of the motor.In addition, conventional methods have the following problems: remains. In other words, in the motor having the structure shown in FIG. 4, all the parts are assembled in a fitting manner, and the machining dimensional errors of each part cannot be absorbed between the parts that are connected to each other. Assemble each part one by one (in the process, errors will accumulate). Moreover, the dimensional errors of each part accumulated in this way will eventually reduce the gap between the stator 1 and rotor 2. As a result, it becomes extremely difficult to maintain a uniform air gap 6 over the entire circumferential area between the stator and rotor. Small rotating electric machines have small air gap dimensions and strict uniformity requirements for the air gap, which requires higher machining accuracy and assembly accuracy, and conventional assembly methods cannot be used. It is extremely difficult to maintain performance quality in a mass production system for rotating electric machines. Figure 4 shows the factors that have a particularly large effect on the causes of uneven air gaps that occur during motor assembly. As shown below: ■ Dimensional errors during machining at the fitting part between stator 1 and bracket 4 and errors in coaxiality during assembly process. ■ During machining at the fitting part between bracket 4 and bearing 5. dimensional error and coaxiality error in the assembly process.If there is a machining dimensional error 1 alignment error in the assembly process in such a part, the accumulation of this error will have a large effect and cause the stator 1 and rotor to 2 cannot be accurately centered, making it impossible to obtain uniformity of the gap.

[Object of the Invention] The present invention has been made in view of the above points, and is designed to absorb the error in the machining dimensional accuracy of each of the component parts in the assembly parts other than the air gap, so that the stator and rotor are connected in the assembled state. It is an object of the present invention to provide a method for assembling a small rotating electrical machine that can easily ensure a uniform gap between the parts. [Summary of the Invention] In order to achieve the above object, the present invention first opens a bearing mounting hole in the center of the bracket with a diameter sufficiently larger than the outer diameter of the bearing, and then assembles the rotor into the stator. In order to maintain a uniform gap between the outer circumferential surface of the rotor and the inner circumferential surface of the stator over the entire circumferential area when the rotor is closed, a spacer is interposed between the outer circumferential surface of the rotor and the inner circumferential surface of the stator. Temporary assembly step for temporary fixing in a centered state, and a step between the inner circumferential surface of the bearing mounting hole of the bracket coupled to the stator and the outer circumferential surface of the outer ring of the bearing fitted and mounted on the shaft in the temporarily assembled state in the above step. A bearing fixing process in which the remaining gap is filled with a curable filler to fix the bracket and the outer ring of the bearing, and a spacer inserted in the gap between the rotor and stator in the above temporary assembly process is used to fix the spacer in the gap area. By assembling the spacer through the spacer removal process, which removes the spacer to the outside and secures the air gap, a uniform air gap is forcibly set between the stator and rotor in the temporarily assembled state using the spacer, and each part can be processed. All the accumulated bone with dimensional errors is absorbed in the remaining gap between the bracket and the bearing, which is later filled with a hardening filler, so that the motor can be assembled with high precision.

[Embodiments of the invention]

1 to 3 each show an assembly process of an assembly method according to a different embodiment of the present invention, and the same members corresponding to FIG. 4 are given the same reference numerals. First, in the embodiment shown in FIG. 1 (al, (bl), fa
Figure 1 shows a temporary assembly state in the middle of motor assembly, and Figure (b) shows a diagram of the completed assembly.First, as shown in figure fa1, the outer diameter of the bearing 5 is pre-assembled in the center part of the bracket 4. Bearing mounting hole 4 selected to have a diameter sufficiently larger than dimension d
a is open. Further, the rotor 2 has a groove 2a formed at both edges of its outer circumferential surface with a step difference from the circumferential surface, and a ring-shaped spacer 7 made of a heat-shrinkable material is installed in the bracket groove 2a in the temporarily assembled state shown in the figure. Interventions are deployed. This spacer 7
The stator 1 and rotor 2 are temporarily fixed by setting a uniform gap 6 in the entire circumferential area between the inner circumferential surface of the stator 1 and the outer circumferential surface of the rotor 2, and in this state, the stator and rotor are connected. The relative centering is maintained. On the other hand, stator 1
Brackets 4 are fixed to both left and right ends of the shaft 3 by screws or adhesive, and bearings 5 are fitted on both sides of the shaft 3 with the rotor 2 in between, at portions of the brackets 4 facing the bearing support portions. Note that 5a is the outer ring of the bearing, 5b is the inner ring, and in this temporarily assembled state, the bracket 4 and the bearing 5 are
are in a free state with no contact between them, and a gap 8 remains between them. Here, a ring-shaped bushing 9 made of, for example, a rubber material is interposed between the rear end surface of the bracket 5 and the circumferentially protruding flange portion of the bearing outer ring 5a so as to seal the back surface of the gap 8. . This bushing 9 serves as a seal when the remaining gap is filled with a curable filler in the next step. Next, in the temporarily assembled state where a uniform gap 6 is set between the stator 1 and the rotor 2 via the spacer 7 in the above process, the bearing mounting hole opened in the center of the bracket 4 is The remaining gap between the inner circumferential surface and the outer circumferential surface of the outer ring 5a of the bearing 5 is filled with a curable filler 10, which is, for example, a molding resin that cures at room temperature, thereby fixing the space between the bracket 4 and the outer ring 5a of the bearing. As the curable filler 10, instead of the room temperature curable mold resin, a thermosetting mold resin that cures at a temperature below the heat shrinkage temperature of the heat shrinkable spacer 7 is used as the curable filler 10. Good too,
In addition, by applying a release material to the area where the outer ring of the bearing 5 and the filler 10 contact, the outer ring of the bearing can be pushed in the axial direction later if necessary to prevent looseness between the outer ring 5a and the inner ring 5b. It is possible to eliminate it. After the above-mentioned bearing fixing step is completed and the curable filler 10 is sufficiently hardened, the next step is a spacer removal step, in which the entire motor is heated to heat-shrink the heat-shrinkable spacer 7. That is, due to the heating of the motor, the heat-shrinkable ring-shaped spacer 7 heat-shrinks as shown in Figure aQ), and the portion that had been protruding into the gap 6 retreats to fit within the groove 2a on the rotor 2 side. removed from the air area. This completes the motor assembly, stator 1 and rotor 2.
A uniform gap 6 is ensured over the entire circumference between the two. Moreover, the accumulated amount of machining spacer error 1 assembly error of each component is all absorbed in the remaining gap 8 between the bracket 4 and the bearing 5 in the temporarily assembled state shown in the TAT diagram.
In the assembled state, there is a gap 6 between the stator 1 and the rotor 2.
It has no effect on Next, Figure 2 fa1. (Another embodiment will be described in bl. In this embodiment, a heat-shrinkable spacer 11 inserted into the gap 6 between the stator 1 and the rotor 2 during the temporary assembly process is attached to the stator 1 side. In other words, the spacer 11 forms a rail-shaped body with an engineering cross section as shown in Figure fa1 before being subjected to heat shrinkage treatment, and as shown in the figure, the coil 1a of the stator 1 is attached to the iron core 1b. is inserted axially along the coil slot lc of the coil slot) lc
The base is fitted into the entrance side bottleneck of the air gap 6, and the tip thereof is attached so as to protrude into the cavity 6. These spacers 11 are distributed and arranged in a plurality of coil slots on the circumferential surface of the stator core, and set the gap 6 between the stator 1 and rotor 2 to a uniform gap over the entire circumferential surface in the temporarily assembled state. Centering is maintained. Note that a coil slot indicated by reference numeral 12 is inserted into the coil slot where the spacer 11 is not attached to hold the coil within the slot. Next, while maintaining the temporarily assembled state centered and maintained in the above step, the remaining gap between the bracket 4 connected to the stator 1 and the bearing 5 mounted on the rotor shaft is filled with hardening material as shown in FIG. The spacer 11 is filled with a material 10 to fix the space between the bracket 4 and the bearing 5, and then in the subsequent spacer removal process the entire motor is heated to heat-shrink the spacer 11. As a result, the spacer 11 becomes as shown in Fig. 2 (1). As shown, the volume shrinks, and the tip of the spacer 11 retreats from the area of the air gap 6 into the coil slot, and a uniform air gap 6 is formed between the stator 1 and the rotor 2 over the entire circumference. This embodiment has the advantage that it is not necessary to form a groove on the circumferential surface of the rotor 2 as in the embodiment shown in FIG. 1, and that the influence on the magnetic characteristics of the motor is small. FIG. 3 shows a further different embodiment of the present invention, and the difference from the embodiment of FIG. 1 is that the spacer has a thickness approximately equal to the gap value of the air gap 6 between the stator 1 and the rotor 2. Centering between the stator 1 and the rotor 2 is set by using a non-heat-shrinkable film-like spacer 13 having the spacer 13 and interposing the spacer 13 in the entire circumference area or a part of the gap 6.
After temporarily fixing the bracket 4 and the bearing 5, the remaining gap between the bracket 4 and the bearing 5 is filled with a hardening filler, and the bracket 4 and the bearing 5 are bonded together.
to fix between. Next, in the spacer removal step, the film-like spacer 13 is drawn out to the outside as indicated by arrow P through the hole 4b previously opened in the end face of the bracket 4 and removed. This ensures a uniform gap 6 between the stator 1 and rotor 2. In addition,
As the film spacer 13, a material 1 having strong mechanical strength and a small coefficient of friction, such as a polyester resin film, is suitable.

【Effect of the invention】

As described above, according to the present invention, the bearing mounting hole is previously opened in the center of the bracket with a diameter sufficiently larger than the outer diameter of the bearing, and when the rotor is assembled in the stator, the outer peripheral surface of the rotor is A spacer is interposed in the entire circumferential area or a part of the gap so that the gap between the inner circumferential surface of the stator and the inner peripheral surface of the stator is maintained uniformly over the entire circumferential area, and the two are temporarily fixed in a centered state. In the assembly process, a hardening filler is applied to the remaining gap between the inner peripheral surface of the bearing mounting hole of the bracket connected to the stator in the temporarily assembled state in the above step and the outer peripheral surface of the outer ring of the bearing fitted and mounted on the shaft. A bearing fixing process in which the spacer is filled and fixed between the bracket and the outer ring of the bearing, and a spacer inserted in the gap between the rotor and stator in the above temporary assembly process is removed outside the gap area to secure the gap. By assembling the rotating electrical machine through a spacer removal process, all machining dimensional errors of the parts that make up the rotating electrical machine are absorbed into the remaining gap between the bracket and the bearing in the temporarily assembled state during assembly, and the stator is then assembled. It is possible to ensure centering and a uniform air gap over the entire circumference between the rotor and the rotor, thereby easing the machining accuracy requirements for machining each component, while also achieving high performance with no variation in characteristics. A rotating electric machine with assembly precision can be easily and inexpensively manufactured.

[Brief explanation of drawings]

FIGS. 1A and 1B are axial cross-sectional views of the motor showing preliminary assembly and completed assembly states in the motor assembly process according to an embodiment of the present invention, FIGS. FIG. 3 is an axial cross-sectional view of the motor showing an intermediate stage of assembly in a different embodiment; FIG. 4 is a structural cross-section of a conventional motor. It is a diagram. In each figure, 1: stator, 1c: coil slot, 2: rotor, 2
a: Groove 3: Shaft, 4 nib bracket, 4a: Bearing mounting hole,
5: Bearing, 5a: Bearing outer ring, 6: Gap, 7: Heat-shrinkable ring-shaped spacer, 10: Curable filler, 11: Heat-shrinkable rail-shaped spacer, 13: Fu (CI) Figure 1 (b) Figure 2 Figure 3 Figure 1-1 Figure 4

Claims (1)

[Scope of Claims] 1) A method for assembling a small rotating electric machine in which a bearing is installed between opposing parts of brackets connected to both ends of a stator and a shaft supporting a rotor, the method comprising: installing a bearing in the center of the bracket in advance; A bearing mounting hole with a diameter sufficiently larger than the bearing outer diameter is opened, and when the rotor is assembled into the stator, the gap between the outer circumferential surface of the rotor and the inner circumferential surface of the stator covers the entire circumference. A temporary assembly step in which a spacer is interposed in the entire circumferential area or a part of the gap so that the space is maintained uniformly, and the two are temporarily fixed in a centered state. A bearing fixing process in which the remaining gap between the inner circumferential surface of the bearing mounting hole and the outer circumferential surface of the outer ring of the bearing fitted on the shaft is filled with a curable filler to fix the bracket and the outer ring of the bearing. , and a spacer removal step in which the spacer inserted in the gap between the rotor and the stator in the temporary assembly step is removed outside the gap area to secure the gap. How to assemble electrical equipment. 2) In the assembly method as set forth in claim 1, the spacer is made of a heat-shrinkable material, and is shrunk by a heat-shrinking treatment performed in the spacer removal step to be retreated and removed outside the void area. A method for assembling a small rotating electric machine characterized by: 3) In the assembly method according to claim 2, the heat-shrinkable spacer is a ring-shaped spacer that fits into a groove formed on the circumferential surface of the rotor and is interposed in the gap between the rotor and the stator. A method for assembling a small rotating electric machine characterized by the following. 4) In the assembly method according to claim 2, the heat-shrinkable spacer has a rail-shaped spacer whose mounting base is inserted into the coil slot of the stator side core and inserted into the gap between the heat-shrinkable spacer and the rotor. A method for assembling a small rotating electric machine characterized by a spacer. 5) In the assembly method described in claim 1, the spacer is a non-heat-shrinkable film-like spacer having a thickness corresponding to the void, and is removed by being taken out to the outside in the spacer removal step. A method for assembling a small rotating electric machine characterized by: