JPH0199449A - Dc servomotor - Google Patents

Abstract

PURPOSE:To eliminate insulation deterioration, to decrease defective shaping waveforms and to improve fabricability by forming a fitting part of an end bracket with a brush slot part, an externally pulled-out connector-fitting part, a brush holder housing and a motor housing into an integral body by means of an insulating material. CONSTITUTION:A plastic end bracket 12 is fitted in a housing 2, an end bracket holder 13 is fitted at the position determined readily by said end bracket 12 and housing 2, and the housing 2 and holder 13 are joined by welding and assembled together. Subsequently, a sub-assembly composed of a brush 14, a brush spring 15 and metal fittings 16 is equipped in the brush holder housing part 17 and connector housing part 18 of the end bracket 12 to constitute a motor 19. Then, a brush slot 32, said brush holder housing part 17 and connector housing part 18 are provided and both housing parts 17 and 18 are connected by a groove 33 to form a place for housing a conductor connecting a brush holder and a connector.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a DC servo motor, and more particularly to a DC servo motor that has improved insulation deterioration and improved ease of assembly and handling.

[Conventional technology]

In a conventional DC servo motor, a rotor core and a commutator are fixed to a shaft, the core is wound, and the rotor is inserted with the end of the winding connected to the commutator, inside a housing to which permanent magnets are bonded. Attach the brush holder assembly, in which the brush is pushed out by a spring, to one of the two end brackets into which the bearing is inserted from the inside, and place it on both sides of the housing.While observing the rectified waveform, determine the positional relationship between the permanent magnet and the brush. After adjusting to the neutral point, the housing and two end brackets are fixed with screws to form a motor part.

Then, the rotating part of the rotation detector is fixed to the shaft by screwing, press-fitting, shrink-fitting, etc., and the sensor and waveform shaping circuit part are faced to the rotating part, and after temporarily fixing with screws, the gap is adjusted, and the sensor After checking the detected amount, fully tighten the screws. Thereafter, a rotation detector was formed by covering the rotation detector portion with a cover to protect it from external forces, thereby constructing a servo motor.

[Problem that the invention seeks to solve]

The above conventional technology lacks consideration for insulation deterioration between the brush holder and end bracket due to brush powder, ease of assembly, and ease of handling.
Since it is made up of multiple parts, the gap between the slot and the brush varies widely, and the play of the brush causes
There was a problem that the defective rate of the rectified waveform was high.

In addition, the external lead wires for the motor and rotation detector are each provided with separate lead wires for assembly, packaging, and
Handling such as transportation and connection was troublesome.

An object of the present invention is to improve insulation deterioration, reduce rectification waveform defects, and improve assembly and handling of a DC servo motor.

[Means for solving problems]

One of the above objectives, to improve insulation deterioration, is to minimize the presence of electrical conductors near the brush holder inside the motor. This is achieved by changing the silviculture to insulators and increasing the insulation distance between the metal frame, such as the housing.

In addition, variations in the brush slots are not solved by assembling multiple parts, but by integrally molding the end bracket with an insulator with good molding precision.

Furthermore, ease of assembly will be improved by eliminating cutting, screwing, lead wire routing, and adjustment work as much as possible, and by using molding and uniquely determined fitting.

In addition, handling can be improved by attaching one of the commercially available standard connectors to the end bracket, even if the capacity of the motor changes.

Can be made into a simple shape that differs only in diameter and length, packaging,
Improved ease of handling such as transportation and connection is achieved.

[Effect]

For small motors that are light in weight and small in size, the strength of insulating materials such as plastic and dimensional changes due to heat or humidity are not a big problem, so it is also possible to take advantage of the advantage of better molding precision than aluminum die-casting. It is possible to integrally mold the end bracket and the slot part of the brush, the connector attachment part for external drawer, the housing of the brush holder, and the fitting part with the motor housing and use them without cutting.

This allows the end bracket and brush slot to
Since it is an insulator, the insulation distance between the live parts around the brushes and the non-live parts of the motor is 5 to 10 times greater than that of conventional products, making it possible to improve insulation deterioration due to brush abrasion powder.

In addition, since it is possible to mold the brush slot part with an accuracy of about 30 μm, it is possible to finish it with high precision with less tolerance accumulation and work variation than when assembling multiple parts. The variation in clearance is small, and it is possible to improve rectification waveform defects due to brush play.

Furthermore, the positioning fitting part eliminates neutral point adjustment, one-touch attachment of the brush holder and motor connector eliminates wiring inside the motor, and the single-turn detector lead is bonded to the end bracket. It eliminates the need for wiring and fixing, and improves assembly efficiency.

As mentioned above, when the external lead wires are made into connectors, the product shape becomes simpler, so robots can take them in and out of transportation cases, and packaging becomes easier. It is now possible to store a large number of products, and it is also possible to make one-touch connections with the connector during inspection and product mounting, improving ease of handling.

〔Example〕

An embodiment of the present invention will be described below.

Figure 1 shows the structure of the motor, with magnet 1
Glue it to the housing 2 made by five drawings of ferromagnetic material,
Make it the stator 3 of the motor.

Press-fit the iron core 5 into the shaft 4, press-fit and glue Komichitaro, and wind the armature coil 7 into the slot of the iron core 5.
The end of the coil is connected to the hook part of the Komichitaro by fusing to form the rotor 8 of the motor.

Then, a spacer 9 and a ball bearing 10 are placed on the anti-commutator side of the rotor 8 and inserted into the stator 3. On the Comichitaro side, there are 10 ball bearings and 1 thrust spring.
1, fit the plastic end bracket 12 to the housing 2, attach the end bracket holder 13 to the end bracket 12 and the housing 2 at a uniquely determined position, and join the housing 2 and the end bracket holder 13 by welding. and assemble.

Next, brush 14. Brush spring 15. A motor 19 is constructed by attaching an assembly consisting of a metal fitting 16 that integrates a brush holder and a motor connector to a brush holder housing portion 17 and a connector housing portion 18 of an end bracket 1-12.

Next, regarding the rotation detector mounted on this motor, an example of mounting a magnetic encoder will be described using FIG. 2.

A ferromagnetic detection gear 20 is fixed to the shaft 4 of a motor 19 so as to face a magnetic sensor 21. Then, the fixing part 24 that includes the magnetic sensor 21 and the waveform shaping circuit 23 is inserted into the slide 22 provided on the end bracket 12, and the gap between the detection gear 20 and the magnetic sensor 21 is defined using a spacer or the like. After setting the value and confirming that the detection signal of the magnetic sensor 21 is greater than the specified value,
Attach the end bracket 12 and fixing part 24 with instant adhesive 25.
Fix between.

Next, it was inserted into the radial groove 26 of the end bracket 12. Lead terminals 29 of the waveform shaping circuit 23 are soldered to a printed board 28 to which a connector 27 for connection with an external circuit is soldered to form an electric circuit. Finally, cover with cover 30 to protect the whole thing.

The magnetic encoder 31 is configured with dustproof, magnetic, and electrostatic shielding.

FIG. 3 is a side view of the end bracket, showing brush slots 32. Brush holder housing part 17. A connector housing portion 18 is provided, and the two types of housing portions are connected by a groove 33, which serves as a storage area for a conductor that connects the brush holder and the connector.

Next, attach the magnetic encoder 3 to the top of the connector housing.
A groove 26 is provided for inserting the first connection connector 27, and the slide 22 of the fixing portion 24 of the magnetic encoder 31 is further provided above the groove 26.

FIG. 4 shows a side view of the end bracket in a direction perpendicular to FIG. 3; The recess 34 is the end bracket holder 13
The recess 35 at the bottom is for positioning to prevent the end bracket 12 from moving in the radial direction.When the housing 2 and the end bracket holder 13 are fixed by pouring liquid, the welding slag enters the motor and the coil This slag pocket is designed to prevent the insulation from deteriorating or from getting into the gaps between the brushes and causing a malfunction.

Figure 6 shows a metal fitting in which the brush holder and motor connector are integrally molded from an elastic body, and the brush holder part is 36 mm.
Connect the pigtail of the brush 14 through the brush spring 15 electrically by soldering or the like.

Connect mechanically. The cut-out portions 37 on both sides fit into the brush holder housing portion 17, and are prevented from falling off by spring force after one-touch installation. connector 38
In this case, the central protrusion 39 is the terminal of the connector, and the cut-out portions 40 on both sides fit into the connector housing portion 18, and the spring force prevents the connector from falling off after one-touch installation.

As mentioned above, conductive structures that reduce the insulation distance between the wiring and the outer frame are eliminated inside the end bracket.
By increasing the creepage distance and spatial distance from the brush to the non-charged metal body compared to conventional products, we were able to improve the insulation deterioration caused by brush dust.

Furthermore, by integrally molding the brush slot portion with the end bracket, we were able to improve accuracy. As a result, we were able to stabilize the behavior of the brush and drastically reduce the rate of defective rectified waveforms.

Further, as shown in FIG. 7, the housing 2 is provided with a fitting part 41 for the end bracket holder 13, and the magnet 1 is adhered using this fitting part as a reference, and the housing 2 and the end bracket 12 are connected to the end bracket holder 13. By fitting them together, the relationship between the motor stator and the brush is uniquely determined, and this is done while looking at the rectified waveform, which was conventionally done.

The system was designed to improve productivity by eliminating the impossible neutral point adjustment work.

Furthermore, the fixed part 24 of the magnetic encoder 31 and the detection gear 2
The gap adjustment work with 0 is an adjustment in 10μm units, and if you perform adjustment or fixing work while applying mechanical force such as screwing, the gap may change due to subtle deformation of the structure such as the end bracket support. The process of re-checking, disassembling and re-fixing became impossible.

As a solution to this problem, the fixing part 24 of the magnetic encoder is fixed to the slide 22 with an instant adhesive after the gap adjustment is completed without applying any mechanical force to the structure.

〔Effect of the invention〕

As described above, according to the present invention, there are provided an end bracket, a brush slot, a brush holder housing, a connector housing, and a rotation detector connector mounting portion.

By integrally molding the positioning part and the fitting part with an insulating material, it is possible to improve insulation deterioration due to brush abrasion powder, rectification waveform improvement 9, ease of assembly, and ease of handling.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the structure of the motor, Fig. 2 is a diagram showing the structure of the magnetic encoder, Fig. 3 is a diagram showing the side surface of the end bracket, and Fig. 4 is a diagram showing the side surface of the end bracket.
5 is a plan view of the end bracket, FIG. 6 is a view showing the metal fitting 36, FIG. 7 is a sectional view of the housing, and FIG. 8 is a sectional view of the end bracket. DESCRIPTION OF SYMBOLS 1... Magnet, 2... Housing, 3... Stator, 4... Shaft, 5... Iron core, 6... Commutator, 7... Coil, 8... Rotor, 9... Spacer, 10... Ball bearing, 11... Thrust spring, 12... End bracket, 13... End bracket holder, 14... Brush, 15...
Brush spring, 16... Metal fitting, 17... Brush holder housing part, 18... Connector housing part, 19
...Motor, 20...Detection gear, 21...Magnetic sensor, 22...Slide, 23...Waveform shaping circuit, 24...Fixing part, 25...Adhesive, 26...・Groove, 27... Connector, 28... Printed board, 29.
...Lead terminal, 30...Cover, 31...Magnetic encoder, 32...Brush slot, 33...Groove,
34... Hollow, 35... Hollow, 36... Brush holder part, 37... Cut-out part, 38... Connector, 39
...Protrusion, 40... Cut-and-raised part, 41... Fitting part. 2 days ago zl--Ichibian 1 ki faint so near 3 figures λZ rate horse map 5 figures 6 days ago

Claims (1)

[Claims] 1. In a DC servo motor configured such that the motor is formed on one side of the molded insulator and the rotation detector is formed on the other side, the intermediate molded insulator is used as an end bracket, and the brush holder housing and motor connector housing are integrally attached to this end bracket. The brush holder and rotation detector connector are arranged so that they do not overlap in the axial direction, and the brush holder and motor connector are integrally molded. , a DC servo motor, characterized in that it is attached to the housing.