JPH0724929Y2 - motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a motor, and more particularly to a structure around a bearing of a motor shaft and a brush holder.

[Conventional technology]

In an electric motor, a rolling bearing is used as a means for rotatably supporting a motor shaft, and the rolling bearing is screwed by a bearing holder to an end bracket serving as a motor housing.

Further, a commutator and an armature are fixedly mounted on the outer periphery of the motor shaft adjacent to the rolling bearing, and a brush is arranged so as to make sliding contact with the commutator.When the armature is energized through the brush and the commutator, By cutting the magnetic field of the field magnet by the magnetic lines of force, the motor shaft is driven to rotate. On the other hand, the brush holder holding the brush is fixed to the brush holder stay, and the brush holder stay is provided adjacent to the rolling bearing.

[Problems to be solved by the device]

However, in such a motor, the rolling bearing receives the vibration that the motor shaft receives,
It is conceivable that the bolts that fix the bearing holder that holds the rolling bearing are loosened.

A first object of the present invention is to provide a motor capable of suppressing the loosening of the bolts fastening the bearing holder and preventing the bolts from falling off even if they are loosened. .

Further, in such a motor, if the brush abrasion powder adheres to the motor housing, the insulation resistance decreases.

A second object of the present invention is to provide a motor capable of preventing a decrease in insulation resistance.

[Means for Solving the Problems]

The motor according to the present invention has a commutator (12) on the outer periphery of the shaft (1) whose one end is supported by the rolling bearing (9).
Is fixed close to the rolling bearing (9), and a part (15) of the motor housing is provided on the outer periphery of the rolling bearing (9).
The bearing holder (14) fixed to the brush holder stay (18) is mounted integrally with the brush holder stay (18) concentric with the commutator (12). ) Is fixed to a brush holder (19) containing a brush (20) which is in sliding contact with the commutator (12), the bearing holder (14) is circumferentially attached to a part (15) of the motor housing. It is fastened by a plurality of bolts (16) arranged at intervals, and a cover (21) formed in a cylindrical shape by using an insulating material is provided in an outer region of the brush (20) in the motor housing. It is fitted so as to cover the inner peripheral surface of the motor housing, and a part of the cover (21) (21
The head of each of the bolts (16) is covered by a).

[Action]

According to the above-mentioned means, since the bolt is covered with the cover, even if the bolt is loosened, it does not come off and the rolling bearing can be retained.

Also, since the area around the brush is surrounded by the cover,
It is possible to prevent a decrease in insulation resistance due to brush abrasion powder.

〔Example〕

FIG. 1 is a side sectional view showing a motor according to an embodiment of the present invention, and FIG. 2 is a partially omitted enlarged partial sectional view taken along the line II-II of FIG.

In this embodiment, a hollow shaft 1 as a drive shaft in the motor according to the present invention includes a main body 2 having a cylindrical shape. A mounting portion 4 for mounting a rolling bearing, which will be described later, is formed on the outer periphery of one end of the hollow shaft main body 2 with a small diameter having a constant width and a constant depth, and a male screw portion 5 is formed on the axially outer side portion of the mounting portion 4. Is engraved.

Further, an engaging groove 6 for engaging a tongue piece of a bearing washer, which will be described later, is formed in a part of the mounting portion 4 in the circumferential direction so as to have a constant width and a constant depth in the axial direction toward the vicinity of the tip of the male screw portion 5. It is buried. That is, the engaging groove 6 is cut to the middle of the male screw portion 5, and a residual wall portion 6a is formed at the outer end portion thereof. Therefore, the reinforcing ring portion 7 having a constant width and a constant thickness is concentrically arranged and integrally projected at the axially outer end of the male screw portion 5 of the hollow shaft body 2.

The rolling bearing 9 is assembled and fixed to the hollow shaft 1 configured as described above as follows. That is, first, the distance ring 8 is fitted into the mounting portion 4 of the hollow shaft 1 until it abuts on the step portion 4a of the mounting portion 4. Then, the rolling bearing 9 is fitted into the mounting portion 4 until it abuts on the distance ring 8.

Then, the bearing washer 10 is fitted to the mounting portion 4 until it abuts on the rolling bearing 9. At this time, the tongue piece 10b is bent on the inner circumference of the bearing washer 10 toward the axial direction bearing side at a substantially right angle.
Is inserted into the forming groove 6 of the mounting portion 4. By inserting the tongue piece 10b into the engaging groove 6, the bearing washer 10 is stopped from rotating with respect to the hollow shaft 1.

Subsequently, the nut 11 is screwed onto the male screw portion 5 of the hollow shaft 1, and the rolling bearing 9 which is externally mounted on the mounting portion 4 is separated by the step portion 4a of the mounting portion 4 and the nut 11 to form the distance ring 8 and the bearing. It is fastened via a washer 10. When the rolling bearing 9 is completely fixed, a part of the plurality of engaging claws 10a radially arranged at equal intervals in the circumferential direction on the outer circumference of the bearing washer 10 has an outer circumference of the nut 11. Engagement grooves that are circumferentially spaced apart and that are recessed radially inward
It is bent and deformed so as to be inserted into 11a. This engaging claw 1
Due to the engagement between 0a and the engaging groove 11a, the nut 11 is in a state in which it is prevented from rotating by the hollow washer 1 through the bearing washer 10, so that the nut 11 is prevented from loosening as the hollow shaft 1 rotates. Will be blocked.

In the present embodiment, a commutator 12 and an armature 13 are sequentially arranged on the outer periphery of the intermediate portion of the hollow shaft 1 as a motor shaft from the side of the mounting portion 4 and are fixed so as to rotate integrally. The rolling bearing 9 is fastened to the mounting portion 4 of the hollow shaft 1 on which the commutator 12 and the armature 13 are fixed by the nut 11 by the above-described assembling work. At this time, the bearing holder 14 is previously press-fitted and fixed to the outer circumference of the outer ring of the rolling bearing 9, and
The bearing holder 14 is fixed to the brush holder stay 18 with the bolt 17
Is fixed, and the head of the bolt 17 is embedded by potting with an epoxy resin or the like. A brush holder 19 is fixed to the brush holder stay 18, and the brush 20 held by the brush holder 19 is slidably contacted with the commutator 12 fixed on the hollow shaft 1.

The hollow shaft 1 has the rolling bearing 9, the bearing holder 14, the brush device, the commutator 12, and the armature 13 fixed thereto, and one end bracket 15 that constitutes a part of the motor housing from the bearing holder 14 side. Inserted in. Then, the bolt 16 is inserted into the bearing holder 14,
The hollow shaft 1 is assembled to the end bracket 15 in a positioned state. Three bolts 16 for fastening the bearing holder 14 to the end bracket 15 are arranged at substantially equal intervals in the circumferential direction and are respectively screwed in in the axial direction, and the heads thereof are the end brackets 13 of the bearing holder 14. It is recessed so that it does not protrude from the end surface on the opposite side.

Next, a resin cover 21 is fitted around the outer periphery of the brush holder stay 18, and the outside of the brush holder stay 18 and the brush holder 19 is surrounded by the cover 21.

The cover 21 is integrally molded into a substantially cylindrical shape by using an insulating material such as resin. The cover 21 has three covering portions 21a at one end thereof, and the bearing holder 14 and the end bracket 13.
Are arranged so as to face the positions of the respective bolts 16 for fastening to, and are respectively provided to project radially inward. A rib 21b is arranged on each coating portion 21a on the opposite side of the bearing holder 14 and is projectingly provided so as to support the coating portion 21a.
Then, in the state where the cover 21 is fitted to the outer periphery of the brush holder stay 18, each covering portion 21a faces the head of each bolt 16 and covers the bolt 16.

A labyrinth ring 31 for forming a labyrinth structure is integrally projectingly provided on the inner periphery of the brush holder stay 18. That is, the labyrinth ring 31 is formed in a ring shape having an L-shaped cross section, and the tip end of the cylinder opening thereof substantially opposes the central portion of the rolling bearing 9 and is located between the bearing holder 14 and the distance ring 8. Are arranged concentrically with the brush holder stay 18 and project radially inward. Therefore, on the rolling bearing 9 side of the labyrinth ring 31, a carbon deposition space 32 is formed between the inner peripheral surface of the bearing holder 14 and an annular shape extending along the space 32.
Labyrinth ring so that the volume of 32 is as large as possible
The thickness of 31 is set thin.

Further, a yoke 22 forming a part of the motor housing is put on the opening of the end bracket 15 in a state of being externally inserted into the hollow shaft 1. The yoke 22 is fastened to the end bracket 15 with a bolt 24 at a flange portion 23 welded to the outer circumference of one end portion thereof. At this time, cover 21
Is held between the end surface of the yoke 22 and the brush holder stay 18. A magnet 25 is circumferentially arranged and fixed to the inner circumference of the yoke 22. The magnet 25 is a hollow shaft 1
It faces the armature 13 fixed to the.

A second end bracket 28 is put on the other end opening of the yoke 22, and a flange 26 welded to the outer periphery of the yoke 22 is attached to the end bracket 28 by a bolt 27. It is joined by being fastened to. A rolling bearing 29 is fitted in the second end bracket 28 and positioned and held by a stopper ring 30. One end of the hollow shaft 1 is fitted in the inner ring of the rolling bearing 29. As a result, the hollow shaft 1 is rotatably supported by the rolling bearings 9 and 29 arranged on both end brackets 15 and 28.

Next, the operation will be described.

In the motor constructed and constructed in this way,
When power is supplied to the armature 13 through the brush 20 and the commutator 12, the magnetic force lines of the armature 13 are magnetized.
By cutting the magnetic field of 25, the hollow shaft 1 is rotationally driven. Then, during this rotational drive, the brush abrasion powder is scattered by sliding with the commutator 12, and the rolling bearing 9
Is transmitted to the bolt 16.

Brush abrasion powder is scattered and the yoke 22 and end bracket 15
Insulation resistance gradually decreases. However, in this embodiment, since the cover 21 made of an insulating material is fitted around the outer periphery of the brush holder stay 18 to enclose the brush holder and the like, brush abrasion powder may adhere to the yoke 22 and the end bracket 15. In addition, a decrease in insulation resistance is prevented. That is, the inner peripheral surface of the area of the yoke 22 and the end bracket 15 facing the brush 20 is covered by the cover 21.
Since it is completely covered by the brush 20, the brush abrasion powder scattered from the sliding contact surface of the brush 20 with the commutator 12 adheres to the inner peripheral surface of the cover 21, so that the inner peripheral surfaces of the yoke 22 and the end bracket 15 are covered. It does not adhere directly to the surface.

Further, when the vibration of the rolling bearing 9 is transmitted to the bolt 16, the bolt 16 may be loosened and come off, but in the present embodiment, the bolt 16 is covered with the covering portion 21a of the cover 21 and Since the cover 21 is sandwiched between the end surface of the yoke 22 and the brush holder stay 18, even if the cover 21 is loosened, it is not pressed down by the covering portion 21a and does not come off. Hold is continued.

By the way, during the motor operation, the brush abrasion powder scattered due to the sliding contact of the brush 20 with the commutator 12 is absorbed by the brush holder stay.
It may move toward the rolling bearing 9 from the inner peripheral portion of 18 or the inner peripheral portion of the brush holder 19.

However, in this embodiment, the labyrinth ring 31 formed in a ring shape having an L-shaped cross section is provided on the inner periphery of the brush holder stay 18 so as to project radially inward, so that the brush 20 and the rolling bearing 9 are separated from each other. Since the connecting space is formed in the labyrinth structure by the brush holder stay 18, the commutator 12, the bearing holder 14 and the distance ring 8,
When the hollow shaft 11 is rotationally driven, even if the brush abrasion powder scatters, the abrasion powder is prevented from invading the rolling bearing 9 side. That is, brush abrasion powder from the inner peripheral portion of the brush holder stay 18 or the inner peripheral portion of the brush holder 19 does not adhere to the end bracket 15 which is a part of the motor housing.

Further, the thickness of the labyrinth ring 31 of the brush holder stay 18 is set so that the volume of the carbon deposition space 32 formed between the brush holder stay 18 and the bearing holder 14 is maximized, so that carbon abrasion powder scatters. In this case, these can be taken in and deposited in the space 32, and the deposited abrasion powder and grease can be prevented from scattering again.

In this embodiment, as shown in FIG. 1, since the extending surface distance L from the outer peripheral surface of the hollow shaft 1 to the segment of the commutator 12 is long,
It is possible to suppress deterioration of insulation even if carbon abrasion powder is attached.

[Effect of device]

As described above, according to the present invention, since the bolt is covered with the cover, even if the bolt is loosened, it does not come off and the holding of the rolling bearing can be maintained.

Also, since the area around the brush is surrounded by the cover,
It is possible to prevent a decrease in insulation resistance due to brush abrasion powder.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a motor according to an embodiment of the present invention, and FIG. 2 is a partially omitted enlarged partial sectional view taken along the line II-II of FIG. 1 ... Hollow shaft (motor shaft), 2 ... Main body, 3 ...
Hollow part, 4 ... Mounting body, 5 ... Male screw part, 6 ... Engaging groove, 6a ...
Remains, 7 ... Reinforcement ring, 8 ... Distance ring,
9 ... Rolling bearing, 10 ... Bearing washer, 10a ... Engaging claw, 10b ...
Tongue piece, 11 ... Nut, 11a ... Engagement groove, 12 ... Commitator, 13
... Armature, 14 ... Bearing holder, 15 ... End bracket, 16, 17, 24, 27 ... Bolt, 18 ... Brush holder stay, 19 ... Brush holder, 20 ... Brush, 21 ... Cover, 21a
... coating part, 21b ... rib, 22 ... yoke, 23, 26 ... flange part, 28 ... end bracket, 29 ... rolling bearing, 30 ... stop ring, 31 ... labyrinth ring, 32 ... carbon deposit part.

Claims (1)

[Scope of utility model registration request] 1. A commutator (12) is fixed to the outer periphery of a shaft (1) whose one end is supported by a rolling bearing (9) in close proximity to the rolling bearing (9). A bearing holder (14) fixed to a part (15) of the motor housing is mounted on the outer periphery, and a brush holder stay (18) concentrically arranged with the commutator (12) is integrally mounted on the bearing holder (14). The brush holder stay (18) has a brush holder (19) containing a brush (20) slidingly contacting the commutator (12) fixed to the brush holder stay (18), wherein the bearing holder (14) is the motor. It is fastened by a plurality of bolts (16) arranged at intervals in the circumferential direction on a part (15) of the housing, and an insulating material is used in an outer region of the brush (20) in the motor housing. Cylindrical shape Together it is a cover (21) is fitted so as to cover the inner circumferential surface of the motor housing, a portion of the cover (21) (21
A motor in which the heads of the bolts (16) are covered by a).