JP2003153488A - Electric motor provided with reduction mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric motor provided with reduction mechanism which has simple structure for protecting a commutator and a brush holder in the case of assembling. SOLUTION: The electric motor provided with reduction mechanism has a motor 17 having a rotating shaft provided with the commutator 30, and a reduction mechanism 18 which reduces rotation of the rotating shaft 24 and transfers the rotation to an output shaft 42. The motor has a holder retaining member 32 for retaining the brush holder 34 in the radial direction outside the commutator 30, and connects electrically the rotating commutator 30 with the brush 35 by accommodating slidably the brush 35 in the brush holder 34. In the holder retaining member 32, a stopper 32d is installed to abut against the commutator 30 in the axial direction and limit axial direction movement of the commutator 30. In the case of assembling, an abutting surface 30c of the commutator 30 abuts against the stopper 32d, thereby surely preventing a connection part 31 of the commutator 30 and an armature coil 29 from coming into contact with the brush holder 34.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor having a speed reducing mechanism, and more particularly to an electric motor with a speed reducing mechanism mounted on an electric component of an automobile.

[0002]

2. Description of the Related Art As an electric motor used for electric components of vehicles such as automobiles, it is operated by a battery, and at a low price, it satisfies the operation requirements of the electric components.
A commutator type DC motor is often used. Since this commutator type motor needs to supply current to the rotating rotor, the commutator provided on the rotating shaft of the rotor is
A brush connected to the power supply is slidably contacted and electrically connected.

In order to adapt such a motor to a wiper device which is an electric component of a vehicle, a deceleration mechanism is required for decelerating the rotation of the motor to a required number of revolutions and increasing the torque. Therefore, for example, a reduction mechanism having a worm gear is attached to such an electric motor, and it is one unit as an electric motor with a reduction mechanism.

In such an electric motor with a reduction mechanism, a thrust bearing is provided at the end of the rotary shaft. Further, an adjusting screw is provided which moves the thrust bearing in the axial direction to adjust the meshing of the gears and regulates the axial movement of the rotating shaft. Then, in order to reduce the thrust bearing and the adjusting screw, for example, as disclosed in Japanese Patent No. 2790987, two worms whose lead angles are opposite to each other are attached to one rotation shaft, and the worm is rotated when the gear rotates. An electric motor with a reduction mechanism has been developed in which thrust bearings and adjusting screws are reduced by mutually canceling out the axial forces.

[0005]

When assembling an electric motor with a reduction mechanism having a thrust bearing, when the armature in which the rotary shaft and the commutator are integrated is assembled, the rotary shaft comes into contact with the thrust bearing. Movement of the armature was restricted, and positioning was easy.

However, at the time of assembling the electric motor with a reduction mechanism that cancels the axial force by the reduction mechanism, the end portion of the rotating shaft of the armature is an open end, so that axial positioning is difficult. It was Further, when the armature is moved in the axial direction at the time of assembly to bring the commutator into sliding contact with the brush, a brush holder provided radially outward of the commutator,
There is a risk that the commutator may come into contact with the connection portion with the armature winding.

When the brush holder and the connecting portion come into contact with each other in this way, the brush holder may be deformed or the connecting portion may be broken or damaged, resulting in poor conduction.

An object of the present invention is to provide an electric motor with a reduction mechanism having a simple structure for protecting the brush holder and the commutator during assembly.

[0009]

An electric motor with a reduction mechanism according to the present invention comprises a rotary shaft having a commutator and an armature, and a reduction mechanism for reducing the rotation of the rotary shaft and transmitting the reduced rotation to an output shaft. An electric motor with a reduction mechanism, comprising: a housing that rotatably accommodates the rotating shaft; and a brush holder that is provided in the housing and in which a brush that slidably contacts the commutator is slidably held. A holder support member that supports radially outward, and provided on the holder support member,
And a stopper for limiting axial movement of the commutator.

The decelerating electric motor of the present invention is characterized in that the commutator comes into contact with the stopper to limit axial movement of the commutator.

The electric motor with a reduction mechanism of the present invention is characterized in that a plurality of the stoppers are provided.

The electric motor with a reduction mechanism of the present invention is characterized in that the stopper is formed in an annular shape.

In the electric motor with a reduction mechanism of the present invention, when the commutator contacts the stopper, the armature-side end of the commutator is axially separated from the brush holder. And

The electric motor with a reduction mechanism of the present invention is characterized in that a plurality of worm gears are used as the reduction mechanism.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic view of a wiper device 10 having an electric motor with a reduction mechanism according to an embodiment of the present invention, and FIG. 2 is a sectional view showing the structure of the electric motor with a reduction mechanism shown in FIG. is there.

The wiper device 10 shown in FIG. 1 has a driver side wiper arm 11a and a passenger side wiper arm 11b that are swingably provided on the vehicle body, and each wiper arm 11a, 11b includes: Wiper blade 12
a and 12b are attached. Each wiper blade 12a, 12b has a wiper arm 11a, 11b.
A spring member (not shown) or the like installed inside is elastically contacted with the windshield 13. Further, the vehicle body is provided with two wiper shafts 14a and 14b, and the base end portions of the wiper arms 11a and 11b are attached to the wiper shafts 14a and 14b, respectively, and serve as swing centers of the wiper arms 11a and 11b, respectively. .

These wiper blades 12a, 12b
However, by swinging the wiping ranges Aa and Ab indicated by the alternate long and short dash line in FIG. 1, it is possible to wipe away rain, snow, etc. adhering to the windshield 13. In order to swing the wiper blades 12a and 12b in this manner, the wiper arms 11a and 11b have crank mechanisms 15a and 15b, respectively.
An electric motor 16 with a reduction mechanism is provided via 15b.

As shown in FIG. 2, the electric motor 16 with a speed reduction mechanism is composed of a motor section 17 and a speed reduction mechanism section 18. The motor housing 19 of the motor portion 17 is formed in a cylindrical shape with a bottom, and the gear housing 20 of the reduction gear mechanism portion 18 includes a gear housing portion 20 a and the motor housing 1.
9, a bearing housing 20 formed in a cylindrical shape having substantially the same size as 9
b. The motor housing 19 and the gear housing 20 are connected by a fastening member (not shown) in a state where the opening end of the motor housing 19 and the bearing housing portion 20b of the gear housing 20 are in contact with each other. 16 housings 21 are formed.

On the inner peripheral surface of the motor housing 19, there are provided two permanent magnets 21a and 21b arranged so that different magnetic poles face each other, and a magnetic field is formed inside the motor housing 19. There is. Also,
An armature, that is, an armature 23 is provided inside the motor housing 19 so as to be located in this magnetic field. The rotating shaft 24 of the armature 23 has a bottom portion of the motor housing 19 and a bearing accommodating portion 20b of the gear housing 20.
They are rotatably supported by self-aligning type bearings 25 and 26 respectively provided on the and.

The armature 23 has an armature core 28 in which a plurality of slots 27 are formed in the axial direction, and the armature core 28 is formed by laminating the armature blanks in the axial direction. Amateur core 28
An insulated copper wire is wound around each of the slots 27 to form an armature coil 29 that is an armature winding. Insulation is provided between the amateur coil 29 and the amateur core 28 by an insulating film.

On the rotary shaft 24 of the amateur 23, a commutator or commutator 30 is provided adjacent to the amateur core 28.
Is fixed. The commutator 30 is composed of a resin body portion 30a fixed to the rotary shaft 24, and a plurality of commutator pieces 30b arranged on the outer circumference of the body portion 30a so as to be insulated from each other. Is 2
Two amateur coils 29 are connected. A hook-shaped connecting portion 31 is formed at one end of the commutator piece 30b, and the end portion of the connecting portion 31 is pressed against the commutator piece 30b with the amateur coil 29 entwined with the connecting portion 31. It is welded by energization and the connecting portion 31 is formed in an annular shape.
Further, a contact surface 30c is formed on the end surface of the body portion 30a on the speed reduction mechanism 18 side.

Inside the bearing accommodating portion 20b of the housing 21, a holder supporting member 32 made of resin is mounted by a fastening member 33. The holder support member 32 includes the rotary shaft 2
It has a through hole 32a for guiding 4 in the center, and has a substantially semicircular mounting portion 32b and an insulating wall 32c formed on a part of the outer periphery of the mounting portion 32b. A box-shaped brush holder 34 is attached to the mounting portion 32b so as to face each other, and an opening is formed inward in the radial direction. A rectangular parallelepiped brush 35 is accommodated in each of the brush holders 34 together with a compression coil spring 36. The brush 35 biased by the compression coil spring 36 and protruding from the opening is provided in the radial direction of the rotary shaft 24. It vertically contacts the brush sliding surface 30d of the child piece 30b. Since the brush 35 is energized, the commutator 30
Even if rotates, it will follow the commutator piece 30b. The brushes 35 are provided with conductive lines 37, respectively. By supplying a current from a control unit (not shown) to each conductive line 37, a reverse current is supplied to each brush 35. Has become.

Further, the through hole 32 of the holder supporting member 32.
A stopper 32d that restricts the axial movement of the commutator 30 by contacting the contact surface 30c of the commutator 30 is formed on the outer peripheral portion of the a in an annular shape. Therefore, when the armature 23 is assembled and the commutator 30 and the brush 35 are brought into sliding contact with each other when the electric motor 16 with the reduction mechanism is assembled, the rotary shaft 2 of the armature 23 is
4 is inserted into the through hole 32a of the holder support member 32 and the stopper 32d and the contact surface 30c of the commutator 30 are brought into contact with each other, whereby the commutator 30 can be easily positioned in the axial direction. Further, at the time of contact, the brush sliding contact surface 30d
Since the formation position of the stopper 32d is set so that the brush holder 34 is arranged radially outward in the upper direction, even when the contact surface 30c of the commutator 30 contacts the stopper 32d, the armature of the commutator 30 does not move. On the side of 23, the connecting portion 31 and the brush holder 34, which are formed in a protruding shape, are provided.
Contact with is prevented. In this way, the brush holder 34
It is possible to prevent deformation and damage of the commutator 30, and it is possible to reliably secure the current supply from the brush 35 to the amateur coil 29.

4A and 4B are perspective views showing holder supporting members 38 and 39 in another embodiment of the present invention. As shown in FIG. 4 (A), the stopper 32d may not be formed in an annular shape, but may be a stopper 38d that axially contacts the contact surface 30c of the commutator 30 by forming a hook-shaped cross section. Also, FIG.
As shown in (B), a plurality of stoppers 39d may be provided.

In such an electric motor, when a reverse current is supplied to each of the conductive wires 37 provided on the brush 35, a current is supplied to the armature coil 29 from the commutator piece 30b slidingly contacting the brush 35. . Here, since all the commutator pieces 30b and all the amateur coils 29 are connected, the current supplied from the commutator piece 30b with which one brush 35 is in sliding contact is the same as that of the two commutator pieces 30b. It is distributed to the amateur coil 29, and is supplied toward the commutator piece 30b with which the other brush 35 is in sliding contact, via the other commutator piece 30b and the other amateur coil 29. By this energization, a rotational force is generated in each of the amateur coils 29 arranged in the magnetic field in accordance with the energizing direction according to Fleming's left-hand rule.
In the current supply at this time, the amateur coil 2 is prevented from canceling the rotational forces depending on the rotation angle, that is, the direction of the magnetic field and the arrangement of the amateur coil 29.
Since it is necessary to switch the energization direction of 9, the energization direction is controlled by energizing the commutator 30 rotating integrally with the armature 23 via the brush 35. The rotation speed and the like can be controlled by controlling the current value.

The speed reducing mechanism housed in the speed reducing mechanism 18 will be described below. As shown in FIG. 2, a rotary shaft 24 projects inside the gear housing 20a, and two worms 40a and 41a each having an opposite advance angle are formed at the tip of the rotary shaft 24. Two worm wheels 40b, 41 are formed inside the gear accommodating portion 20a so as to mesh with the worms 40a, 41a.
Worm gears 40 and 41 are configured by mounting b.

When the worm gears 40 and 41 are constructed in this way, the worms 40a and 41a are replaced by the worm wheel 40.
The thrust force acting in the axial direction of the rotary shaft 24 is received by the b and 41b.
Since the lead angle of 1a is formed in the opposite direction, the thrust forces act in mutually opposite directions, and act as forces for suppressing the movement of the rotary shaft 24 in the thrust direction. Therefore, the rotary shaft 24 is not provided with a thrust bearing or the like for suppressing the movement in the thrust direction.

In addition, these warm wheels 40b, 4
1b are provided with pinion gears 40c and 41c coaxially, and these pinion gears 40c and 41c are provided.
A driven gear 43 integrally formed with the output shaft 42 of the reduction gear mechanism 18 is engaged with the gear. Therefore,
The rotation of the rotary shaft 24 is decelerated by the worm gears 40 and 41, the pinion gears 40c and 41c, and the driven gear 43, and is transmitted to the output shaft 42.
The output shaft 42 is connected to the wiper arms 11a and 11a.
It is connected to b through the crank mechanisms 15a and 15b, and the wiper arms 11a and 11b are made to oscillate about the wiper shafts 14a and 14b.

Electric motor 16 with such a reduction mechanism
The mounting positions of the worm wheels 40b and 41b and the driven gear 43 are set so as to have a certain clearance between the end surface of the commutator 30 and the end surface of the stopper 32d due to the meshing of the gears. Even when the stopper 32d is in contact with the stopper 32d, the rotary shaft 24 rotates and the two worm gears 40 and 41 mesh with each other to secure a certain clearance. Therefore, the stopper 32d and the commutator 30 do not rotate while being in contact with each other.

It is needless to say that the present invention is not limited to the above-mentioned embodiment, and various modifications can be made without departing from the scope of the invention. For example, in the present embodiment, the stoppers 32d, 38d, 39d are formed integrally with the holder supporting members 32, 38, 39, but the holder supporting members 32, 38, 39 have stoppers 32d, 38.
You may fix d and 39d with a fastening member etc.

Further, although the electric motor with the reduction mechanism is used for the wiper device 10 of the automobile, the invention is not limited to this and may be applied as a drive source for other devices such as a power window.

Further, in the present embodiment, both wiper arms 11a and 11b are driven by the individual electric motors 16 with reduction gears. However, both wiper arms 1a and 1b are driven by one electric motor with reduction gears and a link mechanism.
It can also be applied to a type that operates 1a and 11b.

[0034]

According to the present invention, the holder supporting member for supporting the brush holder is provided with the stopper for restricting the axial movement of the commutator to prevent the brush holder and the commutator from contacting each other during assembly. It is possible to prevent the brush holder and the commutator from being deformed or damaged.

According to the present invention, the holder supporting member for supporting the brush holder is provided with the stopper for restricting the axial movement of the commutator when the commutator comes into contact with the holder supporting member. It is possible to reliably prevent contact between the two and prevent the brush holder and the commutator from being deformed or damaged.

According to the present invention, the holder support member for supporting the brush holder is provided with a plurality of stoppers for restricting the axial movement of the commutator when the commutator comes into contact with the holder support member.
It is possible to more reliably prevent contact between the brush holder and the commutator during assembly, and to prevent deformation and damage of the brush holder and the commutator.

According to the present invention, the holder supporting member for supporting the brush holder is provided with the stopper, which restricts the axial movement of the commutator by contacting the commutator, with an annular shape. The contact with the child can be more reliably prevented, and the brush holder and the commutator can be prevented from being deformed or damaged.

According to the present invention, the axial movement of the commutator is restricted by the contact of the commutator with the holder supporting member for supporting the brush holder, and the armature side of the commutator with respect to the brush holder at the time of contact. By providing a stopper that separates the end of the brush holder in the axial direction, it is possible to reliably prevent the contact between the end of the armature side of the commutator and the brush holder during assembly, and prevent the brush holder and the commutator from being deformed or damaged. You can

According to the present invention, the holder supporting member for supporting the brush holder is provided with the stopper for restricting the axial movement of the commutator, so that the contact between the brush holder and the commutator during assembly can be reliably prevented. It is possible to prevent the brush holder and the commutator from being deformed or damaged. Furthermore, by using a plurality of worm gears as the reduction mechanism, a gap can be provided between the stopper and the commutator during operation, and the commutator can be rotated without contacting the stopper.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a wiper device having an electric motor with a reduction mechanism that is an embodiment of the present invention.

FIG. 2 is a sectional view of the electric motor with a reduction mechanism shown in FIG.

FIG. 3 is an exploded perspective view showing a holder support member and an armature shown in FIG.

4A and 4B are perspective views showing a holder support member of an electric motor with a reduction mechanism according to another embodiment of the present invention.

[Explanation of symbols]

10 Wiper device 11a, 11b wiper arm 12a, 12b wiper blade 13 windshield 14a, 14b wiper shaft 15a, 15b crank mechanism 16 Electric motor with reduction mechanism 17 Motor part 18 Speed reduction mechanism (speed reduction mechanism) 19 Motor housing (housing) 20 Gear housing (housing) 20a gear housing 20b bearing housing 21 housing 21a, 21b Permanent magnet 23 Amateur (armature) 24 rotation axis 25,26 bearing 27 slots 28 Amateur Core 29 Amateur Coil 30 commutator (commutator) 30a body 30b commutator piece 30c contact surface 30d brush sliding surface 31 Connection 32 Holder support member 32a through hole 32b mounting part 32c insulation wall 32d stopper 33 Fastening members 34 brush holder 35 brushes 36 Compression coil spring 37 Conductive wire 40,41 Worm gear 40a, 41a warm 40b, 41b warm foil 40c, 41c pinion gear 42 Output shaft 43 Driven gear Aa, Ab wiping range

Continued front page    F-term (reference) 5H605 AA08 BB05 BB09 CC07 CC08                       DD09 EA25                 5H607 AA14 BB01 BB04 BB14 BB26                       CC01 CC03 CC09 DD09 DD10                       DD16 EE32 FF01 HH07 JJ06                 5H613 AA02 AA06 BB27 BB35 GA01                       GA12 GB17 PP03 SS02                 5H623 AA10 BB07 GG13 GG16 GG22                       JJ06

Claims (6)

[Claims] 1. An electric motor with a reduction mechanism, comprising: a rotation shaft having a commutator and an armature; and a reduction mechanism that reduces the rotation of the rotation shaft and transmits the rotation to the output shaft. A housing that rotatably accommodates; a holder support member that is provided in the housing and that supports a brush holder that slidably holds a brush that slidably contacts the commutator, radially outward of the commutator; and the holder An electric motor with a reduction mechanism, comprising: a stopper that is provided on a support member and that limits the axial movement of the commutator. 2. The electric motor with a reduction mechanism according to claim 1, wherein the axial movement of the commutator is restricted by the abutment of the commutator with the stopper. . 3. The electric motor with a reduction mechanism according to claim 2, wherein a plurality of the stoppers are provided. 4. The electric motor with a reduction mechanism according to claim 2, wherein the stopper is formed in an annular shape. 5. The electric motor with a reduction mechanism according to any one of claims 2 to 4, wherein when the commutator comes into contact with the stopper, the brush holder is provided on the armature side of the commutator. An electric motor with a reduction mechanism, characterized in that its ends are axially separated. 6. The electric motor with a reduction mechanism according to claim 1, wherein a plurality of worm gears are used as the reduction mechanism.