JP7457629B2 - Motor device - Google Patents

Description

The present invention relates to a motor device that includes a rotating shaft, a commutator fixed to the rotating shaft, brushes that slide against the commutator, a brush holder that holds the brushes, and a housing that contains the brush holder.

2. Description of the Related Art Conventionally, a motor device with a speed reduction mechanism that is small but can provide a large output is used as a drive source for a power window device or the like mounted on a vehicle such as an automobile. When the operator operates an operation switch provided in the vehicle interior, the motor device is rotated in forward and reverse directions, and the window glass is opened and closed.

Such a motor device is described in, for example, Patent Document 1. The motor device described in Patent Document 1 includes a motor part having an armature shaft, a gear part having a worm rotated by the armature shaft and a worm wheel (reduction mechanism), and a motor case and a gear case (housing) provided inside the motor part. The brush holder includes a brush holder and a connector member connected to the brush holder.

The brush holder, in which electronic components such as brushes and choke coils are installed, is formed into a predetermined shape by injection molding of a resin material such as plastic in order to improve insulation and reduce size and weight. .

International Publication No. 2014/178329

However, in the motor device described in Patent Document 1 mentioned above, when the brush holder is cooled (hardened) after injection molding, there is a risk that the part pressed into the motor case, i.e., the side wall of the brush holder (the part that serves as the reference for positioning), may shrink and warp. If the side wall of the brush holder bends and deforms in this way, the positional accuracy of the brushes and bearings held by the brush holder will decrease when the motor device is assembled. This could increase the rotational resistance of the armature shaft, leading to a decrease in the output torque of the motor device (occurrence of operating loss) and an increase in the operating noise of the motor device.

An object of the present invention is to provide a motor device that can suppress deflection of a portion that serves as a reference for positioning when a brush holder is hardened, and that can improve the molding accuracy of the entire brush holder.

The motor device of the present invention includes a rotating shaft, a commutator fixed to the rotating shaft, a brush slidingly in contact with the commutator, a brush holder holding the brush, and a housing accommodating the brush holder. The brush holder has a base part that extends in a direction intersecting the axial direction of the rotating shaft, and an abutting part that abuts against the housing from the axial direction of the rotating shaft, a side wall portion extending in the axial direction of the rotating shaft on the outer periphery of the base portion; a bearing that rotatably supports the rotating shaft; and a side wall portion extending in the axial direction of the rotating shaft on the inner periphery of the base portion; a bearing support part, and one surface of the base part is provided with the brush , a pressing member that presses the brush toward the commutator , and a support that supports the pressing member , A first reinforcing member that suppresses deflection of the side wall portion is provided on the other surface of the base portion , and the support column and the first reinforcing member are stacked on top of each other in the axial direction of the rotating shaft. do.

According to the motor device of the present invention, the side wall of the brush holder is provided with an abutting portion that abuts against the housing from the axial direction of the rotating shaft, and the other surface of the base is provided with a groove that suppresses deflection of the side wall. 1 reinforcing member is provided. As a result, when the brush holder is cured after injection molding, the side wall portion having the abutment portion (the portion that serves as a reference for positioning) is prevented from warping, and the molding accuracy of the entire brush holder can be improved. It becomes possible. Therefore, it is possible to effectively suppress a decrease in output torque (occurrence of operation loss) and an increase in operation noise of the motor device.

FIG. 2 is a cross-sectional view of a motor with a reduction mechanism. FIG. 3 is a perspective view of the brush unit viewed from the gear case side. FIG. 3 is a perspective view of the brush unit viewed from the motor case side. It is a side view of the brush holder alone. It is a view taken along arrow A in FIG. 4. 5 is a view taken along arrow B in FIG. 4. FIG. 7 is a partial cross-sectional view taken along line CC in FIGS. 5 and 6. FIG. FIG. 8 is a diagram corresponding to FIG. 7 illustrating a movable mold. It is a graph showing improvement in parallelism of the main part with respect to the abutting surface. It is a graph showing improvement in the perpendicularity of the main part with respect to the abutting surface.

EMBODIMENT OF THE INVENTION Hereinafter, one embodiment of this invention will be described in detail using drawings.

Figure 1 is a sectional view of a motor with a speed reduction mechanism, Figure 2 is a perspective view of a brush unit viewed from the gear case side, Figure 3 is a perspective view of the brush unit viewed from the motor case side, and Figure 4 is a single brush holder. 5 is a view in the direction of arrow A in FIG. 4, FIG. 6 is a view in direction of arrow B in FIG. 4, and FIG. 7 is a partial cross-sectional view taken along the line CC in FIGS. 5 and 6. , FIG. 8 is a diagram corresponding to FIG. 7 explaining the movable mold, FIG. 9 is a graph showing improvement in parallelism of the main part to the abutment surface, and FIG. 10 is a graph showing improvement in perpendicularity of the main part to the abutment surface. A graph is shown for each.

As shown in FIG. 1, a motor with a speed reduction mechanism (motor device) 10 is used as a drive source for a power window device mounted on a vehicle such as an automobile, and drives a window regulator that raises and lowers a window glass. . Since the motor 10 with a speed reduction mechanism is installed in a narrow space formed within a door of a vehicle, it is formed in a flat shape with a reduced thickness.

The motor with speed reduction mechanism 10 includes a motor section 20 and a gear section 30. The motor section 20 and the gear section 30 are integrated with a number of fastening screws 11 (only two are shown in the figure). A brush unit 40 is provided between the motor section 20 and the gear section 30 so as to be sandwiched between them. Furthermore, as shown by the arrow M1 in the figure, a connector member 50 is electrically connected to the brush unit 40 from a direction perpendicular to the extension direction of the axis AS. The connector member 50 is electrically connected to an external connector CN on the vehicle side. As a result, the motor with speed reduction mechanism 10 is driven in the forward and reverse directions by the driving current from the external connector CN, which in turn opens and closes the window glass.

The motor section 20 includes a motor case (housing) 21 formed into a cylindrical shape with a bottom by deep drawing a steel plate made of a magnetic material. The cross-sectional shape of the motor case 21 in a direction perpendicular to the axial direction (axis AS) is formed into a substantially oval shape. A total of four permanent magnets 22 (only two are shown in the figure) are fixed inside the motor case 21. These permanent magnets 22 are arranged at 90 degree intervals around the axis AS, and an armature 24 with a coil 23 wound around it is rotatably provided inside each permanent magnet 22 via a small gap (air gap). In other words, the armature 24 is rotatably housed inside the motor case 21.

The bottom side (right side in the figure) of the motor case 21 is formed into a stepped shape, and a bottomed cylindrical portion 21a having a smaller diameter than the main body of the motor case 21 is provided in the stepped portion. ing. A first thrust bearing TB1 and a first radial bearing RB1 are mounted inside the bottomed cylindrical portion 21a. The first thrust bearing TB1 and the first radial bearing RB1 are each provided on the axis AS, and rotatably support one axial side (the right side in the figure) of the armature shaft 25. In this way, the bottomed cylindrical portion 21a rotatably supports one axial side of the armature shaft 25 via the first thrust bearing TB1 and the first radial bearing RB1.

An armature shaft (rotation shaft) 25 is fixed to the rotation center of the armature 24. Further, a commutator 26 is fixed to a portion of the armature shaft 25 near the center in the axial direction and near the armature 24. The coils 23 wound around the armature 24 are electrically connected to the plurality of segments 26a forming the commutator 26, respectively. These armature 24, armature shaft 25, and commutator 26 are also each provided on the axis line AS.

A pair of brushes 45 (see FIG. 3), which are movably held by the brush holder 41, slide against the outer periphery of the commutator 26. The pair of brushes 45 are arranged at 90 degree intervals around the axis AS, and are each pressed toward the commutator 26 with a predetermined pressure by the spring force of the brush spring 46 (see FIG. 3). As a result, by supplying a drive current to the pair of brushes 45, an electromagnetic force is generated in the armature 24, which in turn rotates the armature shaft 25 in a predetermined rotational direction at a predetermined rotational speed.

The other axial side (left side in FIG. 1) of the armature shaft 25 is rotatably supported by a second thrust bearing TB2 and a second radial bearing RB2. The second thrust bearing TB2 and the second radial bearing RB2 are each provided on the axis AS, and are mounted inside the bearing mounting portion 31c of the gear case 31. In this way, the bearing mounting portion 31c rotatably supports the other axial side of the armature shaft 25 via the second thrust bearing TB2 and the second radial bearing RB2.

Further, a portion of the armature shaft 25 near the center in the axial direction is rotatably supported by a third radial bearing RB3. Here, the third radial bearing RB3 is fixed to the tip portion (left side portion in the figure) of a bearing support portion 43 forming the brush holder 41, and the tip portion of the bearing support portion 43 is fixed to the worm housing portion of the gear case 31. 31a and is fixed. The third radial bearing RB3 is also provided on the axis AS. The base portion 42, which is the main body portion of the brush holder 41, is fixed to the opening 21b of the motor case 21 so as not to shake.

In this way, the armature shaft 25 is rotatably supported by the three first radial bearings RB1, second radial bearing RB2, and third radial bearing RB3 provided on the axis AS. In other words, in order to ensure smooth rotation of the armature shaft 25, it is important to increase the coaxiality of each of the radial bearings RB1, RB2, and RB3.

Further, a worm 27 is fixed on the other axial side of the armature shaft 25 and between the second radial bearing RB2 and the third radial bearing RB3. Specifically, the worm 27 is firmly fixed to the other axial side of the armature shaft 25 by press fitting or the like. The worm 27 is engaged with the teeth 28a of a worm wheel 28, and the worm 27 and the worm wheel 28 form a speed reduction mechanism (worm speed reduction gear) SD.

The deceleration mechanism SD decelerates the high-speed rotation of the armature shaft 25 to increase the torque, and outputs the high-torque rotational force to the external window regulator from the output section 28b provided integrally with the worm wheel 28. do. Note that serrations SR consisting of a plurality of concave and convex portions are formed on the outer periphery of the output portion 28b, and the serrations SR are engaged with the driven portion of the window regulator.

Further, a sensor magnet MG formed in a substantially cylindrical shape is provided between the commutator 26 and the third radial bearing RB3 in the axial direction of the armature shaft 25. The sensor magnet MG is fixed to the armature shaft 25 via a bracket BR. That is, the sensor magnet MG is rotated as the armature shaft 25 rotates. Note that the sensor magnet MG is rotated inside the bearing support portion 43 of the brush holder 41. Thereby, adhesion of dust and the like to the sensor magnet MG can be effectively suppressed.

Here, a magnetic sensor SE is provided on the radially outer side of the sensor magnet MG via a bearing support portion 43. The magnetic sensor SE detects the rotational state of the sensor magnet MG, and sends the rotational state of the armature shaft 25 to an on-vehicle controller (not shown). Thereby, the on-vehicle controller grasps the opening/closing speed, opening/closing position, etc. of the window glass, and controls the rotational state of the armature shaft 25 based on this. Note that, for example, a Hall IC or the like that outputs a rectangular wave due to changes in magnetic flux is used as the magnetic sensor SE.

The gear portion 30 includes a gear case 31 formed into a predetermined shape by injection molding a resin material such as plastic. Here, in FIG. 1, the gear case 31 is shown by a two-dot chain line to simplify the illustration of the gear case 31. The gear case 31 is provided with a worm accommodating portion 31a formed in a substantially cylindrical shape, and the worm accommodating portion 31a is arranged on the axis AS. The worm 27, that is, the other axial side of the armature shaft 25 is rotatably housed inside the worm housing portion 31a.

Further, a mounting opening 31b that opens toward the motor section 20 is provided on one axial side (right side in the figure) of the worm housing section 31a. A bearing support portion 43 of the brush holder 41 is inserted into the mounting opening 31b. On the other hand, a bearing mounting portion 31c is integrally provided on the other axial side (left side in the figure) of the worm housing portion 31a. The bearing mounting portion 31c is provided coaxially with the worm housing portion 31a, and a second thrust bearing TB2 and a second radial bearing RB2 are respectively mounted inside the bearing mounting portion 31c.

Further, the gear case 31 is integrally provided with a worm wheel accommodating portion 31d aligned with the worm accommodating portion 31a. The worm wheel 28 is rotatably accommodated in the worm wheel accommodating portion 31d. Further, a connector member accommodating portion 31e into which the connector member 50 is inserted and fixed is provided in a portion of the worm wheel accommodating portion 31d closer to the motor portion 20 (the right side portion in the figure). Thereby, simply by inserting the connector member 50 into the connector member accommodating portion 31e, the magnetic sensor SE is accurately arranged at a prescribed position on the radially outer side of the sensor magnet MG.

Here, the connector member 50 includes an insertion body portion 51 that is inserted into the connector member housing portion 31e, and a connector connection portion 52 that is integrally provided with the insertion body portion 51. Specifically, the insertion main body portion 51 extends in a direction perpendicular to the extending direction of the axis line AS, and the connector connecting portion 52 extends in the extending direction of the axis line AS. That is, the insertion main body portion 51 and the connector connection portion 52 are connected to each other at right angles, and the connector member 50 as a whole is formed in a substantially L-shape.

A sensor board 53 is fixed to the tip side (lower side in the figure) of the insertion main body 51, and a magnetic sensor SE facing the sensor magnet MG is mounted on the sensor board 53. On the other hand, a rubber annular seal SL is attached to the proximal end side (upper side in the figure) of the insertion main body part 51, and is tightly attached to the inner wall of the connector member accommodating part 31e. This prevents dust and the like from entering into the gear case 31 from the connector member accommodating portion 31e.

A proximal end of a connector connecting portion 52 is integrally provided on the proximal end of the insertion main body portion 51 . Then, a vehicle-side external connector CN is connected to the distal end side of the connector connection portion 52. In addition, a plurality of conductive members 54 (two shown in the figure) made of a material with excellent conductivity such as brass are embedded inside the insertion body portion 51 and the connector connection portion 52 by insert molding or the like. Here, two of the plurality of conductive members 54 are used as a power source for supplying a drive current to the brush unit 40, and the other conductive members 54 are used to supply a detection signal ( It is used as a signal to send a weak current (weak current) to the on-vehicle controller.

Further, a total of three mounting leg portions 31f are integrally provided around the gear case 31. Fixing bolts (not shown) for fixing the motor 10 with a speed reduction mechanism to a mounting stay (not shown) provided in the door of the vehicle are inserted into these mounting legs 31f. Thereby, the gear case 31 (motor 10 with a reduction mechanism) is firmly fixed in the door of the vehicle without wobbling. The three mounting legs 31f are distributed around the gear case 31, thereby allowing the output section 28b of the worm wheel 28 to rotate stably without swinging.

As shown in Figures 2 to 6, the brush unit 40 includes a brush holder 41 formed into a predetermined shape by injection molding a resin material such as plastic. The brush holder 41 is housed inside the motor case 21 and the gear case 31. The brush holder 41 is provided with a base portion 42 that is generally flat and extends in a direction intersecting the axial direction (axis AS) of the armature shaft 25, and the shape of the base portion 42 along the direction intersecting the axial direction of the armature shaft 25 is generally oval. This allows the motor with reduction mechanism 10 to have a flat shape.

Specifically, the outer periphery of the base portion 42 includes a pair of straight portions 42a that are arranged opposite to each other with the axis AS (bearing support portion 43) as the center, and a 90-degree angle with respect to the pair of straight portions 42a with the axis AS as the center. A pair of arcuate portions 42b are arranged opposite to each other at positions shifted by degrees. A first surface SF1 serving as a front surface is provided on the gear portion 30 side of the base portion 42, and a second surface SF2 serving as a back surface is provided on the motor portion 20 side of the base portion 42. There is. Furthermore, a through hole 42c is provided in the center of the base portion 42, through which the armature shaft 25 passes through in a non-contact manner.

Here, the second surface SF2 of the base portion 42 constitutes one surface in the present invention, and the first surface SF1 of the base portion 42 constitutes the other surface in the present invention.

As shown in FIGS. 2, 4, and 5, a base end side of a bearing support portion 43 formed in a substantially rectangular parallelepiped shape is fixed to the first surface SF1 of the base portion 42. As shown in FIGS. The bearing support part 43 is hollow, and the inside of the bearing support part 43 communicates with the through hole 42c. That is, the bearing support portion 43 extends from the first surface SF1 of the base portion 42 to the other side in the axial direction of the armature shaft 25 on the inner periphery of the base portion 42.

An annular bearing press-fitting part 43a is provided on the distal end side of the bearing support part 43 and inside thereof, and the bearing press-fitting part 43a has a third ring that rotatably supports a portion of the armature shaft 25 near the center in the axial direction. A radial bearing (bearing) RB3 (see FIG. 1) is press-fitted. A sensor magnet MG (see FIG. 1) fixed to the armature shaft 25 is rotatably housed inside the bearing support portion 43.

A total of four case press-fit parts 43b are provided on the outside of the bearing support part 43. These case press-fit parts 43b extend in the axial direction of the armature shaft 25 (the direction in which the axis line AS extends), and are arranged at equal intervals (90 degree intervals) around the bearing support part 43. Then, the portions of these case press-fit portions 43b closer to the bearing press-fit portion 43a are press-fit into the mounting opening 31b (see FIG. 1) of the gear case 31. As a result, the brush holder 41 is attached to the gear case 31 without rattling, and the bearing support portion 43 is arranged on the axis AS. Here, the tip surface TS of the bearing support portion 43 extends in a direction perpendicular to the axis AS, and the tip surface TS and the base portion 42 are parallel to each other.

As shown in FIG. 5, the first surface SF1 of the base portion 42 is provided with a pair of first mounting portions 42d. These first mounting parts 42d are respectively arranged between the linear part 42a of the base part 42 and the bearing support part 43, with the bearing support part 43 at the center. A choke coil CC (see FIG. 2) is attached to each of the pair of first attachment parts 42d. That is, the pair of choke coils CC are each arranged between the straight portion 42a and the bearing support portion 43. Here, the choke coil CC has a function of reducing electrical noise dissipated to the outside of the motor 10 with a speed reduction mechanism.

Furthermore, as shown in FIG. 5, one second mounting portion 42e and two A third mounting portion 42f is provided. A varistor VS (see FIG. 2) is mounted on the second mounting portion 42e, and a capacitor CP (see FIG. 2) is mounted on the third mounting portion 42f. That is, the varistor VS and the capacitor CP are each arranged between one of the circular arc portions 42b and the bearing support portion 43. Here, the varistor VS has a function of protecting the motor 10 with a reduction mechanism from high voltage (surge), and the capacitor CP has a function of reducing electrical noise dissipated to the outside of the motor 10 with a reduction mechanism. have.

Furthermore, as shown in FIG. 5, two fourth mounting parts 42g are provided between the other circular arc part 42b (lower side in the figure) and the bearing support part 43 on the first surface SF1 of the base part 42. It is being A drive conductive member CM (see FIG. 2) is attached to each of the pair of fourth attachment portions 42g. That is, the pair of driving conductive members CM are arranged between the other circular arc portion 42b and the bearing support portion 43, respectively. These driving conductive members CM are made of a material with excellent conductivity such as brass, and have a function of supplying a driving current to the pair of brushes 45 (see FIG. 3). That is, a power supply conductive member 54 among the plurality of conductive members 54 (see FIG. 1) is electrically connected to each driving conductive member CM.

Here, in FIGS. 2 and 3, in order to make it easier to understand the arrangement relationship of electronic components (components that conduct electricity) with respect to the brush holder 41, these electronic components are each shaded.

As shown in FIGS. 3, 4, and 6, a side wall portion 44 is integrally provided on the second surface SF2 of the base portion 42 so as to surround the periphery of the base portion 42. As shown in FIGS. The side wall portion 44 protrudes from the second surface SF2 of the base portion 42 toward the motor portion 20 at a predetermined height (see FIG. 1). That is, the side wall portion 44 extends from the second surface SF2 of the base portion 42 to one side in the axial direction of the armature shaft 25 on the outer periphery of the base portion 42.

The side wall portion 44 includes a pair of flat wall portions 44a that are arranged opposite to each other with the bearing support portion 43 (axis line AS) at the center, and a 90-degree angle relative to the pair of flat wall portions 44a around the bearing support portion 43. A pair of arcuate wall portions 44b are arranged opposite to each other at offset positions.

As shown in FIG. 6, a fifth mounting portion 42h is located between one flat wall portion 44a (left side in the figure) and the through hole 42c (bearing support portion 43) on the second surface SF2 of the base portion 42. is provided. A first relay conductive member RM1 (see FIG. 3) is attached to the fifth attachment portion 42h. That is, the first relay conductive member RM1 is arranged between the one flat wall portion 44a and the through hole 42c, and the first relay conductive member RM1 is also made of a material with excellent conductivity such as brass. Note that the first relay conductive member RM1 is arranged between one brush 45, one choke coil CC, one capacitor CP, and varistor VS.

Further, a sixth mounting portion 42k is provided between the other flat wall portion 44a (on the right side in the figure) and the through hole 42c (bearing support portion 43) on the second surface SF2 of the base portion 42. A circuit breaker CB (see FIG. 3) is mounted on the sixth mounting portion 42k. That is, the circuit breaker CB is arranged between the other flat wall portion 44a and the through hole 42c. Note that the circuit breaker CB is arranged between the other brush 45 and the second relay conductive member RM2 made of a material with excellent conductivity such as brass. Here, the second relay conductive member RM2 is connected to the other choke coil CC, the other capacitor CP, and the varistor VS. Further, the circuit breaker CB has a function of protecting the motor 10 with a reduction mechanism from overheating.

Furthermore, as shown in FIG. 6, there are a total of four holes between one arcuate wall portion 44b (upper side in the figure) and the through hole 42c (bearing support portion 43) on the second surface SF2 of the base portion 42. A through hole TH is provided. These through holes TH communicate the first surface SF1 side (see FIG. 5) and the second surface SF2 side of the base part 42, and connect the lead wires (total of four wires) of the pair of capacitors CP (see FIG. 2). ) are inserted respectively.

Furthermore, as shown in FIG. 6, there are two holes between the other arcuate wall portion 44b (lower side in the figure) and the through hole 42c (bearing support portion 43) on the second surface SF2 of the base portion 42. A brush box 42m, two supports 42n, and two hooking claws 42p are provided.

The pair of brush boxes 42m are each provided in a portion closer to the flat wall portion 44a, and are arranged at 90 degree intervals with the armature shaft 25 (axis line AS) as the center. Inside each of these brush boxes 42m, carbon brushes 45 (see FIG. 3) each formed into a substantially rectangular parallelepiped shape are movably provided. Note that each brush 45 is movable toward the commutator 26 when the motor 10 with a speed reduction mechanism is assembled. Specifically, the brush 45 is adapted to slide on a brush sliding surface BS provided inside the brush box 42m.

Further, the pair of support columns 42n are arranged between a pair of brush boxes 42m arranged at 90-degree intervals, and these support columns 42n are equipped with a brush spring (pressing member) that presses the brush 45 toward the commutator 26. ) 46 (see FIG. 3). The pair of brush springs 46 are formed into a substantially cylindrical shape by spirally winding a metal wire, and are torsion coil springs (torsion springs) having a pair of end portions 46a. One end 46a is hooked on the hook 42p, and the other end 46a presses against the back surface of the brush 45.

In this way, the pair of brushes 45 each held by the pair of brush boxes 42m and the pair of brush springs 46 each supported by the pair of pillars 42n are arranged in the other arcuate shape on the second surface SF2 of the base portion 42. It is arranged between the wall portion 44b and the through hole 42c.

Further, the pair of hooking claws 42p are arranged between a pair of brush boxes 42m that are spaced apart from each other by 90 degrees, and are arranged closer to the through hole 42c than the pair of support columns 42n. The pair of hooking claws 42p face each other, and the tip end Tp of each hooking claw 42p projects inside a square hole 42s penetrating the base portion 42. Thereby, the end 46a of the brush spring 46 can be hooked onto the hook 42p without coming off.

As shown in FIG. 8, the square hole 42s is a portion formed by the long protrusion LT of the movable mold MM (shaded portion in the figure) used when injection molding the brush holder 41. This makes it possible to expose the tip portions Tp of the pair of hooking claws 42p inside the square hole 42s when the square hole 42s is viewed from the axial direction of the armature shaft 25. In other words, the square hole 42s is a "mold removal hole" for the long protrusion LT of the movable mold MM that is created when molding the tip portions Tp of the hooking claws 42p.

The brush holder 41 is formed by filling a cavity (not shown) formed by butting a fixed mold (not shown) against a movable mold MM with molten resin material at a predetermined pressure. The completed brush holder 41 can then be released from the mold by raising the movable mold MM, as shown by arrow M2 in FIG. 8.

As shown in FIGS. 2 to 6, the side wall portion 44 (flat wall portion 44a and arcuate wall portion 44b) is a portion that is press-fitted and fixed into the opening 21b (see FIG. 1) of the motor case 21. It has become. That is, the base part 42 side along the longitudinal direction of the brush holder 41 is press-fitted into the opening part 21b via the side wall part 44. Therefore, increasing the molding precision of the side wall portion 44 increases the coaxiality of the radial bearings RB1, RB2, and RB3 (see FIG. 1).

As shown in FIGS. 5 and 6, a total of six yoke press-fit portions 44c are provided on the outside of the side wall portion 44. These yoke press-fit portions 44c protrude from the side wall portion 44 at a very small height, and extend in a rod shape in the direction in which the axis AS extends. Thereby, the brush holder 41 (brush unit 40) can be easily press-fitted into the motor case 21 without increasing the press-fitting load so much. Specifically, two yoke press-fit portions 44c are provided on each pair of flat wall portions 44a, and one each is provided on each pair of arcuate wall portions 44b.

In this way, the yoke press-fit portion 44c is the portion that is press-fitted into the opening 21b, and has the function of positioning the brush holder 41 relative to the motor case 21 in a direction that intersects with the axial direction of the armature shaft 25 (extension direction of the axis AS).

In addition, two positioning protrusions 44d are provided on the outside of each of a pair of arc-shaped wall portions 44b that form the side wall portion 44. These positioning protrusions 44d protrude larger than the yoke press-in portion 44c outside the arc-shaped wall portion 44b, and extend in the circumferential direction of the base portion 42. These positioning protrusions 44d have the function of determining the press-in depth of the brush holder 41 into the motor case 21. Specifically, the positioning protrusions 44d are provided with a flat abutment surface 44e (see FIG. 6) on the motor case 21 side.

These abutting surfaces 44e constitute an abutting portion in the present invention, and are formed from the axial direction of the armature shaft 25 with respect to the abutting surface 21c (flat surface) provided on the opening 21b side of the motor case 21. (See Figure 1). Thereby, the brush holder 41 is accurately positioned with respect to the motor case 21. That is, each abutment surface 44e has a function of positioning the armature shaft 25 of the brush holder 41 with respect to the motor case 21 in the axial direction (extending direction of the axis line AS).

Note that the two positioning protrusions 44d provided on one arcuate wall portion 44b (upper side in FIGS. 5 and 6) are arranged at positions apart from each other, that is, at portions closer to the flat wall portion 44a. On the other hand, two positioning protrusions 44d provided on the other arcuate wall portion 44b (lower side in FIGS. 5 and 6) are arranged close to each other. Further, the gear case 31 (see FIG. 1) is abutted against the side of the positioning protrusion 44d opposite to the abutment surface 44e.

As shown in FIGS. 3, 4, 6, and 7, a pair of brush boxes 42m, a pair of supports 42n, and a pair of hooks 42p are provided near the other arcuate wall portion 44b. A pair of brushes 45 and a pair of brush springs 46 (see FIG. 3) are arranged. Therefore, due to space considerations, it is not possible to increase the thickness of the other arcuate wall portion 44b. Therefore, as shown in FIGS. 3 and 6, the thickness of the other arcuate wall portion 44b is thinner than the thickness of the one arcuate wall portion 44b.

Therefore, deformation (thermal contraction) of the other arcuate wall portion 44b due to so-called "sink marks" that occurs when the brush holder 41 is cooled (hardened) after injection molding is reliably prevented, and the brush holder 41 is It is necessary to improve molding accuracy. In this embodiment, a first reinforcing rib Rb1 (see FIG. 5) and a second reinforcing rib Rb2 (see FIG. 6) are provided in the dead space DS near the other arcuate wall portion 44b. In addition, in FIGS. 5 and 6, in order to make the shapes of the first reinforcing rib Rb1 and the second reinforcing rib Rb2 easier to understand, each is shaded.

As shown in FIG. 2, FIG. 4, FIG. 5, and FIG. side) and the bearing support portion 43. Specifically, the first reinforcing rib Rb1 includes a main rib Rb1a formed in a substantially arc shape, and a pair of substantially linear auxiliary ribs integrally provided inside the main rib Rb1a (on the bearing support portion 43 side). Rb1b. The first reinforcing rib Rb1 has a function of suppressing deflection (deformation) of the other arcuate wall portion 44b.

The main rib Rb1a is provided on the first surface SF1 of the base portion 42, following the other circular arc portion 42b. Further, the main rib Rb1a extends from the first surface SF1 of the base portion 42 toward the other axial side (upper side in FIG. 4) of the armature shaft 25 (axis line AS) with a height dimension H1. The main rib Rb1a is overlapped with the other arcuate wall portion 44b (on the right side in FIG. 4) in the axial direction of the armature shaft 25.

Here, as shown in FIGS. 4 and 7, the height H1 of the main rib Rb1a from the first surface SF1 is approximately the height H2 of the other arcuate wall portion 44b from the second surface SF2. It is half the size (H1≒H2/2). Further, the height H1 of the main rib Rb1a from the first surface SF1 is approximately three times the thickness T of the base portion 42 (H1≈3×T).

Further, as shown in FIG. 5, the pair of auxiliary ribs Rb1b extend from the inside of the main rib Rb1a toward the bearing support part 43, and are arranged on both sides of the square hole 42s (left and right sides in the figure). There is. Note that the height dimension of the pair of auxiliary ribs Rb1b from the first surface SF1 is also H1 (see FIG. 7). Furthermore, the pair of auxiliary ribs Rb1b are stacked on each other in the axial direction of the armature shaft 25 (extending direction of the axis line AS) with respect to the pair of support columns 42n shown by broken lines.

In this way, the main rib Rb1a forming the first reinforcing rib Rb1 is provided so as to overlap the other arcuate wall portion 44b in the axial direction of the armature shaft 25 (see FIG. 7), thereby forming the first reinforcing rib Rb1. The auxiliary rib Rb1b is provided so as to overlap the support column 42n in the axial direction of the armature shaft 25 (see FIG. 5). Furthermore, a pair of auxiliary ribs Rb1b are arranged on both sides of the square hole 42s, that is, in the vicinity of the hooking claw 42p.

As a result, the first reinforcing rib Rb1 serves as a reinforcing member, suppressing deformation (thermal shrinkage) of the other arcuate wall portion 44b, which is thinner than the one arcuate wall portion 44b, and ultimately forming the brush holder 41. It becomes possible to improve accuracy. In particular, the other arcuate wall portion 44b is provided with a yoke press-fit portion 44c and an abutment surface 44e that abuts against the abutment surface 21c of the motor case 21 (see FIG. 1). Therefore, the brush holder 41 can be accurately positioned with respect to the motor case 21. Here, the first reinforcing rib Rb1 consisting of one main rib Rb1a and two auxiliary ribs Rb1b constitutes a first reinforcing member in the present invention.

Furthermore, auxiliary ribs Rb1b are arranged near the pair of support columns 42n and the pair of hooking claws 42p, respectively. Therefore, deformation (thermal shrinkage) of the strut 42n and the hook 42p can also be effectively suppressed. Therefore, a decrease in the positional accuracy of the brush spring 46 can be sufficiently suppressed, and the brush 45 can be smoothly moved (operated).

More specifically, by providing the first reinforcing rib Rb1 corresponding to the other arcuate wall portion 44b, improvements as shown in FIGS. 9 and 10 were observed. Here, in FIGS. 9 and 10, the white graphs indicate the magnitude of distortion (bending) of the main part of the brush holder (comparative example) that does not include the first reinforcing rib Rb1, and the shaded graphs indicate It shows the magnitude of distortion (bending) of the main part of the brush holder 41 (present invention) provided with the first reinforcing rib Rb1.

As shown in FIG. 9, when the abutment surface 44e that abuts against the abutment surface 21c of the motor case 21 (see FIG. 1) is used as a reference surface, the brush sliding contact surface BS (see FIGS. 4 and 6) The parallelism to the abutment surface 44e was improved by about 30%, and the parallelism of the tip surface TS (see FIGS. 2 and 4) to the abutment surface 44e was improved by about 50%.

Further, as shown in FIG. 10, when the abutment surface 44e that abuts against the abutment surface 21c of the motor case 21 (see FIG. 1) is used as a reference surface, the bearing press-fit portion 43a (see FIGS. 2 and 5) The perpendicularity to the abutting surface 44e of the yoke press-fitting part 44c (see FIGS. 4 and 6) has been improved by about 80%, and the four case press-fitting parts 43b have been improved by about 80%. The perpendicularity to the abutment surface 44e (see FIGS. 4 and 5) was improved by about 75%.

In this way, it was found that the distortion (deformation) of the entire brush holder 41 was reduced, and the molding accuracy of the entire brush holder 41 was significantly improved. This means that when the brush holder 41 is hardened, the deformation of the portion that serves as a reference for positioning, that is, the other arcuate wall portion 44b provided with the positioning protrusion 44d having the abutting surface 44e, is sufficiently suppressed. are doing.

As shown in FIGS. 4, 6, and 7, the second reinforcing rib Rb2 is provided to assist the first reinforcing rib Rb1, and is provided on the second surface SF2 (one surface) of the base portion 42. At the top, it is provided between the other arcuate wall portion 44b (lower side in FIG. 6) and the pair of support columns 42n. Specifically, a total of four second reinforcing ribs Rb2 are provided inside the other arcuate wall portion 44b and at a portion of the other arcuate wall portion 44b closer to the base portion 42 (base end side). (See Figure 7).

These second reinforcing ribs Rb2 extend from the other arcuate wall portion 44b toward the bearing support portion 43 (through hole 42c) to the extent that they do not contact the brush spring 46 (see FIG. 3) mounted on the support column 42n. The second reinforcing rib Rb2 also has a function of suppressing deflection (deformation) of the other arcuate wall portion 44b.

In this manner, by providing the second reinforcing rib Rb2 that assists the first reinforcing rib Rb1, the deflection (deformation) of the other arcuate wall portion 44b is further suppressed. In other words, the molding accuracy of the brush holder 41 is further improved, and the positioning accuracy of the brush holder 41 with respect to the motor case 21 is further improved. Here, the four second reinforcing ribs Rb2 constitute a second reinforcing member in the present invention.

As described in detail above, according to the motor 10 with a speed reduction mechanism according to the present embodiment, the side wall portion 44 of the brush holder 41 is provided with the abutment surface 44e that abuts against the motor case 21 from the axial direction of the armature shaft 25. A first reinforcing rib Rb1 is provided on the first surface SF1 of the base portion 42 to suppress deflection of the side wall portion 44.

As a result, when the brush holder 41 is hardened after injection molding, the side wall portion 44 having the abutting surface 44e (portion serving as a reference for positioning) is prevented from warping, and the molding accuracy of the entire brush holder 41 is improved. It becomes possible to do so. Therefore, it is possible to effectively suppress a decrease in output torque (occurrence of operation loss) and an increase in operation noise of the motor 10 with a speed reduction mechanism.

In addition, according to the motor 10 with a reduction mechanism of this embodiment, the side wall portion 44 extends from the second surface SF2 of the base portion 42 to one axial side of the armature shaft 25, and the bearing support portion 43 extends from the first surface SF1 of the base portion 42 to the other axial side of the armature shaft 25.

This makes it possible to prevent the brush holder 41 from becoming too large in diameter, thereby enabling the motor 10 with reduction gear mechanism to have a flatter shape.

Furthermore, in the motor with reduction mechanism 10 according to this embodiment, a support 42n that supports the brush spring 46 is provided on the second surface SF2 of the base portion 42, and the support 42n and the first reinforcing rib Rb1 are overlapped with each other in the axial direction of the armature shaft 25.

This makes it possible to suppress the deformation (thermal contraction) of the other arcuate wall portion 44b and also suppress the deformation of the support column 42n due to the spring force load of the brush spring 46.

In addition, according to the motor 10 with a reduction mechanism of this embodiment, a pair of straight portions 42a are arranged opposite each other around the bearing support portion 43 on the outer periphery of the base portion 42, and a pair of arc portions 42b are arranged opposite each other at positions shifted 90 degrees from the pair of straight portions 42a around the bearing support portion 43, and a first reinforcing rib Rb1 is provided between the arc portions 42b and the bearing support portion 43.

This effectively prevents deflection (deformation) of the base portion 42 between the straight portion 42a and the bearing support portion 43 and the base portion 42 between the arc portion 42b and the bearing support portion 43, which is the wider portion of the base portion 42 between the arc portion 42b and the bearing support portion 43.

Furthermore, according to the motor 10 with a speed reduction mechanism according to the present embodiment, the second reinforcing rib Rb2 that suppresses the deflection of the side wall portion 44 is provided on the second surface SF2 of the base portion 42.

As a result, the bending (deformation) of the other arc-shaped wall portion 44b is further suppressed, and the molding accuracy of the brush holder 41 can be further improved. Therefore, it becomes possible to further improve the positioning accuracy of the brush holder 41 with respect to the motor case 21.

It goes without saying that the present invention is not limited to the embodiments described above, and can be modified in various ways without departing from the spirit thereof. For example, in the above embodiment, the motor 10 with a speed reduction mechanism is used as a drive source for a power window device mounted on a vehicle, but the present invention is not limited to this, and can be applied to a sunroof device, a wiper device, and the like. can also be used for other drive sources such as power sliding door devices.

In addition, the material, shape, size, number, installation location, etc. of each component in the above embodiments are arbitrary as long as the present invention can be achieved, and are not limited to the above embodiments.

10: Motor with reduction mechanism (motor device), 11: Fastening screw, 20: Motor part, 21: Motor case (housing), 21a: Bottomed cylinder part, 21b: Opening part, 21c: Abutted surface, 22: Permanent Magnet, 23: Coil, 24: Armature, 25: Armature shaft (rotating shaft), 26: Commutator, 26a: Segment, 27: Worm, 28: Worm wheel, 28a: Teeth, 28b: Output section, 30: Gear section , 31: gear case, 31a: worm accommodating part, 31b: mounting opening, 31c: bearing mounting part, 31d: worm wheel accommodating part, 31e: connector member accommodating part, 31f: mounting leg part, 40: brush unit, 41: Brush holder, 42: Base part, 42a: Straight part, 42b: Arc part, 42c: Through hole, 42d: First mounting part, 42e: Second mounting part, 42f: Third mounting part, 42g: Fourth mounting part , 42h: 5th mounting part, 42k: 6th mounting part, 42m: brush box, 42n: strut, 42p: hooking claw, 42s: square hole, 43: bearing support part, 43a: bearing press-fit part, 43b: case press-fit part, 44: side wall part, 44a: flat wall part, 44b: arcuate wall part, 44c: yoke press-fitting part, 44d: positioning protrusion, 44e: abutment surface (abutment part), 45: brush, 46: brush spring (pressing member), 46a: end, 50: connector member, 51: insertion main body, 52: connector connection section, 53: sensor board, 54: conductive member, BR: bracket, BS: brush sliding surface, CB: Circuit breaker, CC: Choke coil, CM: Drive conductive member, CN: External connector, CP: Capacitor, DS: Dead space, LT: Long protrusion, MG: Sensor magnet, MM: Movable mold, RB1: No. 1 radial bearing, RB2: second radial bearing, RB3: third radial bearing (bearing), RM1: first relay conductive member, RM2: second relay conductive member, Rb1: first reinforcing rib (first reinforcing member), Rb1a: main rib, Rb1b: auxiliary rib, Rb2: second reinforcing rib (second reinforcing member), SD: deceleration mechanism, SE: magnetic sensor, SF1: first surface (other surface of the base part), SF2: second 2 sides (one side of the base), SL: annular seal, SR: serrations, TB1: first thrust bearing, TB2: second thrust bearing, TH: through hole, TS: tip surface, Tp: tip, VS :Barista

Claims (4)

a rotating shaft;
a commutator fixed to the rotating shaft;
a brush that slides into contact with the commutator;
a brush holder that holds the brush;
a housing that accommodates the brush holder;
A motor device comprising:
The brush holder is
a base portion extending in a direction intersecting the axial direction of the rotating shaft;
a side wall portion extending in the axial direction of the rotating shaft on the outer periphery of the base portion, the side wall portion having an abutting portion that abuts against the housing from the axial direction of the rotating shaft;
a bearing support part that has a bearing that rotatably supports the rotating shaft and extends in the axial direction of the rotating shaft on the inner periphery of the base part;
Equipped with
The brush, a pressing member that presses the brush toward the commutator , and a support that supports the pressing member are provided on one surface of the base portion,
A first reinforcing member that suppresses deflection of the side wall portion is provided on the other surface of the base portion ,
The support column and the first reinforcing member are stacked on top of each other in the axial direction of the rotating shaft ,
motor device. The side wall portion extends from one surface of the base portion to one side in the axial direction of the rotating shaft,
The bearing support portion extends from the other surface of the base portion to the other side in the axial direction of the rotating shaft,
The motor device according to claim 1. 3. The motor device according to claim 1 ,
a pair of linear portions disposed opposite to each other around the bearing support portion, and a pair of arcuate portions disposed opposite to each other at positions shifted by 90 degrees from the pair of linear portions around the bearing support portion, on an outer periphery of the base portion;
The first reinforcing member is provided between the arc portion and the bearing support portion.
Motor device. The motor device according to any one of claims 1 to 3 ,
A second reinforcing member that suppresses deflection of the side wall portion is provided on one surface of the base portion,
motor device.

Images