JP2006121788A - Motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor with the size reducible in the axial direction. <P>SOLUTION: A motor section 2 constituting a pump 1 comprises a substantially tubular bottomed yoke housing 4, a rotor 5 rotatably housed in a yoke housing 4, with an armature 10 formed by applying a winding 9 to a core 8 and a commutator 11 being secured to a rotary shaft 12, and a base plate 20 having a through hole 6a for passing the rotary shaft 12 and closing the opening 4a of the yoke housing 4. The rotary shaft 12 has a tip end, supported on the housing 4 via a first bearing 14 and the distal end supported on the base plate 20 via a second bearing 15 being held on the inner circumferential surface of the through hole 6a. The first bearing 14 and the commutator 11 are arranged in the axial direction between the coil ends 9a of the winding 9. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a motor whose rotating shaft is supported by a yoke housing via a bearing.

  As a general motor configuration, for example, an armature (armature) that is rotatably accommodated in a stator in which a magnet is fixed in a yoke housing is known. In such a motor, the armature and the commutator are fixed to the rotating shaft side by side in the axial direction, and the armature is configured to rotate by sliding the power supply brush to the commutator from the outside in the radial direction. .

By the way, in recent years, motors mounted on vehicles such as automobiles have been required to be smaller in size due to multifunctional automobiles, and in some cases, downsizing in the axial direction may be desired. For example, when the motor as described above is used as a pump motor, it is preferably downsized in the axial direction because it receives a pressing force in the radial direction with respect to the rotating shaft. Therefore, as a configuration for miniaturizing the motor in the axial direction, for example, Patent Document 1 proposes a motor in which a commutator is accommodated in an armature of the motor.
Japanese Patent Laid-Open No. 10-248225

  However, in the said patent document 1, since the brush arrange | positioned to radial direction with respect to a commutator cannot be slidably contacted, it is set as the structure which slidably contacts the brush arrange | positioned to an axial direction. For this reason, there has been a problem that the motor is increased in size in the axial direction by the amount of the brush.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a motor that can be miniaturized in the axial direction.

  In order to solve the above-mentioned problem, the invention described in claim 1 is characterized in that a substantially bottomed cylindrical yoke housing, an armature formed by winding a winding around a core, and a commutator are fixed to a rotating shaft. A rotor that is rotatably accommodated in the yoke housing, and a base plate that is formed with a through hole through which the rotating shaft passes and that closes the opening of the yoke housing. The rotary shaft has a base end supported by the yoke housing via a first bearing and a distal end supported by the base plate via a second bearing held on the inner peripheral surface of the through hole. The gist is that at least one of the first bearing and the commutator is disposed between the coil ends of the winding in the axial direction.

  According to a second aspect of the present invention, in the motor according to the first aspect, the commutator includes a substantially cylindrical insulator and a plurality of metal segments disposed in a circumferential direction on an outer peripheral surface of the insulator. The outer diameter of the insulator is formed to be larger than the outer diameter of the second bearing.

  According to a third aspect of the present invention, in the motor according to the second aspect of the present invention, a second bearing for accommodating the end portion of the second bearing on the commutator side on the surface of the insulator on the second bearing side. A housing recess is formed.

  According to a fourth aspect of the present invention, in the motor according to any one of the first to third aspects, the thickness of the portion of the base plate in which the through hole is formed is the thickness in the axial direction of the second bearing. The end of the second bearing on the side opposite to the rotor is provided so as to be exposed from the base plate.

  According to a fifth aspect of the present invention, in the motor according to any one of the first to fourth aspects, an accommodating portion for accommodating the first bearing is formed at the bottom center of the yoke housing. The outer surface of the housing portion is formed so as not to protrude in the axial direction on the outer surface of the bottom portion of the yoke housing.

  According to a sixth aspect of the present invention, in the motor according to any one of the first to fifth aspects, an outer diameter of the commutator is formed larger than an inner diameter of the through hole, and the rotor is the opening. It is biased to the club side.

According to a seventh aspect of the present invention, in the motor according to any one of the first to sixth aspects, the base plate is made of resin.
According to an eighth aspect of the present invention, in the motor according to any one of the first to seventh aspects, a brush is held on the surface of the base plate on the rotor side so as to be movable in the radial direction of the commutator. A holder main body is formed integrally with the base plate.

According to a ninth aspect of the present invention, in the motor according to any one of the first to eighth aspects, the base plate is press-fitted and fixed to the opening of the yoke housing.
A tenth aspect of the present invention is the motor according to any one of the first to ninth aspects, wherein a first bearing for housing the first bearing is provided on a surface of the core on the first bearing side. A bearing housing recess is formed.

(Function)
According to the first aspect of the present invention, since at least one of the first bearing and the commutator is disposed between the coil ends of the winding in the axial direction, the first bearing and the armature or the commutator And the armature are overlapped in the axial direction, and the motor can be reduced in size in the axial direction. Also, since the second bearing is held by the inner peripheral surface of the through hole formed in the base plate, there is no need to interpose a member for holding the second bearing between the second bearing and the commutator, and the motor The size can be reduced in the axial direction. Therefore, it is possible to reduce the size of the motor in the axial direction.

  According to the invention described in claim 2, since the outer diameter of the insulator of the commutator is formed to be larger than the outer diameter of the second bearing, the contact between the metal segment and the second bearing is prevented. Is done. For this reason, the commutator and the second bearing can be brought close to each other in the axial direction, and the motor can be downsized in the axial direction.

  According to the invention described in claim 3, by accommodating the second bearing in the second bearing housing recess, the second bearing and the commutator can be overlapped in the axial direction, and the motor can be downsized in the axial direction. Is possible.

  According to invention of Claim 4, the part accommodated in the yoke housing of a motor can be reduced in an axial direction by exposing a 2nd bearing to a non-rotor side from a baseplate. If the portion exposed from the base plate of the second bearing is supported by the driven member as an inlay with the driven member, the fitting accuracy between the motor and the driven member is improved. The support of the motor can be ensured.

  According to the fifth aspect of the present invention, the housing portion for housing the first bearing is formed at the center of the bottom portion of the yoke housing so that the housing portion does not protrude in the axial direction on the outer surface of the bottom portion of the yoke housing. Since it is formed, the motor can be stably installed while preventing interference with other products.

  According to the invention described in claim 6, since the outer diameter of the commutator is formed larger than the inner diameter of the through hole, and the rotor is biased toward the opening, the commutator is locked to the base plate and Restricted movement in direction. For this reason, it is possible to stably hold the rotor in the motor without forming the through hole in the base plate with high accuracy. Further, since it is not necessary to press-fit the second bearing into the through hole, the motor can be easily manufactured.

According to the seventh aspect of the invention, since the base plate is made of resin, the weight can be reduced as compared with the case where the base plate is made of metal.
According to the eighth aspect of the present invention, the assembly work of the motor can be simplified by integrally forming the holder main body for holding the brush on the base plate.

  According to the ninth aspect of the present invention, since the base plate is press-fitted and fixed to the opening of the yoke housing, it is not necessary to fix the base plate using an assembly member such as a screw, and the motor is axially moved by the thickness of the base plate. Thus, the motor can be prevented from being enlarged in the radial direction.

  According to the tenth aspect of the present invention, the first bearing and the rotor can be overlapped in the axial direction by housing the first bearing in the first bearing housing recess formed on the first bearing side of the core. The motor can be downsized in the axial direction.

  ADVANTAGE OF THE INVENTION According to this invention, the motor which can achieve size reduction in an axial direction can be provided.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing an example in which a motor according to the present invention is used as a motor unit in a pump device. The pump device 1 includes a motor unit 2 and a pump unit 3 that pumps fluid by rotation of the motor.

  The motor unit 2 includes a substantially bottomed cylindrical yoke housing 4, a rotor 5 accommodated in the yoke housing 4, and a brush holder device 6 provided in the opening 4 a of the yoke housing 4.

  A magnet 7 is fixed on the inner peripheral side of the yoke housing 4, and a rotor 5 is rotatably accommodated facing the magnet 7. The rotor 5 is configured by an armature 10 having a winding 9 wound around a core 8 and a commutator 11 fixed to a rotary shaft 12. The outer peripheral surface of the commutator 11 is in sliding contact with a brush 13 provided on the rotor 5 side of the brush holder device 6, and the armature 10 is rotated by power supply from the brush 13.

  The rotating shaft 12 is rotatably supported by a first bearing 14 assembled at an end portion (base end portion) on the armature 10 side and a second bearing 15 assembled slightly on a portion on the pump portion 3 side. The first bearing 14 is accommodated and held in a state where the disc spring 16 is sandwiched between the accommodating portions 4 d formed at the center of the bottom of the yoke housing 4, and the second bearing 15 is formed at the substantially central portion of the brush holder device 6. It is held on the inner peripheral surface of the through hole 6a (see FIG. 2).

  The outer surface 4e at the bottom of the yoke housing 4 (on the side opposite to the opening 4a in the axial direction) is such that the outer surface 4f of the portion where the accommodating portion 4d is formed does not protrude more in the axial direction than the outer surface 4g of the other portion. It is formed as follows. Specifically, the housing portion 4d is formed by bending at the bottom of the yoke housing 4, but the outer surface 4f of the portion where the housing portion 4d is formed is substantially flush with the outer surface 4g of the other portion. It is formed to become.

  Further, the thickness of the portion of the brush holder device 6 where the through hole 6a is formed is smaller than the thickness of the second bearing 15 in the axial direction, and the end of the second bearing 15 on the pump portion 3 side is a brush. It is provided so as to be exposed from the holder device 6.

  The rotating shaft 12 passes through the brush holder device 6 and protrudes toward the pump unit 3, and an eccentric bearing 17 that rotates together with the rotating shaft 12 is fixed to the protruding portion of the rotating shaft 12 toward the pump unit 3. Yes. The eccentric bearing 17 includes a ball bearing 18 and an eccentric bush 19 that is press-fitted into the inner ring thereof, and the rotary shaft 12 is press-fitted and fixed to the shaft core portion of the eccentric bush 19. For this reason, when the rotating shaft 12 rotates, the eccentric bearing 17 moves eccentrically.

  Further, the brush holder device 6 includes a base plate 20 made of resin, and the base plate 20 is press-fitted and fixed to the opening 4a of the yoke housing 4 to close the opening 4a. The base plate 20 is fixed to the yoke housing 4 while being restricted in movement in the insertion direction (axial direction) by a step portion 4 b formed in the vicinity of the opening 4 a of the yoke housing 4. Further, a flange portion 4c extending radially outward is formed in the opening 4a of the yoke housing 4, and this flange portion 4c is fixed to a pump housing 27 described later with bolts 21. Therefore, the position of the brush holder device 6 is fixed in the pump device 1 while the yoke housing 4 is fixed to the pump housing 27.

  The base plate 20 is provided with a holder main body 22 for holding the brush 13 movably in the radial direction of the commutator 11 on the surface on the rotor 5 side, and holds the second bearing 15 on the surface on the side opposite to the rotor 5. A holding portion 23 is provided. The brush holder device 6 is made of resin, and the base plate 20, the holder main body 22, and the holding portion 23 are formed by integral molding. The brush 13 is urged from the radially outer side to the inner side by a spring 24 in the holder main body 22, and the tip surface thereof is provided so as to be in sliding contact with the commutator 11. The holding portion 23 is formed so as to protrude on the side opposite to the rotor 5, and the through hole 6 a is formed in the center portion thereof. As shown in FIG. 2, the inner diameter PD of the through hole 6 a is set slightly larger than the outer diameter BD of the second bearing 15. The second bearing 15 is accommodated in a large-diameter portion 28 a formed in the pump housing in a state where the motor portion 2 is fixed to the pump housing 27, and the holding portion 23 is an annular recess 28 b formed in the pump housing 27. Is housed in.

  As shown in FIG. 2, the commutator 11 includes a substantially cylindrical insulator 25 and a plurality of metal segments 26 disposed on the outer peripheral surface of the insulator 25 in the circumferential direction. The commutator 11 is set such that its outer diameter CD1 is larger than the inner diameter PD of the through hole 6a formed in the substantially central portion of the brush holder device 6 (base plate 20). The outer diameter CD2 of the insulator 25 (the outer diameter of the portion where the segment 26 is provided) is larger than the outer diameter BD of the second bearing 15.

  Further, as shown in FIG. 3, when a portion of the winding 9 that protrudes in the axial direction from both axial end surfaces of the core 8 is a coil end 9 a, the first bearing 14 and the commutator 11 in the motor unit 2 are It is arranged between the coil ends 9a of the winding 9 in the axial direction. The first bearing 14 is accommodated between the coil ends 9 a of the winding 9 by being accommodated in a first bearing accommodating recess 8 a formed on the first bearing 14 side of the core 8. Further, the commutator 11 has an end on the armature 10 side accommodated on the inner peripheral side of the coil end 9a of the winding 9 wound around the radially outer portion of the core 8, so that the coil is formed in the axial direction. Arranged between the ends 9a.

  Specifically, when the axial range between the coil ends 9a of the winding 9 is the range EL, the axial range of the first bearing 14 is the range BL, and the axial range of the commutator 11 is the range CL, in this embodiment Is set so that both ends of the range EL in the axial direction overlap the range BL and the range CL, respectively. As shown in the figure, the axial range EL of the coil end 9a overlaps the axial range BL of the first bearing 14 by the axial length L1, and the axial range CL of the commutator 11 by the axial length L2. overlapping. For this reason, the first bearing 14, the core 8, and the commutator 11 are fixed to the rotating shaft 12 in this order from the base end side. The total axial length is the sum of the axial lengths (BL + EL + CL). Rather than the sum of the overlapped lengths (L1 + L2).

  On the other hand, as shown in FIG. 1, the pump portion 3 includes a pump housing 27, and a housing portion 28 into which the eccentric bearing 17 is inserted is formed in the pump housing 27. A plunger 29 disposed in the pump housing 27 is in contact with a part of the outer peripheral surface of the eccentric bearing 17. Therefore, the oil sucked from the suction hole 30 formed in the pump housing 27 is discharged from the discharge hole 31 by the rotation of the rotating shaft 12.

  Further, the pump housing 27 is formed with a through hole 32 in the axial direction of the rotary shaft 12 slightly below the eccentric bearing 17 in the state shown in FIG. 1, and the brush holder device 6 is formed in the through hole 32. The formed holding part 33 is accommodated. A wiring-use plate 34 is embedded in the holding portion 33, and the holding portion 33 penetrates the through hole 32 to expose one end side of the wiring-use plate 34 from the pump housing 27. The other end of the wiring / use plate 34 is electrically connected to the brush 13.

Next, a method of assembling the pump device 1 having the above configuration will be described with reference to FIG.
First, a method for assembling the motor unit 2 constituting the pump device 1 will be described.
As a method for assembling the motor unit 2, first, the second bearing 15 constituting the rotor 5 is inserted into the through hole 6 a of the brush holder device 6, and the end surface 11 a of the commutator 11 is engaged with the rotor 5 side of the holding unit 23. It abuts on the stop surface 23a. Then, the yoke housing 4 is installed from the first bearing 14 side of the rotor 5, and the base plate 20 is press-fitted into the opening 4a of the yoke housing.

  Since the inner diameter PD of the through hole 6a formed in the brush holder device 6 is set slightly larger than the outer diameter BD of the second bearing 15 (see FIG. 2), the inner peripheral surface of the through hole 6a is the second bearing. 15 is held so as to be movable in the axial direction. Further, since the outer diameter CD1 of the commutator 11 is set to be larger than the inner diameter PD of the through hole 6a (see FIG. 2), the rotor 5 is biased toward the opening 4a by the disc spring 16. Then, the end surface 11 a of the commutator 11 is locked to the locking surface 23 a around the through hole 6 a of the brush holder device 6. For this reason, the movement of the rotor 5 toward the urging side is restricted. That is, in the motor unit 2, the second bearing 15 can be moved in the axial direction in the through hole 6 a of the brush holder device 6 while the rotor 5 is moved to the opening 4 a side when not fixed to the pump housing 27. The commutator 11 is held in a stable state by being energized and locked to the base plate 20.

  And as shown in FIG. 1, the pump part 3 as a driven member is assembled | attached to the motor part 2. As shown in FIG. When the eccentric bearing 17 provided on the opening 4a side of the motor unit 2 is inserted into the housing portion 28 formed in the pump housing 27 from the axial direction, the end surface of the second bearing 15 on the side opposite to the rotor 5 becomes the housing portion. It latches on the latching surface 28c of the large diameter part 28a formed in 28 (refer FIG. 2). Then, the second bearing 15 is pressed toward the bottom side of the yoke housing 4 against the urging force of the disc spring 16. At this time, the entire rotor 5 together with the second bearing 15 is pushed back to the bottom side. At this time, when the second bearing 15 and the large-diameter portion 28a of the pump housing 27 are fitted, the axial and radial positions of the second bearing 15 are fixed.

  In the pump device 1 having the above-described configuration, when the brush 13 is supplied with power through the wiring / use plate 34, the rotor 5 rotates and the eccentric bearing 17 moves eccentrically. Then, the plunger 29 in contact with a part of the peripheral surface of the eccentric bearing 17 reciprocates. As a result, the check ball regularly repeats the open state and the closed state, and the oil sucked from the suction hole 30 is discharged from the discharge hole 31.

Next, the characteristic operation effect of the motor part 2 which comprises the pump apparatus 1 in this embodiment is described.
(1) Since the first bearing 14 and the commutator 11 are disposed between the coil ends 9a of the winding 9 in the axial direction, the first bearing 14 and the armature 10, and the commutator 11 and the armature 10 are The motor part 2 can be reduced in size in the axial direction by being stacked in the axial direction. Further, since the first bearing 14, the armature 10 and the commutator 11 are fixed in order from the base end side of the rotating shaft 12, the brush 13 urged in the radial direction is slidably contacted with the commutator 11. The structure is not necessary, and it is possible to divert the conventional parts, which is highly versatile.

  Further, since the second bearing 15 is held by the inner peripheral surface of the through hole 6 a formed in the brush holder device 6, a member for holding the second bearing 15 is interposed between the second bearing 15 and the commutator 11. There is no need to intervene, and the motor unit 2 can be reduced in size in the axial direction.

  (2) Since the outer diameter BD of the second bearing 15 is set so as not to exceed the outer diameter CD2 of the insulator 25, contact between the metal segment 26 and the second bearing 15 is prevented. For this reason, the commutator 11 and the second bearing 15 can be brought close to each other in the axial direction, and the motor unit 2 can be downsized in the axial direction.

  (3) By exposing the second bearing 15 from the base plate 20 to the side opposite to the rotor 5, the portion accommodated in the yoke housing 4 of the motor unit 2 can be reduced in the axial direction. If the portion of the second bearing 15 exposed from the base plate 20 is supported by the pump housing 27 as an inlay with the pump housing 27 as a driven member, the motor unit 2 and the pump housing Thus, it is possible to ensure the support of the motor unit 2 while improving the fitting accuracy with the motor 27.

  (4) A housing portion 4 d for housing the first bearing 14 is formed at the center of the bottom of the yoke housing 4, and the outer surface of the housing portion 4 d does not protrude in the axial direction on the outer surface 4 e of the bottom surface of the yoke housing 4. Thus, the motor unit 2 (pump device 1) can be stably installed while preventing interference with other products.

  (5) Since the outer diameter CD1 of the commutator 11 is formed to be larger than the inner diameter PD of the through hole 6a, and the rotor 5 is biased toward the opening 4a, the commutator 11 is locked to the base plate 20. And the movement in the axial direction is restricted. For this reason, even if the through-hole 6a is not formed in the brush holder device 6 with high accuracy, the rotor 5 can be stably held in the motor unit 2. Moreover, since it is not necessary to press-fit the second bearing 15 into the through hole 6a, the motor unit 2 can be easily manufactured.

  (6) Since the base plate 20 is press-fitted and fixed in the opening 4 a of the yoke housing 4, there is no need to fix the base plate 20 using an assembly member such as a screw, and the motor portion 2 is axially moved by the thickness of the base plate 20. While being able to reduce in size, it can prevent that the motor part 2 enlarges to radial direction.

  (7) By housing the first bearing 14 in the first bearing housing recess 8a formed on the first bearing 14 side of the core 8, the first bearing 14 and the rotor 5 can be overlapped in the axial direction, and the motor It is possible to reduce the size of the portion 2 in the axial direction.

In addition, you may change embodiment of this invention as follows.
In the above embodiment, the second bearing 15 and the commutator 11 are disposed adjacent to each other in the axial direction. However, they may be configured to overlap in the axial direction. For example, as shown in FIGS. 5 and 6, the second bearing housing recess 25 a for housing the second bearing 15 is formed on the surface of the insulator 25 constituting the commutator 11 on the second bearing 15 side. You may accommodate the 2nd bearing 15 in the 2nd bearing accommodation recessed part 25a. If comprised in this way, the 2nd bearing 15 and the commutator 11 can be piled up in an axial direction, and it becomes possible to miniaturize the motor part 2 in an axial direction.

  In the above embodiment, the first bearing 14 and the commutator 11 are arranged between the coil ends 9a of the winding 9 wound around the core 8, but only one of them is the coil end 9a. You may comprise so that it may be arrange | positioned between. Even in that case, the motor unit 2 can be downsized in the axial direction.

  In the above embodiment, the outer surface 4e of the housing portion 4d for housing the first bearing 14 is configured to be substantially flush with the outer surface 4g of the other portion on the outer surface 4e at the bottom of the yoke housing 4. The outer surface 4f may be formed so as not to protrude from the outer surface 4g of the other part, and the outer surface 4f may be recessed in the outer surface 4e.

  In the above embodiment, the disc spring 16 is used as a biasing member that biases the rotor 5 toward the opening 4a of the yoke housing 4, but the biasing member that biases the rotor 5 is not limited to this. Instead of the disc spring 16, for example, a coil spring or a wave washer may be used.

  In the above embodiment, the outer diameter CD2 of the insulator 25 constituting the commutator 11 is made larger than the outer diameter BD of the second bearing 15, but the segment 26 constituting the commutator 11 is the second bearing 15 The outer diameter of the insulator 25 does not have to be set in this way as long as it can be prevented from touching. For example, in the commutator 11, if the insulator 25 is configured to protrude from the segment 26 toward the second bearing 15, contact between the segment 26 and the second bearing 15 is prevented, so that the second bearing 15 and the commutator 11 are prevented. And the motor unit 2 can be reduced in size in the axial direction.

The base plate 20 is not necessarily made of resin, and may be made of metal, for example.
The base plate 20 may not be fixed to the opening 4a of the yoke housing 4 by press fitting. For example, the yoke housing 4 may be fixed with screws.

  -If the 1st bearing 14 can be arrange | positioned between the coil ends 9a of the coil | winding 9, the 1st bearing accommodation which accommodates this 1st bearing 14 in the surface at the side of the 1st bearing 14 of the core 8 will be carried out. The recess 8a may not be formed.

  The brush holder device 6 may not be made of a resin in which the base plate 20, the holder main body 22, and the holding portion 23 are integrally formed. For example, the holder main body 22 may be made of metal and assembled integrally with the base plate 20.

  The motor unit 2 may be applied to a device other than the pump device 1.

The schematic sectional drawing which shows an example which used the motor concerning this invention for the pump apparatus. FIG. 3 is a main part cross-sectional view for explaining a motor support structure in the present embodiment. FIG. 3 is a cross-sectional view of a main part for explaining an armature portion of the motor in the present embodiment. BRIEF DESCRIPTION OF THE DRAWINGS The schematic sectional drawing for demonstrating the motor in this Embodiment, and the elements on larger scale. The schematic sectional drawing for demonstrating the pump apparatus of another example. The principal part sectional view for demonstrating the support structure of the motor of another example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Pump device, 2 ... Motor part as a motor, 3 ... Pump part, 4 ... Yoke housing, 4a ... Opening part, 4d ... Housing part, 4e ... Outer surface of housing bottom part, 4f ... Outer surface of housing part, 5 DESCRIPTION OF SYMBOLS ... Rotor, 6 ... Brush holder apparatus, 6a ... Through-hole, 8 ... Core, 8a ... 1st bearing accommodation recessed part, 9 ... Winding, 9a ... Coil end, 10 ... Armature, 11 ... Commutator, 12 ... Rotating shaft, DESCRIPTION OF SYMBOLS 13 ... Brush, 14 ... 1st bearing, 15 ... 2nd bearing, 20 ... Base plate, 22 ... Holder main body, 25 ... Insulator, 25a ... 2nd bearing accommodation recessed part, 26 ... Segment, BD ... Outer diameter of 2nd bearing , CD1 ... outer diameter of commutator, CD2 ... outer diameter of insulator, PD ... inner diameter of through hole.

Claims (10)

A substantially bottomed cylindrical yoke housing;
An armature formed by winding a winding around a core and a commutator are fixed to a rotating shaft, and a rotor rotatably accommodated in the yoke housing;
A through-hole through which the rotating shaft passes, a base plate for closing the opening of the yoke housing;
A motor equipped with
The rotating shaft has a base end supported by the yoke housing via a first bearing, and a distal end supported by the base plate via a second bearing held on the inner peripheral surface of the through hole. And
At least one of the first bearing and the commutator is disposed between the coil ends of the winding in the axial direction. The motor according to claim 1,
The commutator includes a substantially cylindrical insulator and a plurality of metal segments disposed on an outer peripheral surface of the insulator in a circumferential direction, and an outer diameter of the insulator is larger than an outer diameter of the second bearing. A motor characterized by being formed so as to be larger. The motor according to claim 2,
2. A motor according to claim 1, wherein a second bearing housing recess for housing the commutator side end of the second bearing is formed on a surface of the insulator on the second bearing side. The motor according to any one of claims 1 to 3,
The thickness of the portion of the base plate where the through hole is formed is smaller than the thickness of the second bearing in the axial direction, and the end of the second bearing on the side opposite to the rotor is exposed from the base plate. A motor characterized by being provided. The motor according to any one of claims 1 to 4,
A housing portion for housing the first bearing is formed in the center of the bottom of the yoke housing, and the outer surface of the housing portion is formed so as not to protrude in the axial direction on the outer surface of the yoke housing bottom. A motor characterized by having In the motor according to any one of claims 1 to 5,
An outer diameter of the commutator is formed larger than an inner diameter of the through hole, and the rotor is biased toward the opening. The motor according to any one of claims 1 to 6,
The motor according to claim 1, wherein the base plate is made of resin. The motor according to any one of claims 1 to 7,
The motor according to claim 1, wherein a holder main body for holding the brush so as to be movable in a radial direction of the commutator is formed integrally with the base plate on the rotor side surface of the base plate. The motor according to any one of claims 1 to 8,
The motor according to claim 1, wherein the base plate is press-fitted and fixed to an opening of the yoke housing. The motor according to any one of claims 1 to 9,
A motor having a first bearing receiving recess for receiving the first bearing formed on a surface of the core on the first bearing side.

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