Motor with reducer

Abstract

To provide a motor with a speed reducer which adopts a new vibration control structure, which makes unnecessary vibration from the motor less likely to be transmitted to a worm and a casing, to enable further noise reduction.SOLUTION: A motor 1 with a speed reducer includes: a speed reducer 2 which is housed in a casing 15 in a state that a resin worm 4 and an output gear 8 engage with each other; and a motor 3 which is attached to the speed reducer 2 and drives the worm 4. A first rotary shaft 5 at the tip side of the worm 4 is pivotally supported by a worm bearing part 18. The worm bearing part 18 is fitted in a first vibration control body and housed in the casing 15 in a fitted state. A drive shaft 3a of the motor 3 is press-fitted into a rotation stop part 19, fitted in a second vibration control body 32, and pushed into the rear end side of the worm 4 in the fitted state. The motor 3 is attached to an attachment plate 36 and attached to the casing 15 with a third vibration control body 33 sandwiched therebetween.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a motor with a speed reducer.

Background Art

[0002] Conventionally, in order to raise and lower a vehicle window glass by gear drive, a reduction gear motor having mounting holes (bushings) provided at three locations on a regulator bracket and connected to an external gear or an external pulley has been proposed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Patent Document 8

Patent Document 9

Summary of the Invention

Problems to be Solved by the Invention

[0004] For improving the comfort inside the vehicle cabin, the motor with a speed reducer is always required to be quiet. In the prior art, a metal worm was used. As a method to achieve quietness, changing to a resin worm can be considered. By using a resin worm, a reduction effect on material costs and processing costs can also be expected. However, a motor with a speed reducer for a power window using a resin worm has not been put into practical use yet. The reasons are that when adopting a resin worm, measures such as increasing the module are necessary to ensure the required strength, and measures such as increasing the gear size are necessary to reduce unnecessary vibrations and noises of the motor. Various studies have been conducted, but even if the gear size is increased by taking measures such as increasing the module with a resin worm, the quieting effect has not reached a level that can sufficiently meet the requirements of vehicle manufacturers. Therefore, when focusing on the vibration source and noise source, it has recently been found that in the conventional structure, unnecessary vibrations from the motor are transmitted from the drive shaft to the worm, and unnecessary vibrations from the worm are transmitted to the output gear, and the sound resonates in the casing, etc., resulting in an amplified sound. In addition, due to the structure in which the motor is attached to the casing, unnecessary vibrations from the motor are transmitted to the casing, and the casing resonates and makes a sound. That is, a new anti-vibration structure is required to further reduce noise.

Means for Solving the Problem

[0005] In view of the above circumstances, the present invention is made, and an object thereof is to provide a motor with a speed reducer that can be quieter than conventional products by providing a new anti-vibration structure in which unnecessary vibrations from the motor are difficult to be transmitted to the worm and the casing.

[0006] As one embodiment, the above problem is solved by the solution disclosed below.

[0007] The motor with a speed reducer according to the present invention is a motor with a speed reducer for raising and lowering the window glass of a vehicle, and includes a speed reducer in which a resin worm is housed in a casing in a state of meshing with an output gear, and a motor attached to the speed reducer for driving the worm. A first rotating shaft is attached to the tip of the worm, the first rotating shaft is pivotally supported by a worm bearing portion, the worm bearing portion is housed in the casing in a state of being fitted into a first vibration isolator, and a second rotating shaft attached to the output gear is pivotally supported by a bearing portion in the casing. A rotation stopper attached to the drive shaft of the motor is connected to the rear end portion of the worm in a state of being fitted into a second vibration isolator. A mounting plate is attached to the motor, and the mounting plate is attached to the casing with a third vibration isolator interposed therebetween.

[0008] According to this configuration, by using a resin worm, the transmission of unnecessary vibration from the worm to the output gear is suppressed, and the gear noise associated with the meshing of the worm and the output gear is also suppressed. Moreover, the unnecessary vibration of the first rotating shaft on the tip side of the worm is attenuated by the interposition of the first vibration isolator, and the transmission of unnecessary vibration to the casing is suppressed. Also, the vibration of the drive shaft of the motor at the rear end portion of the worm is attenuated by the interposition of the second vibration isolator, and the transmission of unnecessary vibration to the worm is suppressed. Further, the vibration of the motor is attenuated by the interposition of the third vibration isolator, and the transmission of unnecessary vibration to the casing is suppressed. That is, by a new vibration isolation structure that suppresses unnecessary vibration from the motor by vibration isolators provided at three connection points along the direction of the first rotating shaft, it is possible to achieve a level of quietness sufficient to meet the requirements of vehicle manufacturers.

[0009] The rear end portion of the worm has convex and concave portions formed alternately around the axis. The drive shaft is press-fitted into the anti-rotation portion, and the anti-rotation portion has protrusions formed at predetermined intervals around the axis. The second vibration isolator has arm portions for fitting the protrusions around the axis formed at the predetermined intervals. It is preferable that the anti-rotation portion with the drive shaft press-fitted therein is fitted into the second vibration isolator in a state where the second vibration isolator is fitted into the rear end portion of the worm. According to this configuration, the second vibration isolator in a state where the anti-rotation portion is fitted into the convex and concave portions of the rear end portion of the worm can be fitted, so that the torque from the motor drive shaft can be efficiently transmitted to the worm. Moreover, since the drive shaft and the anti-rotation portion of the motor are in a state of being fitted into the second vibration isolator, transmission of unnecessary vibration and unnecessary vibration noise to the outside can be effectively suppressed.

[0010] The worm bearing portion has a cylindrical portion with a flange, steel balls accommodated in the cylindrical portion and contacting the recess in the first rotating shaft, and a receiving plate contacting the steel balls at a position facing the recess in the first rotating shaft. The receiving plate is arranged inside the first vibration isolator. It is preferable that inside the first vibration isolator in a state where the receiving plate and the cylindrical portion are fitted, the steel balls contact the recess, and the receiving plate contacts the side of the steel balls opposite to the side contacting the recess. According to this configuration, the worm bearing portion functions as a radial bearing by the combination of the cylindrical portion, the steel balls, and the receiving plate, the rotational movement of the worm is stabilized, and since the worm bearing portion is in a state of being fitted into the first vibration isolator, transmission of unnecessary vibration and unnecessary vibration noise from the worm to the outside can be effectively suppressed.

[0011] It is preferable that the worm, the output gear, the casing, and the lid body are all made of resin. Examples of the resin include polyacetal (POM), polyamide (PA), polypropylene (PP), polycarbonate (PC), polybutylene terephthalate (PBT), and other known engineering plastics. The resin-made in this specification includes a configuration in which metal parts are insert-molded.

[0012] The worm is preferably made of polyacetal, polyamide, or polybutylene terephthalate. The output gear is preferably made of polyacetal, polyamide, or polybutylene terephthalate. By adopting a heat-resistant resin having the heat resistance required for in-vehicle supplies and making the grades of the materials of the worm and the output gear different, and making the material of the output gear a material with a lower elastic modulus than that of the worm, the transmission of unnecessary vibrations to the output gear can be effectively prevented.

[0013] The first vibration isolator, the second vibration isolator, and the third vibration isolator are all preferably made of rubber or an elastomer. Thereby, excellent vibration damping characteristics can be obtained and molding can be easily performed. The elastomer in this specification refers to a rubber-like substance or a polymer compound having rubber elasticity. Examples of the rubber or elastomer include silicone rubber, nitrile rubber, butyl rubber, ethylene propylene rubber, fluororubber, natural rubber, and the like. A material for attenuating vibration and noise is appropriately blended in the rubber or elastomer.

[0014] The third vibration isolator has a first plate, a second plate, and a third plate that share the attenuation of vibration and noise. In the order closer to the casing, the first plate, the second plate, the mounting plate, and the third plate are preferably arranged to overlap in the axial direction. According to this configuration, by making the third vibration isolator have a structure in which the motor mounting plate is sandwiched between vibration isolation plates from both sides, unnecessary vibrations of the motor can be more effectively prevented. According to this configuration, the contact area between the casing and the motor mounting plate can be made less than 30%. And the first plate, the second plate, and the third plate that share the attenuation of the vibration and noise of the motor have different elastic moduli and thicknesses, etc., to share the frequency spectrum of the vibration and noise of the motor, and the attenuation of vibration and noise can be more effectively achieved. A material for attenuating vibration and noise is appropriately blended in the first plate, the second plate, and the third plate. In addition to the above, a configuration in which a fourth plate is stacked on the third plate may be adopted to further enhance the vibration damping characteristics.

[0015] Preferably, the anti-rotation portion is disposed inside the through-holes formed in the first plate and the second plate, respectively, in a state of being fitted into the second vibration isolator. According to this configuration, since the anti-rotation portion is in a state where the second vibration isolator is fitted and built into the third vibration isolator, it is possible to effectively suppress the transmission of unnecessary vibration and unnecessary vibration noise to the outside.

[0016] Preferably, the output gear is a resin molded product in which an S-shaped rib portion and a through portion are alternately formed around the axis. The rotational torque of the output gear is connected to an external gear or an external pulley via the S-shaped rib portion. The rotational load torque received by the external gear or the external pulley includes vibration and impact, resulting in torque fluctuation, which is one of the causes of noise generation. Therefore, by changing the torque fluctuation into a load fluctuation and into deflection by the S-shaped rib portion, noise can be reduced and further quieting can be achieved.

[0017] Preferably, the second elastic modulus of the output gear is 0.15 to 0.8 times the first elastic modulus of the worm. According to this configuration, a structure can be formed that can withstand the torque load required for in-vehicle supplies. For example, after adopting polyacetal having the heat resistance required for in-vehicle supplies and making the grades of the materials of the worm and the output gear different, by making the material of the output gear have a lower elastic modulus than the material of the worm, the transmission of unnecessary vibration to the output gear can be effectively prevented. Moreover, when the module is 1, by increasing the tooth thickness of the output gear in inverse proportion to the ratio of the second elastic modulus of the second resin to the first elastic modulus of the first resin, a structure can be formed that can withstand the torque load required for in-vehicle supplies. Preferably, the output gear has a module of 0.8 to 1.3 and a tooth width of 10 to 24 mm. Thereby, a configuration having excellent torque strength and excellent wear resistance performance can be formed.

[0018] As an example, an external gear connected to the second rotating shaft is provided, and a first bush, a second bush, and a third bush for attaching to the vehicle are provided in an integral structure on the casing. According to this configuration, while increasing the size of the module to further enhance the operating stability, a casing structure can be obtained that can accommodate the enlarged output gear. In addition, by providing the bushes at three locations corresponding to the outer diameter of the output gear, it can be easily attached to the regulator bracket of the vehicle.

[0019] As an example, female threads are formed in all of the first bush, the second bush, and the third bush. The first bush is arranged at a position close to the first vibration isolator, the third bush is arranged at a position close to the third vibration isolator, the second bush is arranged at a position farther from the worm than the first bush, and both the first bush and the second bush are arranged at positions that overlap the output gear in a plan view. By arranging the first bush and the second bush at positions that overlap the output gear in a plan view, it has compatibility with the attachment to the conventionally used regulator bracket, so that a configuration with excellent versatility can be achieved.

[0020] As an example, an external pulley having an integral structure with the output gear is provided, and a first mounting hole, a second mounting hole, and a third mounting hole for attaching to the vehicle are provided in an integral structure on the casing. According to this configuration, it can be made into a configuration suitable for a power window of a vehicle having a structure for raising and lowering a window glass of the vehicle in cooperation with a wire or a belt.

[0021] As an example, the number of teeth of the output gear is set to 60 to 75. Thereby, a reduction ratio suitable for the power window of the vehicle can be obtained.

[0022] The present invention can be applied to a motor with a speed reducer for raising and lowering a window glass of a vehicle, thereby greatly contributing to an improvement in comfort in the vehicle interior. In addition, the operating reliability required for a vehicle unit can be ensured. Moreover, further cost reduction is also possible.

Effects of the Invention

[0023] According to the present invention, unnecessary vibrations from the motor can be suppressed by vibration isolators provided at three connection points along the first rotation axis direction, transmission of unnecessary vibrations from the worm to the output gear can be suppressed, and transmission of unnecessary vibrations from the first rotation axis to the casing can be suppressed. Therefore, a vibration isolation structure capable of significantly reducing unnecessary vibrations from the motor can be achieved, and further quieting can be achieved. In addition, by adopting a resin worm, weight reduction and cost reduction can be achieved compared with a metal worm. Therefore, it can be configured into a suitable structure for a motor with a speed reducer for raising and lowering a vehicle window glass.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0025] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. This embodiment is a motor 1 with a speed reducer used for raising and lowering a window glass of a vehicle. The motor 1 with a speed reducer includes a speed reducer 2 in which a worm 4 and an output gear 8 meshing with the worm 4 are housed in a casing 15 and a lid 16 is attached, and a motor 3 attached to the speed reducer 2 for driving the worm 4. In all the drawings for explaining the embodiment, members having the same function are denoted by the same reference numerals, and repeated explanations may be omitted.

[0026] Here, the worm 4 is made of resin, and as an example, it is injection-molded from polyacetal. The first rotating shaft 5 is inserted into the worm 4. The output gear 8 is made of resin, and as an example, it is injection-molded from polyacetal.

[0027] When the worm 4 is made of polyacetal, the output gear 8 is made of a material grade having a lower elastic modulus than the grade of polyacetal in the worm 4. Or, when the worm 4 is made of polyacetal, the output gear 8 is made of polyamide (nylon). Thereby, the transmission of unnecessary vibration from the worm 4 to the output gear 8 can be effectively prevented. Moreover, it can be structured to withstand the torque load required for in-vehicle supplies.

[0028] [First Embodiment] Figure 1 is a schematic structural view showing an example of a motor 1A with a speed reducer having an external gear 17A according to this embodiment in a plan view, omitting the lid 16 and showing the internal structure. The motor 1A with a speed reducer is provided with a first bush 11, a second bush 12, and a third bush 13 for external attachment in an integral structure to the casing 15.

[0029] The worm 4 and the output gear 8A are accommodated in the casing 15 in a meshed state. In the axial direction of the first axis P1, the first vibration isolator 31, the worm bearing portion 18, the first rotating shaft 5 attached to the worm 4, the worm 4, the second vibration isolator 32, the third vibration isolator 33, and the motor 3 having the drive shaft 3a are arranged in this order. And in the axial direction of the second axis P2 intersecting the first axis P1, the lid body 16, the first bearing portion 21, the gear connecting portion 28 having an integral structure with the second rotating shaft 6A attached to the output gear 8A, the casing 15, and the external gear 17A attached to the gear connecting portion 28 are arranged.

[0030] The drive shaft 3a of the motor 3 and the first rotating shaft 5 are connected via a resin worm 4, and unnecessary vibrations from the drive shaft 3a are attenuated by the worm 4 before being transmitted to the stainless steel first rotating shaft 5. The first end of the second rotating shaft 6A is pivotally supported by the first bearing portion 21 disposed inside the lid body 16. The middle portion between the first end and the second end of the second rotating shaft 6A is assembled to the resin output gear 8A and the resin gear connecting portion 28 and is pivotally supported by the second bearing portion 22 disposed outside the casing 15. And a sintered metal external gear 17A is attached at a position close to the second end.

[0031] The gear connecting portion 28 is made of resin, and as an example, it is formed by outsert molding polyamide on the stainless steel second rotating shaft 6. The gear connecting portion 28, the second rotating shaft 6, and the external gear 17A have an integral structure. For the integral structure of the gear connecting portion 28, the second rotating shaft 6, and the external gear 17A, known techniques such as the above-mentioned patent documents can be applied.

[0032] The first rotating shaft 5 attached to the worm 4 is pivotally supported by the worm bearing portion 18. The worm bearing portion 18 is attached to the casing 15 with the first vibration isolator 31 interposed therebetween. The first rotating shaft 5 is a stainless steel shaft, and the rear end side of the first rotating shaft 5 is pushed into the front end side mounting hole 7a of the tip portion 4a of the worm 4. The tip of the first rotating shaft 5 has a cylindrical depression 5a with an R inside, or a hemispherical depression 5a inside, or a conical depression 5a inside. The depression 5a has a depression shape corresponding to the outer shape of the steel ball 24.

[0033] The worm bearing portion 18 includes a cylindrical portion 23 provided with a flange 23a, a steel ball 24 accommodated in the cylindrical portion 23 and contacting the depression 5a formed in the depression 5a at the tip of the first rotating shaft 5, and a receiving plate 25 contacting the steel ball 24 so as to face the depression 5a at the tip of the first rotating shaft 5. The cylindrical portion 23 is a porous metal tissue structure, and as an example, it is made of Bearfight. Both the steel ball 24 and the receiving plate 25 are made of stainless steel. The receiving plate 25 is arranged in the internal space of the first vibration isolator 31, and the steel ball 24 is arranged at a position contacting the receiving plate 25 arranged in the internal space of the first vibration isolator 31. Then, with the cylindrical portion 23 fitted into the first vibration isolator 31, the tip side of the first rotating shaft 5 is inserted into the internal space of the cylindrical portion 23. According to this configuration, the combination of the cylindrical portion 23, the steel ball 24, and the receiving plate 25 enables the worm bearing portion 18 to function as a radial bearing, stabilizing the rotational movement of the worm 4. At the same time, since the worm bearing portion 18 is in a state of being fitted into the first vibration isolator 31, it is possible to effectively suppress the transmission of unnecessary vibrations and unnecessary vibration noises to the outside.

[0034] The first vibration isolator 31 has a bottomed cylindrical shape, the bottom surface side of the internal space serves as a receiving portion 31a, and notches 31b are formed at predetermined intervals around the axis on the outside, so that the outside bottom portion has a cross shape. Since the notches 31b are formed in the outside bottom portion, it is possible to easily visually recognize from the outside that the steel balls 24 and the receiving plate 25 are accommodated in the internal space. And since the outside bottom portion has a cross shape and the notches 31b are formed, even if unnecessary vibrations accompanying the rotational movement of the first rotating shaft 5 are transmitted to the steel balls 24 and the receiving plate 25 and stress is applied to the first vibration isolator 31, the internal stress is relaxed, and the rotational movement of the worm 4 becomes more stable. The first vibration isolator 31 is made of, for example, silicone rubber.

[0035] The rear end portion 4b of the worm 4 has convex portions 7d and concave portions 7c alternately formed around the axis. The drive shaft 3a of the motor 3 is press-fitted into a shaft hole 19a formed in a rotation prevention portion 19 made of stainless steel. The rotation prevention portion 19 has a cross shape in which protrusions 19b protrude in four directions of up, down, left, and right from a disk-shaped portion in which the shaft hole 19a is formed, and functions as a retaining ring for the drive shaft 3a. When the rotation prevention portion 19 is a sheet metal press-worked product, a plurality of sheets of the sheet material may be pressed and used in a stacked manner.

[0036] The anti-rotation part 19 is fitted into the rear end portion 4b of the worm 4 in a state of being fitted into the second vibration isolator 32. The drive shaft 3a of the motor 3 is inserted into a rear end side mounting hole 7b formed in the rear end portion 4b of the worm 4. The second vibration isolator 32 has arm portions 32b formed at predetermined intervals around the axis from a disk-shaped portion in which a through hole 32a is formed. The arm portions 32b are U-shaped or U-shaped in the axial direction, and the protruding portion 19b of the anti-rotation part 19 is fitted into the rear end portion 4b of the worm 4 in a state of being fitted into the arm portion 32b of the second vibration isolator 32. According to this configuration, the second vibration isolator 32 in a state where the anti-rotation part 19 is fitted into the convex portion 7d and the concave portion 7c of the rear end portion 4b of the worm 4 is fitted, so that the torque from the drive shaft 3a of the motor 3 can be efficiently transmitted to the worm 4. Moreover, since the drive shaft 3a of the motor 3 and the anti-rotation part 19 are in a state of being fitted into the second vibration isolator 32, transmission of unnecessary vibration and unnecessary vibration noise to the outside can be effectively suppressed. The second vibration isolator 32 is made of, for example, nitrile rubber.

[0037] The third vibration isolator 33 has a first plate 34, a second plate 35, a third plate 37, and a fourth plate 38, and in the order close to the casing 15, the first plate 34, the second plate 35, the mounting plate 36, the third plate 37, and the fourth plate 38 are arranged overlapping each other in the axial direction. The first plate 34 has a first through hole 34a having a size capable of accommodating the second vibration isolator 32 and the anti-rotation part 19 formed in the axial direction. The second plate 35 has a second through hole 35a having a size capable of accommodating the second vibration isolator 32 and the anti-rotation part 19 formed in the axial direction. The mounting plate 36 has a first through hole 36a having a shape through which the second vibration isolator 32 and the anti-rotation part 19 can be inserted formed in the axial direction. The third plate 37 has a second through hole 37a having a shape through which the second vibration isolator 32 and the anti-rotation part 19 can be inserted formed in the axial direction. The fourth plate 38 has two members symmetrically arranged with respect to the axis, and a curved shape 38a is formed to allow the housing 3b of the motor 3 to pass through.

[0038] The second through-hole 35a of the second plate 35 is not only circular so that the second vibration isolator 32 and the anti-rotation portion 19 can be accommodated, but also has a hole shape capable of accommodating the head of the first screw 41a. The first screw 41a passes through the third through-hole 36c formed in the mounting plate 36, passes through the fourth through-hole 37c formed in the third plate 37, and is screwed into the first screw hole 41b formed in the housing 3b of the motor 3.

[0039] The auxiliary screw 42a passes through the sixth through-hole 38d formed in the fourth plate 38, passes through the fifth through-hole 37d formed in the third plate 37, and is screwed into the second screw hole 36d formed in the mounting plate 36.

[0040] According to this configuration, by making the third vibration isolator 33 have a structure in which the mounting plate 36 of the motor 3 is sandwiched from both sides by a plurality of vibration isolation plates, the contact area between the casing 15 and the mounting plate 36 can be made less than 30%. Therefore, unnecessary vibrations of the motor 3 can be more effectively prevented. Moreover, the anti-rotation portion 19 is disposed inside the through-holes formed in the first plate 34 and the second plate 35, respectively, in a state of being fitted into the second vibration isolator 32, and is in a state of being built into the third vibration isolator 33. Therefore, the transmission of unnecessary vibrations and unnecessary vibration sounds to the outside can be effectively suppressed.

[0041] The third vibration isolator 33 is made of, for example, nitrile rubber. The rubber hardness of the first plate 34 is a material with a lower rubber hardness than that of the second plate 35. The rubber hardness of the third plate 37 is a material with a lower rubber hardness than that of the second plate 35. The rubber hardness of the fourth plate 38 is a material with a lower rubber hardness than that of the third plate 37. Note that the present invention is not limited to the above configuration, and the first plate 34 and the second plate 35 can be made of rubber plates with the same hardness having an integral structure. Also, the third plate 37 and the fourth plate 38 can be made of rubber plates with the same hardness having an integral structure.

[0042] The output gear 8A is configured to alternately form, in the circumferential direction, an S-shaped rib portion 81b and a through portion 81a that penetrates in a direction parallel to the second axis P2 of the second rotating shaft 6A. According to this configuration, by actively utilizing the elasticity of the S-shaped rib portion 81b, even when the diameter of the output gear 8A is increased, the meshing with the worm 4 can be stabilized, and further quiet operation can be achieved. Moreover, the strength and durability of the output gear 8 can be further improved.

[0043] The mounting plate 36 to which the motor 3 is mounted is fixed to the casing 15 by a plurality of motor mounting screws 44a in a state where the first plate 34 and the second plate 35 overlap in the axial direction. The casing 15 is screwed and fixed to the nut 43c through a washer 43b, through a through hole of the casing 15, and through a through hole of the lid body 16 combined with the casing 15 by a plurality of casing mounting screws 43a. For the fastening structure using such screws or the fastening structure using bolts, known techniques such as the above-mentioned patent documents can be applied.

[0044] The first bush 11, the second bush 12, and the third bush 13 for external mounting are provided in an integral structure on the casing 15. Here, the first center line 11a of the first bush 11 and the second center line 12a of the second bush 12 are parallel to each other. Also, the first center line 11a of the first bush 11 and the second axis P2 of the second rotating shaft 6A are parallel to each other.

[0045] In the present embodiment, the first bush 11 and the second bush 12 are arranged at positions that overlap the output gear 8A in a plan view. In the example shown in FIG. 1, the first bush 11 is arranged at a position on the tip side of the worm 4, the second bush 12 is arranged at a position farther from the worm 4 than the first bush 11, the output gear 8 is arranged at a position between the first bush 11 and the second bush 12, and the third bush 13 is arranged at a position on the rear end side of the worm 4. Female threads for external mounting are formed on the first bush 11, the second bush 12, and the third bush 13, respectively.

[0046] This embodiment has a configuration in which an external gear 17A for raising and lowering a vehicle window glass by gear drive is connected to a second rotating shaft 6. In this embodiment, a reduction gear motor 1A is attached and fixed to a regulator bracket of the vehicle by connecting a screw or a bolt to female threads respectively formed in a first bush 11, a second bush 12, and a third bush 13. According to this configuration, by providing the first bush 11, the second bush 12, and the third bush 13 at three locations corresponding to the outer diameter of the output gear 8A, it can be easily attached to the regulator bracket of the vehicle. The first bush 11, the second bush 12, and the third bush 13 are made of aluminum, and grooves or uneven patterns are formed on the outer periphery at predetermined intervals, and are integrally formed by insert molding when molding a resin casing 15 such as PBT. The lid 16 is molded from the same material as the casing 15.

[0047] According to this embodiment, the reduction gear motor 1 with a novel anti-vibration structure, which can be quieter than conventional products, is achieved by an anti-vibration structure in which unnecessary vibrations from the motor 3 are difficult to be transmitted to the worm 4 and the casing 15. Further, according to this embodiment, the small size of the casing 15 can be maintained, and since it has compatibility with the conventionally used regulator bracket, the reduction gear motor 1 has excellent versatility.

[0048] [Second Embodiment] FIG. 2 is a schematic structural view showing an example of a reduction gear motor 1B provided with an external pulley 17B according to this embodiment in a plan view, showing the internal structure with the lid 16 omitted. The anti-vibration structure in the second embodiment is the same as that in the above-described first embodiment. The differences between the second embodiment and the above-described first embodiment will be described below.

[0049] The external pulley 17B has an integral structure with the output gear 8B and is arranged outside the lid body 16 through the guide hole 16c formed in the lid body 16. The worm 4 and the output gear 8B are accommodated in the casing 15 in a meshed state. In the axial direction of the first axis P1, a motor 3 having a first vibration isolator 31, a worm bearing portion 18, a first rotating shaft 5 attached to the worm 4, the worm 4, a second vibration isolator 32, a third vibration isolator 33, and a drive shaft 3a is arranged in this order. And in the axial direction of the second axis P2 intersecting the first axis P1, the lid body 16, an O-ring 54, the external pulley 17B, the output gear 8B, a second rotating shaft 6B, an O-ring 53, and the casing 15 are arranged. The second rotating shaft 6B is pivotally supported by a bearing portion 52 formed in the casing 15.

[0050] The first mounting hole 61, the second mounting hole 62, and the third mounting hole 63 are formed outside the lid body 16 in a plan view, and mounting holes for mounting to a vehicle are respectively formed. According to this configuration, it can be made into a configuration suitable for a power window of a vehicle having a structure for raising and lowering a vehicle window glass in cooperation with a wire or a belt.

[0051] In the above example, the third vibration isolator 33 has been described as a configuration in which the first plate 34 and the second plate 35 are arranged overlapping in the axial direction, but it is not limited to this, and the first plate 34 and the second plate 35 may be of an integral structure. In the above example, the second vibration isolator 32 has been described as a cross-shaped configuration in which arm portions 32b project in four directions of up, down, left, and right, but it is not limited to this, and it can also be triangular, polygonal, etc. In the above example, the first vibration isolator 31 has been described as a bottomed cylindrical configuration, but it is not limited to this, and it can be of any shape as long as it is a shape corresponding to the accommodating portion of the casing 15, such as a cubic shape with a cylindrical inside or a polyhedral shape with a cylindrical inside. The present invention is not limited to the embodiments described above, and various modifications can be made without departing from the scope of the present invention.

Explanation of Reference Numerals

[0052] 1, 1A, 1B Reduced-speed motor 2 Reducer 3 Motor, 3a Drive shaft, 3b Housing 4 worm, 4a tip, 4b rear end 5 first rotating shaft, 5a depression 6, 6A, 6B second rotating shaft 7a tip side mounting hole, 7b rear end side mounting hole, 7c recess, 7d protrusion 8, 8A, 8B output gear 11 first bush 12 second bush 13 third bush 15 casing 16 cover 17A external gear, 17B external pulley 18 worm bearing part 19 anti-rotation part, 19a shaft hole, 19b protrusion 21 first bearing part 22 second bearing part 23 cylindrical part, 23a flange 24 steel ball 25 receiving plate 28 gear connection part 31 first vibration isolator, 31a receiving part, 31b notch part 32 second vibration isolator, 32a through hole, 32b arm part 33 third vibration isolator 34 first plate, 34a first through hole 35 second plate, 35a second through hole 36 mounting plate 37 third plate 38 fourth plate 41a first screw, 41b first screw hole 42a auxiliary screw 43a casing mounting screw 44a motor mounting screw 81a through part, 81b rib part 82a through part, 82b rib part P1 first axis P2 second axis

Claims

1. A motor with a speed reducer for raising and lowering a vehicle window glass, comprising a speed reducer housed in a casing with a resin worm meshing with an output gear, and a motor attached to the speed reducer for driving the worm. A first rotating shaft is attached to the tip of the worm, the first rotating shaft is pivotally supported by a worm bearing portion, the worm bearing portion is fitted into a first vibration isolator and housed in the casing, a second rotating shaft attached to the output gear is pivotally supported by a bearing portion in the casing, a rotation stopper attached to the drive shaft of the motor is connected to the rear end portion of the worm in a state of being fitted into a second vibration isolator, a mounting plate is attached to the motor, and the mounting plate is attached to the casing with a third vibration isolator sandwiched therebetween. A motor with a speed reducer, characterized by the above.

2. The rear end portion of the worm has convex portions and concave portions alternately formed around its axis, the drive shaft is press-fitted into the rotation stopper, the rotation stopper has protruding portions formed at predetermined intervals around its axis, the second vibration isolator has arm portions for fitting the protruding portions formed at the predetermined intervals around its axis, and the rotation stopper with the drive shaft press-fitted therein is fitted into the second vibration isolator in a state of being fitted into the rear end portion of the worm. The motor with a speed reducer according to claim 1, characterized by the above.

3. The worm bearing portion has a cylindrical portion with a flange, steel balls housed in the cylindrical portion and contacting a recess in the first rotating shaft, and a receiving plate contacting the steel balls at a position facing the recess in the first rotating shaft. The receiving plate is arranged inside the first vibration isolator, the inside of the first vibration isolator with the receiving plate and the cylindrical portion fitted therein has the steel balls contacting the recess, and the receiving plate contacts the side of the steel balls opposite to the side contacting the recess. The motor with a speed reducer according to claim 1 or 2, characterized by the above.

4. The worm is made of polyacetal, polyamide or polybutylene terephthalate, the first vibration isolator, the second vibration isolator and the third vibration isolator are all made of rubber or elastomer. The motor with a speed reducer according to any one of claims 1 to 3, characterized by the above.

5. The third vibration isolator has a first plate, a second plate, and a third plate that share the attenuation of vibration and noise, and in the order closer to the casing, the first plate, the second plate, the mounting plate, and the third plate are arranged overlapping in the axial direction in this order. The motor with a speed reducer according to any one of claims 1 to 4, characterized in that.

6. The anti-rotation part is arranged inside the through holes formed in the first plate and the second plate, respectively, in a state of being fitted into the second vibration isolator. The motor with a speed reducer according to claim 5, characterized in that.

7. The output gear is a resin molded product in which an S-shaped rib portion and a through portion are alternately formed around the axis. The motor with a speed reducer according to any one of claims 1 to 6, characterized in that.

8. The second elastic modulus of the output gear is 0.15 to 0.8 times the first elastic modulus of the worm. The motor with a speed reducer according to any one of claims 1 to 7, characterized in that.

9. The output gear has a module of 0.8 to 1.3 and a tooth width of 10 to 24 mm. The motor with a speed reducer according to any one of claims 1 to 8, characterized in that.

10. An external gear connected to the second rotating shaft is provided, and a first bush, a second bush, and a third bush for mounting to the vehicle are provided integrally with the casing. The motor with a speed reducer according to any one of claims 1 to 9, characterized in that.

11. The first bush, the second bush, and the third bush are all formed with female threads. The first bush is arranged at a position close to the first vibration isolator. The third bush is arranged at a position close to the third vibration isolator. The second bush is arranged at a position farther from the worm than the first bush. The first bush and the second bush are both arranged at positions overlapping the output gear in a plan view. The motor with a speed reducer according to claim 10, characterized in that.

12. An external pulley having an integral structure with the output gear is provided, and a first mounting hole, a second mounting hole, and a third mounting hole for mounting to the vehicle are provided integrally with the casing. The motor with a speed reducer according to any one of claims 1 to 9, characterized in that.

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