Motor with speed reduction mechanism

Abstract

To provide a motor with a speed reduction mechanism capable of holding engagement between gears while suppressing an increase in the number of components.SOLUTION: A block member 70 that rotatably supports a rotating shaft 53 and holds engagement between a pinion gear 61 and a helical gear 62 is provided within a gear case 20 that rotatably accommodates the pinion gear 61 and the helical gear 62 (speed reduction mechanism 60). Due to this structure, the block member 70 can be formed by integrating a bearing part 71 and an engagement holding part 72, and an increase in the number of components can be suppressed. By using the single block member 70, the rotating shaft 53 (pinion gear 61) can be stably rotated, and distortion of the pinion gear 61 can be suppressed. In addition, the engagement between the gears can be appropriately held and early damage of the speed reduction mechanism 60 can be suppressed.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a motor with a reduction mechanism, which is provided with an electric motor and a reduction mechanism. [Background technology]

[0002] Conventionally, small, high-output motors with speed reduction mechanisms have been used as drive sources for wiper devices, power window devices, etc., mounted on vehicles such as automobiles. Such vehicle-mounted motors with speed reduction mechanisms are described in, for example, Patent Document 1.

[0003] The motor with a speed reduction mechanism described in Patent Document 1 includes a brushless motor that rotates a pinion gear, and a helical gear that rotates at a slower speed than the pinion gear. The pinion gear and the helical gear form a speed reduction mechanism, and their respective axes are parallel to each other. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7063758 Summary of the Invention [Problem to be solved by the invention]

[0005] In the technology described in Patent Document 1, a relatively large space is provided inside the gear case on the opposite side of the pinion gear to the side on which the helical gear is provided, which means that if a large reaction force is applied to the pinion gear from the helical gear, the pinion gear will bend away from the helical gear and distort toward the space, which could cause the pinion gear and the helical gear to disengage from each other.

[0006] An object of the present invention is to provide a motor with a reduction mechanism that can maintain meshing between gears while suppressing an increase in the number of parts. [Means for solving the problem]

[0007] In one embodiment of the present invention, a motor with a reduction mechanism includes an electric motor having a rotating shaft, a reduction mechanism having an output shaft that rotates at a slower speed than the rotating shaft, and a case that houses the reduction mechanism, wherein the reduction mechanism has a first gear that is rotatable integrally with the rotating shaft, and a second gear that meshes with the first gear and has the output shaft at its center of rotation, and a block member is provided inside the case that rotatably supports the rotating shaft and maintains the meshing between the first gear and the second gear. Effect of the Invention

[0008] According to the present invention, it is possible to realize a motor with a reduction mechanism capable of maintaining meshing between gears while suppressing an increase in the number of parts. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a perspective view of the motor with a reduction mechanism as viewed from the output shaft side. [Diagram 2] 2 is a perspective view of the motor with a reduction mechanism as viewed from the cover member side. FIG. [Diagram 3] 2 is a cross-sectional view showing the internal structure of a motor with a reduction mechanism. [Figure 4] FIG. [Diagram 5] FIG. 4 is an enlarged cross-sectional view of a block member in FIG. 3. [Figure 6] FIG. 4 is a perspective view of the block member as viewed from the press-fitting portion side. [Figure 7] FIG. 4 is a perspective view of the block member as viewed from the meshing retaining portion side. [Figure 8] 4 is a cross-sectional view taken along line AA in FIG. 3, illustrating a procedure for mounting the block member to the gear case. [Figure 9] FIG. 6 is a cross-sectional view showing a second embodiment and corresponding to FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [Embodiment 1] Hereinafter, the first embodiment of the present invention will be described in detail with reference to the drawings.

[0011] Figure 1 is an oblique view of the motor with a reduction gear mechanism seen from the output shaft side, Figure 2 is an oblique view of the motor with a reduction gear mechanism seen from the cover member side, Figure 3 is a cross-sectional view showing the internal structure of the motor with a reduction gear mechanism, Figure 4 is an oblique view showing the reduction gear mechanism, Figure 5 is an enlarged cross-sectional view of the block member in Figure 3, Figure 6 is an oblique view of the block member seen from the press-in portion side, Figure 7 is an oblique view of the block member seen from the meshing retaining portion side, and Figure 8 is a cross-sectional view along line AA in Figure 3 showing the procedure for installing the block member into the gear case.

[0012] [Outline of motor with reduction gear mechanism] 1 to 3 is used as a drive source for a wiper device mounted on a vehicle such as an automobile. Specifically, the speed reduction motor 10 swings a wiper member (not shown) that is swingably mounted on the front windshield or rear windshield of the vehicle within a predetermined wiping range.

[0013] The motor with speed reduction mechanism 10 includes a housing 11 that forms the outer periphery of the motor. Inside the housing 11, a brushless motor 50 and a speed reduction mechanism 60 are housed so as to be freely rotatable.

[0014] The brushless motor 50 corresponds to the electric motor in the present invention.

[0015] The housing 11 is made up of a gear case 20 and a cover member 30, both of which are made of aluminum die-cast. The gear case 20 and the cover member 30 are fixed to each other by a total of five first fixing screws S1 (only four are shown in FIG. 2).

[0016] A bracket BR formed in a substantially annular shape is fixed to the outside of the gear case 20 by a total of four second fixing screws S2 (only three are shown in FIG. 1). The bracket BR has the function of fixing the reduction gear equipped motor 10 to the vehicle.

[0017] [Gear case] The gear case 20 is formed in a generally bowl shape by injection molding of molten aluminum material. Specifically, the gear case 20 includes a bottom wall portion 21, a side wall portion 22 integrally provided around the bottom wall portion 21, and a bearing holder mounting portion 23 to which a bearing holder 40 (see FIG. 3) is mounted.

[0018] The gear case 20 corresponds to the case in the present invention.

[0019] A boss portion 21a that rotatably supports the output shaft 63 is provided integrally with the bottom wall portion 21 at approximately the center thereof. A plurality of reinforcing ribs 21b formed in a substantially triangular shape are provided integrally with the boss portion 21a on the radially outer side thereof. These reinforcing ribs 21b are provided on the exterior and interior of the gear case 20, respectively, and increase the fixing strength of the boss portion 21a to the bottom wall portion 21. The reinforcing ribs 21b are arranged at equal intervals in the circumferential direction of the boss portion 21a.

[0020] 3, the base end side (lower side in FIG. 3) of the boss portion 21a disposed inside the gear case 20 rotatably supports an annular fixing member FP for fixing the helical gear 62 to the output shaft 63. This prevents the helical gear 62 from tilting when a relatively large external force is applied to the output shaft 63. This allows the reduction mechanism 60 to operate stably.

[0021] A cylindrical bearing member 14, also called a metal, is attached to the radially inner side of the boss portion 21a. This allows the output shaft 63 to rotate smoothly without rattling with respect to the boss portion 21a. A seal member 15 made of an elastic material such as rubber is attached to the radially inner side of the tip side (upper side in FIG. 3) of the boss portion 21a arranged outside the gear case 20. This prevents rainwater, dust, and the like from entering between the output shaft 63 and the bearing member 14.

[0022] Here, an E-type retaining ring 16 is fixed to the center in the longitudinal direction of the output shaft 63. As a result, the boss portion 21a is sandwiched between the annular fixing member FP and the E-type retaining ring 16, and the output shaft 63 is prevented from coming off the boss portion 21a. This prevents the output shaft 63 from rattling against the boss portion 21a, thereby ensuring quietness of the reduction gear motor 10.

[0023] At a position offset from the boss portion 21a of the bottom wall portion 21, a bearing accommodating portion 21c is integrally provided. The bearing accommodating portion 21c is formed in a substantially box shape, and protrudes from the bottom wall portion 21 toward the outside of the gear case 20 (upper side in FIG. 3) at a predetermined height. Inside the bearing accommodating portion 21c, there are provided a bearing mounting portion 21c1 to which the bearing portion 71 (see FIGS. 5 to 7) of the block member 70 is mounted, and a fixed recess 21c2 to which the press-fit portion 73 (see FIGS. 5 to 7) of the block member 70 is fixed by press-fitting. That is, inside the bearing accommodating portion 21c having the bearing mounting portion 21c1, the tip side (upper side in FIG. 3) of the rotating shaft 53 is rotatably accommodated. Here, the inner diameter of the fixed recess 21c2 is smaller than the inner diameter of the bearing mounting portion 21c1.

[0024] The fixing recess 21c2 corresponds to the fixing portion in this invention.

[0025] At a location of the side wall 22 near the bearing holder mounting portion 23 and inside the gear case 20, a meshing retaining portion mounting portion 22a is provided to which the meshing retaining portion 72 (see Figs. 5 to 7) of the block member 70 is mounted. The meshing retaining portion mounting portion 22a is disposed in the vicinity of the bearing mounting portion 21c1. Specifically, as shown in Fig. 5, the fixing recess 21c2, the bearing mounting portion 21c1, and the meshing retaining portion mounting portion 22a are arranged in this order from the side where the bottom wall 21 of the gear case 20 is provided (the upper side of Fig. 5) toward the opening side of the gear case 20 (the lower side of Fig. 5).

[0026] 5, the block member 70 is provided so as to cross the fixed recess 21c2, the bearing mounting portion 21c1 and the meshing holder mounting portion 22a, and is disposed so as to surround the periphery of the pinion gear 61. The structure of the block member 70 will be described in detail later.

[0027] As shown in Fig. 5 and Fig. 8, a pair of case side inclined surfaces 22b are integrally provided on the meshing retainer mounting portion 22a. These case side inclined surfaces 22b face each other in a direction intersecting the axial direction of the pinion gear 61 and the helical gear 62 (see Fig. 4). The pair of case side inclined surfaces 22b are disposed forward in the insertion direction of the block member 70 (see Figs. 5 and 8) into the meshing retainer mounting portion 22a. In other words, the pair of case side inclined surfaces 22b are disposed closer to the bottom wall portion 21 of the gear case 20.

[0028] A pair of block member side inclined surfaces 72d (see Figs. 6 to 8) provided on the meshing retaining portion 72 of the block member 70 abut against the pair of case side inclined surfaces 22b. As a result, as shown by arrow M in Fig. 8, when the meshing retaining portion 72 of the block member 70 is attached to the meshing retaining portion attachment portion 22a, the pair of block member side inclined surfaces 72d abut against the pair of case side inclined surfaces 22b, and the meshing retaining portion 72 of the block member 70 is positioned at a specified position of the meshing retaining portion attachment portion 22a. Therefore, the block member 70 can be easily attached to the gear case 20.

[0029] [Bearing holder] 3, bearing holder 40 mounted on bearing holder mounting portion 23 holds a first ball bearing BB1. Here, first ball bearing BB1 rotatably supports rotating shaft 53 in the approximate center in the axial direction thereof and in the vicinity of pinion gear 61.

[0030] The bearing holder 40 is made of die-cast aluminum and is fixed to the cover member 30 by a first fixing screw S1 without any rattle. Specifically, the bearing holder 40 is disposed so as to be sandwiched between the bearing holder attachment portion 23 and the cover member 30 in the axial direction of the rotating shaft 53.

[0031] Further, the bearing holder 40 is provided at its approximate center with an insertion hole 41 through which the rotating shaft 53 is inserted in a non-contact state.

[0032] [Cover material] 3, the cover member 30 includes a board covering portion 31 formed in a substantially flat plate shape, and a motor accommodating portion 32 formed in a substantially cylindrical shape with a bottom. The board covering portion 31 covers the board 12 accommodated inside the housing 11. Furthermore, a total of three heat dissipation fins 31a (see FIG. 2) are integrally provided on the outside of the board covering portion 31 for dissipating heat from the board 12 and the brushless motor 50 to the outside.

[0033] A connector connection portion (not shown) to which an external connector on the vehicle side is connected is attached to the cover member 30, and the connector connection portion is electrically connected to the brushless motor 50 via the substrate 12. This allows an in-vehicle controller (not shown) connected to the external connector to drive the brushless motor 50 with high precision in response to detection signals from the Hall sensor 12a and the MR sensor 12b mounted on the substrate 12.

[0034] Here, three Hall sensors 12a (only one is shown in the figure) are mounted on the substrate 12. These Hall sensors 12a correspond to the U-phase, V-phase, and W-phase, respectively, and face permanent magnets MG provided on the rotor 52 in the axial direction of the rotating shaft 53. The on-board controller determines the rotation state (rotation speed, rotation direction, etc.) of the brushless motor 50 (rotating shaft 53) from the detection signals of the three Hall sensors 12a, and controls the brushless motor 50 based on this.

[0035] A single MR sensor 12b is mounted on the substrate 12. The MR sensor 12b faces a sensor magnet SM fixed to the rotation center of the helical gear 62 in the axial direction of the output shaft 63. The on-board controller grasps the rotation state (rotation position, etc.) of the output shaft 63 from the detection signal of the MR sensor 12b, and controls the wiping position of the wiper member relative to the wiping surface (not shown) based on this.

[0036] The motor accommodating portion 32 protrudes toward the side opposite to the side where the gear case 20 is provided (the lower side in FIG. 3). The motor accommodating portion 32 faces the bearing accommodating portion 21c of the gear case 20 in the axial direction of the rotating shaft 53, and the brushless motor 50 is accommodated inside the motor accommodating portion 32.

[0037] Further, a bearing mounting cylindrical portion 32a is provided integrally with the motor accommodating portion 32 at approximately the center and on the inner side. A second ball bearing BB2 is mounted on the bearing mounting cylindrical portion 32a. The second ball bearing BB2 rotatably supports the longitudinal base end side (the lower side in FIG. 3) of the rotating shaft 53. In this manner, the rotating shaft 53 including the pinion gear 61 is rotatably supported at a total of three locations, namely, the bearing portion 71 of the block member 70 (see FIGS. 5 to 7), the first ball bearing BB1, and the second ball bearing BB2.

[0038] [Brushless motor] 3, brushless motor 50 accommodated in motor accommodating portion 32 includes stator core 51 formed in a substantially cylindrical shape. Stator core 51 is fixed to bearing holder 40 inside motor accommodating portion 32 by a plurality of fixing bolts (not shown).

[0039] Stator core 51 is formed by laminating multiple thin steel plates, and multiple teeth (not shown) are provided radially outward from the stator core 51. Coils 51a corresponding to U-phase, V-phase, and W-phase are wound around these teeth with a predetermined number of turns by concentrated winding.

[0040] Then, by alternately supplying drive current to U-phase, V-phase, and W-phase coils 51a from the on-board controller at a predetermined timing, rotor 52 disposed radially outside stator core 51 is rotated in a predetermined rotational direction with a predetermined drive torque. Thus, brushless motor 50 according to this embodiment includes stator core 51 and rotor 52, and is an outer rotor type brushless motor.

[0041] 3 and 4, the rotor 52 has a rotating shaft 53 with a pinion gear 61 integrally provided thereon. The rotor 52 also includes a rotor body 54 having a generally U-shaped cross section formed by pressing a thick steel plate or the like. A plurality of permanent magnets MG formed in a generally tile-like shape are fixed to the radial inside of the rotor body 54. The rotating shaft 53 is fixed to the center of rotation of the rotor body 54 by press fitting or the like.

[0042] [Deceleration mechanism] 3 to 5, the reduction mechanism 60 is rotatably housed inside the gear case 20. The reduction mechanism 60 includes a rod-shaped pinion gear 61 that is rotatably mounted on the rotating shaft 53, and a helical gear 62 that is meshed with the pinion gear 61 and has the output shaft 63 at its rotation center. The axis of the pinion gear 61 and the axis of the helical gear 62 are parallel to each other. That is, the rotating shaft 53 and the output shaft 63 are parallel to each other.

[0043] The pinion gear 61 corresponds to the first gear in the present invention. The helical gear 62 corresponds to the second gear in the present invention. Furthermore, the output shaft 63 provided on the helical gear 62 also corresponds to the reduction gear mechanism in the present invention.

[0044] Furthermore, the pinion gear 61 is disposed on the input side (rotation shaft 53 side) of the motor 10 with the reduction mechanism, and the helical gear 62 is disposed on the output side (output shaft 63 side) of the motor 10 with the reduction mechanism. In other words, the reduction mechanism 60 reduces the high-speed rotation of the pinion gear 61, which has a smaller number of teeth, to the low-speed rotation of the helical gear 62, which has a larger number of teeth. Therefore, the helical gear 62 rotates at a slower speed than the pinion gear 61.

[0045] The rotating shaft 53 including the pinion gear 61 is made of metal, and helical teeth 61a are integrally provided around the periphery of the pinion gear 61. The axial length of the pinion gear 61 is longer than the axial length of the helical gear 62. This allows the helical teeth 61a to mesh reliably with the helical gear 62.

[0046] The helical tooth 61a extends continuously in a helical shape in the axial direction of the pinion gear 61, and the pinion gear 61 is provided with only one helical tooth 61a. In other words, the pinion gear 61 has one tooth. As shown in FIG 5, the helical tooth 61a has a substantially semicircular cross-sectional shape and fits into (meshes with) a meshing recess 62d of the helical gear 62.

[0047] The helical gear 62 forming the reduction gear mechanism 60 is made of plastic and has a gear body 62a formed in a substantially disk shape. An annular fixing member FP made of a steel plate is fixed to the rotation center of the gear body 62a. The base end side of the output shaft 63 is fixed to the center of the annular fixing member FP by press fitting or the like.

[0048] In this manner, the output shaft 63 is fixed to the rotation center of the helical gear 62 via the annular fixing member FP, and the output shaft 63 is rotated together with the helical gear 62. In other words, the output shaft 63 is rotated at a slower speed than the rotating shaft 53.

[0049] A sensor magnet SM is fixed to the center of rotation of the gear body 62a on the side where the substrate 12 is provided (the lower side in FIG. 3). The sensor magnet SM also rotates together with the helical gear 62.

[0050] A gear forming portion 62b that is thicker than the gear body 62a is integrally provided on the outer periphery of the gear body 62a. A plurality of helical teeth 62c are provided on the outer periphery of the gear forming portion 62b so as to be aligned in the circumferential direction. These helical teeth 62c are inclined at a predetermined angle with respect to the axial direction of the pinion gear 61, so that the helical gear 62 rotates in conjunction with the rotation of the helical teeth 61a.

[0051] Specifically, an interlocking recess 62d is provided between adjacent helical teeth 62c, and the helical teeth 61a are inserted into and interlocked with the interlocking recess 62d. Note that the interlocking recess 62d is also formed so that its cross-sectional shape is substantially semicircular, as shown in FIG.

[0052] Here, a recess 62e recessed toward the sensor magnet SM is provided on the output shaft 63 side in the axial direction of the helical gear 62. The base end side (lower side in FIG. 3) of the boss portion 21a and the reinforcing rib 21b provided inside the gear case 20 fit into the inside of the recess 62e via a gap.

[0053] Therefore, the helical gear 62 can rotate smoothly relative to the gear case 20. If the helical gear 62 attempts to tilt relative to the gear case 20, the helical gear 62 is supported by the bottom wall portion 21 and the bearing holder 40 without coming into contact with the reinforcing rib 21b. This prevents the helical gear 62 from being significantly tilted relative to the gear case 20, and the meshing state between the pinion gear 61 and the helical gear 62 is properly maintained.

[0054] Here, the number of helical teeth 62c (meshing recesses 62d) provided on the helical gear 62 is 37. That is, in this embodiment, the reduction ratio of the reduction mechanism 60 having the pinion gear 61 and the helical gear 62 is 1 / 37.

[0055] The reduction ratio of the reduction mechanism 60 can be set arbitrarily depending on the specifications required for the motor 10 with the reduction mechanism.

[0056] [Block material] 5 to 7, a block member 70 is provided inside the gear case 20. Specifically, the block member 70 is disposed inside the gear case 20 so as to cross the fixing recess 21c2, the bearing mounting portion 21c1, and the meshing retainer mounting portion 22a.

[0057] The block member 70 is made of a lightweight resin material such as plastic. The block member 70 rotatably supports the rotary shaft 53 and maintains the meshing between the pinion gear 61 and the helical gear 62.

[0058] 5, the block member 70 includes a bearing portion 71 that rotatably supports the rotating shaft 53, and a meshing holding portion 72 that holds the meshing between the pinion gear 61 and the helical gear 62. The bearing portion 71 and the meshing holding portion 72 are aligned in the axial direction of the rotating shaft 53 and are integrated together. The meshing holding portion 72 faces the helical gear 62 across the pinion gear 61 in the radial direction of the rotating shaft 53. This allows the meshing holding portion 72 to support the pinion gear 61.

[0059] Specifically, when the position of the bearing portion 71 with respect to the axial direction of the rotating shaft 53 is used as a reference, the meshing retaining portion 72 is disposed on the side of the bearing portion 71 where the cover member 30 is provided (the lower side in FIG. 5). Also, a press-fitting portion 73 that is press-fitted into the fixed recess 21c2 provided in the gear case 20 is integrally provided on the side of the bearing portion 71 opposite to the side where the cover member 30 is provided (the upper side in FIG. 5). That is, the press-fitting portion 73 faces the meshing retaining portion 72 in the axial direction of the rotating shaft 53, sandwiching the bearing portion 71 therebetween.

[0060] Here, the bearing portion 71, the meshing retaining portion 72, and the press-fit portion 73 are integrated by filling a mold with molten resin and injection molding, and the block member 70 is an injection-molded product. In Fig. 5, in order to make the boundaries between the bearing portion 71, the meshing retaining portion 72, and the press-fit portion 73 easier to see, dashed lines are drawn at the boundaries between the bearing portion 71, the meshing retaining portion 72, and the press-fit portion 73.

[0061] The bearing portion 71 is formed in a thick, generally cylindrical shape, and a cylindrical surface 71a is provided on the outer periphery thereof. The cylindrical surface 71a is attached to a bearing mounting portion 21c1 of the bearing accommodating portion 21c that forms the gear case 20. Here, the cylindrical surface 71a is not in close contact with the bearing mounting portion 21c1. In other words, the bearing mounting portion 21c1 does not have a function of fixing the bearing portion 71, but has a function of positioning the bearing portion 71 with respect to the gear case 20. Therefore, a minute gap (not shown) is formed between the bearing mounting portion 21c1 and the cylindrical surface 71a.

[0062] Furthermore, a bearing surface 71b is provided on the inner periphery of the bearing portion 71. The bearing surface 71b rotatably supports the tip side (upper side in FIG. 5) of the rotating shaft 53. This allows the pinion gear 61 to rotate stably without wobbling. The axial length of the bearing surface 71b is approximately half the axial length of the entire bearing portion 71. This minimizes the number of sliding contact points between the rotating shaft 53 and the bearing portion 71, thereby suppressing an increase in the sliding resistance of the rotating shaft 53 against the bearing surface 71b.

[0063] Furthermore, in the axial direction of the bearing portion 71, an annular abutment surface 71c is provided on the side where the press-fit portion 73 is provided (upper side in FIG. 5). The abutment surface 71c faces forward in the mounting direction of the block member 70 and abuts against the gear case 20. This allows the block member 70 to be positioned at a specified position with respect to the gear case 20 in the axial direction of the rotating shaft 53.

[0064] The meshing retaining portion 72 is formed in a substantially rectangular column shape, and a back surface 72a is provided on the outer periphery thereof opposite to the side where the pinion gear 61 is disposed. The back surface 72a is attached to the meshing retaining portion mounting portion 22a forming the gear case 20. Here, the back surface 72a is not in close contact with the meshing retaining portion mounting portion 22a. In other words, the meshing retaining portion mounting portion 22a does not have the function of fixing the meshing retaining portion 72, but has the function of positioning the meshing retaining portion 72 with respect to the gear case 20. Therefore, a minute gap (not shown) is formed between the meshing retaining portion mounting portion 22a and the back surface 72a.

[0065] Further, a gear accommodating recess 72b is provided on the side opposite to the side where the back surface 72a of the meshing retaining portion 72 is provided. The gear accommodating recess 72b is recessed toward the back surface 72a, and is connected to the inner peripheral portion of the bearing portion 71 in the axial direction of the rotating shaft 53. As a result, when the block member 70 is viewed from the axial direction of the rotating shaft 53, the meshing retaining portion 72 is offset with respect to the bearing portion 71.

[0066] The gear accommodating recess 72b covers the outer periphery of the pinion gear 61 over 180 degrees or more, and a pair of opposing surfaces 72c that face the helical gear 62's helical teeth 62c (meshing recess 62d) are provided on the opening side of the gear accommodating recess 72b. Here, as shown in FIG. 5, a gap δ is formed between the gear accommodating recess 72b and the outer periphery (helical teeth 61a) of the pinion gear 61. In addition, a gap (not shown) that is slightly larger than the gap δ is formed between the pair of opposing surfaces 72c and the helical gear 62. This allows the pinion gear 61 and the helical gear 62 to rotate smoothly without contacting the meshing holder 72.

[0067] However, when a relatively large reaction force is transmitted from the output shaft 63, the pinion gear 61 may be distorted (curved) away from the helical gear 62 toward the meshing retaining portion 72. When the pinion gear 61 is distorted, the approximate center portion in the longitudinal direction of the pinion gear 61 moves inside the gear accommodating recess 72b toward the back surface 72a by the amount of the gap δ and comes into contact with the gear accommodating recess 72b. In other words, the meshing retaining portion 72 supports the pinion gear 61 so as not to distort (bend) any further.

[0068] Therefore, the meshing state between the pinion gear 61 and the helical gear 62 is properly maintained. In this manner, the meshing retaining portion 72 has a function of suppressing the pinion gear 61 from bending significantly when a relatively large reaction force is applied to the output shaft 63.

[0069] Here, a relatively large amount of grease (lubricant) is applied to the meshing portion between the pinion gear 61 and the helical gear 62. The grease is intended to ensure smooth rotation (power transmission) of the pinion gear 61 and the helical gear 62, and is surrounded by the gear accommodating recess 72b. In other words, the gear accommodating recess 72b functions as a so-called "grease reservoir" that prevents grease from being discharged to the outside of the gear accommodating recess 72b.

[0070] Furthermore, in the axial direction of the rotating shaft 53, a pair of block member side inclined surfaces 72d are provided on the side of the meshing retaining portion 72 where the bearing portion 71 is provided. These block member side inclined surfaces 72d are respectively abutted against a pair of case side inclined surfaces 22b (see FIG. 8) provided on the gear case 20. This allows the block member 70 to be aligned straight along the axial direction of the rotating shaft 53, and the meshing retaining portion 72 to be positioned at a specified position on the meshing retaining portion mounting portion 22a.

[0071] The press-fit portion 73 is formed in a generally cylindrical shape that is thinner and has a smaller diameter than the bearing portion 71. The press-fit portion 73 and the bearing portion 71 are arranged coaxially with each other (on the axis of the rotating shaft 53). An annular tapered surface 73a is provided on the outer periphery of the tip side of the press-fit portion 73. Specifically, the annular tapered surface 73a has a tapered shape on the tip side of the press-fit portion 73. This allows the press-fit portion 73 to be easily press-fitted into the fixing recess 21c2 of the bearing accommodating portion 21c when the block member 70 is attached to the gear case 20.

[0072] Thus, the block member 70 is provided with the meshing retaining portion 72 having the pair of case-side inclined surfaces 22b, and the press-fit portion 73 having the annular tapered surface 73a. The case-side inclined surfaces 22b and the tapered surface 73a are each disposed forward in the mounting direction of the block member 70 (upper side in FIG. 8). This allows the block member 70 to be easily mounted to the gear case 20, improving ease of assembly.

[0073] 8, when the block member 70 is attached to the gear case 20, the attachment operation of the block member 70 is guided by the case-side inclined surface 22b and the tapered surface 73a. Therefore, even if the press-fit portion 73 of the block member 70 cannot be visually observed, the press-fit portion 73 can be easily press-fitted into the fixed recess 21c2 of the bearing accommodating portion 21c.

[0074] At this time, among the bearing portion 71, the meshing retaining portion 72, and the press-fit portion 73, only the press-fitting portion 73 is fixed to the gear case 20. Therefore, the press-fit load of the block member 70 to the gear case 20 does not need to be large, and the block member 70 can be fixed with light press-fitting. This improves the ease of assembly of the reduction gear motor 10. Furthermore, the bearing portion 71 and the meshing retaining portion 72 are prevented from being distorted by the press-fitting of the press-fitting portion 73, and thus the accuracy of the bearing portion 71 and the meshing retaining portion 72 can be prevented from decreasing.

[0075] Moreover, the bearing portion 71 and the press-fit portion 73 are arranged coaxially, and the position of the bearing portion 71 and the position of the press-fit portion 73 are different from each other in the axial direction of the rotating shaft 53. Therefore, even if the press-fit portion 73 is distorted by being pressed into the fixed recess 21c2, the bearing portion 71 is not distorted because it is thicker than the press-fit portion 73, and thus it is possible to prevent the axial centers of the bearing portion 71 and the press-fit portion 73 from being misaligned.

[0076] As described above in detail, according to this embodiment, a block member 70 is provided inside gear case 20, which rotatably houses pinion gear 61 and helical gear 62 (reduction mechanism 60), and which rotatably supports rotating shaft 53 and maintains meshing between pinion gear 61 and helical gear 62.

[0077] This allows the block member 70 to be formed by integrating the bearing portion 71 and the meshing retaining portion 72, thereby preventing an increase in the number of parts. Also, the single block member 70 allows the rotating shaft 53 (pinion gear 61) to rotate stably and prevents distortion of the pinion gear 61. Furthermore, the meshing between the gears can be properly maintained, preventing early damage to the reduction mechanism 60.

[0078] In addition, according to this embodiment, the block member 70 includes a bearing portion 71 that rotatably supports the rotating shaft 53, and an engagement retaining portion 72 that retains the engagement between the pinion gear 61 and the helical gear 62, the bearing portion 71 and the engagement retaining portion 72 being aligned in the axial direction of the rotating shaft 53 and being integral with each other, and the engagement retaining portion 72 faces the engagement retaining portion 72 in the radial direction of the rotating shaft 53, sandwiching the pinion gear 61 therebetween.

[0079] This allows the single block member 70 to have both a bearing function for supporting the rotating shaft 53 and a meshing retention function for maintaining meshing between the gears. Also, a part having multiple functions can be realized by the single block member 70, which makes it easy to manage parts.

[0080] Furthermore, according to this embodiment, the block member 70 is integrally provided with a press-fit portion 73 that is pressed into the fixed recess 21c2 provided in the gear case 20, and the press-fit portion 73 faces the meshing retaining portion 72 in the axial direction of the rotating shaft 53, sandwiching the bearing portion 71 therebetween.

[0081] This allows the single block member 70, which has a bearing function and a meshing retention function, to further have a fixing function of fixing the block member 70 to the gear case 20 by press-fitting.

[0082] Furthermore, according to this embodiment, the press-fit portion 73 and the bearing portion 71 are coaxially arranged.

[0083] This allows the bearing portion 71 to be positioned on the axis of the rotating shaft 53 with high precision simply by press-fitting and fixing the press-fit portion 73 into the fixing recess 21c2.

[0084] Furthermore, according to this embodiment, when pinion gear 61 is distorted toward meshing holder 72, it is supported by meshing holder 72.

[0085] As a result, when the pinion gear 61 is not distorted, the pinion gear 61 and the meshing holder 72 are not in contact with each other, and an increase in the operating resistance of the reduction gear mechanism 60 (the pinion gear 61 and the helical gear 62) can be suppressed.

[0086] Furthermore, according to this embodiment, the block member 70 is made of resin.

[0087] This makes it possible to suppress an increase in the weight of the entire speed reduction motor 10. In addition, since the rotating shaft 53 is rotatably supported by the resin bearing portion 71, an increase in the rotational resistance of the rotating shaft 53 can be prevented.

[0088] Furthermore, according to this embodiment, the durability of the reduction gear mechanism 60 can be improved while suppressing an increase in the number of parts, thereby saving manufacturing energy. Therefore, it is possible to achieve the Sustainable Development Goals (SDGs) established by the United Nations, particularly Goal 7 (Affordable and clean energy) and Goal 13 (Take urgent action to combat climate change).

[0089] [Embodiment 2] Next, a second embodiment of the present invention will be described in detail with reference to the drawings. Note that parts having the same functions as those in the first embodiment are given the same reference numerals, and detailed descriptions thereof will be omitted.

[0090] FIG. 9 is a cross-sectional view corresponding to FIG. 5 showing the second embodiment.

[0091] As shown in FIG. 9, a motor 80 with a speed reduction mechanism according to the second embodiment differs from the motor 10 with a speed reduction mechanism according to the first embodiment (see FIG. 5) only in the fixing structure of the block member 70 to the gear case 20.

[0092] Specifically, the bearing accommodating portion 21c of the gear case 20 is provided with a through hole 81 that penetrates in the axial direction of the rotating shaft 53 so as to communicate the inside and outside of the bearing accommodating portion 21c. That is, in the second embodiment, the through hole 81 is provided instead of the fixing recess 21c2 (see FIG. 5) of the first embodiment.

[0093] The through hole 81 corresponds to the fixing portion in the present invention.

[0094] A press-fit portion 82 provided on the block member 70 is fixed by press-fitting into the through hole 81. The press-fit portion 82 of the second embodiment has a longer length in the axial direction of the rotating shaft 53 than the press-fit portion 73 of the first embodiment. Specifically, the axial length of the press-fit portion 82 of the second embodiment is approximately twice as long as the axial length of the press-fit portion 73 of the first embodiment.

[0095] The second embodiment configured as described above can also achieve the same effects as those of the above-mentioned first embodiment. In addition, in the second embodiment, the axial length of the press-fit portion 82 is longer than that of the first embodiment, so that the fixing strength of the block member 70 to the gear case 20 can be increased.

[0096] Furthermore, the block member 70 can be easily removed from the gear case 20 by inserting a jig (not shown) from the outside of the gear case 20 (the upper side in FIG. 9) into the through hole 81 that communicates between the inside and outside of the gear case 20. This improves the recyclability of the reduction gear motor 80. However, the block member 70 removed from the gear case 20 cannot be reused because it is likely to be worn to a certain extent.

[0097] The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention. For example, in the above-mentioned embodiments, the block member 70 is shown with the press-fit portion 72 (73), the bearing portion 71, and the meshing retaining portion 72 arranged in this order from the upper side in Fig. 5 and Fig. 9, but the present invention is not limited to this, and the order of the press-fit portion, the bearing portion, and the meshing retaining portion can be reversed, for example, depending on the structure of the rotating shaft and the housing that form the motor with a reduction mechanism.

[0098] In addition, in each of the above-described embodiments, the motor with speed reduction mechanism 10, 80 is applied to a drive source of a wiper device mounted on a vehicle, but the present invention is not limited to this, and can be applied to other drive sources such as a power window device and a sunroof device.

[0099] Furthermore, in each of the above-described embodiments, the motors 10 and 80 with a speed reducer are provided with a brushless motor 50. However, the present invention is not limited to this, and a motor with brushes can also be used as the electric motor.

[0100] In addition, the material, shape, size, number, installation location, etc. of each component in each of the above-mentioned embodiments are arbitrary as long as the present invention can be achieved, and are not limited to the above-mentioned embodiments. [Explanation of symbols]

[0101] 10: motor with reduction mechanism, 11: housing, 12: circuit board, 12a: hall sensor, 12b: MR sensor, 14: bearing member, 15: seal member, 16: E-type retaining ring, 20: gear case (case), 21: bottom wall, 21a: boss, 21b: reinforcing rib, 21c: bearing accommodating section, 21c1: bearing mounting section, 21c2: fixed recess (fixed section), 22: side wall, 22a: meshing retaining section mounting section, 22b: case side inclined surface, 23: bearing holder mounting section, 30: cover member, 31: circuit board covering section, 31a: heat dissipation fin, 32: motor accommodating section, 32a: bearing mounting cylinder section, 40: bearing holder, 41: insertion hole, 50: brushless motor (electric motor), 51: stator core, 51a: coil, 52: rotor, 53: rotating shaft, 54: rotor body, 60: reducer Structure, 61: pinion gear (first gear), 61a: helical teeth, 62: helical gear (second gear), 62a: gear body, 62b: gear forming portion, 62c: helical teeth, 62d: meshing recess, 62e: recess, 63: output shaft (reduction mechanism), 70: block member, 71: bearing portion, 71a: cylindrical surface, 71b: bearing surface, 71c: abutment surface, 72: meshing holding portion, 72a: back surface, 72b: gear storage Receptacle recess, 72c: opposing surface, 72d: inclined surface on block member side, 73: press-fit portion, 73a: tapered surface, 80: motor with reduction mechanism, 81: through hole (fixing portion), 82: press-fit portion, BB1: first ball bearing, BB2: second ball bearing, BR: bracket, FP: annular fixing member, MG: permanent magnet, S1: first fixing screw, S2: second fixing screw, SM: sensor magnet

Claims

1. an electric motor having a rotating shaft; a reduction gear mechanism having an output shaft that rotates at a slower speed than the rotating shaft; a case that accommodates the reduction mechanism; A motor with a reduction mechanism comprising: The reduction mechanism includes: a first gear provided on the rotating shaft so as to be integrally rotatable; a second gear that is meshed with the first gear and has the output shaft disposed at its rotation center; having A block member is provided inside the case to rotatably support the rotating shaft and to maintain meshing between the first gear and the second gear. Motor with reduction mechanism.

2. 2. The motor with a reduction mechanism according to claim 1, The block member is A bearing portion that rotatably supports the rotating shaft; a meshing holding portion that holds the meshing between the first gear and the second gear; Equipped with the bearing portion and the meshing retaining portion are aligned in the axial direction of the rotating shaft and are integral with each other, The meshing holder faces the second gear across the first gear in a radial direction of the rotation shaft. Motor with reduction mechanism.

3. 3. The motor with a reduction mechanism according to claim 2, The block member is integrally provided with a press-fitting portion that is press-fitted into a fixing portion provided on the case, The press-fit portion faces the meshing holding portion across the bearing portion in the axial direction of the rotating shaft. Motor with reduction mechanism.

4. The press-fit portion and the bearing portion are arranged coaxially. The motor with a reduction mechanism according to claim 3.

5. The first gear is supported by the meshing holding portion when the first gear is distorted toward the meshing holding portion. The motor with a reduction mechanism according to claim 2.

6. The block member is made of resin. The motor with a reduction mechanism according to any one of claims 1 to 5.

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