JP6257163B2 - Rotating shaft and motor with speed reduction mechanism using the same - Google Patents

Description

  The present invention relates to a rotating shaft that rotationally drives a gear and a motor with a speed reduction mechanism using the rotating shaft.

  2. Description of the Related Art Conventionally, a drive motor such as a wiper device mounted on a vehicle such as an automobile employs a motor with a speed reduction mechanism that can provide a large output while being small. The motor with a speed reduction mechanism includes a motor portion having a rotating shaft that is rotationally driven by supply of a drive current, and a gear portion having a speed reducing mechanism that reduces the rotation of the rotating shaft to increase the torque.

  The rotating shaft is formed in a long shape so as to extend over both the motor portion and the gear portion. A worm that meshes with a worm wheel (gear) that forms a speed reduction mechanism is provided on the distal end side in the axial direction of the rotation shaft, and a rotor that generates rotational force is provided on the proximal end side in the axial direction of the rotation shaft. ing. In addition, a bearing member that rotatably holds the rotating shaft is mounted at the axial center of the rotating shaft, whereby the rotating shaft is stably rotated.

  As a motor with a speed reduction mechanism including such a rotation shaft, for example, a technique described in Patent Document 1 is known. The motor with a speed reduction mechanism described in Patent Document 1 includes a rotating shaft having a shaft main body portion and a worm portion, and the diameter dimension of the shaft main body portion is constant along the axial direction. The shaft main body is provided with a second shaft support portion to which the ball bearing is fixed, a core fixing portion to which the rotor core is fixed, and the like. Further, the worm portion is formed with a smaller diameter than the shaft main body portion, and a screw-like worm is formed around the worm portion.

JP 2011-250485 A

  By the way, in the motor with a speed reduction mechanism mounted on the vehicle as described above, it is desired to further reduce the size and weight in order to improve the fuel efficiency of the vehicle and the degree of freedom in vehicle design. Among the components that form the motor with a speed reduction mechanism, if the worm wheel that is relatively large and heavy is made small, the motor with the speed reduction mechanism can be efficiently reduced in size and weight.

  However, in the motor with a speed reduction mechanism described in Patent Document 1 described above, if the worm wheel is simply made smaller, the meshing strength between the worm and the worm wheel decreases, and for example, the teeth of the worm wheel during high torque loads. Problems such as chipping may occur. Therefore, it is conceivable to increase the tooth depth of the worm to ensure the meshing strength between the worm and the worm wheel. In this case, however, the diameter dimension of the worm root, that is, the diameter dimension of the worm portion is reduced. As a result, another problem that the bending strength of the worm portion is lowered may occur. In addition, the diameter dimension of the worm part is increased to ensure the bending strength of the worm part, thereby suppressing the above-described deterioration of the drive system function (such as chipping of the tooth part and lowering of the bending strength of the worm part). This measure is not a preferable measure because it increases the weight and mass of the rotating shaft.

  An object of the present invention is to provide a rotary shaft that can be reduced in size and weight while suppressing a reduction in the function of the drive system without causing an increase in the weight and mass of the rotary shaft, and a motor with a speed reduction mechanism using the rotary shaft. It is to provide.

In one aspect of the present invention, there is provided a rotating shaft for rotating a gear, wherein a worm portion provided with a worm meshed with the gear, a rotor mounting portion to which a rotor generating a rotational force is mounted, A bearing member mounting portion provided between the worm portion and the rotor mounting portion, to which a bearing member is mounted, and the diameter dimension of the worm is set larger than the diameter dimension of the bearing member mounting portion; A diameter dimension of the rotor mounting portion is set to be smaller than a diameter dimension of the bearing member mounting portion, and the rotor abuts between the bearing member mounting portion and the rotor mounting portion, and the rotor step of positioning in the axial direction is provided for, between the said worm portion bearing member mounting portion, the sensor magnet mounting portion is provided, the bearing member along the axial direction of the sensor magnet mounting portion mounted On the side, a washer mounting groove is provided, the said washer mounting groove, wherein the bearing member is a snap ring is mounted for positioning in the axial direction of the bearing member in contact, the said sensor magnet mounting portion worm A jig abutting portion on which a jig for mounting the bearing member and the rotor is abutted is provided between the two portions .

In another aspect of the present invention, a motor with a speed reducing mechanism having a rotating shaft and a speed reducing mechanism that decelerates the rotation of the rotating shaft, wherein the rotating shaft is provided with a worm that meshes with a gear that forms the speed reducing mechanism. A worm portion, a rotor mounting portion to which a rotor that generates rotational force is mounted, a bearing member mounting portion that is provided between the worm portion and the rotor mounting portion and to which a bearing member is mounted, A diameter dimension of the worm is set larger than a diameter dimension of the bearing member mounting portion, a diameter dimension of the rotor mounting portion is set smaller than a diameter dimension of the bearing member mounting portion, and the bearing member mounting A step is provided between the worm portion and the bearing member mounting portion between the worm portion and the bearing member mounting portion. , Sensorama Net mounting portion is provided, wherein the said bearing member fitting portion along the axial direction of the sensor magnet mounting portion, the washer mounting groove is provided, the said washer mounting groove, the bearing member and the bearing member is in contact with A snap ring for positioning in the axial direction is mounted, and a jig abutting between the sensor magnet mounting part and the worm part is abutting a jig for mounting the bearing member and the rotor Is provided .

  In another aspect of the present invention, the jig abutting portion is formed in a planar shape that extends in a direction intersecting the axial direction of the rotating shaft with the rotating shaft as a center.

  In another aspect of the present invention, the rotating shaft is provided with a guide small-diameter portion that is set to have a smaller diameter than the rotor mounting portion and guides the mounting of the rotor to the rotor mounting portion.

  According to the present invention, the diameter dimension of the worm is set larger than the diameter dimension of the bearing member mounting portion, and the diameter dimension of the rotor mounting portion is set smaller than the diameter dimension of the bearing member mounting portion. Without increasing the weight and mass of the worm, the tooth depth of the worm can be increased without changing the diameter dimension of the worm portion. Therefore, the gear can be made small in a state in which the bending strength of the worm portion and the meshing strength between the worm and the gear are sufficient and the deterioration of the function of the drive system is suppressed. Therefore, by using the rotating shaft according to the present invention for the motor with a speed reduction mechanism, the motor with the speed reduction mechanism can be further reduced in size and weight.

It is a perspective view which shows the wiper motor by which this invention was employ | adopted. It is a perspective view which shows the cover member and control board of the wiper motor of FIG. It is a partial expanded sectional view which shows the internal structure of the broken-line circle | round | yen A part of FIG. It is an expansion perspective view which shows the detail of the ball bearing provided in the broken-line circle | round | yen B part of FIG. It is a partial expanded sectional view which shows the internal structure of the broken-line circle C part of FIG. It is a top view which shows the detailed structure of an armature axis | shaft. (A) (b) is explanatory drawing explaining the state (dimensional relationship) of size reduction and weight reduction of this-application structure compared with a comparison structure. (A), (b) is explanatory drawing explaining the assembly | attachment procedure of the ball bearing and armature core with respect to an armature shaft. (A)-(e) is the elements on larger scale figure which show the modification (5 types) of a jig | tool contact part.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  1 is a perspective view showing a wiper motor employing the present invention, FIG. 2 is a perspective view showing a cover member and a control board of the wiper motor of FIG. 1, and FIG. 3 is an internal structure of a broken line circle A portion of FIG. 4 is a partially enlarged sectional view, FIG. 4 is an enlarged perspective view showing details of a ball bearing provided in a broken line circle B portion of FIG. 1, and FIG. 5 is a partially enlarged sectional view showing an internal structure of the broken line circle C portion of FIG. Each is shown.

  As shown in FIG. 1, a wiper motor 10 as a motor with a speed reduction mechanism is used as a drive source of a front wiper device on the front side of a vehicle such as an automobile (not shown). Then, by operating a wiper switch (not shown) provided in the passenger compartment or the like, the wiper motor 10 is rotationally driven in the forward and reverse directions, thereby swinging a wiper member (not shown) on the front windshield. Being exercised. Thus, the wiper motor 10 is a so-called reversing wiper motor that is driven to rotate in the forward and reverse directions based on a predetermined control logic.

  The wiper motor 10 includes a motor unit 20 and a gear unit 30, and the motor unit 20 and the gear unit 30 are connected to each other by a plurality of fastening screws 11 (only one is shown in the drawing). Here, FIG. 1 shows a state in which the cover member 50 (see FIG. 2) for closing the gear case 31 of the gear portion 30 is removed in order to make the internal structure of the wiper motor 10 easy to understand.

  As shown in FIGS. 1 and 3, the motor unit 20 includes a motor case 21 formed in a bottomed cylindrical shape. The motor case 21 is a deep drawing process (press process) of a magnetic material such as a steel plate. By doing so, the bottom side (the right side in the figure) is formed in a stepped shape. A first radial bearing 22 is provided on the bottom 21a of the motor case 21, and the first radial bearing 22 is fixed to the bottom 21a by a fixing member 23 made of a steel plate. The first radial bearing 22 is configured to rotatably hold a guide small diameter portion 24e formed on the axial base end side (right side in the drawing) of the armature shaft (rotating shaft) 24.

  A plurality of permanent magnets 25 (for example, four) whose cross section is formed in a substantially arc shape are fixed to the inner wall of the motor case 21, and these permanent magnets 25 are arranged along the circumferential direction of the motor case 21. They are arranged at intervals (90 degree intervals). Inside each permanent magnet 25, an armature core (rotor) 26 around which a coil (not shown) is wound via a predetermined air gap is rotatably provided. The armature core 26 is fixed to a rotor mounting portion 24 d formed on the proximal end side in the axial direction of the armature shaft 24.

  A commutator (not shown) in which a plurality of brushes are in sliding contact with each other is provided on the gear case 31 side (left side in the drawing) of the armature shaft 24 with respect to the armature core 26 and wound around the armature core 26 via each brush and commutator. A drive current is supplied to the mounted coil. Thereby, an electromagnetic force, that is, a rotational force is generated in the armature core 26, and the armature core 26 rotates the armature shaft 24 in a predetermined rotation direction and number of rotations.

  As shown in FIGS. 1 and 5, the gear unit 30 includes a bottomed gear case 31. The gear case 31 is formed into a predetermined shape by casting a molten aluminum material or the like, and a worm wheel (gear) 32 made of a resin material is rotatably accommodated therein. The proximal end side of the output shaft 33 is fixed to the rotation center of the worm wheel 32, and the distal end side of the output shaft 33 extends to the outside of the gear case 31. A link mechanism (not shown) that forms a front wiper device is fixed to the distal end side of the output shaft 33.

  A tooth portion 32 a is formed on the outer peripheral portion of the worm wheel 32, and the tooth portion 32 a meshes with a worm 24 a that is integrally provided on the front end side (left side in the drawing) of the armature shaft 24. . That is, the armature shaft 24 drives the worm wheel 32 to rotate. Here, the worm 24a and the worm wheel 32 form a speed reduction mechanism SD. The speed reduction mechanism SD decelerates the rotation of the armature shaft 24 to a predetermined rotational speed to increase the torque, and rotates the increased torque. The output is output from the output shaft 33 to an external link mechanism.

  The gear case 31 is integrally formed with an armature shaft support part 34 and a bearing support part 35. The armature shaft support portion 34 is formed in a substantially cylindrical shape, and a cylindrical second radial bearing 36 is fitted and fixed inside the armature shaft support portion 34, and the second radial bearing 36 is rotatable on the front end side in the axial direction of the armature shaft 24. I support it.

  The bearing support portion 35 is also formed in a substantially cylindrical shape, and the bearing support portion 35 has a larger diameter than the armature shaft support portion 34. A ball bearing 40 (see FIG. 4) as a bearing member is fitted inside the bearing support portion 35. After the ball bearing 40 is fitted to the bearing support portion 35, the stopper member 37 made of a steel plate is inserted into the gear case 31, so that the ball bearing 40 is prevented from being detached from the bearing support portion 35.

  As shown in FIG. 4, the ball bearing 40 includes a steel inner race 41, an outer race 42, and a plurality of steel balls 43. Further, shields 44 for preventing leakage of sliding grease (not shown) held between the inner race 41, the outer race 42, and the steel balls 43 to the outside are provided on both sides in the axial direction of the ball bearing 40. ing. Here, the ball bearing 40 employs an inexpensive general-purpose product.

  The inner race 41 of the ball bearing 40 is fixed to a bearing member mounting portion 24c (see FIG. 6) formed at the axial center of the armature shaft 24. Further, the outer race 42 of the ball bearing 40 is fixed to a bearing support portion 35 (see FIG. 1) of the gear case 31. Thus, by fixing the inner race 41 to the armature shaft 24 and fixing the outer race 42 to the gear case 31, the armature shaft 24 cannot move in the axial direction with respect to the motor case 21 and the gear case 31. Therefore, a thrust bearing for supporting both axial ends of the armature shaft 24 is omitted, and the number of parts can be reduced.

  The opening part (front side in FIG. 1) of the gear case 31 is closed by a cover member 50 shown in FIG. The cover member 50 is formed of a resin material such as plastic so as to have substantially the same outer shape as the opening portion of the gear case 31, and the control board 51 is mounted inside the cover member 50. A pair of armature shaft magnetic sensors AS for detecting the rotation state of the armature shaft 24 and a pair of worm wheel magnetic sensors WS for detecting the rotation state of the worm wheel 32 are mounted on the control board 51. Further, other electronic components such as a capacitor CD and a choke coil CC are mounted on the control board 51.

  Here, as shown in FIGS. 1 and 4, an annular first sensor magnet SM1 is disposed in the vicinity of the worm 24a on the armature shaft 24, and the first sensor magnet SM1 is a magnet for each armature shaft. It faces the sensor AS. As shown in FIG. 1, an annular second sensor magnet SM2 is disposed in the vicinity of the output shaft 33 of the worm wheel 32, and the second sensor magnet SM2 is connected to each worm wheel magnetic sensor WS. It comes to be opposed. Note that the shape of the second sensor magnet SM2 is not limited to an annular shape, and may be a cylindrical shape, and the shape is not limited.

  As shown in FIG. 5, a partition member 52 made of a resin material such as plastic is provided between the worm wheel 32 and the control board 51. The partition member 52 plays a role in preventing sliding grease (not shown) applied between the worm wheel 32 and the worm 24a from being scattered and attached to the control board 51.

  Next, the structure of the armature shaft 24 will be described in detail with reference to FIGS.

  FIG. 6 is a plan view showing the detailed structure of the armature shaft, and FIGS. 7A and 7B are explanatory views for explaining the state (dimensional relationship) of the structure of the present application in comparison with the comparative structure in terms of size and weight reduction. Show.

  As shown in FIG. 6, the armature shaft 24 is formed in a stepped shape by cold forging a base material made of a steel bar having a circular cross section. By forming the armature shaft 24 in a stepped shape by cold heading in this way, it is possible to suppress waste of material. Furthermore, since it is cold heading, there is no need to heat the base material, and processing energy can be reduced to save energy.

  The armature shaft 24 is arranged across both the motor unit 20 and the gear unit 30 (see FIG. 1), and the length dimension thereof is set to L1. The armature shaft 24 includes a worm portion 24b, a bearing member mounting portion 24c, and a rotor mounting portion 24d from the gear portion 30 side (axially distal end side) to the motor portion 20 side (axially proximal end side). , In that order.

  The length dimension of the worm portion 24b is set to a length dimension L2 that is approximately 1/3 of the length dimension L1 of the armature shaft 24 (L2≈L1 / 3). Further, the diameter dimension of the worm portion 24b is set to d1 (for example, 4.3 mm), and the diameter dimension d1 is a diameter dimension that provides sufficient bending strength to the worm portion 24b. Therefore, when the wiper motor 10 is rotationally driven, there is no problem that the armature shaft 24 is bent and shakes.

  A spiral worm 24a is integrally provided around the worm portion 24b, and the diameter dimension of the worm 24a is set to a diameter dimension d2 (for example, 11.2 mm) larger than the diameter dimension d1 of the worm section 24b. (D2> d1). The diameter dimension d2 of the worm 24a is set to a diameter dimension larger than the diameter dimension d3 (for example, 8.0 mm) of the bearing member mounting portion 24c (d2> d3).

  Here, the magnitude relationship between the diameter dimensions d1, d2, and d3 is set to d2> d3> d1, and when the diameter dimension d3 of the bearing member mounting portion 24c is used as a reference, in the present embodiment, In general, d2≈1.4 · d3, d1≈0.5 · d3.

  Here, as shown in FIG. 7, the length dimension of the armature shaft a of the comparative structure (prior structure) is the same as the length dimension L1 of the armature shaft 24 of the present structure, and the bearing member of the comparative structure is mounted. The diameter dimension of the part b is the same as the diameter dimension d3 of the bearing member mounting part 24c of the present structure, and the diameter dimension of the worm part c of the comparative structure is the same diameter dimension as the diameter dimension d1 of the worm part 24b of the present structure. And The difference in size between the structure of the present application and the comparative structure will be described below using these dimensional relationships as a reference for comparison.

  In the present application structure, as described above, the diameter dimension d2 of the worm 24a is set to be larger than the diameter dimension d1 of the worm part 24b and the diameter dimension d3 of the bearing member mounting part 24c (d2> d3>). d1). Thereby, as shown in FIG. 7, the tooth depth (= (d2-d1) / 2) of the worm 24a of the structure of the present application is larger than that of the comparative structure. That is, in the tooth width of the comparative structure (= (d3-d1) / 2), the diameter dimension of the worm d of the comparative structure is substantially equal to the diameter dimension d3 of the bearing member mounting portion b. It is smaller than the toothpaste.

  However, as the diameter dimension d2 of the worm 24a increases, the deceleration efficiency deteriorates, that is, the rotational resistance of the worm 24a increases. Therefore, it is necessary to increase the torque by increasing the armature core 26 to counter this. Therefore, in order to avoid an increase in size (increase in weight) of the armature core 26, the diameter dimension d2 of the worm 24a is 1.4 times or less of the diameter dimension d3 of the bearing member mounting portion 24c (d2 ≦ 1.4 · d3). In addition, the diameter should be such that the meshing strength can be sufficiently secured.

  The pitch of the worm 24a of the present structure is set to be narrower than the pitch of the worm d of the comparative structure. Therefore, even if the worm wheel 32 is made smaller, the strength at the meshing portion CP between the worm 24a and the tooth portion 32a, that is, the meshing strength, can be set to the same meshing strength as the meshing portion CP of the comparative structure. Specifically, the diameter dimension D1 (for example, 57.0 mm) of the worm wheel 32 of the present structure is approximately 90% of the diameter dimension D2 (for example, 62.5 mm) of the worm wheel e of the comparative structure. . However, the thickness dimension of the worm wheel 32 of the present structure and the thickness dimension of the worm wheel e of the comparative structure are set to substantially the same thickness dimension.

  As shown in FIG. 6, the bearing member mounting portion 24c is provided between the worm portion 24b and the rotor mounting portion 24d, and the ball bearing 40 is mounted on the bearing member mounting portion 24c. . The length dimension of the bearing member mounting portion 24c is set to a length dimension L3 that is substantially half of the length dimension L2 of the worm portion 24b (L3≈L2 / 2). Further, the diameter dimension of the bearing member mounting portion 24c is set to d3, and the diameter dimension d3 is a diameter dimension capable of mounting a general-purpose ball bearing 40 (see FIG. 4).

  The length of the rotor mounting portion 24d is set to a length L4 that is substantially the same as the length L2 of the worm portion 24b (L4≈L2). Further, the diameter dimension of the rotor mounting part 24d is set to a diameter dimension d4 (for example, 6.0 mm) smaller than the diameter dimension d3 of the bearing member mounting part 24c (d4 <d3). The magnitude relationship between the diameter dimension d4 of the rotor mounting portion 24d and the diameter dimension d2 of the worm 24a is approximately d4≈0.5 · d2.

  Here, the diameter dimension d4 of the rotor mounting portion 24d is a diameter dimension that can provide sufficient strength without being bent or twisted by rotational torque or the like acting on the armature core 26 when the wiper motor 10 is driven to rotate. It has become. In this way, the diameter dimension d4 of the rotor mounting part 24d is made smaller than the diameter dimension d3 of the bearing member mounting part 24c, thereby increasing the diameter dimension of the worm part 24b without increasing the overall weight of the armature shaft 24. The tooth depth of the worm 24a can be increased without changing d1. In the present embodiment, the setting of the diameter dimension d4 of the rotor mounting portion 24d is not only for increasing the tooth depth of the worm 24a but also for reducing the overall weight and mass of the armature shaft 24. Contributing.

  Further, as shown in FIG. 7, the diameter dimension d4 of the rotor mounting portion 24d in the structure of the present application is set to a diameter dimension smaller than the diameter dimension d3 of the rotor mounting portion f in the comparative structure. When the armature core is set so as to obtain the above, the armature core 26 of the present structure has a diameter dimension d6, and the armature core g of the comparative structure has a larger diameter dimension d7 (d7> d6). Thus, the armature shaft 24 having the structure of the present application also contributes to the reduction in size and weight of the armature core 26 (motor unit 20).

  However, if the dimensional difference between the diameter dimension d4 of the rotor mounting portion 24d and the diameter dimension d2 of the worm 24a is too large, the limit that can be formed by cold heading is exceeded, and as a result, sufficient for the armature shaft 24. There is a risk that productivity may be reduced, such as failure to obtain rigidity. Therefore, considering the manufacturing condition of the armature shaft 24, the dimensional difference between the diameter dimension d4 of the rotor mounting portion 24d and the diameter dimension d2 of the worm 24a is set so as to satisfy the relationship of d4 ≧ 0.5 · d2. Is desirable.

  As shown in FIG. 6, a guide small-diameter portion 24e is provided adjacent to the rotor mounting portion 24d on the axial base end side of the armature shaft 24. The length of the guide small diameter portion 24e is set to a length L5 that is approximately 1/3 of the length L4 of the rotor mounting portion 24d (L5≈L4 / 3). The diameter of the guide small diameter portion 24e is set to be slightly smaller than the diameter size d4 of the rotor mounting portion 24d (d5 <d4).

  Thus, by providing the guide small diameter portion 24e having the length L5 and the diameter d5, the armature core 26 can be easily mounted on the rotor mounting portion 24d from the axial base end side of the armature shaft 24. . That is, the guide small diameter portion 24e guides the mounting of the armature core 26 to the rotor mounting portion 24d. Furthermore, in the process of mounting the armature core 26 to the rotor mounting portion 24d, the guide small diameter portion 24e is hardly damaged. Therefore, the guide small diameter portion 24e can sufficiently function as a rotary sliding portion, and as a result, is smoothly rotated and held by the first radial bearing 22 (see FIG. 3).

  A sensor magnet mounting portion 24f is provided between the worm portion 24b of the armature shaft 24 and the bearing member mounting portion 24c. The diameter dimension of the sensor magnet mounting part 24f is set to the same diameter dimension as the diameter dimension d3 of the bearing member mounting part 24c. The first sensor magnet SM1 is fixed around the sensor magnet mounting portion 24f (see FIG. 4).

  A jig contact portion 24g is provided between the worm portion 24b of the armature shaft 24 and the bearing member mounting portion 24c on the worm portion 24b side along the axial direction of the sensor magnet mounting portion 24f. The jig contact portion 24g is formed in a planar shape extending radially in the direction intersecting the axial direction of the armature shaft 24 with the armature shaft 24 as a center, and therefore the jig contact portion 24g is formed in an annular plane. Has been. The jig contact portion 24g includes jigs T1 and T2 (see FIG. 8) used for mounting the ball bearing 40 on the bearing member mounting portion 24c and the armature core 26 on the rotor mounting portion 24d, respectively. It comes to contact. The jigs T1 and T2 may be used for mounting the first sensor magnet SM1 on the sensor magnet mounting portion 24f of the armature shaft 24 (not shown).

  On the other hand, a washer mounting groove 24h is provided between the worm portion 24b of the armature shaft 24 and the bearing member mounting portion 24c on the bearing member mounting portion 24c side along the axial direction of the sensor magnet mounting portion 24f. A snap ring SR (see FIG. 4) for positioning the ball bearing 40 with respect to the bearing member mounting portion 24c is mounted in the washer mounting groove 24h. As this snap ring SR, for example, a general-purpose C-type snap ring is used. Here, the snap ring SR is attached to the armature shaft 24 in a preparatory step before the ball bearing 40 and the armature core 26 are assembled to the armature shaft 24.

  Next, a procedure for assembling the ball bearing 40 and the armature core 26 to the armature shaft 24 will be described in detail with reference to FIG.

  FIGS. 8A and 8B are explanatory views for explaining a procedure for assembling the ball bearing and the armature core with respect to the armature shaft.

[Preparation process]
First, as shown in FIG. 8A, an armature shaft 24 manufactured in another manufacturing process (cold forging process) is prepared, and a washer mounting groove 24h (see FIG. 6) of the armature shaft 24 is prepared. The snap ring SR is attached. Moreover, while preparing the ball bearing 40, as shown in FIG.8 (b), the armature core 26 manufactured by another manufacturing process is prepared. This completes the preparation process.

[Ball bearing assembly process]
Next, as shown in FIG. 8A, the ball bearing 40 is set so as to lie on the first base BS1 of the assembling apparatus AD. Then, as shown by an arrow (1) in the figure, the guide small diameter portion 24e side of the armature shaft 24 to which the snap ring SR is mounted faces the ball bearing 40, and the inner race 41 of the ball bearing 40 (see FIG. 4). ). Thereafter, as indicated by an arrow (2) in the figure, the jigs T1 and T2 of the assembling apparatus AD are driven so as to be close to each other, and the tips P of the jigs T1 and T2 are moved to the jig of the armature shaft 24. It is made to contact | abut to the contact part 24g.

  Here, each jig | tool T1, T2 is comprised so that it may become a substantially cylindrical shape under the state which mutually adjoined. Therefore, the worm 24a of the armature shaft 24 is disposed inside each of the jigs T1 and T2 by bringing the tip portion P of each jig T1 and T2 into contact with the jig contact portion 24g of the armature shaft 24. It has come to be. Accordingly, when the armature shaft 24 is moved using the jigs T1 and T2, the worm 24a can be protected and the worm 24a can be prevented from being damaged.

  Next, the jigs T1 and T2 are driven downward as indicated by an arrow (3) in the drawing to bring the jigs T1 and T2 closer to the first base BS1. Thereby, the ball bearing 40 is press-fitted into the bearing member mounting portion 24 c from the axial base end side of the armature shaft 24. Thereafter, the jigs T1 and T2 are further driven downward, so that the ball bearing 40 comes into contact with the snap ring SR and is positioned at a predetermined position of the bearing member mounting portion 24c. Thereby, the assembly of the ball bearing 40 to the armature shaft 24 is completed, and the ball bearing assembly process is completed.

[Assembly core assembly process]
After the ball bearing assembly process, the armature shaft 24 to which the ball bearing 40 is mounted is removed from the first base BS1, and the process proceeds to the next armature core assembly process. Then, the armature core 26 is set so as to stand on the second base BS2 of the assembling apparatus AD. That is, the armature core 26 is attached to the second base BS2 in a direction in which the direction of the hole formed in the armature core 26 for inserting the armature shaft 24 through the armature core 26 and the direction in which the armature shaft 24 is assembled. set.

  Next, as shown by an arrow (4) in the drawing, the armature shaft 26 with the ball bearing 40 mounted thereon faces the armature core 26 and the armature core 26 is inserted through the armature core 26. Thereafter, as indicated by an arrow (5) in the figure, the jigs T1 and T2 of the assembling apparatus AD are driven so as to be close to each other, and the tips P of the jigs T1 and T2 are moved to the jig of the armature shaft 24. It is made to contact | abut to the contact part 24g.

  Next, the jigs T1 and T2 are driven downward as indicated by an arrow (6) in the drawing to bring the jigs T1 and T2 closer to the second base BS2. As a result, the armature core 26 is press-fitted into the rotor mounting portion 24d from the axial base end side of the armature shaft 24. Thereafter, the jigs T1 and T2 are further driven downward to bring the armature core 26 into contact with the step S between the bearing member mounting portion 24c and the rotor mounting portion 24d, so that a predetermined position of the rotor mounting portion 24d is reached. Is positioned. Thereby, the assembly of the armature core 26 to the armature shaft 24 is completed, and the armature core assembly process is completed.

  Here, the pressing force of each of the jigs T1 and T2 is a part having the highest rigidity of the armature shaft 24 via the jig contact part 24g, that is, the sensor magnet mounting part 24f having a diameter dimension of d3 (maximum diameter). (See FIG. 6). Therefore, in the [ball bearing assembling step] and [armature core assembling step], the armature shaft 24 is not distorted.

  In order to simplify the shapes and operations of the jigs T1 and T2, the worm portion 24b (diameter dimension d1) is formed by simply pressing the axial tip (upper end in the figure) of the armature shaft 24. There is a risk of distortion. The distortion of the worm portion 24b causes generation of motor noise (mechanical noise) when the armature shaft 24 rotates, and is a design matter that should be surely eliminated.

  Also, the tips P of the jigs T1 and T2 are brought into contact with the jig contact part 24g of the armature shaft 24. The jig contact part 24g is formed with a worm 24a or mounted with a ball bearing 40. It is provided in the part which is not done. Therefore, even if the surface of the jig contact portion 24g is slightly scratched by the tip portion P of each jig T1, T2, the rotational state of the armature shaft 24 is not adversely affected.

  Further, since the jig abutting portion 24g is formed by an annular plane extending radially in the direction intersecting the axial direction of the armature shaft 24 with the armature shaft 24 as a center, the armature shaft is formed by the jigs T1 and T2. 24 can be pressed substantially straight. Therefore, the armature shaft 24 does not squeeze the ball bearing 40 or the armature core 26, and a smooth assembling work is possible.

  Next, various modifications of the jig contact portion 24g will be described in detail with reference to FIG. In addition, since the jig | tool contact part of each modification has the function similar to the jig | tool contact part 24g mentioned above, the same code | symbol is attached | subjected to the jig | tool contact part of each modification example. Yes.

  FIGS. 9A to 9E are partially enlarged perspective views showing modified examples (five types) of the jig contact portion.

  The jig contact portion 24g shown in FIG. 9A forms an annular groove 60 extending in the circumferential direction of the sensor magnet mounting portion 24f near the worm portion 24b along the axial direction of the sensor magnet mounting portion 24f. Is provided.

  The jig abutting portion 24g shown in FIG. 9B has an armature shaft 24 so as to face the end of the sensor magnet mounting portion 24f on the worm portion 24b side along the axial direction with the axis of the armature shaft 24 interposed therebetween. It is provided by forming the two recessed parts 61 depressed toward the axial base end side.

  The jig contact portion 24g shown in FIG. 9C is arranged at equal intervals (90 degree intervals) in the circumferential direction of the sensor magnet mounting portion 24f, close to the worm portion 24b along the axial direction of the sensor magnet mounting portion 24f. Two fan-shaped grooves 62 (only three are shown in the figure) are formed.

  The jig contact portion 24g shown in FIG. 9 (d) has an armature shaft 24 so as to face the end portion on the worm portion 24b side along the axial direction of the sensor magnet mounting portion 24f with the axis of the armature shaft 24 interposed therebetween. Are formed by forming two semicircular recesses 63 (only one is shown in the figure) that are recessed toward the inside in the radial direction. In this case, the jig contact portion 24g is formed in a curved surface shape.

  The jig abutting portion 24g shown in FIG. 9 (e) has an armature shaft 24 so as to face the end of the sensor magnet mounting portion 24f on the worm portion 24b side along the axial direction with the axis of the armature shaft 24 interposed therebetween. Are provided by forming two triangular recesses 64 (only one is shown in the figure) that are recessed toward the inside in the radial direction. In this case, the jig contact portion 24g is formed at the top of the triangle.

  The jig contact portions 24g described in FIGS. 9A to 9E can move the jigs T1 and T2 away from the worm 24a. Therefore, it is possible to reliably prevent the worm 24a from being damaged by the jigs T1 and T2.

  As described above in detail, according to the armature shaft 24 and the wiper motor 10 according to the present embodiment, the diameter dimension d2 of the worm 24a is set larger than the diameter dimension d3 of the bearing member mounting portion 24c, and the rotor mounting portion 24d. Is set to be smaller than the diameter dimension d3 of the bearing member mounting portion 24c, so that the worm 24a does not change without changing the diameter dimension d1 of the worm portion 24b without increasing the overall weight and mass of the armature shaft 24. The toothpaste can be increased. Accordingly, the worm wheel 32 can be made small in a state in which the bending strength of the worm portion 24b and the meshing strength between the worm 24a and the worm wheel 32 are sufficient, and the deterioration of the function of the drive system is suppressed. . Therefore, the wiper motor 10 provided with the armature shaft 24 can be further reduced in size and weight.

  In addition, the armature shaft 24 is formed in a stepped shape, but the end portion of the stepped shape is chamfered on the insertion direction side of the assembly part to the armature shaft 24. Therefore, the insertability of each assembly part into the armature shaft 24 is improved.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, in the above-described embodiment, a motor with a brush is used as the motor unit 20 of the wiper motor 10. However, the present invention is not limited to this, and a brushless motor can be used as the motor unit. In this case, a rotor core (permanent magnet) as a rotor is attached to a rotor shaft as a rotating shaft.

  By adopting the brushless motor in this way, it is not necessary to wind a coil around the rotor core. Therefore, rotational vibration caused by coil winding unevenness does not occur, and the inertial mass of the rotating body composed of the rotor shaft and the rotor core can be reduced. Accordingly, the load acting on the rotor mounting portion is reduced, and as a result, the diameter dimension of the rotor mounting portion can be further reduced.

  In the above embodiment, the ball bearing 40 is used as the bearing member. However, the present invention is not limited to this, and other types of bearing members such as a cylindrical roller bearing (roller bearing) are used. You can also.

  Further, in the above-described embodiment, the armature shaft 24 is formed in the stepped shape, so that the cold forging process is shown. However, the present invention is not limited to this, and the cutting process may be used.

  Moreover, in the said embodiment, although the diameter dimension d4 of the rotor mounting | wearing part 24d showed what was set smaller than the diameter dimension d3 of the bearing member mounting | wearing part 24c, this invention is not restricted to this, rotation The diameter dimension d4 of the child mounting part 24d and the diameter dimension d3 of the bearing member mounting part 24c may be the same (d4 ≦ d3). Further, similarly, the diameter dimension d5 of the guiding small diameter part 24e may be the same as the diameter dimension d4 of the rotor mounting part 24d (d5 ≦ d4).

  Moreover, in the said embodiment, although each jig | tool T1, T2 showed what was comprised so that it might become a substantially cylindrical shape under the state which mutually adjoined, this invention is not restricted to this, The shape is not limited as long as the distal end portion P can be brought into contact with the jig contact portion 24g of the armature shaft 24 or can be used when the armature shaft 24 is moved.

  Furthermore, in the above embodiment, the wiper motor 10 is shown as the motor with the speed reduction mechanism. However, the present invention is not limited to this, and the speed reduction mechanism used as a drive source for a power window device, a power slide door device, or the like. It can also be applied to an attached motor. Moreover, it is not limited to being driven to rotate in forward and reverse directions, and may be driven to rotate only in one direction.

10 Wiper motor (motor with reduction mechanism)
DESCRIPTION OF SYMBOLS 11 Fastening screw 20 Motor part 21 Motor case 21a Bottom part 22 First radial bearing 23 Fixing member 24 Armature shaft (rotating shaft)
24a Worm 24b Worm portion 24c Bearing member mounting portion 24d Rotor mounting portion 24e Guide small diameter portion 24f Sensor magnet mounting portion 24g Jig abutting portion 24h Washer mounting groove 25 Permanent magnet 26 Armature core (rotor)
30 Gear part 31 Gear case 32 Worm wheel (gear)
32a Tooth part 33 Output shaft 34 Armature shaft support part 35 Bearing support part 36 Second radial bearing 37 Stopper member 40 Ball bearing (bearing member)
41 inner race 42 outer race 43 steel ball 44 shield 50 cover member 51 control board 52 partition member 60 annular groove 61 recess 62 fan groove 63 semicircular recess 64 triangular recess CC choke coil CD capacitor AS armature shaft magnetic sensor WS worm Magnetic sensor for wheel SM1 First sensor magnet SM2 Second sensor magnet SD Deceleration mechanism CP Engagement part S Step SR Snap ring AD Assembly device BS1 First base BS2 Second base T1, T2 Jig P Tip a armature shaft ( Comparative structure)
b Bearing member mounting part (comparison structure)
c Worm part (comparison structure)
d Worm (comparison structure)
e Worm wheel (comparative structure)
f Rotor mounting part (comparison structure)
g Armature core (comparison structure)

Claims (6)

A rotating shaft for rotationally driving the gear,
A worm portion provided with a worm with which the gear is engaged;
A rotor mounting portion to which a rotor that generates rotational force is mounted;
A bearing member mounting portion provided between the worm portion and the rotor mounting portion and mounted with a bearing member;
With
The diameter dimension of the worm is set larger than the diameter dimension of the bearing member mounting part, the diameter dimension of the rotor mounting part is set smaller than the diameter dimension of the bearing member mounting part,
Between the bearing member mounting portion and the rotor mounting portion, a step is provided for positioning the rotor in the axial direction by contacting the rotor,
A sensor magnet mounting portion is provided between the worm portion and the bearing member mounting portion,
On the bearing member mounting part side along the axial direction of the sensor magnet mounting part, a washer mounting groove is provided ,
The washer mounting groove is mounted with a snap ring that contacts the bearing member to position the bearing member in the axial direction,
A rotating shaft , wherein a jig abutting portion on which a jig for mounting the bearing member and the rotor is abutted is provided between the sensor magnet mounting portion and the worm portion . The rotating shaft according to claim 1 ,
The jig contact portion is a rotation shaft formed in a planar shape extending in a direction intersecting the axial direction of the rotation shaft with the rotation shaft as a center. The rotating shaft according to claim 1 or 2 ,
A rotating shaft, wherein the rotating shaft is provided with a guide small-diameter portion that is set to have a smaller diameter than the rotor mounting portion and guides the mounting of the rotor to the rotor mounting portion. A motor with a speed reduction mechanism having a rotation shaft and a speed reduction mechanism for reducing the rotation of the rotation shaft,
The rotation axis is
A worm portion provided with a worm meshed with a gear forming the speed reduction mechanism;
A rotor mounting portion to which a rotor that generates rotational force is mounted;
A bearing member mounting portion provided between the worm portion and the rotor mounting portion and mounted with a bearing member;
With
The diameter dimension of the worm is set larger than the diameter dimension of the bearing member mounting part, the diameter dimension of the rotor mounting part is set smaller than the diameter dimension of the bearing member mounting part,
Between the bearing member mounting portion and the rotor mounting portion, a step is provided for positioning the rotor in the axial direction by contacting the rotor,
A sensor magnet mounting portion is provided between the worm portion and the bearing member mounting portion,
On the bearing member mounting part side along the axial direction of the sensor magnet mounting part, a washer mounting groove is provided ,
The washer mounting groove is mounted with a snap ring that contacts the bearing member to position the bearing member in the axial direction,
A motor with a speed reduction mechanism , wherein a jig abutting portion on which a jig for mounting the bearing member and the rotor is abutted is provided between the sensor magnet mounting portion and the worm portion . The motor with a speed reduction mechanism according to claim 4 ,
The jig contact portion is a motor with a speed reduction mechanism that is formed in a planar shape that extends in a direction intersecting the axial direction of the rotation axis with the rotation axis as a center. The motor with a speed reduction mechanism according to claim 4 or 5 ,
A motor with a speed reduction mechanism, wherein the rotating shaft is provided with a guide small-diameter portion that is set to have a smaller diameter than the rotor mounting portion and guides the mounting of the rotor to the rotor mounting portion.

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