JP2016191448A - Reduction gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reduction gear allowing carrier pins to be easily and firmly fixed.SOLUTION: A reduction gear comprises: a shaft member 31 supported rotatably around the axis; an internal tooth gear; an external tooth gear 8 that engages with the internal tooth gear and is formed with through holes 82 between the center and the outer peripheral edge along the circumferential direction; an eccentric body 4 eccentrically and oscillationally rotating the external tooth gear with the shaft member connected thereto and rotating; carrier pins 7 inserted in the through holes 82 of the external tooth gear; first carriers 5 and second carriers 6 that are fixed to both ends of the carrier pins and rotate around the axes. The carrier pin has a cylindrical body part 71, a large-diameter part 73 provided on one end side of the body part, and a male screw 72 provided on the other end side. The first and second carriers are formed with through holes 53, 63 in which both ends of the carrier pins are inserted. The male screws of the carrier pins are fixed to the first carriers, and the second carries receive the large diameter parts to prevent the carrier pins from passing through to the first carrier side.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a reduction gear.

  In recent years, various reduction gears have been proposed. For example, a reduction gear as disclosed in Patent Document 1 has been proposed. The reduction gear rotates the external gear eccentrically by an eccentric body connected to the input shaft. And a carrier pin is each inserted in the some through-hole formed in the external gear, and the both ends of this carrier pin are each fixed to a pair of disk-shaped carriers. Each carrier has the same axis as the input shaft. An output shaft is connected to one carrier. Thereby, the rotational speed input from the input shaft can be greatly reduced and output from the output shaft.

JP 2008-304020 A

  By the way, in the reduction gear of patent document 1, both ends of the carrier pin are fixed to each carrier by press-fitting. However, fixing by press-fitting requires a dedicated assembling apparatus, and there is a problem that the manufacturing apparatus becomes large. The present invention has been made to solve the above-described problem, and an object of the present invention is to provide a reduction gear capable of easily and firmly fixing a carrier pin.

  The speed reducer according to the present invention is engaged with a shaft member rotatably supported around an axis, an internal gear, and the internal gear, and at least one penetrating along the circumferential direction between the center and the outer peripheral edge. At least one external gear having a hole formed therein, the shaft member is connected, an eccentric body rotating eccentrically by rotating with the shaft member, and a through hole of the external gear A carrier pin extending in parallel with the axis, fixed to both ends of the carrier pin, and sandwiching the external gear from both ends in the axial direction, and a first carrier and a first carrier that are rotatable about the axis 2 carrier, and the carrier pin is provided with a cylindrical main body portion, a large diameter portion provided on one end portion side of the main body portion and having a diameter larger than that of the main body portion, and the other end portion side of the main body portion. A male screw provided on the In the first carrier and the second carrier, through holes through which both ends of the carrier pin are inserted are formed, and the first carrier is fixed with a male screw of the carrier pin. The second carrier has a receiving portion that receives the large-diameter portion of the carrier pin and prevents the carrier pin from coming off to the first carrier side.

  According to this configuration, the other end portion of the carrier pin is fixed to the second carrier by the large-diameter portion so that the other end portion is fixed to the first carrier by screwing. Therefore, the carrier pin can be easily fixed to both carriers. Further, the external gear may be inclined with respect to the shaft center during rotation, and in this case, a thrust force may act on the carrier pin. However, even in such a case, since one end of the carrier pin is screwed, rotation around the axis of the carrier pin and movement in the axial direction can be prevented. Therefore, it is possible to prevent the carrier pins from being displaced or detached from both carriers.

  In the speed reducer, there are various methods for screwing the carrier pin. For example, there are the following methods.

  For example, at least a part of the male screw of the carrier pin is configured to protrude from the through hole of the first carrier, and the carrier pin is fixed to the first carrier by a nut screwed into the protruding portion. Can do.

  Alternatively, a female screw can be formed in the through hole of the first carrier, and the male screw of the carrier pin can be screwed into the female screw.

  In each of the speed reducers, the first bearing is disposed on the outer peripheral surface of the first carrier and rotatably supports the first carrier, and is disposed on the outer peripheral surface of the second carrier, and rotates the second carrier. And a second bearing that is freely supported. The first carrier includes a first flange portion that engages with the first bearing from one side of the axis, and the first carrier moves to the other side of the axis by the engagement of the first flange portion. The second carrier includes a second flange portion that engages with the second bearing from the other side of the axis, and the second flange portion engages the second carrier. The two carriers can be configured to be restricted from moving to one side of the axis.

  According to this configuration, the following effects can be obtained. That is, when the carrier pin is screwed, the male screw is tightened, and accordingly, both carriers act in the proximity direction. On the other hand, as described above, when each carrier is provided with a flange portion, each flange portion engages with each bearing, so that both carriers can be prevented from moving in the proximity direction, and Both carriers can be firmly fixed at a predetermined interval.

  In each of the speed reducers, a male screw of the carrier pin can be formed to have a smaller diameter than the main body portion, and a through hole of the first carrier has a first diameter portion corresponding to the male screw, The main body portion and the second diameter portion corresponding to the main body portion can be formed so as to be larger than the first diameter portion.

  According to this configuration, since the first diameter portion and the second diameter portion having different inner diameters are formed continuously in the through hole of the first carrier, a step is formed between both diameter portions. . Therefore, this step enables positioning of the carrier pin in the axial direction with respect to the first carrier, and also enables restriction of movement in the axial direction while screwing the carrier pin to the first carrier.

  According to the speed reducer according to the present invention, the carrier pin can be easily and firmly fixed.

It is sectional drawing of the drive device provided with the reduction gear which concerns on one Embodiment of this invention. It is the sectional view on the AA line of FIG. FIG. 1 is an enlarged sectional view of the transmission. It is an expanded sectional view showing other examples of a carrier pin and its fixing method. It is an expanded sectional view showing other examples of a carrier pin and its fixing method. It is a perspective view which shows the other example of a carrier pin and a roller. It is the perspective view (a) and sectional drawing (b) of the chamfering process of the edge part of an external gear. It is sectional drawing which shows the other example of a needle bearing. It is sectional drawing which shows the other example of a needle bearing. It is sectional drawing which shows the other example of a needle bearing. It is sectional drawing which shows the other example of a needle bearing. It is sectional drawing which shows the other example of a needle bearing. It is a perspective view which shows the other example of an external gear. It is a perspective view which shows the apparatus which finishes the recessed part surface where an internal tooth pin is arrange | positioned.

  Hereinafter, an embodiment in which a reduction gear according to the present invention is applied to a drive device including a motor will be described with reference to the drawings. 1 is a cross-sectional view of the drive device, FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, and FIG. 3 is an enlarged cross-sectional view of the transmission of FIG.

  As shown in FIG. 1, the drive device according to this embodiment includes a speed reducer 1 and a motor 2, which are integrally connected. With this configuration, the rotational force transmitted from the motor 2 via the input shaft 31 is decelerated by the speed reducer 1 and output from the output shaft 32. Hereinafter, for convenience of explanation, the motor side (right side) in FIG. 1 may be described as the front end side or the front side, and the reduction gear side (left side) as the rear end side or the rear side. In addition, the rotation axes of the input shaft 31 and the output shaft 32 may be referred to as an axis X, and this direction may be referred to as an axial direction. First, the reduction gear 1 will be described.

  As shown in FIGS. 1 to 3, the speed reducer 1 includes a casing 11 that houses a speed reduction mechanism, and an input shaft 31 to which a rotational force is applied by a motor 2 is connected to a front end side of the casing 11. ing. The casing 11 includes a disk-shaped first support plate 111 disposed on the front end side, and a disk-shaped second support plate 112 disposed on the rear end side with a smaller diameter than the first support plate 111. These are arranged in parallel. A cylindrical outer cylinder 113 is disposed between the support plates 111 and 112 and is connected to the support plates 111 and 112 by bolts 114. Specifically, a plurality of through holes 1131 extending in the front-rear direction are formed on the outer peripheral edge of the outer cylinder 113 at a predetermined interval, and penetrate the both support plates 111 and 112 so as to correspond thereto. Holes 115 and 116 are formed. Then, the bolt 114 inserted into the through hole 115 from the front end surface on the first support plate 111 side is screwed into the female screw formed in the through hole 116 of the second support plate 112, thereby providing the first support. The plate 111, the outer cylinder 113, and the second support plate 112 are integrally connected to constitute the casing 11. Thereby, a cylindrical internal space is formed in the casing 11, and the speed reduction mechanism is accommodated.

  A central through hole 117 is formed at the center of the first support plate 111, and the input shaft 31 is inserted through the central through hole 117 via a bearing 121. The distal end portion of the input shaft 31 is rotatably connected to the internal space of the motor 2 as described later, and the rear end portion is splined to the eccentric body 4 as described later.

  Next, the speed reduction mechanism housed in the casing 11 will be described. As shown in FIG. 3, the speed reduction mechanism includes a first carrier 5 disposed on the front end side of the internal space of the casing 11 and a second carrier 6 disposed on the rear end side. The first carrier 5 is formed in a disc shape, and is rotatably supported in the internal space by a first bearing 51 disposed between the outer peripheral surface thereof and the inner peripheral surface of the outer cylinder 113. Further, a first flange portion 52 that protrudes radially outward is formed on the outer peripheral surface of the first carrier 5 on the front end side, and this first flange portion 52 is engaged with the first bearing 51 from the front end side. doing. On the other hand, the second carrier 6 is also configured in the same manner, and is disposed on the rear end side of the internal space with a space between the second carrier 6 and the first carrier 5. And, like the first carrier 5, it is formed in a disc shape, and is rotatably supported in the internal space by the second bearing 61 disposed between the outer peripheral surface thereof and the inner peripheral surface of the outer cylinder 113. Has been. Further, a second flange portion 62 projecting radially outward is formed on the outer peripheral surface of the rear end side of the second carrier 6, and the second flange portion 62 is formed on the second bearing 61 from the rear end side. Is engaged.

  An output shaft 32 is connected to the rear end surface of the second carrier 6 so as to rotate together with the second carrier 6. The output shaft 32 protrudes to the outside from a central through hole 118 formed at the center of the second support plate 112 of the casing 11. A bearing 119 is provided on the inner peripheral surface of the central through hole 118, and the output shaft 32 is supported by the central through hole 118 through the bearing 119. In addition, the 1st and 2nd bearings 51 and 61 can be comprised by a ball bearing etc.

  The first carrier 5 and the second carrier 6 are connected by a plurality of carrier pins 7 formed in a cylindrical shape. Hereinafter, the carrier pin 7 and its connection structure will be described. In the speed reducer according to the present embodiment, as shown in FIG. 2, four carrier pins 7 are provided every 90 degrees around the axis line X of the speed reducer. As shown in FIG. 3, each carrier pin 7 includes a cylindrical main body portion 71, a small diameter portion 72 is formed on the front end side of the main body portion 71, and a cylindrical shape on the rear end side of the main body portion 71. The large diameter portion 73 is formed. The small diameter portion 72 is formed in a cylindrical shape having a smaller diameter than the main body portion 71, and a male screw is formed on the outer peripheral surface. The large diameter portion 73 is formed in a cylindrical shape having a larger diameter than the main body portion 71.

  The second carrier 6 is formed with a through hole 63 that receives the main body portion 71 and the large diameter portion 73 of the carrier pin 7. The through-hole 63 includes a first diameter portion 631 having an inner diameter that is substantially the same as the outer diameter of the main body portion 71, and a second diameter portion 632 having an inner diameter that is substantially the same as the outer diameter of the large diameter portion 73. The 1st diameter part 631 and the 2nd diameter part 632 are continuously formed in this order from the front end side. On the other hand, the first carrier 5 is formed with a through hole 53 that receives the main body 71 and the small diameter portion 72 of the carrier pin 7. The through-hole 53 includes a first diameter portion 531 having an inner diameter substantially the same as the outer diameter of the small diameter portion 72, and a second diameter portion 532 having an inner diameter substantially the same as the outer diameter of the main body portion 71. The 1 diameter part 531 and the 2nd diameter part 532 are continuously formed in this order from the front end side.

  Next, fixing of the carrier pin 7 and each of the carriers 5 and 6 will be described. First, the small-diameter portion 72 of the carrier pin 7 is directed to the front end side, and is inserted into the through hole 63 from the rear end surface side of the second carrier 6, and then inserted into the through hole 53 of the first carrier 5. When the large diameter portion 73 of the carrier pin 7 is disposed in the second diameter portion 632 of the through hole 63 of the second carrier 6, the distal end portion of the small diameter portion 72 from the distal end side of the through hole 53 of the first carrier 5. Has come to protrude. Next, the nut 33 is screwed into the male screw of the small diameter portion 72 protruding from the through hole 63 of the first carrier 5 and tightened. Thereby, both the carriers 5 and 6 are integrally connected via the plurality of carrier pins 7.

  When the nut 33 is tightened, a force acts on the first carrier 5 so as to move toward the rear end side, and a force acts on the second carrier 6 so as to move toward the front end side. However, since the first carrier 5 is provided with the first flange portion 52 and is engaged with the first bearing 51 from the front end side, the backward movement of the first carrier 5 is restricted. Similarly, since the second carrier 6 is provided with a second flange portion 62 and is engaged with the second bearing 61 from the rear, the forward movement of the second carrier 6 is restricted.

  As shown in FIG. 3, a cylindrical eccentric body 4 extending along the axis X is disposed between the carriers 5 and 6. The eccentric body 4 includes a small-diameter front end portion 41 formed on the front end side and a small-diameter rear end portion 42 formed on the rear end side. And between the front-end | tip part 41 and the rear-end part 42, two eccentric parts eccentric from the axis line X, ie, the 1st eccentric part 43, and the 2nd eccentric part 44, are formed. Here, the 1st eccentric part 43 is arrange | positioned at the front end side, and the 2nd eccentric part 44 is arrange | positioned at the rear-end side.

  The distal end portion 41 of the eccentric body 4 is inserted into a through hole 54 formed at the center of the first carrier 5, and is rotatably supported by a bearing 55 disposed on the rear end side of the through hole 54. On the other hand, the rear end portion 42 of the eccentric body 4 is inserted into a through hole 64 formed in the center of the second carrier 6, and is rotatably supported by a bearing 65 disposed on the front end side of the through hole 64. ing. Thereby, the eccentric body 4 is rotatable with respect to both the carriers 5 and 6. Further, a recess 45 is formed at the tip of the tip 41 of the eccentric body 4, and the rear end of the input shaft 31 is inserted into the recess 45 and is splined. Therefore, the eccentric body 4 rotates about the axis X together with the input shaft 31.

  Each eccentric part 43,44 of the eccentric body 4 is formed in disk shape, and is connected integrally in the front-back direction with a slight gap. As shown in FIG. 2, the axis X1 of the first eccentric portion 43 and the axis X2 of the second eccentric portion 44 are both eccentric from the axis X of the speed reducer 1 and are shifted by 180 degrees about the axis X. Placed in position.

  A first needle bearing 56 is disposed on the outer peripheral surface of the first eccentric portion 43, and the first external gear 8 is connected to the first eccentric portion 43 via the needle bearing 56. That is, a central through hole 81 is formed at the center of the first external gear 8, and the first eccentric portion 43 is disposed in the central through hole 81 via the first needle bearing 56. As shown in the enlarged view of FIG. 3, the first needle bearing 56 includes a plurality of rollers 561 formed in a cylindrical shape and an annular shell 562 that supports the rollers 561. The shell 562 is a cylindrical base portion 563 that is fixed along the inner peripheral surface of the central through hole 81 of the first external gear 8, and a plate shape that extends radially inward from the front end and the rear end of the base portion 563. The first support portion 564 and the second support portion 565 are formed. The plurality of rollers 561 are arranged in the circumferential direction along the base portion 563 and are sandwiched between the first and second support portions 564 and 565, so that movement in the front-rear direction is restricted. The plurality of rollers 561 are rotatably supported by the shell 562 and are in contact with the outer peripheral surface of the first eccentric portion 43, whereby the first external gear 8 is rotatable around the first eccentric portion 43. It has become.

  Next, the first external gear 8 will be described. Since the axis X1 of the first eccentric portion 43 is eccentric from the axis X, when the first eccentric portion 43 rotates, the first external gear 8 rotates in an eccentric manner. As shown in FIG. 2, in the first external gear 8, four carrier pin through holes 82 through which the carrier pins 7 are inserted are formed between the center and the outer peripheral edge. These carrier pin through holes 82 are larger than the carrier pins 7 and rollers 83 to be described later, and are formed every 90 degrees about the axis of the first external gear 8. In each carrier pin 7, a cylindrical roller 83 is provided at a position passing through the carrier pin through hole 82. The roller 83 is disposed so as to be rotatable with respect to the outer peripheral surface of the carrier pin 7. The outer peripheral surface of the roller 83 is in contact with the inner peripheral surface of the carrier pin through hole 82, and the pressing force from the inner peripheral surface is reduced by the roller. It is transmitted to the carrier pin 7 via 83.

  Further, the external teeth 84 of the first external gear 8 have a trochoidal tooth profile defined by an epitrochoid parallel curve represented by the following formula.

Where θ is the angle between the line segment connecting the center of the internal pin and the intersection of the fixed circle / rolling circle and the horizontal line segment, and cos θ and sin θ are the points of the envelope of the internal pin track Indicates coordinates. φ is a variable (rotation angle of the rolling circle) for drawing a trochoid curve, Za is the number of teeth of the external gear, Zb is the number of internal teeth pins, and x is a correction coefficient.

  The external teeth 84 of the first external gear 8 configured as described above mesh with the internal gear 15 formed on the inner peripheral surface of the casing 11. Hereinafter, the internal gear 15 will be described. First, as shown in FIG. 2, on the inner peripheral surface of the outer cylinder 113 of the casing 11, a concave portion 151 having an arc cross section is provided between the first bearing 51 and the second bearing 61 at a predetermined interval along the circumferential direction. Is formed. A cylindrical inner tooth pin 152 extending in the front-rear direction is rotatably disposed in each recess 151, and a part of the outer peripheral surface of the inner tooth pin 152 is radially from the inner peripheral surface of the outer cylinder 113. Projects inward. Thus, the inner tooth pin 152 protrudes from the inner peripheral surface of the outer cylinder 113 at a predetermined interval, whereby irregularities are formed along the circumferential direction on the inner peripheral surface of the outer cylinder 113. Configure.

  On the other hand, a second needle bearing 66 is disposed on the outer peripheral surface of the second eccentric portion 44, and the second external gear 9 is connected to the second eccentric portion 44 via the second needle bearing 66. Yes. Since the structure of the 2nd needle bearing 66 and the 2nd external gear 9 is the same as that of the 1st needle bearing 56 and the 1st external gear 8, detailed description is abbreviate | omitted. In each carrier pin 7, a cylindrical roller 93 is provided at a position passing through the carrier pin through hole 92 of the second external gear 9. Similarly to the first external gear 8, the second external gear 9 meshes with the internal gear 15 of the outer cylinder 113 described above.

  The first external gear 8 and the second external gear 9 have the same number of teeth, but are smaller than the number of teeth of the internal gear 15. In the present embodiment, as an example, the number of teeth of both the external gears 8 and 9 is 29, and the number of teeth of the internal gear (the number of internal teeth pins 152) is 30.

  Further, regarding the rollers 83 and 93 attached to the carrier pin 7, the roller 83 disposed in the through hole 82 of the first external gear 8 and the roller 93 disposed in the through hole 92 of the second external gear 9. Between the two, a plate-like first regulating plate 86 is disposed. The first restricting plate 86 is formed in a disc shape having a through hole, and the carrier pin 7 is inserted through the through hole. The first restricting plate 86 restricts movement of the roller 83 in the front-rear direction.

  Similarly, a plate-like second regulating plate 96 is disposed between the roller 93 disposed in the through hole 92 of the second external gear 9 and the second carrier 6. The second restricting plate 96 is also formed in a disk shape having a through hole, and the carrier pin 7 is inserted through the through hole. The second restricting plate 96 restricts the movement of the roller 93 in the front-rear direction. Such restricting plates 86 and 96 can also be provided between the roller 83 disposed in the through hole 82 of the first external gear 8 and the first carrier 5.

  Next, the motor 2 will be described. The motor 2 is attached to the input shaft 31 and is accommodated in the motor housing 21. As shown in FIG. 1, the motor housing 21 includes a cylindrical side surface portion 211 that extends forward from the outer peripheral surface of the first support plate 111 of the casing 11, and a disk-shaped closing portion 212 that closes the front end opening of the side surface portion. It is equipped with. The stator 22 and the rotor 23 of the motor are accommodated in an internal space surrounded by the first support plate 111, the side surface portion 211, and the closing portion 212 of the casing 11. A bearing 213 is attached to the inner surface of the closing portion 212, and the tip end portion of the input shaft 31 is rotatably attached to the bearing 213.

  The stator 22 of the motor 2 is attached to the inner surface of the closing portion 212 so as to surround the input shaft 31. The stator 22 is formed in an annular shape so as to surround the input shaft 31 and is provided with a coil 221 to which electric power is supplied. On the other hand, the rotor 23 is fixed to the input shaft 31. More specifically, a pair of blade portions 231 that extend radially outward is attached to the rear end portion of the input shaft 31, and extends forward at the tip of the blade portion 231, facing the coil 221 of the stator 22. The plate-like support portions 232 are connected. A magnet 233 facing the coil 221 is attached to the radially inner surface of the support portion 232. By configuring the stator 22 and the rotor 23 as described above, the rotor 23 rotates around the axis 22 around the axis X together with the input shaft 31.

  Next, the operation of the drive device configured as described above will be described. First, when the motor 2 is driven, the input shaft 31 rotates together with the rotor 23. Since the input shaft 31 is splined to the eccentric body 4, the eccentric body 4 rotates about the axis X together with the input shaft 31. When the eccentric body 4 rotates, the first external gear 8 performs eccentric oscillating rotation around the first eccentric portion 43. As a result, a phenomenon occurs in which the meshing positions of the first external gear 8 and the internal gear 15 are sequentially shifted. The first external gear 8 rotates relative to the fixed internal gear 15 by a difference in the number of teeth from the internal gear 15. That is, the first external gear 8 rotates. Similarly, the second external gear 9 also rotates eccentrically and rotates relative to the internal gear 15. Thus, the rotation components of both external gears 8 and 9 are transmitted to both carriers 5 and 6 via the carrier pin 7 and the output shaft 32 rotates.

  In the present embodiment, the number of external teeth of the external gears 8 and 9 is 29, the number of internal teeth (external pin 129) of the internal gear 122 is 30, and the difference in the number of teeth is 1. Therefore, each time the input shaft 31 (eccentric body 4) rotates, the external gears 8 and 9 are shifted (rotated) by one tooth with respect to the internal gear 15. Thereby, one rotation of the input shaft 31 is decelerated to 1/30 rotation of the external gears 8 and 9. The rotation of the input shaft 31 and the output shaft 32 is opposite.

  As described above, according to the present embodiment, the following effects can be obtained. That is, the rear end portion of the carrier pin 7 is fixed by the large-diameter portion 73 so as not to come out of the second carrier 6, and the front end portion of the carrier pin 7 is fixed to the first carrier 5 by screwing. Therefore, the carrier pin 7 can be easily fixed to both the carriers 5 and 6. In addition, the external gears 8 and 9 may be inclined with respect to the axis X during rotation due to processing accuracy or assembly error. In this case, the carrier pin through holes 82 and 92 are in relation to the carrier pin 7. There is a risk that thrust force will be applied without contact at right angles. However, even in such a case, since the tip of the carrier pin 7 is screwed, rotation around the axis of the carrier pin 7 and movement in the axial direction can be prevented. Therefore, it is possible to prevent the carrier pin 7 from being displaced from or separated from the carriers 5 and 6.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible unless it deviates from the meaning.

  For example, the carrier pin can be fixed in various ways, for example, as shown in FIG. As shown in the figure, in this example, the axial lengths of the first diameter portion 531 and the second diameter portion 532 of the through hole 53 of the first carrier 5 are adjusted, and the first diameter portion 531 has a female screw. Is forming. The male screw 72 of the carrier pin 7 is screwed into this female screw. Also by this, the carrier pin 7 can be firmly fixed to both the carriers 5 and 6, and there is no problem even if the above-described thrust force is applied. In addition, a tool recess 77 into which a tool such as a hexagon wrench can be inserted in order to rotate and fix the carrier pin 7 is formed on the rear end surface of the large-diameter portion 73 of the carrier pin 7. Moreover, the structure of the through holes for the carrier pins of the first carrier 5 and the second carrier 6 can be changed as appropriate so that the directions of the carrier pins 7 are reversed. That is, the male screw side of the carrier pin 7 can be fixed to the second carrier 6. Further, input can be performed from the second carrier 6 side and output from the first carrier 5.

  Moreover, it can also be as shown in FIG. In this example, the axial lengths of the first diameter portion 531 and the second diameter portion 532 of the through hole 53 of the first carrier 5 are adjusted, and a plurality of portions extending in the axial direction on the inner peripheral surface of the first diameter portion 531. Grooves are formed. On the other hand, the rear end portion of the carrier pin 7 is not provided with a large-diameter portion, and a spline 79 is formed at the front end portion of the carrier pin 7 instead of the male screw. Thereby, the front-end | tip part of the carrier pin 7 and the 1st diameter part 531 of the 1st carrier 5 are spline-coupled. Further, a third flange portion 58 protruding outward in the radial direction is formed on the outer peripheral edge on the rear end side of the first carrier 5, and the first flange portion is eliminated.

  On the other hand, the first diameter portion 631 of the through hole 63 of the second carrier 6 is made to correspond to the main body portion 71 of the carrier pin 7, and the second diameter portion 632 has a smaller diameter than the first diameter portion 631. The lengths of the parts 631 and 632 are adjusted. Further, a fourth flange portion 68 protruding outward in the radial direction is formed on the outer peripheral edge on the distal end side of the second carrier 6, and the second flange portion is eliminated. Further, a protrusion 16 that presses the first bearing 51 is formed on the rear end surface of the first support plate 111 of the casing 11, and a second bearing 61 is formed on the front end surface of the second support plate 112. A protrusion 17 is formed to press the.

  According to the configuration as described above, the first support plate 111 and the second support plate 112 are brought into close proximity by tightening the bolt 114 of the casing 11, thereby bringing both the bearings 51 and 61 close together. Thus, the first bearing 51 presses the first carrier 5 backward via the third flange portion 58, and the second bearing 61 presses the second carrier 6 forward via the fourth flange portion 68. As a result, since the carrier pin 7 is pressed from both sides in the axial direction by both the carriers 5 and 6, it is firmly fixed to both the carriers 5 and 6, and there is no problem even if the above-described thrust force is applied.

  The rollers 83 and 93 of the carrier pin 7 are rotatably attached to the carrier pin 7. In order to facilitate this rotation, the rollers 83 and 93 can be configured as follows. That is, as shown in FIG. 6A, a plurality of grooves 831 extending in the axial direction are formed on the inner peripheral surfaces of the rollers 83 and 93, and lubricating oil is supplied to the grooves 831. Alternatively, as shown in FIG. 6B, a plurality of grooves 78 extending in the axial direction can be formed on the outer peripheral surface of the carrier pin 7, and lubricating oil can be supplied to the grooves 78. By doing so, the rollers 83 and 93 rotate smoothly, and the wear resistance of the rollers 83 and 93 and the carrier pin 7 is improved. Further, since the gap between the inner peripheral surface of the rollers 83 and 93 and the outer peripheral surface of the carrier pin 7 is filled with the lubricating oil, noise during driving can be reduced. The groove 78 can take various forms, for example, can be formed in a threaded shape. Thereby, since the number of grooves is reduced, there is an advantage that the contact area between the two is increased and the strength is improved.

  Chamfering can be applied to the boundary between the end surface on the front end side and the end surface on the rear end side of each external gear 8 and 9 and the tooth surface (hereinafter referred to as edge portions 88 and 98). If the edge portions 88 and 98 are sharp, there is a risk of breakage due to stress concentration. Although the chamfering method is not particularly limited, for example, as shown in FIG. 7, it can be processed by electric discharge machining or electrolytic polishing. FIG. 7A is a perspective view of the chamfering process, and FIG. 7B is a cross-sectional view. As shown in the figure, a recess 102 having a circular arc cross section is formed at the periphery of the lower end of the cylindrical tool 101. The concave portion 102 is brought into contact with the edge portions 88 and 98 of the external gears 8 and 9, and the tool 101 is moved along the edge portions 88 and 98 of the external gears 8 and 9 while rotating around the axis Z. To go. At this time, the external gears 8 and 9 are electrically connected to the positive electrode, the tool 101 is electrically connected to the negative electrode, and a voltage is applied between the two. As a result, the edge portions 88 and 98 of the external gears 8 and 9 are polished in an arc shape by electrical polishing and chamfered.

  The needle bearing according to the above embodiment can be attached to the central through holes 81 and 91 of the external gears 8 and 9 as follows so as not to come out in the axial direction during the rotation. In the following, since the configurations of both needle bearings are substantially the same, the first needle bearing 55 will be described. First, as shown in FIG. 8, the outer side in the radial direction of the base portion 563 of the shell 562 is shown for convenience of manufacturing. The surface of is inclined. That is, the outer diameter of the base 563 of the shell 562 is reduced from the front to the rear. Due to this shape, the needle bearing 55 is easily removed from the external gear 8. Then, the shell 562 in which the roller 561 is accommodated is pressed into the central through hole 81 of the first external gear 8 from the front, and is fixed to the first external gear 8. Further, the rear end portion of the base portion 563 is fixed to the inner peripheral edge of the central through hole 81 of the first external gear 8 by welding 103, for example.

  As shown in FIG. 9, a flange portion 821 that protrudes inward in the radial direction is formed on the inner peripheral edge on the rear end side of the central through hole 81 of the first external gear 8. The shell 562 is formed in the same manner as in FIG. 8, and the shell 562 in which the roller 561 is accommodated is press-fitted from the front into the central through hole 81 of the first external gear 8. The shell 562 is fixed to the first external gear 8 by press-fitting and abuts against the flange portion 821, so that the backward movement of the needle bearing 55 is restricted.

  Furthermore, as shown in FIG. 10, the inner peripheral surface of the central through hole 81 of the first external gear 8 is formed so that the inner diameter decreases from the front toward the rear. Then, a shell 562 similar to that in FIG. 8 is used to press-fit into the central through hole 81 of the first external gear 8. Also by this, the shell 562 is fixed to the first external gear 8 by press-fitting and the inner peripheral surface of the central through hole 81 is inclined, so that the backward movement of the needle bearing 55 is restricted.

  Moreover, in order to rotate the roller 561 smoothly in the shell 562, it can be comprised as follows. For example, as shown in FIG. 11, a through hole 5641 is formed in the support portion 564 of the shell 562 so that the lubricating oil can be easily introduced into the roller 561 from the through hole 5541. Or as shown in FIG. 12, the outer peripheral surface of each eccentric part 43 and 44 of the eccentric body 4 is formed in cross-sectional arc shape. That is, it is curved so as to protrude outward in the radial direction. Thereby, since a clearance gap is formed between the front end side and the rear end side of the roller 561 and the outer peripheral surfaces of the eccentric portions 43 and 44, it is possible to easily introduce the lubricating oil into the clearance. 11 and FIG. 12, the lubricating oil is sufficiently supplied to the roller 561, so that the roller 561 can be smoothly rotated and the wear resistance is improved.

  As shown in FIG. 13, a ring-shaped weight 105 can be attached to the peripheral edge of the central through-hole 81 on the front and rear end faces of the external gears 8 and 9. Thereby, the following effect can be acquired. First, in the speed reducer 1, vibration may occur due to a decrease in balance during driving. In order to reduce this vibration, it is necessary to distribute the load evenly. As a method therefor, there is a method of increasing the number of teeth of the external gears 8 and 9 and dispersing the load acting on the tooth surface. However, if this is done, the number of parts increases and the assemblability deteriorates. Therefore, as described above, the mass 105 can be concentrated near the center by attaching the weight 105 with the bolt 106 or the like near the center of the external gears 8 and 9. As a result, the moment from the center of the external gears 8 and 9 is reduced, and vibration can be reduced even if the balance is reduced.

  As shown in FIG. 14, the surface of a plurality of concave portions 151 having a circular arc cross section formed on the inner peripheral surface of the outer cylinder 113 of the casing 11 is finished by electrical polishing with a tool 201. This tool 201 is cylindrical and has substantially the same diameter as the recess 151, and is supported so as to be rotatable around the axis S. At this time, the casing 11 is electrically connected to the positive electrode, the tool 201 is electrically connected to the negative electrode, and a voltage is applied between the two. The tools 201 are arranged in an arc shape with the same number as the recesses 151 and the same distance as the interval between them, and are unitized by the frame 202. The frame 202 can be moved toward and away from the D direction in a state where the axial direction S of the tool 201 is parallel to the rotational axis X of the casing 11 and rotates each tool 201 in synchronization. As a result, all the concave portions 151 are simultaneously electrically polished by the polishing process. The polished recess 151 smoothly guides the rotation of the internal tooth pin 152.

  In the above embodiment, two external gears are provided, but one or three or more may be used. Further, the number of carrier pins is not particularly limited.

  In the said embodiment, although the internal gear 15 was formed by providing an internal tooth pin, an internal tooth can also be directly formed in the inner periphery of an outer cylinder.

1 Reduction gear 15 Internal gear 31 Input shaft (shaft member)
5 1st carrier 51 1st bearing 52 1st flange part 53 Through-hole 6 2nd carrier 61 2nd bearing 62 2nd flange part 63 Through-hole 632 2nd diameter part (receiving part)
7 Carrier pin 72 Male screw 73 Large diameter portion 8 First external gear 9 Second external gear

Claims (5)

A shaft member rotatably supported about an axis,
An internal gear,
At least one external gear meshing with the internal gear and having at least one through hole formed in the circumferential direction between the center and the outer peripheral edge is connected to the shaft member, and rotates together with the shaft member. An eccentric body for rotating the external gear eccentrically,
A carrier pin inserted through the through hole of the external gear and extending parallel to the axis;
A first carrier and a second carrier fixed to both ends of the carrier pin, sandwiching the external gear from both ends in the axial direction, and rotatable around the axis;
With
The carrier pin includes a cylindrical main body, a large-diameter portion that is provided on one end of the main body and has a larger diameter than the main body, and a male screw that is provided on the other end of the main body. , And
Each of the first carrier and the second carrier has a through hole through which both ends of the carrier pin are inserted,
The first carrier is configured such that a male screw of the carrier pin is fixed,
The speed reducer, wherein the second carrier has a receiving portion that receives a large-diameter portion of the carrier pin and prevents the carrier pin from coming off to the first carrier side.   The male pin of the carrier pin is configured to protrude from a through hole of the first carrier, and the carrier pin is fixed to the first carrier by a nut screwed into the protruding portion. Item 1. A reduction gear according to item 1. A female screw is formed in the through hole of the first carrier,
The reduction gear according to claim 1, wherein a male screw of the carrier pin is screwed into the female screw. A first bearing disposed on an outer peripheral surface of the first carrier and rotatably supporting the first carrier;
A second bearing disposed on an outer peripheral surface of the second carrier and rotatably supporting the second carrier;
Further comprising
The first carrier includes a first flange portion that engages with the first bearing from one side of the axis, and the engagement of the first flange portion causes the first carrier to move to the other side of the axis. Is configured to be regulated,
The second carrier includes a second flange portion that engages with the second bearing from the other side of the axis, and the second carrier moves to one side of the axis by the engagement of the second flange portion. The speed reducer according to claim 1, wherein the speed reducer is configured to be regulated. The male screw of the carrier pin is formed with a smaller diameter than the main body part,
In the through hole of the first carrier, a first diameter portion corresponding to the male screw and a second diameter portion corresponding to the main body portion having a larger diameter than the first diameter portion are formed continuously. The speed reducer according to any one of claims 1 to 4.