JP2016008661A - Gear transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a gear transmission in which a crank shaft is supported by a simple structure.SOLUTION: A crank shaft 12 of a gear transmission 100 is supported by a supporting member 2. The supporting member 2 has a first supporting part 2a and a second supporting part 2c. The crank shaft 12 has a first shaft part 16 extending from an eccentric body 18 and a second shaft part 38 extending from an eccentric body 36. The first shaft 16 is supported at a first supporting part 2a through a first cylindrical roller bearing 22. The second shaft part 38 is supported at the second supporting part 2c through a second cylindrical roller bearing 32. The second shaft part 38 passes through the second supporting part 2c. At the gear transmission 100, a pair of restricting members 42, 44 for restricting motion of the crank shaft 12 toward a rotating shaft 40 are fixed to the second shaft part 38. The second supporting part 2c is arranged between the pair of restricting members 42, 44.

Description

  This specification discloses the technique regarding a gear transmission.

  2. Description of the Related Art A gear transmission device that includes an eccentric rotating gear that rotates eccentrically and a rotation gear that meshes with the eccentric rotating gear is known. In such a gear transmission, an eccentric rotating gear is eccentrically rotated using a crankshaft having an eccentric body. The crankshaft is supported by the carrier. The carrier is formed by fixing two plates (hereinafter referred to as a first plate and a second plate) facing each other with a gap therebetween. In the gear transmission of Patent Document 1, a cylindrical roller bearing is disposed between the crankshaft and the carrier to restrict movement of the crankshaft in the radial direction. Further, two washers are attached to the crankshaft, and each washer is brought into contact with the corresponding first plate or second plate, thereby restricting the movement of the rank shaft in the axial direction.

JP 2008-202664 A

  As described above, in the gear transmission of Patent Document 1, the movement of the crankshaft in the axial direction is restricted by bringing the washer into contact with the first plate and the second plate. For example, when the surface of the first plate and the surface of the second plate are not parallel, a local load may be applied to the crankshaft and the carrier. Therefore, in the gear transmission of Patent Document 1, it is necessary to process and assemble the carrier (first plate and second plate) so that the surface of the first plate and the surface of the second plate are parallel to each other. . That is, in the gear transmission of Patent Document 1, the processing / assembly accuracy of two parts affects the rotation of the crankshaft. The present specification, which solves the above-described problems, discloses a technique for realizing a gear transmission that supports a crankshaft with a simpler structure than the conventional one.

  A gear transmission disclosed in this specification includes a crankshaft having an eccentric body, an eccentric rotating gear, a rotating gear, and a support member. The eccentric rotation gear is engaged with the eccentric body and rotates eccentrically with the rotation of the crankshaft. The rotation gear meshes with the eccentric rotation gear, and has a number of teeth different from the number of teeth of the eccentric rotation gear. The support member supports the crankshaft. The support member has a first support part and a second support part. The first support part and the second support part are arranged to face each other with a space therebetween, and are fixed via a columnar part. The crankshaft has a first shaft portion extending from the eccentric body to one side in the rotation axis direction, and a second shaft portion extending from the eccentric body to the other side in the rotation axis direction. The first shaft portion is supported by the first support portion via a first cylindrical roller bearing. The 2nd shaft part is supported by the 2nd support part via the 2nd cylindrical roller bearing. The second shaft portion passes through the second support portion. In this gear transmission, a pair of regulating members that regulate movement of the crankshaft in the direction of the rotation axis are fixed to the second shaft portion. Moreover, the 2nd support part is arrange | positioned between a pair of control members.

  In said gear transmission, the 2nd support part is arrange | positioned between a pair of control members. In other words, the pair of regulating members sandwich the front and back surfaces of the second support part. In the above gear transmission, the movement of the crankshaft in the axial direction is restricted by sandwiching the second support part between the pair of restricting members. In the case of the above gear transmission, if the front and back surfaces of the second support portion are parallel, it is possible to prevent a local force from being applied to the crankshaft and the support member. That is, if the front surface and the back surface of the second support portion are made parallel, it is possible to support the cran shaft in the axial direction without being affected by the assembly accuracy of the first support portion and the second support portion. In other words, the positioning accuracy in the axial direction of the crankshaft can be controlled by one component instead of two components.

  The “spinning gear” does not necessarily have to rotate when the gear transmission is observed from the outside. The rotation gear only needs to rotate relative to the eccentric rotation gear. In the gear transmission disclosed in this specification, when the gear transmission is observed from the outside, the rotating gear may be stationary and the eccentric rotating gear may rotate with respect to the rotating gear while rotating eccentrically. . That is, “the rotation gear rotates with respect to the eccentric rotation gear” includes a mode in which the rotation gear and the eccentric rotation gear rotate relative to each other by the rotation of the eccentric rotation gear without rotating itself.

Sectional drawing of the gear transmission of 1st Example is shown. FIG. 2 shows a cross-sectional view along the line II-II in FIG. 1. The enlarged view of the part enclosed with the broken line III of FIG. 1 is shown. The enlarged view of the part enclosed with the broken line IV of FIG. 3 is shown. The figure which planarly viewed the 2nd plate is shown. The figure which planarly viewed the 2nd plate from the opposite side of Drawing 5 is shown. The figure which planarly viewed the 4th washer is shown. The figure which planarly viewed the input gear is shown. Sectional drawing of the gear transmission of 2nd Example is shown.

  Hereinafter, some technical features of the gear transmission disclosed in this specification will be described. The items described below have technical usefulness independently.

  The gear transmission may include an eccentric rotating gear and a crankshaft that rotates the eccentric rotating gear eccentrically. The crankshaft may include an eccentric body. The eccentric body may be provided in the middle of the rotation axis direction of the crankshaft. More specifically, the crankshaft may have a first shaft portion extending from the eccentric body in one direction of the rotation axis and a second shaft portion extending from the eccentric body in the other direction of the rotation axis. There may be one eccentric body, or two or more eccentric bodies. When the crankshaft includes a plurality of eccentric bodies, the eccentric directions of the eccentric bodies may be different with respect to the rotation shaft of the crankshaft. When the crankshaft includes a plurality of eccentric bodies, the first shaft portion extends from the eccentric body arranged at one end portion in the rotation axis direction, and the second shaft portion is the other in the rotation axis direction. It may extend from the eccentric body arrange | positioned at the edge part.

  The gear transmission may include a support member that supports the crankshaft. The crankshaft may be rotatably supported by the support member. The crankshaft may be supported on the support member by a pair of cylindrical roller bearings. For example, the crankshaft includes a first cylindrical roller bearing disposed between the first shaft portion and the support member, and a second cylindrical roller bearing disposed between the second shaft portion and the support member. The support member may be supported. In this case, the eccentric body is located between the first cylindrical roller bearing and the second cylindrical roller bearing. The crankshaft may include an input gear. The input gear may be fixed to the crankshaft outside the pair of cylindrical roller bearings (first cylindrical roller bearing, second cylindrical roller bearing). When the input gear is fixed to the second shaft portion, the second shaft may pass through the support member.

  The support member may include a first support part, a second support part, and a columnar part. The first support part and the second support part may be arranged to face each other with an interval therebetween. The first support part and the second support part may be fixed via a columnar part. The first support part and / or the second support part may be a flat plate. In the present specification, “flat plate” means that the front surface and the back surface are at least partially parallel. In other words, the “flat plate” does not need to be a flat surface on the entire surface and the back surface, and it is sufficient that at least a part of the front surface and the back surface is parallel. These forms are also included in the “flat plate”.

  The columnar part may be integrated with the first support part or the second support part. For example, the first support part may be integrated with the columnar part, and the second support part may be a flat plate. The second support part may be integrated with the columnar part, and the first support part may be a flat plate. The first support part may support the first shaft part of the crankshaft, and the second support part may support the second shaft part of the crankshaft. The 1st shaft part may be supported by the 1st support part via the 1st cylindrical roller bearing. Moreover, the 2nd shaft part may be supported by the 2nd support part via the 2nd cylindrical roller bearing. The second shaft portion may pass through the through hole of the second support portion and extend to the outside of the second support portion. In other words, the second shaft portion may extend from the inside of the support member (between the first support portion and the second support portion) to the outside of the support member. The first shaft portion may remain in the through hole of the first support portion. In other words, the end portion of the first shaft portion may be located in the through hole of the first support portion.

  The gear transmission may include a rotation gear that meshes with the eccentric rotation gear and has a number of teeth different from the number of teeth of the eccentric rotation gear. The rotation gear may rotate relative to the eccentric rotation gear while meshing with the eccentric rotation gear. The eccentric rotation gear may be an external gear, and the rotation gear may be an internal gear. Alternatively, the eccentric rotation gear may be an internal gear, and the rotation gear may be an external gear. The external gear may rotate eccentrically while meshing with the internal gear. In this case, the internal gear rotates with respect to the external gear. The internal gear may rotate eccentrically while meshing with the external gear. In this case, the external gear rotates with respect to the internal gear.

  In the case where the external gear rotates eccentrically, the case of the gear transmission may also serve as an internal gear member (a part of the internal gear). That is, the internal gear may be formed on the inner periphery of the case. In this case, the internal gear may include an internal gear member and a columnar member inserted in a groove provided on the internal peripheral surface of the internal gear member. More specifically, the internal gear may be formed by a groove formed on the inner peripheral surface of the internal tooth member and a cylindrical member inserted into the groove. A support member (carrier), a crankshaft, and an external gear that rotatably support the crankshaft may be disposed inside the case.

  The eccentric rotating gear may engage with the eccentric body of the crankshaft and rotate eccentrically as the crankshaft rotates. A third cylindrical roller bearing may be disposed between the eccentric body of the crankshaft and the eccentric rotating gear. In this case, the third cylindrical roller bearing may be disposed between the first cylindrical roller bearing and the second cylindrical roller bearing in the rotation axis direction of the crankshaft. The input gear may be fixed to the crankshaft (second shaft portion) outside the pair of cylindrical roller bearings (first cylindrical roller bearing, second cylindrical roller bearing).

  The 1st control member may be arrange | positioned between the 1st cylindrical roller bearing and the 3rd cylindrical roller bearing. The first restricting member may be attached to the first shaft portion of the crankshaft. The axial ends of the first cylindrical roller bearing and the third cylindrical roller bearing may be in contact with the first restriction member. The 2nd control member may be arrange | positioned between the 2nd cylindrical roller bearing and the 3rd cylindrical roller bearing. The second restricting member may be attached to the second shaft portion of the crankshaft. The axial ends of the second cylindrical roller bearing and the third cylindrical roller bearing may be in contact with the second restricting member.

  The 3rd control member may be fixed to the 1st shaft part on the opposite side to the 1st control member to the 1st cylindrical roller bearing. In this case, the first cylindrical roller bearing is disposed between the first restriction member and the third restriction member. The first restriction member and the third restriction member may restrict the first cylindrical roller bearing from exerting a force on the other cylindrical roller bearing (third cylindrical roller bearing). In other words, even if a force that moves toward the first restricting member is applied to the first cylindrical roller bearing, and the first cylindrical roller bearing applies a force to the first restricting member, the first cylindrical roller bearing is the third cylindrical roller. The positions of the first restricting member and the third restricting member may be fixed so as not to apply force to the bearing.

  The 4th control member may be fixed to the 2nd shaft part on the opposite side to the 2nd control member to the 2nd cylindrical roller bearing. In this case, the second cylindrical roller bearing is disposed between the second restriction member and the fourth restriction member. The second restriction member and the fourth restriction member may restrict the second cylindrical roller bearing from exerting a force on the other cylindrical roller bearing (third cylindrical roller bearing). In other words, even if a force that moves toward the second restricting member is applied to the second cylindrical roller bearing, and the second cylindrical roller bearing applies a force to the second restricting member, the second cylindrical roller bearing is the third cylindrical roller. The positions of the second restriction member and the fourth restriction member may be fixed so that no force is applied to the bearing. Similarly, even if a force that moves toward the second restricting member acts on the third cylindrical roller bearing, and the third cylindrical roller bearing applies a force to the second restricting member, the third cylindrical roller bearing becomes the second cylindrical roller. The positions of the second restriction member and the fourth restriction member may be fixed so that no force is applied to the bearing.

  The second restriction member and the fourth restriction member may be a pair of restriction members that restrict movement of the crankshaft in the rotation axis direction. In this case, the 2nd support part may be arranged between the 2nd regulating member and the 4th regulating member. Specifically, the second restricting member may contact the surface of the second support portion on the first support portion side, and the fourth restricting member may contact the surface of the second support portion opposite to the first support portion. . In other words, the second restriction member and the fourth restriction member may sandwich the second support portion. The crankshaft may be restricted from moving in the axial direction by sandwiching the second support portion between the second restriction member and the fourth restriction member.

  The first to fourth regulating members may be ring-shaped parts. The first to fourth regulating members may be washers, for example. The outer diameter of the first restricting member may be larger than the outer diameter of the first cylindrical roller bearing. Moreover, the outer edge of the 1st control member may be located outside the internal peripheral surface of a 3rd cylindrical roller bearing. When the crankshaft is observed from the rotation axis direction, the eccentric body may be located inside the outer edge of the first restricting member. The outer diameter of the second restricting member may be larger than the outer diameter of the second cylindrical roller bearing. Further, the outer edge of the second restricting member may be located outside the inner peripheral surface of the third cylindrical roller bearing. When the crankshaft is observed from the rotation axis direction, the eccentric body may be located inside the outer edge of the second restricting member. The outer diameter of the third restricting member may be smaller than the outer diameter of the first cylindrical roller bearing. Further, the outer diameter of the fourth regulating member may be larger than the outer diameter of the second cylindrical roller bearing. When the input gear is fixed to the second shaft portion outside the first cylindrical roller bearing and the second cylindrical roller bearing, the input gear may be the fourth restriction member.

(First embodiment)
With reference to FIG.1 and FIG.2, the basic structure of the gear transmission 100 is demonstrated. FIG. 1 shows a longitudinal sectional view of the gear transmission 100 (a sectional view along the axis 46 of the gear transmission 100). FIG. 2 shows a cross-sectional view of the gear transmission 100 (cross-sectional view along a line perpendicular to the axis 46 of the gear transmission 100). The gear transmission 100 includes an internal gear 56, a carrier 2, a crankshaft 12, and two external gears 26 and 28. The internal gear 56 is an example of a rotation gear, the carrier 2 is an example of a support member, and the external gears 26 and 28 are examples of an eccentric rotation gear.

  The internal gear 56 includes a case 54 and an internal tooth pin 52. An internal gear 56 is formed by arranging a plurality of internal gear pins 52 on the inner periphery of the case 54. The internal tooth pin 52 has a cylindrical shape and is disposed on the inner peripheral surface of the case 54. The carrier 2 is rotatably supported by the case 54 by a pair of bearings 50. The pair of bearings 50 restrict the carrier 2 from moving in the axial direction and the radial direction with respect to the case 54. In the gear transmission 100, angular ball bearings are used as the pair of bearings 50. The internal tooth pin 52 is disposed between the pair of bearings 50.

  The carrier 2 includes a first plate 2a and a second plate 2c. The first plate 2a and the second plate 2c are arranged to face each other with a space therebetween. The first plate 2a includes a columnar portion 2b. The columnar portion 2b is integral with the first plate 2a and extends from the first plate 2a toward the second plate 2c. The second plate 2c is a flat plate. The columnar part 2 b and the second plate 2 c are fixed by bolts 51. That is, the first plate 2a and the second plate 2c are fixed. The first plate 2a and the second plate 2c are fixed by aligning the positions of the columnar portion 2b and the second plate 2c using the positioning pins 49 and fastening the bolts 51 to the columnar portion 2b. The first plate 2a and the second plate 2c are detachable. The first plate 2a is an example of a first support part, and the second plate 2c is an example of a second support part.

  A through hole 2d is provided in the center of the first plate 2a, and a cap 4 is attached to the end of the through hole 2d. A through hole 2f is provided at a position offset from the center of the first plate 2a. A part of the crankshaft 12 (first shaft portion 16) is located in the through hole 2f. A cap 14 is attached to the end of the through hole 2f. An oil seal 58 is provided between the first plate 2 a and the case 54. A through hole 2e is provided at the center of the second plate 2c. A through hole 2g is provided at a position offset from the center of the second plate 2c. The through hole 2f and the through hole 2g are coaxial. A part of the crankshaft 12 (second shaft portion 38) passes through the through hole 2g and extends to the outside of the second plate 2c. The second plate 2 c is also provided with a bolt hole 51 a for allowing the bolt 51 to pass therethrough and a pin hole 49 a for allowing the positioning pin 49 to pass therethrough.

  The crankshaft 12 is rotatably supported by the carrier 2 by a pair of cylindrical roller bearings (a cylindrical roller bearing 22 and a cylindrical roller bearing 32). The crankshaft 12 includes an input gear 34 and two eccentric bodies 18 and 36. The eccentric direction of the eccentric body 18 and the eccentric direction of the eccentric body 36 are symmetric with respect to the rotation axis 40 of the crankshaft 12. The first shaft portion 16 extends from the eccentric body 18 to one side in the direction of the rotation axis 40. The end of the first shaft portion 16 is located in the through hole 2f. The second shaft portion 38 extends from the eccentric body 36 to the other side in the direction of the rotation axis 40 of the crankshaft 12. The second shaft portion 38 passes through the through hole 2 g, and the end portion of the second shaft portion 38 is located outside the carrier 2.

  The first shaft portion 16 is rotatably supported by the first plate 2 a by a cylindrical roller bearing 22. The second shaft portion 38 is rotatably supported by the second plate 2c by the cylindrical roller bearing 32. The eccentric bodies 18 and 36 are disposed between the pair of cylindrical roller bearings 22 and 32. The cylindrical roller bearing 22 is an example of a first cylindrical roller bearing, and the cylindrical roller bearing 32 is an example of a second cylindrical roller bearing. The cylindrical roller bearings 22 and 32 are sometimes called needle bearings.

  The input gear 34 is fixed to the second shaft portion 38. The input gear 34 is fixed to the second shaft portion 38 outside the pair of cylindrical roller bearings 22 and 32. In other words, the input gear 34 is fixed to the second shaft portion 38 on the side opposite to the eccentric body 36 with respect to the cylindrical roller bearing 32. The input gear 34 is attached to the second shaft portion 38 outside the carrier 2 and is detachable from the second shaft portion 38. The input gear 34 meshes with an output gear 48 of a motor (not shown).

  The external gear 26 is engaged with the eccentric body 18 via the cylindrical roller bearing 24. The external gear 28 is engaged with the eccentric body 36 via the cylindrical roller bearing 30. The eccentric bodies 18 and 36 can rotate with respect to the external gears 26 and 28. As the crankshaft 12 rotates, the external gears 26 and 28 eccentrically rotate around the axis 46 while meshing with the internal gear 56. The external gear 26 and the external gear 28 are eccentrically symmetrical with respect to the axis 46.

  The first washer 6 is disposed between the cylindrical roller bearing 22 and the cylindrical roller bearing 24. A second washer 44 is disposed between the cylindrical roller bearing 32 and the cylindrical roller bearing 30. The third washer 10 is fixed to the first shaft portion 16 on the side opposite to the eccentric body 18 with respect to the cylindrical roller bearing 22. The fourth washer 42 is fixed to the second shaft portion 38 on the opposite side of the eccentric body 36 with respect to the cylindrical roller bearing 32. Washers 6, 44, 10 and 42 are arranged coaxially with the rotating shaft 40. Details of the washers 6, 44, 10 and 42 will be described later.

  When the motor torque is transmitted to the input gear 34, the crankshaft 12 rotates around the rotation shaft 40. When the crankshaft 12 rotates, the eccentric bodies 18 and 36 rotate eccentrically around the rotation shaft 40. As the eccentric bodies 18 and 36 rotate eccentrically, the external gears 26 and 28 rotate eccentrically while meshing with the internal gear 56. The external gears 26 and 28 eccentrically rotate around the axis 46 of the gear transmission 100. The external gear 26 and the external gear 28 rotate eccentrically symmetrically with respect to the axis 46. The number of teeth of the external gears 26 and 28 is different from the number of teeth of the internal gear 56 (the number of internal pins 52). Therefore, when the external gears 26 and 28 rotate eccentrically, the internal gear 56 rotates relative to the external gears 26 and 28 according to the number of teeth difference between the external gears 26 and 28 and the internal gear 56. The external gears 26 and 28 are supported by the carrier 2 via the crankshaft 12. The internal gear 56 is formed on the inner periphery of the case 54. Therefore, when the external gears 26 and 28 rotate eccentrically, the case 54 rotates with respect to the carrier 2.

  The case 54 and the carrier 2 are in a relationship of rotating relative to each other when the gear transmission 100 is driven. Therefore, if the carrier 2 is fixed to the base (not shown) and the mating member (rotated member) is fixed to the case 54, the case 54 rotates when the gear transmission 100 is driven. Further, if the case 54 is fixed to the base and the mating member is fixed to the carrier 2, the carrier 2 rotates when the gear transmission 100 is driven.

  The structure around the crankshaft 12 will be described with reference to FIG. The cylindrical roller bearing 22 includes a cage 22a and rollers (rolling elements) 22b. The cylindrical roller bearing 32 includes a cage 32a and rollers 32b. The cylindrical roller bearing 24 includes a cage 24a and rollers 24b. The cylindrical roller bearing 30 includes a cage 30a and a roller 30b. The cylindrical roller bearing 22 is disposed between the first plate 2 a and the first shaft portion 16. The cylindrical roller bearing 32 is disposed between the second plate 2 c and the second shaft portion 38. The cylindrical roller bearing 24 is disposed between the eccentric body 18 and the external gear 26. The cylindrical roller bearing 30 is disposed between the eccentric body 36 and the external gear 28.

  The first washer 6 and the third washer 10 are attached to the first shaft portion 16. The first washer 6 is in contact with the eccentric body 18. The first washer 6 is restricted from moving in the direction of the rotation shaft 40 by the cylindrical roller bearing 22 and the eccentric body 18. The first washer 6 is not in contact with the first plate 2a. A retaining ring 9 is fixed to the first shaft portion 16. The movement of the third washer 10 in the direction of the rotating shaft 40 is restricted by the cylindrical roller bearing 22 and the retaining ring 9. That is, the first washer 6, the cylindrical roller bearing 22 and the third washer 10 are restricted from moving in the direction of the rotation shaft 40 by the eccentric body 18 and the retaining ring 9.

  The outer diameter L6 of the first washer 6 is larger than the outer diameter L22 of the cylindrical roller bearing 22. Therefore, the cage 22 a of the cylindrical roller bearing 22 can contact the surface of the first washer 6. Further, when the first washer 6 is viewed in plan (observed from the direction of the rotation axis 40), the outer edge of the first washer 6 is located outside the outer edge of the eccentric body 18. Therefore, the cage 24a of the cylindrical roller bearing 24 can contact the first washer 6 on the surface opposite to the surface with which the cage 22a contacts. In other words, the first washer 6 prevents the cylindrical roller bearing 22 and the cylindrical roller bearing 24 from contacting each other. More specifically, the end portion of the cage 22a in the bearing center axis direction and the end portion of the cage 24a in the bearing center axis direction are prevented from contacting by the first washer 6.

  The outer diameter L10 of the third washer 10 is smaller than the outer diameter L22 of the cylindrical roller bearing 22. Therefore, the 3rd washer 10 does not contact the 1st plate 2a. The retainer 22 a of the cylindrical roller bearing 22 can come into contact with the third washer 10. As described above, the first washer 6 and the third washer 10 are positioned with respect to the first shaft portion 16 by the eccentric body 18 and the retaining ring 9. Even if a force that moves the cylindrical roller bearing 22 in the direction of the center axis of the bearing acts on the cylindrical roller bearing 22, it is possible to prevent the force from being applied to the cylindrical roller bearing 24. More specifically, by preventing the retainer 22a and the retainer 24a from contacting each other, it is possible to prevent force from being concentrated on the end of the retainer 22a and / or the end of the retainer 24a. Can do. For example, when the cage 22a and the cage 24a come into contact, the force that moves the cylindrical roller bearings 22 and 24 may concentrate on the cages 22a and 24a. As a result, the cages 22a and 24a may be deformed, and the rotation axes of the rollers 22b and 24b may be displaced with the deformation of the cages 22a and 24a. By preventing the cage 22a and the cage 24a from coming into contact with each other, it is possible to prevent the cages 22a and 24a from being deformed and to prevent the rotational axes of the rollers 22b and 24b from being displaced.

  A second washer 44 and a fourth washer 42 are attached to the second shaft portion 38. The second washer 44 is in contact with the eccentric body 36. The movement of the second washer 44 in the direction of the rotating shaft 40 is restricted by the cylindrical roller bearing 32 and the eccentric body 36. The second washer 44 and the fourth washer 42 are in contact with the second plate 2c. More specifically, the second washer 44 is in contact with the surface of the second plate 2c on the first plate 2a side, and the fourth washer 42 is the surface of the second plate 2c opposite to the first plate 2a side. Touching. The second washer 44 and the fourth washer 42 are an example of a pair of regulating members.

  The input gear 34 is in contact with the surface of the fourth washer 42 on the opposite side of the second plate 2c from the first plate 2a. In other words, the fourth washer 42 is sandwiched between the second plate 2 c and the input gear 34. The input gear 34 is splined to a groove 62 provided in the second shaft portion 38. A retaining ring 64 is fixed to the second shaft portion 38 on the side opposite to the fourth washer 42 with respect to the input gear 34. The fourth washer 42 and the input gear 34 are sandwiched between the retaining ring 64 and the second plate 2c, and are restricted from moving in the direction of the rotation shaft 40. The movement of the second washer 44, the cylindrical roller bearing 32, the fourth washer 42, and the input gear 34 in the direction of the rotating shaft 40 is restricted by the eccentric body 36 and the retaining ring 64. The outer diameter L44 of the second washer 44 and the outer diameter L42 of the fourth washer 42 are equal. The outer diameter L44 and the outer diameter L42 are larger than the outer diameter L32 of the second cylindrical roller bearing 32.

  As described above, the second washer 44 and the fourth washer 42 are positioned with respect to the second shaft portion 38 by the eccentric body 36 and the retaining ring 64. Therefore, even if a force that moves the cylindrical roller bearing 32 in the direction of the bearing center axis acts on the cylindrical roller bearing 32, it is possible to prevent the force from being applied to the cylindrical roller bearing 30. More specifically, by preventing the cage 32a and the cage 30a from contacting each other, it is possible to prevent the force from concentrating on the end of the cage 32a and / or the end of the cage 30a. Can do. By preventing the cage 32a and the cage 30a from coming into contact with each other, it is possible to prevent the cages 32a and 30a from being deformed and to prevent the rotational axes of the rollers 32b and 30b from being displaced.

  A flange 60 is provided at the center of the crankshaft 12 (between the eccentric body 18 and the eccentric body 36). The flange 60 has a circular shape coaxial with the rotation shaft 40. The flange 60 is integral with the crankshaft 12. When the flange 60 is viewed in plan, the outer edge of the flange 60 is positioned outside both the outer edge of the eccentric body 18 and the outer edge of the eccentric body 36. The cage 60 a of the cylindrical roller bearing 24 and the cage 30 a of the cylindrical roller bearing 30 can contact the surface of the flange 60.

  A structure around the second shaft portion 38 will be described with reference to FIGS. FIG. 5 is a view of the second plate 2c as viewed in the direction of the arrow A1 in FIG. FIG. 6 is a view of the second plate 2c as viewed in the direction of arrow A2 in FIG. FIG. 8 is a view of the input gear 34 as viewed in the direction of the arrow A1.

  As shown in FIGS. 4 and 5, a plurality of grooves 70 (70a, 70b, 70c and 70d) are provided on the surface of the second plate 2c on the second washer 44 side. The groove 70a extends from the through hole 2g toward the center of the second plate 2c, and connects the through hole 2g and the through hole 2e. The groove 70b extends from the through hole 2g toward the radial end of the second plate 2c, and connects the through hole 2g and the outside of the second plate 2c. The grooves 70c and 70d extend from the through hole 2g in a direction perpendicular to a straight line connecting the center of the through hole 2g and the center of the through hole 2e. The groove 70c and the groove 70d extend in opposite directions. Two grooves 70a to 70d are provided on the surface of the second plate 2c. Each of the two grooves 70a is inclined symmetrically with respect to a line connecting the through hole 2g and the through hole 2e with the shortest distance. The two grooves 70b are inclined symmetrically with respect to a line connecting the through hole 2g and the radial end of the second plate 2c with the shortest distance. The two grooves 70c are inclined symmetrically with respect to a line orthogonal to a straight line connecting the center of the through hole 2g and the center of the through hole 2e. Similarly, the two grooves 70d are inclined symmetrically with respect to a line orthogonal to a straight line connecting the center of the through hole 2g and the center of the through hole 2e.

  The second washer 44 is in contact with the second plate 2c at a portion where the groove 70 is not provided, and is not in contact with the second plate 2c at a portion where the groove 70 is provided. In other words, a gap is provided between the second washer 44 and the second plate 2c in the portion where the groove 70 is provided. Further, as shown in FIG. 5, the groove 70 extends beyond the outer edge of the second washer 44 from the through hole 2 g. Therefore, the inside of the through hole 2g is not sealed by the second washer 44, but supports the outside of the through hole 2g (the inside of the through hole 2e, the gap between the second plate 2c and the external gear 28, and the second plate 2c. The space around the bearing 50 is in communication. The lubricant can move outside the through hole 2g and inside the through hole 2g (the space in which the cylindrical roller bearing 32 is disposed). It is possible to suppress the occurrence of oil film breakage in the cylindrical roller bearing 32.

  The groove 72 will be described with reference to FIG. The shape of the groove 72 is substantially equal to the groove 70. Therefore, the description overlapping with the groove 70 may be omitted with respect to the characteristics of the groove 72. A plurality of grooves 72 (72a, 72b, 72c and 72d) are provided on the surface on the fourth washer 42 side of the second plate 2c. The groove 72a connects the through hole 2g and the through hole 2e, and the groove 72b connects the through hole 2g and the end of the second plate 2c. Two grooves 72a to 72d are provided on the surface of the second plate 2c. The fourth washer 42 is in contact with the second plate 2c at a portion where the groove 72 is not provided, and is not in contact with the second plate 2c at a portion where the groove 72 is provided. In the portion where the groove 72 is provided, a gap is provided between the fourth washer 42 and the second plate 2c. The inside of the through hole 2g is not sealed by the fourth washer 42, but supports the outside of the through hole 2g (the inside of the through hole 2e, the gap between the second plate 2c and the input gear 34, and the second plate 2c. It is possible to communicate with a space around the bearing 50.

  As shown in FIGS. 4 and 7, the fourth washer 42 is provided with three through holes 42 a. The three through holes 42 a are arranged at equal intervals in the circumferential direction of the fourth washer 42. As shown in FIGS. 4 and 8, the input gear 34 is provided with a groove 74. The groove 74 makes a round in the circumferential direction of the input gear 34. The through hole 42 a communicates with the through hole 2 g and the groove 74. Three through holes 34 a are provided in the groove 74. The three through holes 34 a are arranged at equal intervals in the circumferential direction of the input gear 34. A tooth portion 34 b that meshes with the spline groove 62 is provided at the center of the input gear 34. The through holes 42 a and 34 a communicate with each other through a groove 74. Therefore, the lubricant can move inside and outside the through hole 2g.

  The advantages of the gear transmission 100 will be described. In the gear transmission 100, when the 2nd washer 44 and the 4th washer 42 contact the 2nd plate 2c, it controls that the crankshaft 12 moves to an axial direction. The restriction of the crankshaft 12 in the axial direction does not depend on the processing / assembly state of the first plate 2a and the second plate 2c. That is, if the front surface and the back surface of the second plate 2c are parallel (the surface on which the second washer 44 is provided and the surface on which the second washer 42 is provided), the movement of the crankshaft 12 in the axial direction is restricted. can do. As described above, the second plate 2c is a flat plate. Processing the front and back surfaces of the flat plate in parallel is much easier than processing and assembling so that the opposing surfaces of the two parts (first plate 2a and second plate 2c) are parallel. Gear transmission Compared with a conventional gear transmission, the crankshaft 12 can be regulated in the axial direction by simple machining.

  Another advantage of the gear transmission 100 will be described. The cylindrical roller bearings 22, 24, 30 and 32 do not apply force to the other cylindrical roller bearings. Therefore, it is possible to prevent the cylindrical roller bearings 22, 24, 30 and 32 from being prevented from rotating by other cylindrical roller bearings. More specifically, the gear transmission 100 can prevent force from concentrating on the cages 22a, 24a, 30a and 32a of the cylindrical roller bearings 22, 24, 30 and 32, respectively.

  The first washer 6 is positioned with respect to the first shaft portion 16. Therefore, even if a force that moves the cylindrical roller bearing 24 in the direction of the center axis of the bearing acts on the cylindrical roller bearing 24, the force can be prevented from being applied to the cylindrical roller bearing 22. Similarly, the second washer 44 is positioned with respect to the second shaft portion 38. Therefore, even if a force that moves the cylindrical roller bearing 30 in the direction of the bearing center axis acts on the cylindrical roller bearing 30, it is possible to prevent the force from being applied to the cylindrical roller bearing 32. Further, since the flange 60 is integral with the crankshaft 12, it is possible to prevent the force that the cylindrical roller bearing 24 moves in the bearing central axis direction from being applied to the cylindrical roller bearing 30. It is possible to prevent the force that moves in the direction from being applied to the cylindrical roller bearing 24.

  An input gear 34 is attached to the crankshaft 12 (second shaft portion 38) outside the pair of cylindrical roller bearings 22 and 32. Therefore, the input gear 34 can be removed from the crankshaft 12 without separating the carrier 2 (the first plate 2a and the second plate 2c). For example, when an input gear having a diameter larger than that of the input gear 34 is attached instead of the input gear 34, the main structure of the gear transmission (the internal gear 56, the external gears 26 and 28, the crankshaft 12, etc.) There is no need to change.

(Second embodiment)
The gear transmission 200 will be described with reference to FIG. The gear transmission 200 is a modification of the gear transmission 100. Description of the gear transmission 200 may be omitted by giving the same reference numerals to the same parts as the gear transmission 100 or the same reference numerals in the last two digits. The gear transmission 200 does not include the fourth restriction member 42 (see FIG. 1). In the gear transmission 200, the second plate 2 c is disposed between the second washer 44 and the input gear 234. The second washer 44 and the input gear 234 are an example of a pair of regulating members.

  In the case of the gear transmission 200, the second washer 44 and the input gear 234 can restrict the cylindrical roller bearing 32 from moving in the axial direction and can restrict the crankshaft 212 from moving in the direction of the rotating shaft 40. it can. Compared with the gear transmission 100, the gear transmission 200 can reduce the number of parts by the amount not using the second washer 44.

  The technology disclosed in this specification is a gear transmission in which a crankshaft is rotatably supported by a support member having a pair of support portions (first support portion, second support portion). Can be applied to various gear transmissions in which one of the support portions is disposed between a pair of restricting members, and is not limited to the embodiment described above.

  For example, in the gear transmission 100, a second retaining ring other than the retaining ring 64 may be attached between the fourth washer 42 and the input gear 34. Thereby, even if the input gear 34 is removed from the crankshaft 12, the position of the crankshaft 12 in the direction of the rotation axis 40 can be prevented from shifting.

  In the above embodiment, the gear transmission provided with two eccentric bodies has been described. However, the number of eccentric bodies may be one, or three or more. Moreover, although the said Example is a gear transmission in which an external gear rotates eccentrically, the technique disclosed by this specification can also be applied to the gear transmission in which an internal gear rotates eccentrically.

  In the above embodiment, the gear transmission in which the fourth washer and the input gear are provided with through holes has been described. The number of through holes provided in the fourth washer is not limited to three. It is sufficient that at least one through hole is provided at a position corresponding to the groove of the input gear. It is sufficient that at least one through hole provided in the input gear is provided at a position communicating with the groove. Note that the fourth washer and / or the through hole of the input gear may be omitted. A gap is provided between the second plate and the fourth washer by a groove formed in the second plate. Therefore, even if the through hole of the fourth washer and / or the input gear is omitted, the lubricant can be supplied to the second cylindrical roller bearing through the groove.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

2: support member 12: crankshaft 16: first shaft portion 18: eccentric body 22: first cylindrical roller bearing 26: eccentric rotation gear 28: eccentric rotation gear 32: second cylindrical roller bearing 36: eccentric body 38: second Shaft portion 42: restriction member 44: restriction member 56: rotation gear 100: gear transmission

Claims (5)

A crankshaft having an eccentric body;
An eccentric rotating gear engaged with the eccentric body and rotating eccentrically with rotation of the crankshaft;
A rotating gear meshing with an eccentric rotating gear and having a number of teeth different from the number of teeth of the eccentric rotating gear;
A first support portion that supports the crankshaft and is disposed to face the crankshaft, and a support member in which the second support portion is fixed via a columnar portion;
The crankshaft has a first shaft portion extending from the eccentric body to one side in the rotation axis direction, and a second shaft portion extending from the eccentric body to the other side in the rotation axis direction,
The first shaft portion is supported by the first support portion via the first cylindrical roller bearing,
The second shaft portion passes through the second support portion and is supported by the second support portion via the second cylindrical roller bearing,
A pair of regulating members that regulate movement of the crankshaft in the direction of the rotation axis are fixed to the second shaft portion,
A gear transmission in which the second support portion is disposed between the pair of regulating members. The first support part is integral with the columnar part,
The gear transmission according to claim 1, wherein the second columnar part is a flat plate.   The gear transmission according to claim 1 or 2, wherein both of the pair of regulating members are washers.   Of the pair of regulating members, the regulating member positioned on the eccentric body side from the second support portion is a washer, and the regulating member located on the side opposite to the eccentric body with respect to the second support portion rotates the crankshaft. The gear transmission according to claim 1 or 2, wherein the gear transmission is an input gear. The gear transmission according to any one of claims 1 to 4, wherein the second cylindrical roller bearing is restricted from moving in the axial direction by a pair of restriction members.

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