JP2013221545A - Cage for cylindrical roller bearing, and gear transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cage excelling in performance in introducing a lubricant into a cylindrical roller bearing.SOLUTION: A cage 50 is used in a cylindrical roller bearing. The cylindrical roller bearing is used in a gear transmission. In the cage 50, a plurality of protrusions 50d are provided at each of both end faces 50b in a bearing center axis direction. When a regulating member for regulating the axial movement of the cylindrical roller bearing contacts the cage 50, the protrusions 50d contact the regulating member. A clearance is therefore secured between the end face 50b of the cage 50 and the regulating member. A lubricant is introduced into the cylindrical roller bearing from the clearance.

Description

  This specification discloses the technique regarding the holder of a cylindrical roller bearing, and the technique regarding the gear transmission provided with the cylindrical roller bearing.

  The gear transmission includes a plurality of components that rotate relative to each other. Cylindrical roller bearings may be used between two parts that rotate relative to each other. Patent Document 1 discloses a gear transmission in which an external gear rotates eccentrically while meshing with an internal gear. In the gear transmission of patent document 1, an external gear is eccentrically rotated using the crankshaft which has an eccentric body. A cylindrical roller bearing is interposed between the eccentric body and the external gear. In patent document 1, in order to introduce | transduce a lubrication agent into the inside of a cylindrical roller bearing, the through-hole is formed in the edge part of the bearing center axis direction of a holder | retainer.

JP 2010-230171 A

  In the case of a cylindrical roller bearing, it is necessary to restrict the rolling element (cylindrical roller) from moving in the bearing central axis direction (rotational axis direction of the cylindrical roller). In the case of the gear transmission of Patent Document 1, in order to restrict the movement of the rolling elements in the bearing central axis direction, a washer is fixed to the crankshaft, and a retainer of a cylindrical roller bearing is brought into contact with the washer. Therefore, it may happen that the washer closes the through hole formed in the cage and the lubricant is not sufficiently introduced into the cylindrical roller bearing. The present specification provides a cage excellent in performance of introducing a lubricant into a cylindrical roller bearing, and a gear transmission including a cylindrical roller bearing including the cage.

  The cage disclosed in this specification is preferably used in a cylindrical roller bearing included in a gear transmission. The cage is ring-shaped. The cage is provided with a plurality of protrusions on the surfaces of both end portions in the bearing central axis direction. In the case of the above cage, the protrusion comes into contact with a regulating member (for example, a washer) that regulates the movement of the cylindrical roller bearing. A gap can be secured between the surface of the end portion of the cage in the bearing central axis direction and the regulating member. The lubricant can move through the gap into the cylindrical roller bearing. As a result, deterioration of the cylindrical roller bearing can be suppressed. In the following description, the “surface of the end portion of the cage in the bearing central axis direction” may be simply referred to as “cage end surface”. Further, the “cylindrical roller bearing” in the present specification is not limited to the “cylindrical roller bearing” in a narrow sense. That is, it should be noted that the “cylindrical roller bearing” in the present specification means a bearing using a cylindrical “roller” and includes a “needle roller bearing”.

  The present specification further provides a gear transmission including a cylindrical roller bearing including the above-described cage. The gear transmission includes an internal gear, an external gear, a crankshaft, a cylindrical roller bearing including the above-described cage, and a regulating member. The external gear rotates relatively eccentrically while meshing with the internal gear. The crankshaft has an eccentric body. The eccentric body engages with a through hole formed in one of the internal gear and the external gear, and rotates the engaged gear eccentrically. The cylindrical roller bearing is interposed between the inner peripheral surface of the through hole and the outer peripheral surface of the eccentric body. The restricting member restricts the movement of the cylindrical roller bearing in the bearing central axis direction. “The external gear rotates relatively eccentrically while meshing with the internal gear” means that both the case where the external gear rotates eccentrically and the case where the internal gear rotates eccentrically are included. To do. That is, when the eccentric body is engaged with the through hole of the internal gear, the internal gear rotates eccentrically, and when the eccentric body is engaged with the through hole of the external gear, the external gear rotates eccentrically. To do.

Sectional drawing of the gear transmission of 1st Example is shown. The expanded sectional view of the part enclosed with the broken line II of FIG. 1 is shown. The perspective view of the holder | retainer used with the gear transmission of 1st Example is shown. The figure (side view) which looked at the cage | basket shown in FIG. 3 from the direction orthogonal to a bearing central axis is shown. The partial expanded sectional view when the 3rd bearing used with the gear transmission of 1st Example is attached to a crankshaft is shown. The partial expanded sectional view when the 3rd bearing used with the gear transmission of 2nd Example is attached to a crankshaft is shown. The perspective view of the holder | retainer used with the gear transmission of 3rd Example is shown. The side view of the holder | retainer used with the gear transmission of 3rd Example is shown. The figure (plan view) which looked at the cage | basket shown in FIG. The partial expanded sectional view when the 3rd bearing used with the gear transmission of 3rd Example is attached to a crankshaft is shown. The side view of the holder | retainer used with the gear transmission of 4th Example is shown. The top view of the holder | retainer shown in FIG. 11 is shown. Sectional drawing of the gear transmission of 5th Example is shown. Sectional drawing of the gear transmission of 6th Example is shown. Sectional drawing of the gear transmission of 7th Example is shown.

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

  (Feature 1) When the cylindrical roller bearing is attached to the shaft, a gap may be provided between the inner peripheral edge of the end of the cage and the shaft. The lubricant easily moves from the gap between the cage and the shaft to the inside of the cylindrical roller bearing. The “shaft” means a part that is circular and has a cylindrical roller bearing attached to the outer periphery. In other words, the “shaft” means a component that is disposed on the inner peripheral side of the cylindrical roller bearing and is coaxial with the bearing central axis of the cylindrical roller bearing.

  (Feature 2) The length of the protrusion in the circumferential direction of the cage may be shorter than the diameter of the cylindrical roller. Thereby, even if the regulating member that regulates the movement of the cage and the cylindrical roller bearing comes into contact, the lubricant is supplied to all the rolling elements (cylindrical rollers).

  (Characteristic 3) The protrusion may be provided at a position away from both the inner peripheral edge and the outer peripheral edge of the cage. Lubricant outside the cylindrical roller bearing can move from the entire circumference of the outer peripheral edge of the cage to the gap between the cage end surface and the regulating member. Similarly, the lubricant present in the gap between the cage end face and the regulating member can move from the entire circumference of the inner circumferential edge of the cage into the cylindrical roller bearing. Lubricant easily spreads over the entire rolling element.

  (Feature 4) When the cage is viewed in plan, the length of the protrusion in the radial direction of the cage may be longer than the length in the circumferential direction of the cage. Between adjacent projections becomes a passage for the lubricant, and the lubricant easily moves in and out of the cylindrical roller bearing. The “plan view” means that the cage is viewed from the bearing central axis direction.

  (Feature 5) The protrusion may constitute an impeller. When the cage rotates, the lubricant moves in and out of the cylindrical roller bearing while swirling. The lubricant is more likely to move in and out of the cylindrical roller bearing.

  (Characteristic 6) When the protrusion constitutes an impeller, the direction of the impeller at one end of the cage and the direction of the impeller at the other end may be opposite to each other. When the cage rotates, a force for introducing the lubricant into the cylindrical roller bearing acts on one end of the cage, and a force for discharging the lubricant to the outside of the cylindrical roller bearing acts on the other end of the cage. . The lubricant easily circulates inside the cylindrical roller bearing. The direction of the impeller at one end of the cage and the direction of the impeller at the other end may be the same. When the cage rotates, a force for introducing the lubricant into the cylindrical roller bearing from both ends of the cage acts. More lubricant can be introduced into the cylindrical roller bearing.

  (Feature 7) The gear transmission is engaged with a case in which an internal gear is formed on the inner periphery, an external gear that rotates eccentrically while meshing with the internal gear, and a through-hole formed in the external gear. A crankshaft that eccentrically rotates the external gear and a carrier that is supported by the case coaxially with the internal gear, and that supports the crankshaft, and an inner peripheral surface of the through hole And a cylindrical roller bearing interposed between the outer peripheral surface of the eccentric body and a regulating member for regulating movement of the cylindrical roller bearing in the bearing central axis direction. The cylindrical roller bearing may include the above-described cage. In the case of this embodiment, the eccentric body corresponds to the above-described shaft.

  (Feature 8) The clan shaft may be supported by the carrier via the second cylindrical roller bearing, and the second cylindrical roller bearing may include the cage described above.

(First embodiment)
FIG. 1 shows a cross-sectional view of the gear transmission 100. The gear transmission 100 is a type of reduction device that rotates eccentrically while the external gear 22 meshes with the internal gear 30. The gear transmission 100 uses the difference in the number of teeth between the external gear 22 and the internal gear 30 to increase the torque transmitted to the crankshaft 14 (decelerate the rotation) and output it from the carrier 2. In other words, the carrier 2 is rotated with respect to the case 38 using the difference in the number of teeth between the external gear 22 and the internal gear 30.

  The gear transmission 100 includes three types of bearings. The first bearing 20 is interposed between the carrier 2 and the case 38. A second bearing 8 is interposed between the carrier 2 and the crankshaft 14. The third bearing 6 is interposed between the external gear 22 and the eccentric body 16 of the crankshaft 14. Details of the bearings 20, 8, and 6 will be described later. Hereinafter, the basic structure of the gear transmission 100 will be briefly described.

  The gear transmission 100 includes a case 38, a carrier 2, a crankshaft 14, and two external gears 22X and 22Y. The internal gear 30 includes a case 38 and a plurality of internal teeth pins 24 arranged on the inner periphery of the case 38. The carrier 2 is supported by the case 38 coaxially with the internal gear 30 by a pair of first bearings 20. The carrier 2 includes a first plate 2a and a second plate 2c. A columnar portion 2b extends from the first plate 2a toward the second plate 2c, and the columnar portion 2b and the second plate 2c are fixed. The columnar portion 2 b of the carrier 2 passes through the through holes 4 X and 4 Y of the external gear 22. A gap is secured between the inner walls of the through holes 4X and 4Y and the columnar part 2b. Note that the axis 36 is the axis of the carrier 2 and the internal gear 30. In the following description, when there are a plurality of parts of the same type and the features common to those parts are described, the alphabet of reference numerals may be omitted.

  An oil seal 40 is disposed between the first plate 2 a and the case 38. The oil seal 40 prevents the lubricant or the like injected into the gear transmission 100 from leaking outside the gear transmission 100.

  The carrier 2 supports the crankshaft 14 and the external gear 22. The crankshaft 14 is supported by the carrier 2 via the second bearings 8X and 8Y. The axis 32 of the crankshaft 14 is parallel to the axis 36. That is, the crankshaft 14 extends parallel to the axis 36 at a position offset from the axis 36. The axis 32 is coaxial with the bearing central axis of the second bearing 8. The crankshaft 14 includes an input gear 34 and two eccentric bodies 16X and 16Y. Each of the eccentric bodies 16X and 16Y is located in the through hole of the external gears 22X and 22Y. The outer shape of the eccentric body 16 (the shape in the direction orthogonal to the axis 36) is a circle.

  The third bearing 6 is interposed between the inner peripheral surface of the through hole of the external gear 22 and the outer peripheral surface of the eccentric body 16. The eccentric body 16 is engaged with the external gear 22 via the third bearing 6. The rotating shaft of the eccentric body 16 is coaxial with the bearing central axis of the third bearing 6. The external gear 22 is supported by the carrier 2 via the crankshaft 14. The gear transmission 100 includes a plurality of crankshafts 14. In FIG. 1, one of the plurality of crankshafts 14 appears. The respective crankshafts 14 are arranged at equal intervals around the axis 36. Further, the input gear 34 may or may not be fixed to the other crankshaft 14 (a crankshaft not shown in FIG. 1).

  The first restricting members 18X and 18Y and the second restricting members 10X and 10Y are attached to the crankshaft 14. The first restricting member 18X is disposed between the first plate 2a and the eccentric body 16X, and the first restricting member 18Y is disposed between the second plate 2c and the eccentric body 16Y. The first restricting member 18X is in contact with the first plate 2a, and the first restricting member 18Y is in contact with the second plate 2c. For this reason, the first restricting member 18 restricts the crankshaft 14 from moving in the direction of the axis 32 with respect to the carrier 2. In other words, the carrier 2 (the first plate 2 a and the second plate 2 c) is in contact with the first restricting member 18, so that the crankshaft 14 is restricted from moving in the direction of the axis 32 with respect to the carrier 2. An example of the first regulating member 18 is a washer.

  The second restricting member 10 is attached to the crankshaft 14 outside the first restricting member 18 in the direction of the axis 32. That is, the first regulating member 18 is disposed between the second regulating members 10X and 10Y. In the direction of the axis 32, the retaining ring 12 is fitted into the crankshaft 14 outside the second restriction member 10. The second restricting member 10 is fixed to the crankshaft 14 by a retaining ring 12. An example of the second regulating member 10 is a washer.

  When torque of a motor (not shown) is transmitted to the input gear 34, the crankshaft 14 rotates. The eccentric body 16 rotates eccentrically with respect to the axis 32 as the crankshaft 14 rotates. As the eccentric body 16 rotates eccentrically, the external gear 22 rotates eccentrically while meshing with the internal gear 30. The number of teeth of the external gear 22 and the number of teeth of the internal gear 30 (the number of internal pins 24) are different. As described above, the external gear 22 is supported by the carrier 2, and the internal gear 30 is formed on the inner peripheral surface of the case 38. Therefore, when the external gear 22 rotates eccentrically, the carrier 2 rotates relative to the case 38 in accordance with the difference in the number of teeth between the external gear 22 and the internal gear 30. In the gear transmission 100, the crankshaft 14 may rotate (forward rotation) in the 14F direction or may rotate (reverse rotation) in the 14R direction.

  The first bearing 20 will be described. The pair of first bearings 20 </ b> X and 20 </ b> Y is interposed between the case 38 and the carrier 2. The first bearing 20 is an angular ball bearing and may be called a main bearing of the gear transmission 100. The first bearing 20X includes an inner race 20Xa, a rolling element (ball) 20Xb, and an outer race 20Xc. The first bearing 20X is interposed between the case 38 and the first plate 2a. The outer peripheral surface of the first plate 2a also serves as the inner race 20Xa of the first bearing 20X. The first bearing 20Y includes an inner race 20Ya, a rolling element 20Yb, and an outer race 20Yc. The first bearing 20Y is interposed between the case 38 and the second plate 2c. The outer peripheral surface of the second plate 2c also serves as the inner race 20Ya of the first bearing 20Y. That is, the carrier 2 also serves as the inner race 20 a of the first bearing 20. The pair of first bearings 20 restricts the carrier 2 from moving in the axial direction and the radial direction.

  The outer races 20Xc and 20Yc are located at both ends of the internal tooth pin 24 in the rotation axis direction. That is, the internal tooth pin 24 is disposed between the outer races 20Xc and 20Yc. The outer race 20c restricts the inner tooth pin 24 from moving in the axial direction (in the direction of the axis 36). The outer race 20c also restricts the external gear 22 from moving in the axial direction.

  The second bearing 8 will be described. The second bearings 8X and 8Y are cylindrical roller bearings and are interposed between the carrier 2 and the crankshaft 14. The crankshaft 14 is supported by the second bearing 8 so as to be rotatable with respect to the carrier 2. The second bearing 8X is interposed between the first plate 2a and the crankshaft 14. The second bearing 8Y is interposed between the second plate 2c and the crankshaft 14. Further, the second bearing 8 is disposed between the first restriction member 18 and the second restriction member 10 in the direction of the axis 32. As described above, the first restriction member 18 and the second restriction member 10 are attached to the crankshaft 14. Therefore, when the second bearing 8 attempts to move in the axial direction, the axial end portion of the second bearing 8 contacts the first restriction member 18 or the second restriction member 10. As a result, the second bearing 8 is restricted from moving in the axial direction with respect to the crankshaft 14.

  The third bearing 6 will be described. The third bearing 6 is a cylindrical roller bearing and is interposed between the eccentric body 16 and the external gear 22. In the direction of the axis 32, the third bearings 6X and 6Y are disposed between the first restricting members 18X and 18Y. A spacer plate 26 is interposed between the third bearings 6X and 6Y. The spacer plate 26 prevents the third bearing 6X and the third bearing 6Y from contacting each other. When the third bearing 6 tries to move in the axial direction, the axial end portion of the third bearing 6 contacts the first regulating member 18. As a result, the movement of the third bearing 6 in the axial direction is restricted with respect to the crankshaft 14 (the eccentric body 16). Focusing only on the third bearing 6X (or the third bearing 6Y), the spacer plate 26 corresponds to a regulating member that regulates the movement of the third bearing 6X (the third bearing 6Y) in the axial direction.

  The features of the second bearing 8 and the third bearing 6 will be described in detail with reference to FIGS. The second bearings 8X and 8Y have substantially the same structure. The third bearings 6X and 6Y have substantially the same structure. Therefore, in the following description, characteristics of the second bearing 8X and the third bearing 6X will be described. As described above, the second bearing 8 and the third bearing 6 are cylindrical roller bearings, and the basic structure is the same. Therefore, in the following description, the features common to the second bearing 8X and the third bearing 6X will be described in detail for the third bearing 6X, and description of the second bearing 8X may be omitted.

  As shown in FIG. 2, the third bearing 6 </ b> X includes a cage 50 and a plurality of cylindrical rollers 52. In FIG. 2, one of the plurality of cylindrical rollers 52 appears. When the third bearing 6X moves in the axial direction, the cage 50 comes into contact with the first regulating member 18 or the spacer plate 26. FIG. 2 shows a state where the cage 50 is in contact with the spacer plate 26. The second bearing 8 </ b> X includes a cage 60 and a plurality of cylindrical rollers 62. FIG. 2 shows a state where the cage 60 is in contact with the first restricting member 18.

  As shown in FIGS. 3 and 4, a plurality of protrusions 50d are provided on the surfaces 50b (hereinafter referred to as cage end surfaces 50b) at both ends of the cage 50 in the bearing central axis direction. Each protrusion 50d is hemispherical. As shown in FIG. 2, the protrusion 50 d is in contact with the spacer plate 26. Therefore, a gap 56 is secured between the spacer plate 26 and the cage end surface 50b. Even when the cage 50 contacts the first regulating member 18, a gap 54 is secured between the first regulating member 18 and the cage end surface 50b. Similarly, even if the second bearing 8 contacts the first restriction member 18 or the second restriction member 10, the gap 66 between the cage 60 and the first restriction member 18 and the gap between the cage 60 and the second restriction member 10. 64 is secured.

  Here, the shape of the cage 50 will be described in detail. As shown in FIGS. 3 and 4, the cage 50 has a ring shape and includes a plurality of protrusions 50 d on the cage end surface 50 b. A plurality of pockets 50a are formed in the radial direction of the cage 50 (direction perpendicular to the bearing central axis). In other words, the plurality of pillars 50c are connected between the two ring-shaped plates having the plurality of protrusions 50d. The pillars 50c are arranged at equal intervals in the circumferential direction of the ring-shaped plate. In addition, both ends of the cage 50 in the bearing central axis direction protrude inward, and a plurality of pockets 50a are formed in the middle portion of the cage 50 in the bearing central axis direction. It can also be expressed that a plurality of protrusions 50d are provided. A cylindrical roller 52 is disposed in each of the plurality of pockets 50a (see also FIG. 2). The shape of the cage 60 is substantially equal to the shape of the cage 50. Therefore, description of the shape of the cage 60 is omitted.

  The advantages of the third bearing 6 will be described. As shown in FIG. 5, the protrusion 50d is provided at a position away from both the edge 50e (hereinafter referred to as the outer edge 50e) of the outer peripheral surface of the cage 50 and the edge 50f (hereinafter referred to as the inner edge 50f) of the inner peripheral surface. ing. In other words, the protrusion 50d is provided in the radial direction middle of the cage 50 on the cage end surface 50b. As described above, in the third bearing 6, since the protrusion 50d contacts the spacer plate 26 (or the first regulating member 18), a gap 56 is formed between the cage end surface 50b and the spacer plate 26 (see FIG. 2). reference). Therefore, an outer space 50g in which the lubricant can move is formed on the entire circumference on the outer edge 50e side of the cage end surface 50b. Similarly, an inner space 50h in which the lubricant can move is formed on the entire circumference on the inner edge 50f side of the cage end surface 50b. For example, when the lubricant moves from the outside of the third bearing 6 to the inside (region where the cylindrical rollers are disposed) through the gap 56, the lubricant is retained from the entire circumference on the outer edge 50e side of the cage 50. It can move to the end face 50b. Further, when the lubricant moves from the cage end surface 50 b to the inside of the third bearing 6 (inside the cage 50), the lubricant enters the inside of the third bearing 6 from the entire circumference of the inner edge 50 f of the cage 50. Can move. The lubricant can be easily supplied into the third bearing 6, and the oil film breakage of the cylindrical roller 52 can be suppressed. As a result, wear of the third bearing 6 is suppressed.

  The inner edge 50f at the end of the cage 50 does not contact the eccentric body 16 (see also FIG. 2). That is, a gap is secured between the inner edge 50 f of the cage 50 and the outer peripheral surface of the eccentric body 16. Therefore, the lubricant on the cage end surface 50 b easily moves into the third bearing 6. Similarly, the edge of the inner peripheral surface of the end portion of the cage 60 does not contact the crankshaft 14 (see FIG. 2). That is, a gap is secured between the edge of the inner peripheral surface of the cage 60 and the outer peripheral surface of the crankshaft 14. As described above, the rotation axis of the eccentric body 16 is coaxial with the bearing center axis of the third bearing 6, and the rotation axis (axis line 32) of the crankshaft 14 is coaxial with the bearing center axis of the second bearing 8. Therefore, the cages 50 and 60 are arranged on the inner peripheral side of the cage end when they are attached to the shaft (which is disposed on the inner peripheral side of the cylindrical roller bearing and is coaxial with the bearing central axis of the cylindrical roller bearing). It can be said that a gap is provided between the edge of the shaft and the shaft.

  The size of the protrusion 50 d is smaller than the size of the cylindrical roller 52. More specifically, the length of the protrusion 50 d in the circumferential direction of the cage 50 is shorter than the diameter of the cylindrical roller 52. As described above, the protrusion 50d contacts the restricting member (the first restricting member 18 or the spacer plate 26). If the length of the protrusion 50 d in the circumferential direction is longer than the diameter of the cylindrical roller 52, the lubricant is hardly supplied to some of the plurality of cylindrical rollers 52. By making the length of the protrusion 50 d in the circumferential direction shorter than the diameter of the cylindrical roller 52, the lubricant is easily supplied to all the cylindrical rollers 52.

(Second embodiment)
With reference to FIG. 6, the gear transmission of 2nd Example is demonstrated. The gear transmission of this embodiment is different from the gear transmission 100 of the first embodiment only in the shape of the third bearing. Specifically, the shape of the cage of the third bearing is different. FIG. 6 shows a range corresponding to the range shown in FIG. 5 of the gear transmission 100 for the gear transmission of this embodiment. In the gear transmission of this embodiment, a third bearing 106 is interposed between the eccentric body 16 and the external gear 22. The third bearing 106 is different from the third bearing 6 only in the shape of the protrusion provided on the cage 150 (see also FIG. 5). The features common to the third bearing 106 and the third bearing 6 may be omitted because the same or the last two digits are given the same number.

  The cage 150 is provided with a rectangular protrusion 150d on the cage end surface 150b. When the cage 150 is viewed in plan from the bearing central axis direction, the radial length of the cage 150 of the projection 150d is longer than the circumferential length of the cage 150 of the projection 150d. The protrusion 150d is provided at a position away from both the outer edge 150e and the inner edge 150f of the cage 150. The protrusion 150d extends from the outer peripheral surface of the cage 150 toward the bearing central axis. By forming such a protrusion 150d, a wide lubricant passage is formed between adjacent protrusions 150d. Further, as the cage 150 rotates, the longitudinal side surface of the protrusion 150d stirs the lubricant. That is, as the cage 150 rotates, the lubricant is promoted to move in the radial direction of the cage 150.

  For example, when the crankshaft 14 rotates, the lubricant on the cage end surface 150b is pressed against the side surface (surface in the longitudinal direction) of the protrusion 150d. As a result, the lubricant moves along the side surface of the protrusion 150d as indicated by an arrow 70. The third bearing 106 can further facilitate supplying the lubricant into the third bearing 106. In addition, it replaces with the holder | retainer 60 (refer FIG. 1, 2) of the 2nd bearing 8, and the holder | retainer 150 can also be used. Further, like the protrusion 250d described later, the protrusion 150d may have a thicker central portion (length in the bearing central axis direction) than the end portion.

(Third embodiment)
With reference to FIGS. 7-10, the gear transmission of 3rd Example is demonstrated. The gear transmission of the present embodiment is different from the gear transmission of the first and second embodiments only in the shape of the third bearing. Specifically, as shown in FIGS. 7 to 10, the shapes of the protrusions provided on the cage of the third bearing are different. In the gear transmission of the present embodiment, a cage 250 is used. The holder 250 includes a plurality of protrusions 250d. The direction in which the protrusion 250d extends has an angle with respect to a line connecting the outer peripheral surface of the cage 250 and the bearing central axis. Each of the plurality of protrusions 250d is inclined in the same direction. Such a plurality of protrusions 250d function as an impeller. In other words, when the cage 250 rotates, the plurality of protrusions 250d function like a pump and push the lubricant in a certain direction.

  As shown in FIG. 9, when the cage 250 is seen through from the bearing center axis direction, the direction of the wing gear at one end of the cage end surface 250b is opposite to the direction of the other end. That is, the direction in which the protrusion 250d extends is the opposite direction at one end and the other end of the cage end surface 250b. Further, as shown in FIG. 8, the thickness (length in the bearing central axis direction) of the central portion 250dc of the protrusion 250d is thicker than the thickness of the end portion 250dc. The central portion 250dc of the protrusion 250d means the center in the longitudinal direction of the protrusion 250d. The end portion 250dc of the protrusion 250d means both ends in the longitudinal direction of the protrusion 250d. This feature can also be expressed as follows. In the longitudinal direction, the thickness of the protrusion 250d increases toward the center of the protrusion 250d. Alternatively, in the longitudinal direction, the shape of the protrusion 250d can be expressed as being symmetric with respect to the central portion 250dc.

  As shown in FIG. 10, in the case of the cage 250, when the crankshaft 14 rotates, the lubricant is supplied into the third bearing 206 while swirling along the protrusion 250 d as indicated by an arrow 72. That is, a force for drawing the lubricant into the third bearing 206 is generated.

  As described above, in the cage 250, the direction of the bevel gear is opposite between the one end and the other end of the cage end surface 250b. In the cage 250, for example, when the crankshaft 14 rotates in the forward direction (rotation of the arrow 14F in FIG. 1), a force that draws the lubricant into the third bearing 206 works at one end of the cage end surface 250b. At the other end, there is a force for discharging the lubricant to the outside of the third bearing 206. Further, when the crankshaft 14 rotates in the reverse direction (rotation of the arrow 14R in FIG. 1), the lubricant is drawn from the other end of the cage end surface 150b, and the lubricant is discharged from one end of the cage end surface 250b. In other words, when the cage 250 rotates, the protrusions 250d provided at both ends of the cage 250 serve as an impeller that moves the lubricant in the reverse direction on the cage end surface 250b. Note that the reverse direction means a direction toward the outside in the radial direction and a direction toward the center. If the cage 250 is used, it is possible to prevent the lubricant in the third bearing 206 from being lost or to retain the lubricant in the third bearing 206 indefinitely.

(Fourth embodiment)
The gear transmission of the fourth embodiment will be described with reference to FIGS. The gear transmission of the present embodiment is different from the cage 250 of the third embodiment in the direction of the bevel gear. In the gear transmission of this embodiment, a cage 250X is used. As shown in FIG. 11, a plurality of protrusions 250d extend in the same direction at the same position on both of the cage end surfaces 250b. Therefore, as shown in FIG. 12, when the cage 250X is seen through from the bearing center axis direction, the protrusion 250d inclined in the same direction stirs the lubricant as the cage 250X rotates, like an impeller. . As shown in FIG. 12, when the cage 250X is seen through from the bearing center axis direction, the projection 250d at one end of the cage end surface 250b and the projection 250d at the other end overlap (see FIG. 9 for comparison). That is, when the cage 250X is seen through from the bearing center axis direction, the direction of the blade gear at one end of the cage end surface 150b is the same as the direction of the other end.

  When the direction of the bevel gear at one end of the cage end surface 150b is the same as the direction of the other end, a force for drawing the lubricant into the third bearing 206 is generated on both sides of the cage 250 in the bearing central axis direction. By using the cage 250X, the lubricant can be drawn into the third bearing 206 from both sides of the cage end surface 250b. As a result, a large amount of lubricant can be introduced into the third bearing 206. The oil film breakage of the cylindrical roller 52 (see FIG. 10) can be further suppressed.

(5th Example)
The gear transmission 300 will be described with reference to FIG. The gear transmission 300 is a modified example of the gear transmission 100, and the same components as the gear transmission 100 may be denoted by the same reference numerals or the same two lower digits, and the description thereof may be omitted. The gear transmission 300 is different from the second bearing 8 of the gear transmission 100 only in the structure of the second bearing 308.

  The second bearing 308 is a tapered roller bearing and is interposed between the carrier 2 and the crankshaft 14. In the case of the second bearing 308, a hook is formed on the inner race 308a, and the hook restricts the movement of the tapered roller 308b in the rotation axis direction. In the case of the second bearing 308, unlike the first embodiment, it is not necessary to bring the cage (or the tapered roller) into contact with the regulating member in order to regulate the movement of the second bearing 8. Therefore, it is difficult for the lubricant in the second bearing 308 to run out. In addition, the 3rd bearing 6 is shown by FIG. 11 (refer also FIG. 5). Instead of the cage 50 of the third bearing 6, a cage 150 (see FIG. 6), a cage 250 (see FIGS. 7 to 10), or a cage 250X (see FIGS. 11 and 12) can be used. .

(Sixth embodiment)
The gear transmission 400 will be described with reference to FIG. The gear transmission 300 is a modification of the gear transmission 300, and the same components as the gear transmission 300 may be denoted by the same reference numerals or the lower two digits with the same reference numerals, and description thereof may be omitted. The gear transmission 400 is different from the crankshaft 14 of the gear transmission 300 only in the shape of the crankshaft 414.

  In the crankshaft 414, the spacer plate 426 is fixed to the eccentric bodies 416X and 416Y. More specifically, the spacer plate 426 and the eccentric body 416 are integrally formed. Therefore, rattling of the spacer plate 426 during driving of the gear transmission 400 can be suppressed. In addition, it can replace with the crankshaft 14 of the gear transmission 100 (refer FIG. 1), and can also use the crankshaft 414. FIG.

(Seventh embodiment)
The gear transmission 500 will be described with reference to FIG. The gear transmission 500 is a modified example of the gear transmission 100, and the same components or the same two lower digits as those of the gear transmission 100 may be denoted by the same reference numerals and the description thereof may be omitted. The gear transmission 500 is different from the gear transmission 100 only in the structure for restricting movement of the crankshaft 514 in the axial direction (direction of the axis 32).

  In the gear transmission 500, the retaining ring 12 (hereinafter referred to as the first retaining ring 12) is fitted into the crankshaft 514 on the outside of the second restricting member 510 in the direction of the axis 32. Further, in the direction orthogonal to the axis 32 (the radial direction of the gear transmission 500), the retaining ring 509 (hereinafter referred to as the second retaining ring 509) is disposed outside the first retaining ring 12 with the carrier 502 (first plate 502a). , The second plate 502c). The first retaining ring 12 and the second retaining ring 509 are disposed at substantially the same position in the direction of the axis 32. The first restricting member 518, the second bearing 8, and the second restricting member 510 are disposed between the eccentric body 516, the first retaining ring 12, and the second retaining ring 509. The second restriction member 510 is in contact with the second retaining ring 509, the first restriction member 518 is in contact with the eccentric body 516, and the second bearing 8 is interposed between the first restriction member 518 and the second restriction member 510. doing. Therefore, the eccentric body 516 cannot move in the direction of the axis 32 with respect to the carrier 502. That is, the crankshaft 514 is restricted from moving in the direction of the axis 32 with respect to the carrier 502 by the second retaining ring 509 (second retaining rings 509X and 509Y).

  In the above embodiment, the gear transmission in which the external gear rotates eccentrically has been described. However, the technique disclosed in this specification can also be applied to a gear transmission in which an internal gear rotates eccentrically. What is important is that a cylindrical roller bearing having a protrusion provided on the end face of the cage has an outer peripheral surface of the eccentric body and a through hole of a gear (external gear or internal gear) that rotates eccentrically by engaging with the eccentric body. Between the two. Alternatively, a cylindrical roller bearing having a protrusion provided on the end face of the cage is disposed between a crankshaft supporting part (a carrier in the embodiment) and the crankshaft.

  In this specification, the technique regarding the retainer of a cylindrical roller bearing and the gear transmission provided with the cylindrical roller bearing was disclosed. The technique disclosed in this specification can also be applied to a cage for a needle roller bearing and a gear transmission provided with the needle roller bearing. The “cylindrical roller bearing” and the “needle roller bearing” are distinguished mainly by the size of the “roller (rolling element)” to be used. Generally, when the diameter of the cylindrical “roller” is 6 mm or less and the length is 3 to 10 times the diameter, it is called “needle roller”. A bearing using such a “needle roller” as a rolling element is referred to as a “needle roller bearing”.

  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: Gear transmission 6: Cylindrical roller bearing 50: Cage 50d: Protrusion

Claims (11)

A cylindrical roller bearing retainer used in a gear transmission,
A cage having a ring shape and a plurality of protrusions provided on the surfaces of both end portions in the bearing central axis direction. When the cylindrical roller bearing is attached to the shaft,
The cage according to claim 1, wherein a gap is provided between an inner peripheral edge of the end portion and the shaft.   The cage according to claim 1 or 2, wherein a length of the protrusion in a circumferential direction of the cage is shorter than a diameter of the cylindrical roller.   The retainer according to any one of claims 1 to 3, wherein the protrusion is provided at a position away from both an inner peripheral edge and an outer peripheral edge of the retainer.   The cage according to any one of claims 1 to 4, wherein the length of the protrusion in the radial direction of the cage is longer than the length in the circumferential direction of the cage when the cage is viewed in plan.   The cage according to any one of claims 1 to 4, wherein the protrusion constitutes an impeller.   The cage according to claim 6, wherein the direction of the impeller at one end of the cage and the direction of the impeller at the other end are opposite to each other.   The cage according to claim 6, wherein the direction of the impeller at one end of the cage and the direction of the impeller at the other end are the same. An internal gear,
An external gear that rotates relatively eccentrically while meshing with the internal gear;
A crankshaft that has an eccentric body that engages with a through-hole formed in one of the internal gear and the external gear, and that rotates the one gear eccentrically;
A cylindrical roller bearing interposed between the inner peripheral surface of the through hole and the outer peripheral surface of the eccentric body;
A regulating member that regulates movement of the cylindrical roller bearing in the bearing central axis direction,
A gear transmission comprising a cylindrical roller bearing including the cage according to any one of claims 1 to 8. A case in which the internal gear is formed on the inner periphery;
A carrier that is supported by the case coaxially with the internal gear, and that supports the crankshaft,
The gear transmission according to claim 9, wherein the through hole is formed in the external gear. The clan shaft is supported by a carrier via a second cylindrical roller bearing;
The gear transmission according to claim 10, wherein the second cylindrical roller bearing includes the cage according to any one of claims 1 to 8.

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