JP2018150981A - Planetary gear device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly spread a lubricant to the neighborhood of a main bearing of a planetary gear device.SOLUTION: In a planetary gear device G1 including a casing 12, an internal gear 14 integrated with the casing, a planetary gear 15 internally meshing with the internal gear, a carrier 25 disposed on an axial side portion of the planetary gear, a main bearing 21 disposed between the casing and the carrier, and an oil seal 37 disposed between the casing and the carrier at an axially counter-planetary gear side of the main bearing, a communication passage 81 is disposed to communicate a first space 21P1 between the main bearing and the oil seal with a second space 28P2 in which the air in the first space is movable, and the communication passage is positioned at a counter-planetary gear side with respect to an end face 21F at a planetary gear side, of the main bearing.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a planetary gear device.

  Patent Document 1 discloses a planetary gear device including a casing, an internal gear integrated with the casing, and a planetary gear that is in mesh with the internal gear.

  The planetary gear device includes a carrier disposed on an axial side portion of the planetary gear, and a main bearing disposed between the casing and the carrier. In this planetary gear device, an oil seal is disposed between the casing and the carrier on the axially opposite planetary gear side of the main bearing.

Japanese Patent Laying-Open No. 2011-2063 (FIG. 5)

  In such a planetary gear device, there is a problem that the lubricant may not be distributed well in the vicinity of the main bearing. If the lubricant cannot be satisfactorily distributed in the vicinity of the main bearing, it will cause a decrease in the life of the main bearing.

  The present invention has been made to solve such a problem, and an object thereof is to satisfactorily distribute the lubricant in the vicinity of the main bearing of the planetary gear device.

  The present invention includes a casing, an internal gear integrated with the casing, a planetary gear inscribed in mesh with the internal gear, a carrier disposed on an axial side of the planetary gear, and the casing. A planetary gear device comprising: a main bearing disposed between the carrier; and an oil seal disposed between the casing and the carrier on an axially anti-planetary gear side of the main bearing; A communication path that communicates the first space between the main bearing and the oil seal with a second space in which the air in the first space can move; the communication path on the planetary gear side of the main bearing; The above problem is solved by adopting a configuration that is located on the side of the anti-planetary gear with respect to the end face.

  In the present invention, the first space between the main bearing and the oil seal is provided with a communication path communicating with the second space in which the air in the first space can move. And this communicating path is comprised so that it may be located in the anti- planetary gear side rather than the end surface by the side of the planetary gear of a main bearing.

  Thereby, since the air in the first space between the main bearing and the oil seal can be moved to the second space side, it is possible to avoid a situation where the air is trapped in the first space, The lubricant can be distributed well in the vicinity of the main bearing.

  According to the present invention, the lubricant can be distributed well in the vicinity of the main bearing of the planetary gear device.

FIG. 3 is an overall cross-sectional view of the planetary gear device according to an example of the embodiment of the present invention, taken along line II in FIG. FIG. 1 is an enlarged cross-sectional view of the vicinity of the input shaft in FIG. Sectional view along the arrow III-III line of FIG. Sectional drawing which follows the arrow IV-IV line of FIG. Side view of carrier showing configuration of communication path Side view of the carrier corresponding to FIG. 5 showing a configuration example of the third communication path FIG. 8 is an overall cross-sectional view taken along the line VII-VII in FIG. 8 of a planetary gear device according to another embodiment of the present invention. Sectional drawing which follows the arrow VIII-VIII line of FIG.

  Hereinafter, an example of an embodiment of the present invention will be described in detail based on the drawings.

  FIG. 1 is an overall cross-sectional view of a planetary gear device according to an example of an embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view showing the vicinity of the input shaft of FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1, and FIG. 4 is a cross-sectional view taken along line IV-IV in FIG.

  The planetary gear device G1 is an eccentric oscillating planetary gear device in which the planetary gear is inwardly meshed with the internal gear while oscillating. The planetary gear device G1 includes a casing 12, an internal gear 14 integrated with the casing 12, and external gears 15 and 16 (first external gear 15 and the first external gear 15 and the first external gear 15). 2 external gears 16: planetary gears).

  The external gears 15 and 16 are in mesh with the internal gear 14 while being swung by the crankshaft 18. Carriers 25 and 26 (first carrier 25 and second carrier 26) are arranged on the axial side portions of the external gears 15 and 16. Main bearings 21 and 22 (first main bearing 21 and second main bearing 22) are arranged between casing 12 and carriers 25 and 26. An oil seal 37 is disposed between the casing 12 and the first carrier 25 on the axially opposite external gear side of the first main bearing 21.

  In the planetary gear device G1, an oil seal 29 is provided between a cover casing 31 (to be described later) and the center shaft member 40 in the vicinity of the second main bearing 22. However, the present invention is not applied to the vicinity of the second main bearing 22 in the planetary gear device G1.

  First, the configuration of the power transmission system of the planetary gear device G1 will be described.

  A pre-gear set 30 is provided between the motor shaft 13 (not shown) and the input shaft 28 of the planetary gear device G1. The pre-gear set 30 includes a pinion 32 provided at the tip of the motor shaft 13 and a gear 34 provided on the input shaft 28 of the planetary gear device G1 and meshing with the pinion 32. The rotation of the motor is input to the input shaft 28 after first-stage deceleration by the pre-gear set 30.

  The input shaft 28 has input shaft bearings 17 and 19 (first input shaft bearings) in the input shaft support holes 25Q and 26Q (first input shaft support hole 25Q and second input shaft support hole 26Q) of the carriers 25 and 26. 17 and a second input shaft bearing 19). In this planetary gear device G1, the input shaft bearings 17 and 19 are configured by tapered roller bearings that are assembled face-to-face.

  The input shaft space 28P2 including the first input shaft support hole 25Q is released to the outside of the planetary gear device G1, and constitutes a second space in which air in a main bearing space 21P1 (first space) described later can move. Yes. An input shaft lubricant passage 41 penetrating through the second carrier 26 is formed at a position corresponding to the axis C28 of the input shaft 28 of the second carrier 26.

  An input gear 36 is integrally provided on the input shaft 28. The input gear 36 meshes with the center gear 38. The center gear 38 is rotatably supported on the outer periphery of the center shaft member 40 via the needle 39. The center shaft member 40 is disposed at the radial center of the planetary gear device G1 (on the axis C14 of the internal gear 14), and includes a large-diameter hollow portion 40A.

  The center gear 38 meshes with a crankshaft gear 42 for driving the crankshaft 18. A plurality of crankshafts 18 (three in the planetary gear unit G1) are arranged at positions offset from the axis C14 of the internal gear 14 by Rc18.

  Each crankshaft 18 is integrally provided with two eccentric bodies 45, 46 (first eccentric body 45 and second eccentric body 46) that swing the external gears 15, 16. The eccentric bodies 45 and 46 have shaft centers C45 and C46 that are eccentric with respect to the shaft center C18 of the crankshaft 18. The eccentric phase difference between the eccentric bodies 45 and 46 is 180 degrees (eccentric in a direction away from each other).

  The phases of the first eccentric bodies 45 at the same position in the axial direction of the crankshafts 18 are aligned. The phases of the second eccentric bodies 46 at the same position in the axial direction of the crankshafts 18 are also aligned. Eccentric body bearings 51 and 52 (the first eccentric body bearing 51 and the second eccentric body bearing 52) are arranged between the eccentric bodies 45 and 46 and the external gears 15 and 16. The external gears 15 and 16 are in mesh with the internal gear 14 while swinging through eccentric body bearings 51 and 52.

  In this planetary gear device G1, the internal gear 14 is rotatably supported by an internal gear main body 14A integrated with the casing 12 and the internal gear main body 14A, and constitutes internal teeth of the internal gear 14. A cylindrical internal tooth pin 14B is provided. The internal tooth pin 14B is rotatably disposed in a pin groove 14C formed in the internal gear main body 14A.

  As shown in FIG. 3, in the planetary gear device G1, the internal gear pins 14B are arranged in a state where two pins are alternately thinned out with respect to the pin grooves 14C formed in the internal gear main body 14A. Yes. The pin groove 14C is not actually formed in the thinned portion (see the imaginary line in FIG. 3). The substantial number of internal teeth of the internal gear 14 corresponds to the number of all pin grooves 14C including the pin grooves 14C in which the internal tooth pins 14B are not disposed. In this example, the internal teeth actually disposed. There are 120 pins, twice the number of pins 14B (60 pins). Since the number of external teeth of the external gears 15 and 16 is 118 in this example, the number of internal teeth of the internal gear 14 (equivalent number of the pin grooves 14C) is the number of external teeth of the external gears 15 and 16. Slightly more than the number (in this example, only “2”).

  Carriers 25 and 26 are disposed on the axial side portions (in this example, both sides) of the external gears 15 and 16. The carriers 25 and 26 are supported by the casing 12 of the planetary gear device G1 via main bearings 21 and 22. As shown in FIG. 4, carrier pillars 58 (6 in this example) integrally project from the second carrier 26. The carrier pillar 58 penetrates the external gears 15 and 16 in a non-contact manner, and the tip thereof engages and abuts on the recess 25 </ b> K of the first carrier 25. The first carrier 25 is connected to the second carrier 26 via a carrier pillar 58 and a carrier bolt 60.

  The crankshaft 18 is supported by the crankshaft support holes 25M and 26M of the carriers 25 and 26 via a pair of crankshaft bearings 61 and 62 (first crankshaft bearing 61 and second crankshaft bearing 62). . In this planetary gear device G1, the crankshaft bearings 61 and 62 are constituted by tapered roller bearings arranged face to face.

  The crankshaft support hole 25 </ b> M of the first carrier 25 is closed at the end by a closing cap 65. A crankshaft end closed space 18P3 formed by the closed crankshaft support hole 25M forms a third space to be described later. A crankshaft lubricant passage 43 passing through the second carrier 26 is formed at a position corresponding to the axis C18 of the crankshaft 18 of the second carrier 26.

  In the planetary gear device G1, a first relative rotating member (for example, a base member of a robot) (not shown) is connected to the casing 12 via a bolt (only a bolt hole 12P is shown). Further, a second relative rotating member (not shown) (for example, a rotating body of a robot) to be rotated relative to the first relative rotating member on the first carrier 25 is a bolt (only the tap hole 25P is illustrated). ).

  In addition, a cover casing 31 that closes an axial end of the planetary gear device G1 is connected to the casing 12 via a bolt 44. The cover casing 31 is provided with a greasing port 33. Reference numeral 35 denotes an insertion ring that regulates the interval between the two external gears 15 and 16.

  In the planetary gear device G1, the present invention is applied in order to allow the lubricant to be well distributed in the main bearing space 21P1 (first space) between the first main bearing 21 and the oil seal 37. As described above, the present invention is not applied to the second main bearing 22 side. Therefore, hereinafter, the configuration will be described mainly focusing on the first main bearing 21 side.

  First, the structure around the main bearing 21 will be described in detail.

  As already described, in the planetary gear device G1, the carrier 25 is arranged on the axial side portion of the external gear 15 (planetary gear). A main bearing 21 is disposed between the casing 12 and the carrier 25. The main bearing 21 of the planetary gear unit G1 is an angular ball bearing having an inner ring 23, an outer ring 24, and balls (rolling elements) 27.

  An oil seal 37 is arranged between the casing 12 and the carrier 25 on the axially opposite external gear side of the main bearing 21. In addition, the configuration in which “the oil seal 37 is disposed between the casing 12 and the carrier 25 on the axially opposite external gear side of the main bearing 21” is different from that of the present embodiment. As described above, when the planetary gear device G1 is used in the vertical position, the external gear 15, the main bearing 21, and the oil seal 37 are arranged in this order from the lower side in the vertical direction. That is, when the planetary gear device G1 is used in a vertical position, the oil seal 37 is at a position higher than the main bearing 21 (upper side in the vertical direction).

  The outer periphery of the carrier 25 of the planetary gear unit G1 has a small-diameter portion 25S on the external gear 15 side, a large-diameter portion 25L on the counter-external gear side, and a step wall 25W between the small-diameter portion 25S and the large-diameter portion 25L. doing. The main bearing 21 is incorporated in such a manner that the inner ring 23 comes into contact with the small diameter portion 25S and the step wall 25W of the carrier 25.

  That is, the small diameter portion 25S of the carrier 25 constitutes the arrangement surface of the inner ring 23 of the main bearing 21 (hereinafter, the small diameter portion 25S of the carrier 25 may be referred to as the inner ring arrangement surface 25S of the main bearing 21). The oil seal 37 is incorporated in the large diameter portion 25L of the carrier 25. That is, the large-diameter portion 25L of the carrier 25 forms an arrangement surface for the oil seal 37 (hereinafter, the large-diameter portion 25L of the carrier 25 may be referred to as an oil seal arrangement surface 25L).

  That is, the oil seal arrangement surface (large diameter portion) 25L of the carrier 25 is located radially outside the inner ring arrangement surface (small diameter portion) 25S of the main bearing 21. Considering the case where the inner ring 23 is integrally formed with the carrier 25, it can be said that the oil seal arrangement surface 25 </ b> L is radially outside the rolling surface of the inner ring 23.

  In the planetary gear unit G1, the radius R25L of the oil seal arrangement surface 25L of the carrier 25 is larger than the radius R12F of the arrangement surface 12F of the outer ring 24 of the main bearing 21 of the casing 12. That is, the oil seal arrangement surface 25L is on the radially outer side than the arrangement surface 12F of the outer ring 24 of the main bearing 21. Considering the case where the outer ring 24 is integrally formed with the casing 12, it can be said that the oil seal arrangement surface 25 </ b> L is located radially outside the rolling surface of the outer ring 24.

  In the planetary gear device G1, the distance Rc18 from the axis C14 of the internal gear 14 of the axis C18 of the crankshaft 18 is the distance from the axis C14 of the internal gear 14 of the axis C28 of the input shaft 28. It is larger than Rc28 (see FIG. 3). That is, the crankshaft 18 is located radially outside the input shaft 28 with respect to the axis C14 of the internal gear 14.

  2, the radius R25S of the inner ring arrangement surface 25S of the main bearing 21 of the carrier 25 (= the radius R26S of the inner ring arrangement surface 26S of the main bearing 22 of the carrier 26) is the axis C18 of the crankshaft 18. The radius R25S of the inner ring arrangement surface 25S of the main bearing 21 of the carrier 25 is larger than the distance Rc18 from the axis C14 of the internal gear 14 and the outer shape of the crankshaft bearing 61 that supports the crankshaft 18. It is larger than the distance L61A from the axis C14 of the internal gear 14 of 61A (= same distance L62A on the crankshaft bearing 62 side).

  As described above, in the planetary gear device G1, the input shaft 28 is supported via the input shaft bearing 17 in the input shaft support hole 25Q penetrating the carrier 25 in the axial direction. The input shaft space 28 </ b> P <b> 2 including the input shaft support hole 25 </ b> Q that supports the input shaft 28 communicates with the housing recess 25 </ b> G of the pre-gear set 30. The input shaft space 28P2 constitutes an input shaft space 28P2 (second space) in which air in the main bearing space 21P1 (first space) between the main bearing 21 and the oil seal 37 can move.

  The planetary gear device G1 has the above-described configuration, and an input through which air in the main bearing space 21P1 can move in the main bearing space 21P1 (first space) between the main bearing 21 and the oil seal 37. A communication path 81 communicating with the input shaft space 28P2 (second space) including the shaft support hole 25Q is provided. At least a part of the communication path 81 (all of the communication path 81 in the planetary gear device G1) is located on the side opposite to the external gear than the end face 21F on the external gear 15 side of the main bearing 21.

  Here, the configuration “at least a part of the communication path 81 is located on the side opposite to the external gear than the end face 21F on the external gear 15 side of the main bearing 21” is, in other words, When the planetary gear device G1 is used in the vertical position as in the embodiment, “at least a part of the communication path 81 is positioned higher in the vertical direction than the end surface 21F on the lower side in the vertical direction of the main bearing 21. It is.

  Note that “when the planetary gear device G1 is used in a vertical position” means “when the shaft C14 of the internal gear 14 of the planetary gear device G1 is oriented in the vertical direction” in a narrow sense. However, in the present specification, it means “when the upper surface of the lubricant is used in a mode crossing the axis C14 of the internal gear 14”, and includes the concept of a wider usage mode. That is, it includes a case where the axis C14 of the internal gear 14 of the planetary gear device G1 is used in a state inclined from the horizontal direction. More specifically, for example, if the angle formed by the axis C14 of the internal gear 14 with respect to the vertical direction is within 45 °, it is clearly included in the category when used vertically. In other words, the installation is located in the order of the oil seal 37, the main bearing 21, and the external gear 15 from the upper side in the vertical direction.

  Referring mainly to FIGS. 2 and 5, the communication path 81 of the planetary gear device G1 includes a radial groove 81A, an axial groove 81B, and a radial through hole 81C.

  The radial groove 81A of the communication path 81 is formed in the step wall 25W of the carrier 25 in the radial direction along the end surface 21E on the side opposite to the external gear of the main bearing 21 (the inner ring 23). The radially outer end 81A1 of the radial groove 81A is positioned radially outward by δ (81A1-23A) from the radially outer end 23A of the inner ring 23 of the main bearing 21. That is, the radial groove 81A faces (opens) the main bearing space 21P1 between the main bearing 21 and the oil seal 29.

  The axial groove 81B of the communication passage 81 is formed continuously with the radially inner end 81A2 of the radial groove 81A, and is axially formed on the inner ring arrangement surface 25S of the carrier 25 along the inner circumference of the inner ring 23 of the main bearing 21. Is formed. The axial groove 81B reaches and opens the axial end surface 25E of the carrier 25. That is, the axial groove 81B faces the space 15P on the side of the external gear 15 of the carrier 25, and is connected to the input shaft space 28P2 (second space) including the input shaft support hole 25Q via the space 15P. Yes.

  The radial through hole 81C of the communication path 81 connects the axial groove 81B and the input shaft space 28P2 in the radial direction at a position on the axially anti-external gear side of the axial groove 81B (the upper position in this example). doing.

  In the planetary gear device G1, the crankshaft 18 is supported by the crankshaft support hole 25M of the carrier 25 via the crankshaft bearing 61. The crankshaft support hole 25M is a closed hole whose end is closed by a closing cap 65. In other words, a crankshaft end closed space 18P3 (third space) formed by a sealed crankshaft support hole 25M exists between the crankshaft 18 and the closing cap 65.

  The planetary gear device G1 includes three sets of second communication passages 82 communicating with the crankshaft end closed space 18P3 and the main bearing space 21P1. The second communication path 82 is formed in a configuration similar to the communication path 81 in the planetary gear device G1. That is, the second communication passage 82 has a radial groove 82A formed in the step wall 25W of the carrier 25 in the radial direction along the end surface 21E on the counter-external gear side of the main bearing 21 (the inner ring 23). Further, it is formed continuously at the radially inner end of the radial groove 82A, and is axially formed on the inner ring placement surface 25S of the carrier 25 along the inner circumference of the inner ring 23 of the main bearing 21. Have. Then, at a position on the axially anti-external gear side of the axial groove 82B (an upper position in this example), a radial penetration that connects the axial groove 82B and each crankshaft end closed space 18P3 in the radial direction. Has a hole 82C. Since the main bearing space 21P1 (first space) is continuous in the circumferential direction, each crankshaft end closed space 18P3 (third space) includes the second communication path 82, the main bearing space 21P1, and the communication path 81. Is communicated with the input shaft space 28P2 (second space) that is released via the.

  Instead of the second communication path 82 or in combination with the second communication path 82, for example, as shown in FIG. 6, the input shaft space 28P2 (second space) which is a released space is sealed. The ring-shaped groove 83 (third communication passage) that directly communicates with the crankshaft end closed space 18P3 (third space), which is the formed space, is formed in such a manner that the inner periphery of the carrier 25 goes around once. May be.

  Next, the operation of the planetary gear device G1 will be described.

  First, the operation of the power transmission system will be described. When the motor shaft 13 of the motor rotates, the first-stage deceleration is performed through the pre-gear set 30 including the pinion 32 and the gear 34, and the input shaft 28 rotates. When the input shaft 28 rotates, the center gear 38 meshed with the input gear 36 rotates, and the three crankshaft gears 42 meshed simultaneously with the center gear 38 rotate. As a result, the three crankshafts 18 rotate in the same direction at the same rotational speed.

  As a result, the first external gear 15 oscillates and rotates through the first eccentric body 45 whose eccentric phases are aligned in each crankshaft 18. Further, the second external gear 16 swings and rotates through the second eccentric body 46 whose eccentric phase is aligned with the first eccentric body 45 by an eccentric phase difference of 180 degrees.

  The external gears 15 and 16 are in mesh with the internal gear 14, and the substantial number of teeth of the internal gear 14 (the number of pin grooves 14 </ b> C) is the number of teeth of the external gears 15 and 16. 2 more than the number. Accordingly, each of the external gears 15 and 16 is swung once every time the crankshaft 18 is rotated once, and only the difference in the number of teeth from the internal gear 14 (two teeth in this planetary gear device G1). Out of phase.

  As a result, the crankshaft 18 passing through the external gears 15, 16 revolves around the axis C <b> 14 of the internal gear 14. This revolution is transmitted to the carriers 25 and 26 that support the crankshaft 18 via the crankshaft bearings 61 and 62. When the carriers 25 and 26 rotate, the second relative rotating member connected to the first carrier 25 rotates relative to the first relative rotating member connected to the casing 12.

  A lubricant is enclosed in the casing 12 of the planetary gear unit G1 so that these actions are performed satisfactorily. In the planetary gear device G1, grease is used as a lubricant. Grease is pushed and injected from a greasing port 33 formed in the cover casing 31. The injected lubricant gradually rises in the lubrication surface and fills the casing 12, and eventually overflows from the input shaft space 28P2.

  Conventionally, when the closing operation is about to end, the air in the main bearing space 21P1 between the main bearing 21 and the oil seal 37 is trapped by the lubricant whose liquid level has risen, and the main bearing space. There was a problem that the lubricant did not spread sufficiently to 21P1. This inconvenience occurred remarkably when the planetary gear device G1 was used vertically as in the present embodiment.

  However, the planetary gear device G1 includes a communication path 81 that communicates the main bearing space 21P1 with the input shaft space 28P2 through which the air in the main bearing space 21P1 can move. The air or lubricant in the main bearing space 21P1 can move to the input shaft space 28P2 side through the radial groove 81A, the axial groove 81B, and the radial through hole 81C of the communication path 81.

  The communication path 81 is located on the side opposite to the planetary gear with respect to the end surface 21 </ b> F on the external gear 15 side of the main bearing 21. That is, when the planetary gear device G1 is used in a vertical position, the communication path 81 is positioned above the end surface 21F on the external gear 15 side of the main bearing 21 in the vertical direction.

  Therefore, the air in the main bearing space 21P1 can move to the input shaft space 28P2 side through the communication path 81, and the lubricant can enter the main bearing space 21P1 without hindrance. As a result, the vicinity of the main bearing 21 can be sufficiently lubricated.

  In particular, in this embodiment, the communication path 81 is located on the side opposite to the external gear (upper side) than the end surface 21E on the side opposite to the external gear of the main bearing 21. That is, the communication path 81 is not closed by the lubricant until the radial through hole 81C is filled with the lubricant. Therefore, the lubricant can be guided very smoothly into the main bearing space 21P1.

  Further, in the planetary gear device G1, the oil seal arrangement surface 25L of the carrier 25 is radially outward from the inner ring arrangement surface 25S of the main bearing 21. More specifically, in the planetary gear device G1, the oil seal arrangement surface 25L of the carrier 25 is located on the radially outer side than the arrangement surface 12F of the outer ring 24 of the main bearing 21. In this configuration, the main bearing space 21P1 often becomes an isolated sealed space, and the lubricant often does not easily enter the main bearing space 21P1. However, in the planetary gear device G1, the presence of the communication path 81 makes it possible to supply the lubricant in the vicinity of the main bearing 21 satisfactorily.

  The planetary gear device G1 includes an input shaft 28, a crankshaft 18 that swings the external gear 15, an input gear 36 provided on the input shaft 28, and a crankshaft gear 42 provided on the crankshaft 18. And a center gear 38 that meshes with the input gear 36 and the crankshaft gear 42. The input shaft 28 has an input shaft support hole 25Q that penetrates the carrier 25 in the axial direction and supports the input shaft 28. In the planetary gear device G1 having such a configuration, the communication path 81 communicates the input shaft support hole 25Q with the main bearing space 21P1. Therefore, the communication path 81 can be easily formed at low cost by utilizing the existing input shaft space 28P2.

  On the other hand, in such a configuration, in the planetary gear device G1, the end of the crankshaft support hole 25M is closed by the closing cap 65. However, in the planetary gear device G1, the crankshaft end closed space 18P3 (third space) formed by the crankshaft support hole 25M whose end is closed communicates with the main bearing space 21P1 (first space). A second communication path 82 is provided. Accordingly, the planetary gear unit G1 is delivered to the user with the closing cap 65 attached to the crankshaft 18, and the situation is such that the user (without special knowledge or product know-how) encloses the lubricant. However, the user can supply the lubricant well to the crankshaft end closed space 18P3 simply by sealing the lubricant at the time of sealing the lubricant. Can be lubricated.

  Further, as in the modification shown in FIG. 6, the third communication passage 83 is configured to communicate the input shaft space 28P2 (second space) and the crankshaft end closed space 18P3 (third space). In addition, a good lubricant can be supplied. That is, in this case, the crankshaft end closed space 18P3 is communicated with the input shaft space 28P2 through a route via the third communication passage 83. The third communication path 83 has a great merit in that the configuration is simple and the input shaft space 28P2 and the crankshaft end closed space 18P3 which are located in the circumferential direction can be directly communicated with each other.

  7 and 8 show a planetary gear device according to another embodiment of the present invention. In this embodiment, the present invention is applied to another type of eccentric oscillating planetary gear unit G101.

  In this planetary gear device G101, the external gears (planetary gears) 115 and 116 are swinging gears that are inscribed in the internal gear 114 while swinging. A configuration is adopted in which three crankshafts 118 for swinging the external gears 115 and 116 are provided and the external gear 115 is swung by the three crankshafts 118.

  However, in this embodiment, as shown in FIG. 8, the rotation of the input gear 136 of the input shaft 128 that is also used as the motor shaft of the motor M is first applied to one crankshaft 118 (118A) as a crankshaft gear 142A. The center gear 138 and the crankshaft gears 142B and 142C rotate in mesh with the crankshaft gear 142A to which power is first transmitted to the other two crankshafts 118 (118B and 118C). It is set as the structure to which motive power is transmitted via.

  As shown in FIG. 7, the crankshaft 118 is supported via a crankshaft bearing 161 in a crankshaft support hole 125 </ b> M provided through the carrier 125 in the axial direction. The crankshaft support hole 125M is released to the crankshaft end release space 118P2 (second space). The communication path 181 communicates the crankshaft end opening space 118P2 as the second space including the crankshaft support holes 125M of the three crankshafts 118 (118A to 118C) and the main bearing space 121P1.

  The communication path 181 has a radial groove 181A formed in the step wall 125W of the carrier 125 in the radial direction along the end surface 121E on the side opposite to the external gear of the main bearing 121 (inner ring 123). The communication path 181 is formed continuously at the radially inner end of the radial groove 181A, and is formed in the inner ring arrangement surface 125S of the carrier 125 in the axial direction along the inner circumference of the inner ring 123 of the main bearing 121. And an axial groove 181B. The communication passage 181 has an axial groove 181B and each crankshaft end release space 118P2 (second space) at a position on the axially anti-external gear side of the axial groove 181B (the upper position in this example). Are provided in the radial direction through-hole 181C.

  Also in this planetary gear device G101, the air (or lubricant) in the main bearing space 121P1 can move to the crankshaft end portion release space 118P2 (second space) side through the communication path 181 and lubricate. The agent can enter the main bearing space 121P1 without hindrance. As a result, the vicinity of the main bearing 121 can be lubricated satisfactorily.

  Note that the crankshaft end opening space 118P2 (second space) is secured in a mode of being closed by the plate 185 above each crankshaft support hole 125M (on the side opposite to the external gear of the carrier 125). The plate 185 is connected to the axial motor side end face 125 </ b> H of the carrier 125 via a bolt 191. The plate 185 is formed with an air vent hole 187 closed with a stopper 186.

  The air vent hole 187 is not always necessary when the volume of the crankshaft end opening space 118P2 is sufficiently large. However, if the grease is sealed with the plug 186 removed and the plug 186 is closed after the sealing, the crankshaft Even when the volume of the end opening space 118P2 is small, the intended effect of the present invention can be obtained satisfactorily.

  Such a plate 185 may also be provided on the end surface on the side of the axial direction motor of the carrier 25 in the planetary gear unit G1. By providing such a plate 185, it is possible to hold the lubricant without any trouble even when the planetary gear device G1 or G101 is used in a horizontal position.

  In the planetary gear device G101, the crankshaft 118A to which power is first transmitted can be regarded as an input shaft. In this case, as in the planetary gear device G1, the communication path 181 It can also be understood that the input shaft space (released) and the main bearing space 121P1 are in communication.

  Since the other configuration is the same as that of the previous embodiment, in FIG. 7 and FIG. 8, the same reference numerals are given to the parts corresponding to those of the previous embodiment, and redundant description is omitted. .

  In each of the above embodiments, the case where the planetary gear device is used in a vertically placed state has been exemplified, but the present invention is not limited to use in a vertically placed state, and is used in a horizontally placed state. It does not exclude doing. Even when used in a horizontal position, the communication path can function as a lubricant path for smoother circulation of air and lubricant between the first space and the second space.

  In the above embodiments, the present invention is not particularly applied to the space between the main bearing 22 and the oil seal 29 on the counter motor side, but the present invention is also applied to the counter motor side. You may make it do. Also in this case, the communication path can function as a lubricant path for facilitating the flow of air and lubricant to the main bearing space.

  In each of the above embodiments, the space on the side opposite to the external gear of the first carrier (the space above the first carrier in the case of vertical installation) is used as the second space of the movement destination. However, the present invention is not particularly limited as to which space is used as the second space of the movement destination. For example, a configuration in which the external space of the planetary gear device is used as the destination space may be used.

  In the above embodiments, the present invention has been applied to the eccentric oscillating planetary gear device having a plurality of crankshafts at positions offset from the axis of the internal gear. The specific power transmission structure of the planetary gear device is not limited to the above example. For example, the present invention may be applied to an eccentric oscillating planetary gear device having only one crankshaft on the axis of the internal gear. Further, the present invention may be applied to a simple planetary gear device.

  Further, in the above embodiment, for example, the communication path is configured by the groove and the through hole formed around the main bearing. However, in the present invention, for the specific shape and configuration of the communication path, However, it is not particularly limited to the above configuration example.

G1 ... Planetary gear unit 12 ... Casing 14 ... Internal gear 15 ... External gear (planetary gear)
21 ... Main bearing 21P1 ... Main bearing space (first space)
21F: End surface on the external gear side of the main bearing 25 ... Carrier 28 ... Input shaft 28P2 ... Input shaft space (second space)
37 ... Oil seal 81 ... Communication path

Claims (7)

A casing, an internal gear integrated with the casing, a planetary gear internally meshing with the internal gear, a carrier disposed on an axial side portion of the planetary gear, the casing and the carrier A planetary gear device comprising: a main bearing disposed between; and an oil seal disposed between the casing and the carrier on an axially anti-planetary gear side of the main bearing,
A communication path that communicates the first space between the main bearing and the oil seal with the second space in which the air in the first space can move;
The communication path is located on the side opposite to the planetary gear with respect to the end surface on the planetary gear side of the main bearing. In claim 1,
The planetary gear device, wherein an arrangement surface of the oil seal of the carrier is located radially outside an arrangement surface of the inner ring of the main bearing. In claim 2,
The planetary gear device, wherein the arrangement surface of the oil seal of the carrier is located radially outside the arrangement surface of the outer ring of the main bearing. The planetary gear device according to any one of claims 1 to 3,
A crankshaft for swinging the planetary gear,
The carrier has a support hole that penetrates the carrier in the axial direction and supports the crankshaft;
The planetary gear device, wherein the communication path communicates the first space with a space including a support hole of the crankshaft as the second space. The planetary gear device according to any one of claims 1 to 3,
An input shaft, a crankshaft that swings the planetary gear, an input gear provided on the input shaft, a crankshaft gear provided on the crankshaft, and a center gear that meshes with the input gear and the crankshaft gear And comprising
The carrier has a support hole that passes through the carrier in the axial direction and supports the input shaft;
The planetary gear device, wherein the communication path communicates the first space with a space including a support hole of the input shaft as the second space. The planetary gear set according to claim 5,
The carrier has a support hole for supporting the crankshaft;
The support hole of the crankshaft is closed at the end,
A planetary gear device comprising: a second communication path communicating with the first space in a third space formed by a support hole of the crankshaft whose end is closed. The planetary gear set according to claim 5,
The carrier has a support hole for supporting the crankshaft;
The support hole of the crankshaft is closed at the end,
A planetary gear device comprising: a third space formed by a support hole of the crankshaft whose end is closed, and a third communication path that communicates with the second space.

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