JP2014051994A - Eccentric oscillation type gear device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an eccentric oscillation type gear device which can be thinned with a simple structure.SOLUTION: An eccentric oscillation type gear device 10 includes: an outer cylinder 12 which has a plurality of inner teeth on the inner circumferential surface; an eccentric part 20b; an oscillating gear 18 having an insertion hole to which the eccentric part 20b is inserted, being engaged with the inner teeth in conjugation with the rotation of the eccentric part 20b and, at the same time, being rotated in the outer cylinder; a carrier 14 which has a bolt insertion hole 14c penetrating in the thickness direction, is fixed to a fixation objective member 70 by a bolt screwed to the bolt insertion hole 14c and is relatively rotated with respect to the outer cylinder 12 because rotation of the oscillating gear 18 is transmitted; and a closing member 60 which closes an opening part 14d of the bolt insertion hole 14c.

Description

  The present invention relates to an eccentric oscillating gear device.

  Conventionally, an eccentric oscillating gear device that relatively rotates an outer cylinder and a carrier by oscillating and rotating an oscillating gear (external gear) in conjunction with rotation of an eccentric portion provided on a crankshaft. It has been known. In this gear device, it has been studied to reduce the thickness of the device in the axial direction of the crankshaft.

  For example, Patent Document 1 discloses a gear device that employs a configuration in which only one oscillating gear is provided and a main bearing is disposed only on one side (the same side as the carrier) of the oscillating gear. Has been. In this gear device, the gear device can be made thinner than the configuration in which the main bearings are disposed on both sides of the plurality of external gears.

  Patent Document 2 discloses a gear device having a protruding portion in which a part of a carrier protrudes into a rocking gear. In this gear device, by providing the protrusion, the depth of the mounting hole for mounting the mating member can be sufficiently secured while being compact in the axial direction.

JP 2010-91073 A JP 2012-67802 A

  By the way, a counterpart member (fixed member) is fixed to the carrier of the gear device. For this reason, the carrier has a bolt insertion hole for fixing the mating member. Accordingly, the thickness of the carrier needs to be at least the length (depth) of the bolt insertion hole.

  Further, since it is necessary to prevent the lubricant in the gear unit from flowing out through the bolt insertion hole, the bolt insertion hole is provided so as not to penetrate the carrier, and the bolt insertion hole is formed in the carrier. It is necessary to leave no part (non-penetrating part). The non-penetrating portion is set to a certain size (thickness) so as not to penetrate the carrier even if the drilling depth varies when the bolt insertion hole is drilled with a tool. That is, at the time of drilling the bolt insertion hole, it is necessary to stop the machining with the tool at a position considerably before the tip of the tool reaches the inner surface of the carrier.

  A female screw for screwing the bolt is formed in the bolt insertion hole. This female screw is provided in the following procedure. That is, first, a pilot hole (drilled hole) is formed by a tool at a predetermined portion of the carrier, and then an internal thread is formed by threading the inner peripheral surface of the pilot hole. Here, the shape of the end portion on the back side of the prepared hole has a shape corresponding to the shape of the tip portion of the tool, that is, a tapered conical shape (see the conical portion 117 in FIG. 4B). An internal thread cannot be formed in the conical part 117 and its vicinity.

  In other words, in the gear device, in the thickness direction of the carrier, it is necessary to secure the length of the non-through portion while securing the length of the bolt insertion hole necessary for fastening the bolt, and further, the conical portion of the pilot hole Causes an increase in the thickness of the carrier. From this point of view, the gear device of Patent Document 1 has room for further thinning.

  Further, when a projecting portion in which a part of the carrier projects into the swing gear as in Patent Document 2 is provided, the structure of the device becomes complicated, resulting in an increase in cost.

  An object of the present invention is to provide an eccentric oscillating gear device that can be thinned with a simple structure.

  The eccentric oscillating gear device of the present invention has an outer cylinder having a plurality of internal teeth on an inner peripheral surface, an eccentric portion, and a through hole into which the eccentric portion is inserted, and is interlocked with the rotation of the eccentric portion. A rocking gear that rotates in the outer cylinder while meshing with the inner teeth, and a bolt insertion hole that penetrates in the thickness direction, and is fixed to the fixing target member by a bolt that is screwed into the bolt insertion hole, A carrier that rotates relative to the outer cylinder by transmitting the rotation of the oscillating gear, and a closing member that closes the opening of the bolt insertion hole.

  With this configuration, a bolt insertion hole that penetrates the carrier in the thickness direction is provided, and a structure in which the opening of the bolt insertion hole is closed by a closing member can be used to reduce the thickness with a simple structure. it can. That is, in this configuration, the opening of the bolt insertion hole that penetrates the carrier is closed by the closing member, so that the lubricant in the gear device can be prevented from flowing out through the bolt insertion hole. Since the bolt insertion hole is formed so as to penetrate the carrier in the thickness direction, the conical portion formed in the conventional pilot hole is not formed in the bolt insertion hole. In addition, since the opening is closed with a blocking member after the pilot hole that penetrates the carrier is formed, a relatively large non-penetration is considered in consideration of variations in the drilling depth of the bolt insertion hole as in the past. There is no need to provide a part. Therefore, in this configuration, the thickness of the carrier can be further reduced as compared with the conventional case. As described above, in this configuration, even if a complicated structure as in Patent Document 2 is not adopted, the lubricant in the gear device is prevented from flowing out through the bolt insertion hole, and the thickness is reduced. be able to.

  In the eccentric oscillating gear device, the bolt insertion hole has an internal thread portion in which an internal thread for screwing the bolt is formed, an internal thread is not formed, and at least a part of the closing member is disposed. A configuration in which the inner diameter of the female screw portion is the same as the inner diameter of the arrangement portion can be exemplified.

  In this configuration, the inner diameter of the female screw portion is the same as the inner diameter of the arrangement portion. Therefore, in this configuration, a bolt insertion hole can be provided in the carrier by first forming a pilot hole penetrating the carrier and then forming a female screw on a part of the inner peripheral surface of the pilot hole. Therefore, in this configuration, it is possible to suppress an increase in the manufacturing process when forming the disposing portion for the closing member. Further, in this configuration, since the female screw is not formed in the arrangement portion and at least a part of the closing member is arranged in this arrangement portion, for example, when the female screw is formed in the entire axial direction of the bolt insertion hole As compared with the above, the degree of liquid-tightness between the inner peripheral surface of the arrangement portion and the outer peripheral surface of the closing member can be increased.

  Further, in the eccentric oscillating gear device, the bolt insertion hole includes an internal thread portion in which an internal thread for screwing the bolt is formed, and an internal thread is not formed, and at least a part of the closing member is disposed. A configuration in which an inner diameter of the arrangement portion is larger than an inner diameter of the female screw portion.

  In this configuration, since the inner diameter of the arrangement portion is larger than the inner diameter of the female screw portion, the bolt can be arranged so that the tip end portion of the bolt extends over the arrangement portion, and the options of the bolt to be used are widened. Further, in this configuration, since the step portion is formed at the boundary between the female screw portion and the arrangement portion, it becomes easy to position the closing member in the step portion in the case as shown in FIG.

  Further, in the eccentric oscillating gear device, the bolt insertion hole includes an internal thread portion in which an internal thread for screwing the bolt is formed, and an internal thread is not formed, and at least a part of the closing member is disposed. The arrangement portion has a reduced diameter portion whose inner diameter decreases as it goes in the bolt insertion direction, and the closing member is in contact with the inner surface of the reduced diameter portion. Also good.

  In this configuration, since the closing member is in contact with the inner surface of the reduced diameter portion, the closing member is prevented from being displaced in the bolt insertion direction. Further, in this configuration, since the female screw is not formed in the arrangement portion and at least a part of the closing member is arranged in this arrangement portion, for example, when the female screw is formed in the entire axial direction of the bolt insertion hole As compared with the above, the degree of liquid-tightness between the inner peripheral surface of the arrangement portion and the outer peripheral surface of the closing member can be increased.

  According to the present invention, the eccentric oscillating gear device can be thinned with a simple structure.

It is sectional drawing which shows the eccentric rocking | fluctuation type gear apparatus which concerns on 1st Embodiment of this invention. It is sectional drawing in the II-II line of FIG. (A) is sectional drawing which shows the bolt insertion hole and obstruction | occlusion member of the carrier of the eccentric rocking | fluctuation type gear apparatus which concerns on 1st Embodiment. (B) is a top view which shows the said obstruction | occlusion member. (A) is sectional drawing which shows the structure where the fixation object member is fixed to a carrier with a volt | bolt in the eccentric rocking | fluctuation type gear apparatus which concerns on 1st Embodiment. (B) is a sectional view showing a structure in which a member to be fixed is fixed to a carrier by a bolt in an eccentric oscillating gear device according to a reference example. (A) is sectional drawing which shows the bolt insertion hole and obstruction | occlusion member of the carrier of the eccentric rocking | fluctuation type gear apparatus which concerns on the modification 1 of 1st Embodiment. (B) is sectional drawing which shows the bolt insertion hole and obstruction | occlusion member of a carrier of the eccentric rocking | fluctuation type gear apparatus which concerns on the modification 2 of 1st Embodiment. (A) is sectional drawing which shows the bolt insertion hole and obstruction | occlusion member of a carrier of the eccentric rocking | fluctuation type gear apparatus which concerns on the modification 3 of 1st Embodiment. (B) is sectional drawing which shows the bolt insertion hole and obstruction | occlusion member of a carrier of the eccentric rocking | fluctuation type gear apparatus which concerns on the modification 4 of 1st Embodiment. (A) is sectional drawing which shows the bolt insertion hole and obstruction | occlusion member of a carrier of the eccentric rocking | fluctuation type gear apparatus which concerns on the modification 5 of 1st Embodiment. (B) is sectional drawing which shows the bolt insertion hole and obstruction | occlusion member of a carrier of the eccentric rocking | fluctuation type gear apparatus which concerns on the modification 6 of 1st Embodiment. It is sectional drawing which shows the eccentric rocking | fluctuation type gear apparatus which concerns on 2nd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  An eccentric oscillating gear device (hereinafter simply referred to as a gear device) according to the present embodiment is a gear configured as a speed reducer used in, for example, a revolving part such as a revolving trunk or arm joint of a robot or a revolving part of various machine tools. Device.

(First embodiment)
As shown in FIGS. 1 and 2, the gear device 10 according to the first embodiment includes an outer cylinder 12, a carrier 14, a rocking gear (external gear) 18, a crankshaft 20, and a closing member 60. It has. The carrier 14 has a bolt insertion hole 14c penetrating in the thickness direction (left-right direction in FIG. 1). The closing member 60 is for closing the opening of the bolt insertion hole 14c. The closing member 60 will be described in detail later.

  The outer cylinder 12 has a cylindrical shape that is short in the axial direction (left-right direction in FIG. 1), and includes a main body portion 22 and a flange portion 24 provided on one side of the main body portion 22 in the axial direction. . The flange portion 24 is provided so as to protrude radially outward from the main body portion 22, and the flange portion 24 is provided with bolt insertion holes 24 a at equal intervals in the circumferential direction. The bolt insertion hole 24a is used for fastening the outer cylinder 12 to a mating member not shown.

  The main body 22 of the outer cylinder 12 is divided into two in the axial direction. That is, the main body portion 22 includes two members, and the two members are joined to each other in the axial direction. Specifically, the main body 22 includes a first member 27 and a second member 28, and the first end surface 27a of the first member 27 and the first end surface 28a of the second member 28 are in contact with each other. In the state, the first member 27 and the second member 28 are fastened to each other by an unillustrated bolt. Both the first member 27 and the second member 28 are formed in a cylindrical shape, and both the members 27 and 28 have inner peripheral surfaces having the same inner diameter. A recess (O-ring groove) is formed in the first end surface 27a of the first member 27, and an O-ring 30 is attached to the recess. In this state, the first member 27 and the second member 28 are joined. Has been. In the first member 27, a mating member (not shown) is joined to the second end surface 27b which is the end surface opposite to the first end surface 27a in the crankshaft 20 direction.

  The first member 27 is integrally formed with the flange portion 24 on the outer peripheral portion thereof, and a plurality of circular grooves are formed on the inner peripheral surface of the first member 27 at equal intervals in the circumferential direction. A cylindrical inner pin 32 that functions as an inner tooth of the outer cylinder is fitted in the circular groove. The swing gear 18 is provided corresponding to the position of the internal tooth pin 32. That is, the oscillating gear 18 is brought close to one end side of the outer cylinder 12 in the axial direction (the right side in FIG. 1).

  A recess 34 is formed in the second end surface 27b of the first member 27, which is the end surface of the first member 27 opposite to the first end surface 27a, over a predetermined range radially outward from the inner peripheral surface. A thin disc-shaped cover 36 is fitted in the recess 34. The cover 36 has a thickness that can be accommodated between the second end surface 27 b and the swing gear 18, and has a thickness that does not protrude in the axial direction from the first member 27. By attaching the cover 36 to the recess 34 of the outer cylinder 12, the inner space of the outer cylinder 12 is closed from one side. Thereby, even when lubricating oil is filled in the inner space, oil leakage can be prevented from the second end face 27b side of the first member 27.

  The second member 28 has a recess 38 formed in the inner peripheral surface at a portion opposite to the first member 27, and the inner diameter is increased at this portion. A seal member 40 such as an oil seal is disposed in the recess 38. Thereby, it is possible to prevent the lubricating oil from leaking from the second member 28. The flange portion 24 may be provided on the second member 28 instead of the first member 27.

  The carrier 14 is inserted into the outer cylinder 12 from the other end side (left side in FIG. 1) in the axial direction with respect to the outer cylinder 12. The carrier 14 is disposed on one side in the axial direction of the crankshaft 20 with respect to the swing gear 18.

  The carrier 14 is supported by the outer cylinder 12 by the main bearing 16 and is rotatable coaxially with the outer cylinder 12. That is, the carrier 14 is rotatable relative to the outer cylinder 12. The carrier 14 can be fastened to the fixation target member 70 (see FIG. 4A), and relative rotation between the carrier 14 and the outer cylinder 12 causes relative rotation around the axis at the turning portion. It is possible. The fixation target member 70 is a mating member different from the mating member joined to the second end surface 27b described above.

  The main bearing 16 is located on the same side as the carrier 14 with respect to the rocking gear 18 in the axial direction of the crankshaft 20, and is disposed where the first member 27 and the second member 28 of the outer cylinder 12 are in contact with each other. Has been. Specifically, a conical surface (first conical surface) 27d inclined with respect to the inner peripheral surface is formed on the first end surface 27a of the first member 27, and the first end surface 28a of the second member 28 is also formed on the inner surface. A conical surface (second conical surface) 28c inclined with respect to the peripheral surface is formed. The first conical surface 27d and the second conical surface 28c form a concave groove having a triangular cross section extending over the entire inner circumferential surface of the outer cylinder 12 in the circumferential direction.

  In the present embodiment, the main bearing 16 is composed of a cross roller bearing, but is not limited to this, and other bearings such as a four-point contact ball bearing may be employed. The roller 16a of the main bearing 16 is disposed in contact with the conical surfaces 27d and 28c. The rollers 16a are arranged at intervals in the circumferential direction of the outer cylinder 12, and are oriented in directions in which the rolling axes of the rollers 16a adjacent in the circumferential direction are orthogonal to each other.

  On the other hand, on the outer peripheral surface of the carrier 14, a concave groove 42 is formed corresponding to the first conical surface 27 d of the first member 27 and the second conical surface 28 c of the second member 28. The concave groove 42 has a first conical surface 42 a parallel to the first conical surface 27 d of the first member 27 and a second conical surface 42 b parallel to the second conical surface 28 c of the second member 28. Therefore, for every other roller 16a, the first conical surface 27d of the first member 27 serves as an outer rolling surface, and the first conical surface 42a of the carrier concave groove 42 serves as an inner rolling surface. For the other rollers 16a, the second conical surface 28c of the second member 28 serves as an outer rolling surface, and the second conical surface 42b of the carrier concave groove 42 serves as an inner rolling surface. In other words, a part of the outer cylinder 12 functions as an outer ring of the main bearing 16 and a part of the carrier 14 functions as an inner ring of the main bearing 16. Since the inner ring and the outer ring of the main bearing 16 are formed integrally with the carrier 14 and the outer cylinder 12, respectively, the outer cylinder 12 is divided into the first member 27 and the second member 28, and the main bearing 16 is also transferred to the carrier 14 In this state, the first member 27 and the second member 28 are fastened together.

  The carrier 14 and the rocking gear 18 are formed with central through holes 14a and 18a passing through the axis of the outer cylinder 12, respectively. The center through holes 14a and 18a may have a configuration in which an input shaft (not shown) is inserted, but in this embodiment, the input shaft is not inserted. By providing the carrier 14 and the rocking gear 18 with the central through holes 14a and 18a, the carrier 14 and the swing gear 18 can be shared with other types of gear devices. Moreover, weight reduction of the gear apparatus is also achieved by forming the central through holes 14a and 18a. When the input shaft is inserted through the central through holes 14a and 18a, a recess (O-ring groove) 27e provided on the outer peripheral side of the second end surface 27b of the first member 27 with the cover 36 removed is shown in FIG. A substantially O-ring is attached, and the second end face 27b is joined to the mating member. Thereby, it can prevent that lubricating oil leaks from the joint surface of the 2nd end surface 27b and a counterpart member.

  The carrier 14 is formed with a crankshaft hole 14b through which the crankshaft 20 is inserted. Further, the swinging gear 18 is formed with a first through hole 18b for allowing the crankshaft 20 to be inserted therethrough. In this embodiment, since three crankshafts 20 are provided, three crankshaft holes 14b and three first through holes 18b are provided. Note that a plurality of second through holes 18c are formed in the oscillating gear 18 at intervals in the circumferential direction, but nothing is inserted through the second through holes 18c in this embodiment. The 2nd through-hole 18c can be utilized when the rocking gearwheel 18 is used for another type of gear apparatus. Further, since the second through hole 18 c is formed in the swing gear 18, it contributes to the weight reduction of the swing gear 18.

  The crankshaft 20 has a shaft body 20a and an eccentric portion 20b formed integrally with the shaft body 20a. In the present embodiment, only one eccentric portion 20b is provided and formed at the end portion of the crankshaft 20, but the present invention is not limited to this. When a plurality of eccentric parts are provided, a plurality of swing gears corresponding to these eccentric parts are provided. The crankshaft 20 is disposed so that the eccentric portion 20b is parallel to the axial direction of the outer cylinder 12 in a posture where the eccentric portion 20b is on the first member 27 side, and the swinging gear 18 is connected to the eccentric portion 20b via a rolling bearing 43. Is attached.

  One end portion 20c of the shaft main body 20a opposite to the eccentric portion 20b is splined, and a transmission gear 44 is attached to the one end portion 20c. A rotational driving force is applied to the transmission gear 44 from a driving gear (not shown), and the gear device 10 is driven by this rotational driving force.

  The crankshaft 20 is rotatably supported by the carrier 14 via a crank bearing 48. In the present embodiment, only one crank bearing 48 is provided, and is disposed on the same side as the main bearing 16 with respect to the swing gear 18. The crank bearing 48 is attached to the shaft body 20a between the splined end portion 20c and the eccentric portion 20b. A plurality of crank bearings may be provided.

  The main bearing 16 and the crank bearing 48 are disposed so as to be located on the same plane orthogonal to the crankshaft 20. That is, the main bearing 16 and the crank bearing 48 are arranged so that the main bearing 16 and the crank bearing 48 overlap at least partly when viewed in a direction orthogonal to the crankshaft 20.

  The crank bearing 48 is constituted by a cross roller bearing, but is not limited thereto. The crank bearing 48 includes an inner ring 48b configured separately from the crankshaft 20, and an outer ring 48c configured separately from the carrier 14, and the roller 48a rolls between the inner ring 48b and the outer ring 48c. .

  In the gear device 10 according to the present embodiment, when the transmission gear 44 is rotated by a driving force of a motor (not shown), the crankshaft 20 is also rotated integrally. The rotation of the crankshaft 20 causes the oscillating gear 18 to rotate while meshing with the internal tooth pin 32 as the eccentric portion 20b oscillates. At this time, the crankshaft 20 revolves around the axis of the outer cylinder 12 while rotating, and accordingly, the carrier 14 rotates. The rotational speed of the carrier 14 is a rotational speed that is decelerated at a predetermined ratio with respect to the rotational speed input to the transmission gear 44.

  Next, the bolt insertion hole 14c of the carrier 14 and the closing member 60 disposed in the bolt insertion hole 14c will be described. As shown in FIGS. 3A and 4A, the fixing target member 70 is fixed to the carrier 14 by a bolt 80 screwed into the bolt insertion hole 14c. The closing member 60 is for closing the opening 14 d of the bolt insertion hole 14 c in the carrier 14. The opening 14d is an opening that opens on the end surface (the inner surface 14f of the carrier 14) opposite to the inlet into which the bolt is inserted, out of the two openings at both ends of the bolt insertion hole 14c. Examples of the fixing target member 70 include a turning arm of a robot and a rotary table of a machine tool.

  As shown in FIG. 3A, the bolt insertion hole 14c of the carrier 14 penetrates the carrier 14 in the thickness direction of the carrier 14 (vertical direction in FIG. 3A). The bolt insertion hole 14c has an opening 14d (opening 14d that opens in the bolt insertion direction D) that opens on the inner surface 14f of the carrier 14 and an opening 14e that opens on the outer surface 14g of the carrier 14 (the direction opposite to the bolt insertion direction D). And an opening 14e) that is open to the surface. The bolt 80 is inserted into the bolt insertion hole 14c along the bolt insertion direction D from the opening 14e.

  The bolt insertion hole 14 c includes an internal thread portion 141 and an arrangement portion 142. A female screw 141 a for screwing the bolt 80 is formed in the female screw portion 141. The closing member 60 is arranged in the arrangement part 142. An internal thread is not formed on the inner peripheral surface 142 a of the arrangement portion 142.

  The arrangement part 142 is provided on the bolt insertion direction D side with respect to the female screw part 141. In the present embodiment, the arrangement portion 142 is provided on the inner surface 14 f side (oscillation gear 18 side) of the carrier 14 with respect to the female screw portion 141, and the female screw portion 141 is on the outer surface 14 g side of the carrier 14 with respect to the arrangement portion 142. Is provided.

  In the present embodiment, the shape of the bolt insertion hole 14 c is circular when the bolt insertion hole 14 c is viewed in the bolt insertion direction D. Specifically, the shape of the female screw portion 141 and the shape of the arrangement portion 142 are circular when the bolt insertion hole 14c is viewed in the bolt insertion direction D.

  In the present embodiment, the inner diameter D1 of the female screw portion 141 (the inner diameter of the crest portion of the female screw 141a) is the same as the inner diameter D2 of the arrangement portion 142, but is not limited thereto. For example, the inner diameter D2 of the arrangement portion 142 may be larger than the inner diameter D1 of the female screw portion 141, and the inner diameter D2 of the arrangement portion 142 may be smaller than the inner diameter D1 of the female screw portion 141 as in Modification 3 described later. .

  In the present embodiment, the inner diameter D2 of the arrangement portion 142 is constant throughout the bolt insertion direction D, but is not limited thereto. For example, as in Modifications 5 and 6 described later, the inner diameter D2 of the arrangement portion 142 may not be constant over the entire bolt insertion direction D.

  In the present embodiment, the length L1 of the female screw portion 141 in the bolt insertion direction D is larger than the length L2 of the arrangement portion 142 in the bolt insertion direction D, but is not limited thereto. However, from the viewpoint of making the thickness of the carrier 14 as small as possible, the length L2 of the arrangement portion 142 is preferably smaller than the length L1 of the female screw portion 141.

  The shape and size of the closing member 60 correspond to the shape and size of the arrangement portion 142. By disposing the closing member 60 in the arrangement portion 142 and closing the opening portion 14d of the bolt insertion hole 14c, it is possible to suppress the lubricant in the gear device 10 from flowing out through the bolt insertion hole 14c.

  As the material of the closing member 60, various materials such as synthetic resin, natural resin, plastic, synthetic rubber, and metal can be used. For example, when an elastic material is used as the material of the closing member 60, the closing member 60 can be inserted by being elastically deformed when inserted into the placement portion 142. As a result, it is easy to place the closing member 60 on the placement portion 142, and the degree of liquid-tightness between the inner peripheral surface 142a of the placement portion 142 and the outer peripheral surface 60b of the closing member 60 can be increased. Examples of the elastic material include synthetic rubber having elasticity.

  Further, when the carrier 14 and the closing member 60 are both made of metal, the closing member 60 can be joined to the placement portion 142 using a joining means such as welding. In the case where the closing member 60 is made of plastic, the closing member 60 can be joined to the placement portion 142 using a joining means such as adhesion or fusion.

  As shown in FIGS. 3A and 3B, the closing member 60 in the present embodiment includes a disk-shaped bottom portion 61 and a side wall portion 62 that stands up from the periphery of the bottom portion 61, and the bottom portion 61 and the side wall portion 62. However, the present invention is not limited to this. For example, a configuration (solid) that does not have a hollow portion as in Modification 2 shown in FIG. 5B, Modification 5 shown in FIG. 7A, Modification 6 shown in FIG. Form).

  When the closing member 60 has the hollow part 63, the material cost of the closing member 60 can be reduced. Further, when the closing member 60 has the hollow portion 63 and the closing member 60 is formed of an elastic material, the side wall portion 62 of the closing member 60 is more easily elastically deformed. The arrangement work to the part 142 becomes still easier.

  In this embodiment, in the state (state shown in FIG. 4A) where the closing member 60 is disposed on the placement portion 142, there is a gap between the inner peripheral surface 142 a of the placement portion 142 and the outer peripheral surface 60 b of the closure member 60. Is hardly formed. In the present embodiment, the surface 60a of the bottom 61 of the closing member 60 is located on substantially the same plane as the inner surface 14f of the carrier 14, but the present invention is not limited to this. For example, as in Modification 1 shown in FIG. 5A, the surface 60 a of the bottom 61 of the closing member 60 may not be located on the same plane as the inner surface 14 f of the carrier 14.

  As shown in FIG. 3B, the outer diameter D3 of the closing member 60 before being arranged in the arrangement portion 142 is substantially the same as the inner diameter D2 of the arrangement portion 142 or larger than the inner diameter D2. For example, when the closing member 60 is made of an elastic material, the outer diameter D3 of the closing member 60 may be larger than the inner diameter D2 of the arrangement portion 142. In this case, when the closing member 60 is inserted into the placement portion 142, it may be inserted by being elastically deformed. When the closing member 60 is placed at the placement portion 142, a high liquid-tight state can be obtained.

  In the present embodiment, the length L3 of the closing member 60 in the bolt insertion direction D (the thickness L3 of the closing member 60) is smaller than the length L2 of the arrangement portion 142, but is not limited thereto. For example, as in Modification 6 shown in FIG. 7B, the thickness L3 of the closing member 60 may be substantially the same as the length L2 of the placement portion 142. Although illustration is omitted, a part of the blocking member 60 may be disposed in the placement portion 14 and another part of the blocking member 60 may enter the female screw portion 141. Furthermore, although illustration is omitted, a part of the closing member 60 may be disposed in the placement portion 14 and another part of the closing member 60 may protrude from the opening 14d to the outside of the bolt insertion hole 14c.

  In the present embodiment shown in FIG. 4A, the bolt 14 is inserted through the carrier 14 in the thickness direction (bolt insertion direction D) in the carrier 14, and a cap-shaped closing member 60 is fitted into the through hole from the inside. Adopted. Specifically, in the present embodiment, first, a pilot hole (drilling hole) penetrating the carrier 14 is formed in the carrier 14, and then a female screw 141a is formed in a part of the axial direction of the pilot hole to form the female screw portion. 141 is formed. The remaining portion where the female screw 141 a is not formed becomes the arrangement portion 142. The female thread portion 141 is formed in consideration of a bolt fastening length necessary for fastening the bolt 80.

  In the present embodiment, the thickness L3 of the closing member 60 is smaller than the length L2 of the arrangement portion 142 as shown in FIG. 3A, and the closing member 60 is in the female thread portion 141 as shown in FIG. However, if the closing member 60 is further brought closer to the female screw portion 141, the length L2 of the placement portion 142 can be further reduced, so that the carrier 14 can be further reduced in thickness.

  On the other hand, in the eccentric oscillating gear device according to the reference example shown in FIG. 4B, the non-penetrating portion (non-penetrating portion) 116 is left in order to prevent the lubricant in the gear device from flowing out. In this state, a bolt insertion hole 114c is formed in the carrier 114. As described above, the non-penetrating portion 116 is set to a certain size (thickness) so as not to penetrate the carrier even if the drilling depth varies when the bolt insertion hole is drilled by a tool. Is done. That is, at the time of drilling the bolt insertion hole, it is necessary to stop the machining with the tool at a position considerably before the tip of the tool reaches the inner surface of the carrier. Thus, in the reference example, since the bolt insertion hole 114c does not penetrate the carrier 114, a relatively large non-penetrating portion 116 is provided in consideration of the safety factor at the time of drilling. The thickness L13 of the non-penetrating portion 116 is one of the causes that increase the thickness of the carrier. In the reference example shown in FIG. 4B, the length L1 of the female screw portion 115 of the bolt insertion hole 114c is the same as the length L1 of the female screw portion 141 in the present embodiment shown in FIG.

  In this reference example, since the bolt insertion hole 114c does not penetrate the carrier 114, the end of the bolt insertion hole 114c on the non-penetrating part 116 side is a tool used for drilling the bolt insertion hole 114c. A conical portion 117 having a shape corresponding to the tip shape is formed. An internal thread cannot be formed on the inner peripheral surface of the conical portion 117. Therefore, in the reference example, the thickness L12 of the conical portion 117 causes an increase in the thickness of the carrier.

  Bolt insertion holes 71 are formed in the fixing target member 70. When fixing the fixing target member 70 to the carrier 14, the screw portion 82 of the bolt 80 is inserted into the bolt insertion hole 71 with the position of the bolt insertion hole 71 aligned with the position of the bolt insertion hole 14c of the carrier 14. The tool is fitted to the head 81 of the bolt 80 and the bolt 80 is screwed into the female thread portion 141. As shown in FIG. 3A, the closing member 60 is inserted into the placement portion 142 from the inner surface 14 f side of the carrier 14 and is fitted to the placement portion 142. The closing member 60 may be inserted into the placement portion 142 from the outer surface 14g side of the carrier 14.

(Modification 1)
FIG. 5A is a cross-sectional view showing the bolt insertion hole 14c and the closing member 60 of the carrier 14 of the gear device 10 according to Modification 1 of the first embodiment. In the first modification, the closing member 60 is disposed on the rear side (the female screw portion 141 side) in the arrangement portion 142 as compared with the embodiment shown in FIG. In the embodiment shown in FIG. 4 (A), the surface 60a of the bottom 61 of the closing member 60 is located substantially on the same plane as the inner surface 14f of the carrier 14, but in Modification 1, the bottom 61 of the closing member 60 is The front surface 60a is located on the back side (internal thread portion 141 side) with respect to the inner surface 14f of the carrier 14.

(Modification 2)
FIG. 5B is a cross-sectional view showing the bolt insertion hole 14c and the closing member 60 of the carrier 14 of the gear device 10 according to the second modification of the first embodiment. In the second modification, the closing member 60 has a cylindrical shape. The closing member 60 does not have the hollow portion 63 like the closing member 60 shown in FIG. 3A, and the inside of the closing member 60 is solid.

(Modification 3)
FIG. 6A is a cross-sectional view showing the bolt insertion hole 14c and the closing member 60 of the carrier 14 of the gear device 10 according to Modification 3 of the first embodiment. In the third modification, the inner diameter D2 of the arrangement portion 142 is larger than the inner diameter D1 of the female screw portion 141. Accordingly, the outer diameter of the closing member 60 is adjusted to match the inner diameter D2 of the arrangement portion 142.

  In Modification 3, since the inner diameter D2 of the arrangement portion 142 is larger than the inner diameter D1 of the female screw portion 141, a step portion 14h is formed at the boundary portion between the arrangement portion 142 and the female screw portion 141. The step portion 14h has an annular shape when the bolt insertion hole 14c is viewed from the arrangement portion 142 side.

  In the third modification, a pilot hole (drilling hole) penetrating the carrier 14 is formed in the carrier 14, and then a female screw 141a is formed in a part of the pilot hole in the axial direction to form the female screw part 141. And the arrangement | positioning part 142 is formed by giving the process which further enlarges the internal diameter of the part (part by the side of the inner surface 14f of the carrier 14) in which the internal thread 141a is not formed. This diameter expansion processing is performed from the inner surface 14f side of the carrier 14 in the direction opposite to the bolt insertion direction D. The diameter expansion process may be performed before the process of forming the female screw 141a.

(Modification 4)
FIG. 6B is a cross-sectional view showing the bolt insertion hole 14c and the closing member 60 of the carrier 14 of the gear device 10 according to Modification 4 of the first embodiment. In the fourth modification, the position of the closing member 60 in the arrangement portion 142 is different from that in the third modification, and the other configurations are the same as those in the third modification.

  In the modified example 4, in the arrangement | positioning part 142, the closure member 60 is arrange | positioned in the state which adjoins to the level | step-difference part 14h, or the state which contact | connects the level | step-difference part 14h. That is, the end surface 60c on the female screw portion 141 side of the closing member 60 is close to or in contact with the surface of the annular stepped portion 14h. In this modification 4, it is easy to position the closing member 60 at the step 14h. In the modification 4, the surface 60a of the closing member 60 is located closer to the female screw portion 141 than the inner surface 14f of the carrier 14, but the present invention is not limited to this. The surface 60a of the closing member 60 may be at the same position as the inner surface 14f of the carrier 14, for example (may be flush).

(Modification 5)
FIG. 7A is a cross-sectional view showing the bolt insertion hole 14c and the closing member 60 of the carrier 14 of the gear device 10 according to Modification 5 of the first embodiment. In the fifth modification, the inner diameter of the arrangement portion 142 is not constant over the entire bolt insertion direction D. The arrangement portion 142 of the modified example 5 has a reduced diameter portion 144 that decreases in inner diameter in the bolt insertion direction D. Specifically, the placement portion 142 includes a portion 143 having a constant inner diameter and the reduced diameter portion 144. The constant inner diameter portion 143 is located closer to the female screw portion 141 than the reduced diameter portion 144.

  In the fifth modification, the constant inner diameter portion 143 can be omitted. Further, instead of the reduced diameter portion 144, a not-illustrated enlarged diameter portion (a portion where the inner diameter increases in the bolt insertion direction D) may be provided.

  The closing member 60 has a shape that matches the shapes of the constant inner diameter portion 143 and the reduced diameter portion 144. Specifically, the closing member 60 includes a portion 64 having a constant outer diameter and a reduced diameter portion 65 that decreases in the outer diameter in the bolt insertion direction D. The outer surface 64a of the constant outer diameter portion 64 is in contact with the inner surface 143a of the constant inner diameter portion 143, and the outer surface 65a of the reduced diameter portion 65 is in contact with the inner surface 144a of the reduced diameter portion 144. In the fifth modification, the inner surface 144a of the reduced diameter portion 144 with which the outer surface 65a of the reduced diameter portion 65 contacts has a function of preventing the closing member 60 from moving out of the bolt insertion hole 14c.

  In the fifth modification, the closing member 60 is inserted into the bolt insertion hole 14c from the opening 14e side.

(Modification 6)
FIG. 7B is a cross-sectional view showing the bolt insertion hole 14c and the closing member 60 of the carrier 14 of the gear device 10 according to Modification 6 of the first embodiment. This modified example 6 is different from modified example 5 in that the end surface 60 d on the female screw portion 141 side of the closing member 60 is close to or in contact with the tip end portion 82 a of the screw portion 82 of the bolt 80. Thereby, the displacement of the closing member 60 at the placement portion 142 is suppressed.

  Further, in this modified example 6, when the closing member 60 is formed of an elastic material and the end surface 60d of the closing member 60 is in contact with the tip end portion 82a of the screw portion 82 of the bolt 80, the following is performed. An effect is obtained. That is, when the end surface 60d of the closing member 60 is pressed in the bolt insertion direction D by the tip end portion 82a of the bolt 80, the closing member 60 is elastically deformed, so that the inner peripheral surface 142a of the arrangement portion 142 and the outer periphery of the closing member 60 The degree of liquid tightness between the surface 60b is further increased.

(Second Embodiment)
FIG. 8 is a sectional view showing an eccentric oscillating gear device according to the second embodiment of the present invention. The second embodiment is a so-called center crank type gear device 10. Although specifically described below, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the gear device 10 according to the second embodiment, the crankshaft 20 is inserted into the center through holes 14 a and 18 a of the carrier 14 and the rocking gear 18. That is, the crankshaft 20 is disposed on the axis of the outer cylinder 12.

  The crankshaft 20 is provided with a shaft hole 56 penetrating the central portion in the axial direction, and the shaft hole 56 is provided with a key groove 56a. Then, for example, an input shaft (not shown) is inserted into the shaft hole 56, and the crankshaft 20 rotates integrally with the input shaft. In the present embodiment, unlike the first embodiment, the end of the crankshaft 20 is not splined and the transmission gear 44 is omitted. Therefore, the thickness is further reduced compared to the first embodiment. In the second embodiment, the transmission gear 44 may be provided. In this case, a rotational driving force is applied to the transmission gear 44 from a driving gear (not shown), and the gear device 10 is driven by this rotational driving force.

  In the present embodiment, the crank bearing 48 that rotatably supports the crankshaft 20 is constituted by a deep groove ball bearing.

  Unlike the first embodiment, the carrier 14 is not provided with the crankshaft hole 14b, but a plurality of (for example, nine) shaft holes 14k are provided around the central through hole 14a. The shaft holes 14k are arranged at equal intervals in the circumferential direction.

  A through hole 18 d is formed in the swing gear 18 at a position corresponding to the shaft hole 14 k of the carrier 14. A shaft 58 is inserted across the shaft hole 14 k of the carrier 14 and the through hole 18 d of the rocking gear 18. A bush 90 is externally fitted to the shaft 58 at a position located in the through hole 18d.

  While the shaft 58 is press-fitted into the shaft hole 14k, it is inserted into the through hole 18d with a gap. When the swing gear 18 rotates while meshing with the inner tooth pin 32 of the outer cylinder 12 as the crankshaft 20 rotates, the position of the shaft 58 also moves around the axis of the outer cylinder 12, thereby causing the carrier 14. Rotates.

  Also in the second embodiment, the closing member 60 is disposed in the bolt insertion hole 14 c of the carrier 14. In the second embodiment, the same bolt insertion hole 14c and closing member 60 as in the first embodiment shown in FIG. 1 are provided, but the present invention is not limited to this. Also in the second embodiment, the bolt insertion hole 14c and the closing member 60 as in the first to sixth modifications of the first embodiment can be employed.

  As described above, in each embodiment and each modification, the bolt insertion hole 14c penetrating the carrier 14 is provided in the thickness direction, and the opening 14d of the bolt insertion hole 14c is blocked by the closing member 60. By adopting, thinning can be achieved with a simple structure. That is, in these aspects, since the opening 14d of the bolt insertion hole 14c penetrating the carrier 14 is blocked by the closing member 60, the lubricant in the gear device 10 flows out through the bolt insertion hole 14c. Can be prevented. Since the bolt insertion hole 14c is formed so as to penetrate the carrier 14 in the thickness direction, the conical portion 117 formed in the conventional pilot hole is not formed in the bolt insertion hole 14c. In addition, since the opening 14d is closed by the closing member 60 after the pilot hole penetrating the carrier 14 is formed, the variation in the drilling depth of the bolt insertion hole is relatively considered as in the prior art. There is no need to provide a large non-penetrating part. Therefore, in these aspects, the thickness of the carrier 14 can be further reduced as compared with the conventional case. As described above, in these aspects, the lubricant in the gear device 10 is prevented from flowing out to the outside through the bolt insertion hole 14c without using a complicated structure as in Patent Document 2, and is thin. Can be achieved.

  Moreover, in each embodiment and each modification, since parts other than the internal thread part 141 are utilized as the arrangement | positioning part (cap fitting part) 142 among pilot holes, compared with the carrier in the reference example shown to FIG. 4 (B). The thickness of the carrier 14 can be reduced. Since the carrier 14 can be thinned in this way, in this embodiment, it is not necessary to adopt the technique as in Patent Document 2, so that the shape is complicated and the weight is not as in the technique of Patent Document 2. In addition, it is possible to avoid the increase in processing cost and material cost.

  Further, in an aspect in which the inner diameter of the female screw portion is the same as the inner diameter of the arrangement portion, first, a pilot hole penetrating the carrier 14 is formed, and then a female screw 141a is formed on a part of the inner peripheral surface of the pilot hole, Bolt insertion holes 14 c can be provided in the carrier 14. Therefore, the increase in the manufacturing process at the time of forming the bolt insertion hole 14c can be suppressed.

  Further, in the aspect in which the closing member 60 is in contact with the inner surface 144a of the reduced diameter portion 144 of the arrangement portion 142, the closing member 60 is prevented from being displaced in the bolt insertion direction D.

  Moreover, in each embodiment and each modification, since the internal thread is not formed in the arrangement | positioning part 142, since at least one part of the closure member 60 is arrange | positioned in this arrangement | positioning part 142, for example in the axial direction in the bolt insertion hole 14c The degree of liquid-tightness between the inner peripheral surface 142a of the arrangement portion 142 and the outer peripheral surface 60b of the closing member 60 can be increased as compared with the case where female threads are formed as a whole. In addition, the internal thread part 141 is formed in the whole axial direction in the bolt insertion hole 14c, and the arrangement | positioning part 142 does not need to exist. The closing member 60 is disposed in the female screw portion 141. Even in this case, the degree of liquid-tightness between the female screw 141a and the outer peripheral surface 60b of the closing member 60 is obtained by using an elastic material as the material of the closing member 60. Can be increased.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to these embodiment, A various change, improvement, etc. are possible in the range which does not deviate from the meaning.

  For example, in the above-described embodiment, the case where the closing member 60 is arranged only in the arrangement part 142 and does not enter the female screw part 141 is illustrated, but the present invention is not limited to this. Since it is only necessary that at least a part of the closing member 60 is disposed in the arrangement part 142, a part of the closing member 60 may enter the female screw part 141, and a part of the closing member 60 may be a bolt insertion hole. You may protrude from the opening part 14d of 14c.

  Moreover, although the case where the number of the oscillating gear 18 is one was illustrated in the said embodiment, it is not limited to this. In the gear device 10, a plurality of oscillating gears 18 may be provided.

  Moreover, although the case where the carrier 14 is disposed only on one side in the axial direction of the crankshaft 20 with respect to the rocking gear 18 is illustrated in the above embodiment, the present invention is not limited to this. The carrier 14 is, for example, a first end plate (not shown) disposed on one side in the axial direction with respect to the rocking gear 18 and a second end disposed on the other side in the axial direction with respect to the rocking gear 18. A board part may be provided.

  Further, either the carrier 14 or the outer cylinder 12 may be fixed. In other words, the carrier 14 may be fixed and the outer cylinder 12 may be rotated relative to the carrier 14. The outer cylinder 12 may be fixed and the carrier 14 may be rotated relative to the outer cylinder 12. Form may be sufficient.

  Further, the crank bearing 48 may be constituted by a pair of tapered roller bearings instead of the cross roller bearing. Moreover, you may comprise by a pair of angular contact ball bearing and a double row tapered roller bearing.

  In the above-described embodiment, the crank bearing 48 is disposed only on the same side as the main bearing 16 with respect to the swing gear 18, and the crank bearing 48 and the main bearing 16 are located on the same plane orthogonal to the crankshaft 20. However, the present invention is not limited to this.

DESCRIPTION OF SYMBOLS 10 Eccentric oscillating gear apparatus 12 Outer cylinder 14 Carrier 14c Bolt insertion hole 14d Opening part 18 Oscillating gear 20 Crankshaft 60 Closure member 70 Fixing target member 80 Bolt 141 Female thread part 142 Arrangement part 143 Constant inside diameter 144 Reduced diameter part D Bolt insertion direction D1 Internal diameter of female thread D2 Internal diameter of placement section

Claims (4)

An outer cylinder having a plurality of internal teeth on the inner peripheral surface;
An eccentric part,
A rocking gear that has a through-hole into which the eccentric portion is inserted, and rotates in the outer cylinder while meshing with the inner teeth in conjunction with the rotation of the eccentric portion;
It has a bolt insertion hole that penetrates in the thickness direction, is fixed to a member to be fixed by a bolt that is screwed into the bolt insertion hole, and rotates relative to the outer cylinder by transmitting the rotation of the swing gear. With a career to
An eccentric oscillating gear device comprising: a closing member that closes an opening of the bolt insertion hole. The bolt insertion hole is
An internal thread portion in which an internal thread for screwing the bolt is formed;
An internal thread is not formed, and an arrangement portion in which at least a part of the closing member is arranged, and
The eccentric oscillating gear device according to claim 1, wherein an inner diameter of the female screw portion is the same as an inner diameter of the arrangement portion. The bolt insertion hole is
An internal thread portion in which an internal thread for screwing the bolt is formed;
An internal thread is not formed, and an arrangement portion in which at least a part of the closing member is arranged, and
The eccentric oscillating gear device according to claim 1, wherein an inner diameter of the arrangement portion is larger than an inner diameter of the female screw portion. The bolt insertion hole is
An internal thread portion in which an internal thread for screwing the bolt is formed;
An internal thread is not formed, and an arrangement portion in which at least a part of the closing member is arranged, and
The placement portion has a reduced diameter portion that decreases in inner diameter as it goes in the bolt insertion direction,
The eccentric oscillating gear device according to claim 1, wherein the closing member is in contact with an inner surface of the reduced diameter portion.

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