JP2014084951A - Eccentric oscillation type gear device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To previously prevent an eccentric oscillation type gear device from being damaged due to metal powder.SOLUTION: An eccentric oscillation type gear device 1 includes eccentric parts 10a, 10b, swing gears 14, 16, an external cylinder 2 having an internal tooth pin 3 to be engaged with external teeth 14a, 16a of the swing gear 14, 16, a carrier 4, and an oil seal cap 30. A closed space S for accommodating the swing gears 14, 16 is formed by the carrier 4 and the external cylinder 2. A through-hole 4d communicated to the closed space S and a crank shaft attaching hole 4e are formed on the carrier 4. The oil seal cap 30 is arranged on the through-hole 4d and the crank shaft attaching hole 4e and has ferromagnetism capable of adsorbing metal powder.

Description

  The present invention relates to an eccentric oscillating gear device.

  Conventionally, as disclosed in Patent Document 1 below, an eccentric oscillating gear device is known that reduces the rotational speed at a predetermined reduction ratio between two counterpart members. The eccentric oscillating gear device includes an outer cylinder fixed to one counterpart member, and a carrier disposed in the outer cylinder and fixed to the other counterpart member. The carrier has a substrate portion in which a shaft portion is integrally formed, and an end plate portion formed separately from the substrate portion. A swing gear attached to the eccentric part of the crankshaft is sandwiched between the substrate part and the end plate part, and in this state, the shaft part and the end plate part are fastened to each other by bolts. Then, when the swing gear rotates with the crankshaft rotating while meshing with the inner teeth of the outer cylinder, the carrier and the outer cylinder rotate relative to each other.

JP 2009-191946 A

  In the eccentric oscillating gear device, since a bearing or a gear is used, a lubricant is enclosed. For this reason, metal wear powder may be generated from bearings and gears, and metal generated on the side of the base (for example, industrial robot, machine tool, etc.) that is the counterpart to which the eccentric oscillating gear device is attached. Foreign matter (iron powder, wear powder, etc.) may enter the eccentric oscillating gear device. These wear powders and foreign matters may damage the bearings and gears, and in some cases, may lead to early breakage.

  Therefore, the present invention has been made in view of the above prior art, and an object of the present invention is to prevent damage to the eccentric oscillating gear device due to metal powder.

  In order to achieve the above object, the present invention provides a gear device that transmits a driving force by converting a rotational speed at a predetermined rotational speed ratio between a first member and a second member. And a swing gear having an insertion hole into which the eccentric portion is inserted and a tooth portion, and the tooth of the swing gear, the tooth of the swing gear being configured to be attachable to one of the first member and the second member. An outer cylinder having internal teeth meshing with a portion, a carrier configured to be attachable to the other of the first member and the second member, and an oil seal cap, and the carrier and the outer cylinder, A closed space for accommodating the oscillating gear is formed, one of the carrier and the outer cylinder is formed with a communication hole communicating with the closed space, and the oil seal cap is disposed in the communication hole. Has ferromagnetism capable of adsorbing metal powder And it has a eccentrically oscillating gear device.

  In the present invention, the lubricant can be sealed in the closed space by the oil seal cap. Further, since the oil seal cap is configured so that the metal powder can be adsorbed by a magnetic force, the oil seal cap can adsorb the metal powder when the metal powder enters the communication hole. Therefore, it is possible to prevent the metal powder from being caught in the meshing portion of the gear or from being caught in the bearing portion, thereby preventing the eccentric oscillating gear device from being damaged.

  The oil seal cap may include a cap body configured to close the communication hole, and a suction portion that is configured by a magnet and attached to the cap body.

  In this aspect, even if the cap body is not processed, it can function as a cap that plugs the communication hole as it is. Moreover, since the oil seal cap has a structure in which an adsorption portion made of a magnet is attached to the cap main body, it can have a magnetic attraction function without special processing.

  The oil seal cap may have a metal member, and the metal member may be magnetized.

  In this aspect, since the metal member provided in the oil seal cap is magnetized, the oil seal cap can have a magnetic attraction function without attaching a magnet.

  As described above, according to the present invention, it is possible to prevent the eccentric oscillating gear device from being damaged by the metal powder.

It is sectional drawing of the eccentric rocking | fluctuation type gear apparatus which concerns on embodiment of this invention. It is the side view which looked at the said eccentric rocking | fluctuation type gear apparatus from the board | substrate part side. It is sectional drawing of the oil seal cap provided in the said eccentric rocking | fluctuation type gear apparatus. It is sectional drawing of the oil seal cap provided in the eccentric rocking | fluctuation type gear apparatus which concerns on other embodiment of this invention.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.
An eccentric oscillating gear device (hereinafter referred to as a gear device) 1 according to this embodiment is applied as a speed reducer to, for example, a revolving part of a revolving trunk or arm joint of a robot, a revolving part of various machine tools, or the like. is there.

  The gear device 1 according to the present embodiment is configured to rotate the oscillating gears 14 and 16 by rotating the eccentric portions 10a and 10b of the crankshaft 10, thereby obtaining an output rotation decelerated from the input rotation. Has been. Thereby, for example, relative rotation can be caused between the base of the robot (one counterpart member) and the swing drum (the other counterpart member). For example, a base is illustrated as a 1st member, for example, a turning body is illustrated as a 2nd member.

  As shown in FIGS. 1 and 2, the gear device 1 includes an outer cylinder 2, a carrier 4, a plurality of (for example, three) crankshafts 10, and oscillating gears (first oscillating gear 14, second oscillating gear). A gear 16), a plurality of (for example, three) transmission gears 20, and an oil seal cap 30.

  The outer cylinder 2 constitutes the outer surface of the gear device 1 and has a substantially cylindrical shape. A large number of pin grooves 2 b are formed on the inner peripheral surface of the outer cylinder 2. Each pin groove 2b is disposed so as to extend in the axial direction of the outer cylinder 2, and has a semicircular cross-sectional shape in a cross section orthogonal to the axial direction. These pin grooves 2 b are arranged on the inner peripheral surface of the outer cylinder 2 at equal intervals in the circumferential direction.

  The outer cylinder 2 has a large number of internal tooth pins 3. Each internal tooth pin 3 is attached to a pin groove 2b. Specifically, each internal tooth pin 3 is fitted in the corresponding pin groove 2 b and is arranged in a posture extending in the axial direction of the outer cylinder 2. Thereby, the many internal tooth pins 3 are arranged at equal intervals along the circumferential direction of the outer cylinder 2. The first external teeth 14 a of the first oscillating gear 14 and the second external teeth 16 a of the second oscillating gear 16 are engaged with these internal tooth pins 3.

  The outer cylinder 2 is provided with a flange portion, and the flange portion is formed with an insertion hole 2a for inserting a fastener (bolt) for fixing to the base of the robot, for example.

  The carrier 4 is accommodated in the outer cylinder 2 in a state of being arranged coaxially with the outer cylinder 2. The carrier 4 rotates relative to the outer cylinder 2 around the same axis. Specifically, the carrier 4 is arranged on the radially inner side of the outer cylinder 2, and in this state, the carrier 4 can be rotated relative to the outer cylinder 2 by a pair of main bearings 6 provided to be separated from each other in the axial direction. It is supported by. An annular seal member 25 is provided between the outer cylinder 2 and the carrier 4.

  The carrier 4 includes a base portion 5 having a substrate portion 4a and a plurality of (for example, three) shaft portions 4c, and an end plate portion 7 formed separately from the base portion 5.

  The substrate portion 4a is disposed in the vicinity of one end portion in the axial direction in the outer cylinder 2. A circular through hole 4d is provided in the central portion in the radial direction of the substrate portion 4a. Around the through hole 4d, a plurality of (for example, three) crankshaft mounting holes 4e (hereinafter simply referred to as mounting holes 4e) are provided at equal intervals in the circumferential direction (see FIG. 2).

  A fastening hole 4g for fastening a fastener (bolt) (not shown) for fixing the carrier 4 to, for example, a revolving drum of the robot is formed in the substrate portion 4a.

  The end plate portion 7 is provided to be separated from the substrate portion 4a in the axial direction, and is disposed in the vicinity of the other end portion in the axial direction in the outer cylinder 2. A through hole 7 a is provided at the radial center of the end plate portion 7. Around the through hole 7a, a plurality of (for example, three) crankshaft mounting holes 7b (hereinafter simply referred to as mounting holes 7b) are provided at positions corresponding to the plurality of mounting holes 4e of the substrate portion 4a.

  In the outer cylinder 2, a closed space S surrounded by both inner surfaces of the end plate part 7 and the substrate part 4 a facing each other and the inner peripheral surface of the outer cylinder 2 is formed. That is, the closed space S is formed by the outer cylinder 2 and the carrier 4. The through holes 4d and 7a and the mounting holes 4e and 7b are communication holes that allow communication between the outside and the closed space S.

  The three shaft portions 4c are provided integrally with the substrate portion 4a, and linearly extend from one main surface (inner surface) of the substrate portion 4a to the end plate portion 7 side. The three shaft portions 4c are arranged at equal intervals in the circumferential direction. Each shaft portion 4 c is fastened to the end plate portion 7 by a bolt 9. That is, a bolt insertion hole 7c is formed in the end plate portion 7, and a fastening hole 4f is formed in the shaft portion 4c (base portion 5) so as to extend in the axial direction from the distal end surface. A bolt 9 is inserted into the bolt insertion hole 7 c of the end plate portion 7 from the side opposite to the base portion 4. The bolt 9 is screwed into the fastening hole 4f of the shaft portion 4c. Thereby, the board | substrate part 4a, the shaft part 4c, and the end plate part 7 are integrated. Further, the base portion 5 and the end plate portion 7 are positioned with respect to each other by a positioning pin 11.

  The three crankshafts 10 are arranged at equal intervals around the central through holes 4d and 7a in the outer cylinder 2. Each crankshaft 10 is supported by a pair of crank bearings 12a and 12b so as to be rotatable about the axis with respect to the carrier 4. Specifically, a first crank bearing 12a is attached to one axial end portion of each crankshaft 10, and the first crank bearing 12a is attached to the attachment hole 4e of the substrate portion 4a. On the other hand, a second crank bearing 12 b is attached to a portion on the other end side in the axial direction of each crankshaft 10, and the second crank bearing 12 b is attached to the attachment hole 7 b of the end plate portion 7. Thereby, the crankshaft 10 is rotatably supported by the board | substrate part 4a and the end plate part 7. FIG.

  Each crankshaft 10 includes a shaft main body 10c and eccentric portions 10a and 10b formed integrally with the shaft main body 10c. The 1st eccentric part 10a and the 2nd eccentric part 10b are arrange | positioned along with the axial direction between the parts supported by both crank bearings 12a and 12b. Each of the first eccentric portion 10a and the second eccentric portion 10b has a columnar shape, and both of the first eccentric portion 10a and the second eccentric portion 10b protrude radially outward from the shaft body 10c in a state of being eccentric with respect to the shaft center of the shaft body 10c. The first eccentric portion 10a and the second eccentric portion 10b are each eccentric from the shaft center by a predetermined eccentric amount, and are disposed so as to have a phase difference of a predetermined angle.

  The first oscillating gear 14 is disposed in the closed space S in the outer cylinder 2 and is attached to the first eccentric portion 10a of each crankshaft 10 via a first roller bearing 18a. When each crankshaft 10 rotates and the first eccentric portion 10a rotates eccentrically, the first swing gear 14 swings and rotates while meshing with the internal tooth pin 3 in conjunction with the eccentric rotation.

  The first oscillating gear 14 has a size slightly smaller than the inner diameter of the outer cylinder 2. The first swing gear 14 includes a first external tooth 14a, a central through hole 14b, a plurality (for example, three) of first eccentric portion insertion holes 14c, and a plurality (for example, three) of shaft portion insertion holes 14d. And have. The first external teeth 14 a have a wave shape that is smoothly continuous over the entire circumferential direction of the oscillating gear 14.

  The central through hole 14 b is provided in the central portion in the radial direction of the first oscillating gear 14.

  The three first eccentric portion insertion holes 14c are provided at equal intervals in the circumferential direction around the central through hole 14b in the first swing gear 14. The first eccentric portions 10a of the respective crankshafts 10 are inserted into the first eccentric portion insertion holes 14c with the first roller bearings 18a interposed therebetween.

  The three shaft portion insertion holes 14d are provided at equal intervals in the circumferential direction around the central portion through hole 14b in the first swing gear 14. Each shaft portion insertion hole 14d is disposed at a position between the three first eccentric portion insertion holes 14c in the circumferential direction. The corresponding shaft portion 4c is inserted into each shaft portion insertion hole 14d with play.

  The second oscillating gear 16 is disposed in the closed space S in the outer cylinder 2 and is attached to the second eccentric portion 10b of each crankshaft 10 via the second roller bearing 18b. The first oscillating gear 14 and the second oscillating gear 16 are provided side by side in the axial direction corresponding to the positions of the first eccentric portion 10a and the second eccentric portion 10b. When each crankshaft 10 rotates and the second eccentric portion 10b rotates eccentrically, the second swinging gear 16 swings and rotates while meshing with the internal tooth pin 3 in conjunction with the eccentric rotation.

  The second oscillating gear 16 has a size slightly smaller than the inner diameter of the outer cylinder 2 and has the same configuration as the first oscillating gear 14. That is, the second oscillating gear 16 includes a second external tooth 16a, a central through hole 16b, a plurality of (for example, three) second eccentric portion insertion holes 16c, and a plurality of (for example, three) shaft portion insertion holes 16d. Have. These have the same structure as the first external teeth 14a, the central through hole 14b, the plurality of first eccentric portion insertion holes 14c, and the plurality of shaft portion insertion holes 14d of the first swing gear 14. The second eccentric portion 10b of the crankshaft 10 is inserted into each second eccentric portion insertion hole 16c with the second roller bearing 18b interposed therebetween.

  A transmission gear 20 is attached to one end portion of each crankshaft 10, that is, a portion on the axially outer side of a portion attached to the attachment hole 7b of the end plate portion 7. Each transmission gear 20 has external teeth 20a that mesh with an input gear (not shown). The input gear functions as an input unit to which rotational driving force is input from a drive motor (not shown). Each transmission gear 20 rotates integrally with the crankshaft 10 around the same axis as the corresponding rotation axis of the crankshaft 10, and transmits the rotation of the input gear to the crankshaft 10. When each crankshaft 10 rotates, the swing gears 14 and 16 attached to the eccentric portions 10a and 10b swing while meshing with the internal tooth pin 3 as the eccentric portions 10a and 10b rotate. And the outer cylinder 2 rotates relatively to each other.

  The oil seal cap 30 is used to enclose lubricating oil as a lubricant in the closed space S, and is a communication hole formed in the carrier 4, that is, a through hole that allows communication between the outside and the closed space S. Is arranged. Specifically, the oil seal cap 30 is fitted into the through hole 4d and the crankshaft mounting hole 4e of the substrate portion 4a.

  As shown in FIG. 3, the oil seal cap 30 includes a disk-shaped bottom plate portion 30a and an annular cylindrical portion 30b protruding from the outer peripheral portion of the bottom plate portion 30a. The cylindrical portion 30b is in close contact with the inner peripheral surface of the through hole 4d or the crankshaft mounting hole 4e. Thereby, the lubricating oil sealed in the carrier 4 is prevented from leaking. Since the oil seal cap 30 has a metal rigid member 30c, the cylindrical portion 30b is pressed against the inner peripheral surface of the through hole 4d or the crankshaft mounting hole 4e by its rigidity.

  The rigid member 30c is made of a magnetic material such as iron and magnetized. That is, since the rigid member 30c is magnetized, the oil seal cap 30 has ferromagnetism capable of attracting metal powder with magnetic force.

  As described above, in the present embodiment, the lubricant can be enclosed in the closed space S by the oil seal cap 30. In addition, since the oil seal cap 30 is configured to be able to adsorb metal powder with magnetic force, when metal powder such as wear powder enters the through hole 4d or the crankshaft mounting hole 4e, the oil seal cap 30 The cap 30 can adsorb the metal powder. Accordingly, it is possible to prevent the metal powder from being caught in the meshing portions of the oscillating gears 14 and 16 and from being caught in the bearing portions such as the crank bearings 12a and 12b and the roller bearings 18a and 18b. It is possible to prevent the device 1 from being damaged.

  In addition, in the present embodiment, the rigid member 30c built in the oil seal cap 30 has a magnetic configuration, so that the oil seal cap 30 has a magnetic attraction function without attaching a magnet. be able to.

  Note that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the rigid member 30c incorporated in the oil seal cap 30 is magnetized. However, the present invention is not limited to this. For example, as shown in FIG. 4, the oil seal cap 30 includes a cap body 30f having a shape that closes the communication hole, and an adsorbing portion 30g attached to the cap body 30f. The cap main body 30f has a bottom plate portion 30h and a cylindrical portion 30i. The cap body 30f includes a rigid member 30c made of a metal material such as iron. The attracting part 30g is composed of a magnet and is attached to the cap body 30f. The adsorption part 30g may be attached to the cap body 30f by its magnetic force, or may be attached to the cap body 30f by an adhesive or the like. In this embodiment, even if the cap body 30f is not processed, it can function as a cap that plugs the communication hole as it is. Further, since the oil seal cap 30 has a configuration in which an adsorption portion 30g made of a magnet is attached to the cap body 30f, it can have a magnetic attraction function without special processing.

  Moreover, in the said embodiment, although the rigid member 30c was set as the structure which has a ferromagnetism in any of the oil seal cap 30 arrange | positioned at the through-hole 4d and the crankshaft attachment hole 4e, it is not restricted to this. Alternatively, only one of the oil seal caps 30 may be configured to be able to adsorb the metal powder with a magnetic force.

  Moreover, in the said embodiment, although the oil seal cap 30 was set as the structure arrange | positioned in the through-hole 4d and the crankshaft attachment hole 4e of the board | substrate part 4a, it is not restricted to this. The oil seal cap 30 may be disposed in the through hole 7 a of the end plate portion 7. When the transmission gear 20 is provided on the side of the substrate portion 4a or between the eccentric portions 10a and 10b, the oil seal cap 30 may be disposed in the mounting hole 7b of the end plate portion 7. Further, when a communication hole is formed in the outer cylinder 2, the oil seal cap 30 may be disposed in the communication hole.

  In the above embodiment, the two oscillating gears 14 and 16 are provided. However, the present invention is not limited to this. For example, a configuration in which one oscillating gear is provided or a configuration in which three or more oscillating gears are provided may be employed.

  In the above embodiment, the plurality of crankshafts 10 are arranged around the central through holes 4d and 7a. However, the present invention is not limited to this. For example, a center crank type in which the crankshaft 10 is disposed at the center of the carrier 4 may be employed.

DESCRIPTION OF SYMBOLS 1 Eccentric rocking gear apparatus 2 Outer cylinder 3 Internal tooth pin 4 Carrier 4a Base plate part 4c Shaft part 5 Base part 7 End plate part 10 Crankshaft 10a 1st eccentric part 10b 2nd eccentric part 12a 1st crank bearing 12b 2nd crank Bearing 10c Shaft body 14 First oscillating gear 14a External tooth 14c Eccentric part insertion hole 16 Second oscillating gear 16a External tooth 16c Eccentric part insertion hole 30 Oil seal cap 30c Rigid member 30f Cap main body 30g Adsorption part

Claims (3)

A gear device that transmits a driving force by converting a rotational speed at a predetermined rotational speed ratio between a first member and a second member,
An eccentric part,
An oscillating gear having an insertion hole into which the eccentric part is inserted and having a tooth part;
An outer cylinder configured to be attachable to one of the first member and the second member, and having an inner tooth that meshes with the tooth portion of the swing gear;
A carrier configured to be attachable to the other of the first member and the second member;
An oil seal cap,
A closed space for accommodating the swing gear is formed by the carrier and the outer cylinder,
One of the carrier and the outer cylinder is formed with a communication hole communicating with the closed space,
The oil seal cap is an eccentric oscillating gear device that is disposed in the communication hole and has ferromagnetism capable of adsorbing metal powder.   2. The eccentric oscillating gear device according to claim 1, wherein the oil seal cap includes a cap main body configured to close the communication hole, and a suction portion that is configured by a magnet and attached to the cap main body.   The eccentric oscillating gear device according to claim 1, wherein the oil seal cap includes a metal member, and the metal member is magnetized.

Images