JP2008304019A - Eccentrically oscillating speed reducer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an eccentrically oscillating speed reducer in which external gears are smoothly oscillatingly rotated even if a strong radial eccentric load is applied from a load side thereto. <P>SOLUTION: This eccentrically oscillating speed reducer 110 comprises first and second carriers 124A, 124B, and a pair of angular ball bearings 134A, 134B incorporated in the first and second carriers 124A, 124B and supporting an eccentric shaft 114 at its opposite ends. The angular ball bearings 134A, 134B are so incorporated that their front surfaces are abutted on each other and can apply a preload to the eccentric shaft 114 in the axial direction. The external gears 118A, 118B are axially movably fitted to eccentric bodies 116A, 116B through needle bearings 132A, 132B, respectively. The second carrier 124B is connectable to a connection member 150 on the driven side through a spline 160 having a gap in the radial direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an eccentric swing reduction device.

  For example, Patent Document 1 discloses an eccentric swing reduction device as shown in FIGS. 5 and 6.

  The eccentric rocking speed reduction device 10 is configured such that the external gears 18A and 18B are eccentrically rocked radially inward of the internal gear 22 by the eccentric bodies 16A and 16B provided on the eccentric body shaft 14 corresponding to the input shaft. It is what.

  A pair of first and second carriers 24A and 24B are arranged on both sides in the axial direction of the external gears 18A and 18B, and inner pins (connectors) that pass through the inner pin holes 36A and 36B of the external gears 18A and 18B. 26 are connected.

  The first and second carriers 24A and 24B are rotatably supported by the casing 20 by a pair of ball bearings 28A and 28B. Among these, the second carrier 24B is integrated with the output shaft 30.

  The external gears 18A and 18B are assembled to the eccentric bodies 16A and 16B via ball bearings 32A and 32B. The eccentric body shaft 14 is supported by first and second carriers 24A and 24B via ball bearings 34A and 34B.

  External teeth 27 such as a trochoidal tooth profile are provided on the outer circumferences of the external gears 18A and 18B, and are in mesh with the internal gear 22. In this disclosed example, the internal teeth of the internal gear 22 have a structure in which an external pin 29 is loosely fitted in the external pin hole 31 and is held easily.

  When the eccentric body shaft 14 corresponding to the input shaft rotates, the eccentric bodies 16A and 16B rotate integrally. Due to the rotation of the eccentric bodies 16A and 16B, the external gears 18A and 18B also try to swing and rotate around the eccentric body shaft 14, but the rotation of the external gears is restricted by the internal gear 22, so the external teeth The gears 18 </ b> A and 18 </ b> B almost swing only while being inscribed in the internal gear 22.

  For example, when the number of external teeth 27 of the external gears 18A and 18B is N and the number of internal teeth (external pin 29) of the internal gear 22 is N + 1, the difference in the number of teeth is 1. Therefore, for each rotation of the eccentric body shaft 14, the external gears 18 </ b> A and 18 </ b> B are shifted (rotated) by one tooth with respect to the internal gear 22 fixed to the casing 20. This means that one rotation of the eccentric body shaft 14 is decelerated to -1 / N rotation of the external gears 18A and 18B. Note that the sign of-indicates that the rotation direction is reversed.

  The rotation of the external gears 18A, 18B is absorbed by the clearance between the inner pin 26 and the inner pin holes 36A, 36B, and only the rotation component is transmitted through the inner pin 26 to the second carrier 24B, It is transmitted to the output shaft 30 integrated with the second carrier 24B.

  In this disclosed example, the internal gear 22 is integrated with the casing 20 and maintained in a fixed state, and the first and second carriers 24A, 24B are rotated by the rotation components of the external gears 18A, 18B via the internal pins 26. The output shaft 30 side is fixed (the first and second carriers 24A and 24B are fixed), and the rotation components of the external gears 18A and 18B are set to the first, It can also be used as a so-called frame rotation type that is restrained by synchronizing with the second carriers 24A and 24B and uses the internal gear 22 side as an output system.

Japanese Patent No. 2888673

  However, when the eccentric swing reduction device having such a structure is applied to a turning drive device of a work machine used outdoors such as a shovel car, the shovel car does not necessarily work on a flat ground. Therefore, when the output shaft is tilted, a strong radial load may be applied to the output shaft. When a strong eccentric load is applied to the output shaft, a phenomenon occurs in which the carrier integrated with the output shaft (second carrier 24B in the example shown in the figure) touches, and the external gears 18A and 18B smoothly swing eccentrically. Is inhibited.

  The present invention has been made to solve such a conventional problem, and the external gear smoothly swings even when used in a situation where a strong offset load is applied to the output shaft. An object of the present invention is to provide an eccentric rocking reduction device that can rotate.

  The present invention provides an eccentric oscillation reduction device in which an external gear is eccentrically oscillated radially inward of an internal gear by eccentric bodies provided on the eccentric body shaft, and is disposed on both axial sides of the external gear. And a pair of carriers that are coupled by a coupling body that passes through the external gear and synchronizes with the rotation component of the external gear, and a pair of bearings that are respectively incorporated in the pair of carriers and that support the eccentric body shaft at both ends. And the pair of bearings are configured to be front-to-front with each other and capable of being pressurized to restrict axial movement of the eccentric shaft relative to the carrier, and the external gear is a needle bearing. And the one of the carriers is connected to the driven-side connecting member with a gap in the radial direction through the eccentric body so as to be movable in the axial direction. Solved the above problem Than is.

  In the present invention, a pair of carriers are arranged on both sides in the axial direction of the external gear, and each carrier is firmly connected by the connecting body. The eccentric body shaft is supported at both ends by a pair of bearings incorporated in the pair of carriers. The pair of bearings are assembled in a “front-to-front” manner and can be pressurized in the axial direction with respect to the eccentric body shaft. That is, the eccentric body shaft is restricted from moving in the axial direction with respect to the carrier. Then, one of the carriers is connected to the driven side connecting member in a connecting manner having a gap in the radial direction.

  As a result, even if a radial load or the like is applied to the driven side connecting member, it is difficult for the load to be transmitted to the carrier side. The eccentric body shafts are connected to each other and supported by both ends of the pair of strongly connected carrier bodies without being rattled (always in a state where the core is always out).

  When the external gear is configured to be fitted to the eccentric body through the needle bearing so as to be movable in the axial direction, the eccentric gear shaft is moved in the axial direction with respect to the carrier by the bearing capable of being pressurized, Even if the pair of carriers and the mass of the eccentric body shaft move in the axial direction, the external gear can be rotated more smoothly by moving in the axial direction on the eccentric body. Smooth engagement with the internal gear can be started or maintained.

  According to the present invention, it is possible to obtain an eccentric oscillating speed reducer capable of smoothly starting or continuing rotation even if a radial load or the like is applied from the load side.

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

  FIG. 1 is a longitudinal sectional view of an eccentric rocking reduction device 110 according to an example of an embodiment of the present invention, and FIG. 2 is a sectional view taken along line II-II in FIG.

  FIG. 3 is an overall schematic perspective view of an excavator car 180 to which the eccentric swing reduction device 110 is applied.

  Referring to FIG. 3, in the excavator car 180, a vehicle body 186 including a driver's seat 184 is placed on an upper portion of a traveling caterpillar 182 so as to be able to turn. From the vehicle body 186, a boom 188, an arm 190, and an attachment 192 are installed in a cantilever state. The vehicle body 186 has an internal gear 194 fixed to the base side. The pinion 196 is engaged with the internal gear 194 so that the vehicle body 186 can turn around the axis 198. Yes. The eccentric rocking reduction device 110 is used to rotate the pinion 196.

  With reference to FIG.1 and FIG.2, the eccentric rocking | fluctuation reduction device 110 is demonstrated in detail.

  The eccentric oscillating speed reducer 110 includes a motor M, an eccentric oscillating type speed reducer 111, and a connecting member 150 integrally including the pinion 196 described above.

  The motor M and the speed reducer 111 are integrated through a bolt 152. An output shaft (motor shaft) 154 of the motor M is connected to the input shaft 112 via a spline 156.

  The input shaft 112 also serves as the eccentric body shaft 114. Angular ball bearings 134A and 134B supporting the eccentric body shaft 114 will be described later. Eccentric bodies 116 </ b> A and 116 </ b> B are integrally formed on the outer periphery of the eccentric body shaft 114.

  The mechanical reduction mechanism itself of the speed reducer 111 is basically the same as the previous example. That is, the external gears 118 </ b> A and 118 </ b> B are eccentrically oscillated radially inward of the internal gear 122 by being guided by the outer circumferences of the eccentric bodies 116 </ b> A and 116 </ b> B.

  External gears 118A and 118B are mounted on the outer circumferences of the eccentric bodies 116A and 116B via needle bearings 132A and 132B. The needle bearings 132A and 132B will be described later.

  The external gears 118A and 118B are provided with inner pin holes 136A and 136B that penetrate the external gears 118A and 118B in the axial direction, and the inner pin 126 is connected to the inner pin holes 136A and 136B via the inner rollers 138A and 138B. It penetrates (free fitting). The inner rollers 138A and 138B are provided between the inner pin 126 and the external gears 118A and 118B to reduce the sliding resistance between these members 126, 118A and 118B. The inner pin 126 is press-fitted and fixed to the first and second carriers 124A and 124B, functions as a coupling body that firmly connects the first and second carriers 124A and 124B, and has external gears 118A and 118B. It functions as a member for taking out the rotation component. A trochoidal external tooth 127 is formed on the outer periphery of the external gears 118 </ b> A and 118 </ b> B and meshes with an external pin 129 that constitutes an internal tooth of the internal gear 122. The outer pin 129 is rotatably fitted in an outer pin hole 131 formed in the internal gear 122.

  The internal gear 122 is integrated with the casing 120 and is maintained in a fixed state in this embodiment. Further, the second carrier 124A is connected to the connecting member 150 via both the second carrier 124A and the connecting member 150 via a spline 160 formed with a gap in the radial direction. The coupling member 150 is integrally formed with the pinion 196 and is supported by the casing 120 via self-aligning roller bearings 162 and 164.

  Here, the built-in structure of each member will be described in detail. Since the connecting member 150 directly receives a load in the radial direction or the thrust direction from the driven side, the casing 120 is supported by a pair of spherical roller bearings 162 and 164. Is movably supported. The spline 160 allows the movement of the connecting member 150 in both the radial direction and the axial direction.

  The first and second carriers 124A and 124B are disposed on both axial sides of the external gears 118A and 118B, and are rotatably supported by the casing 120 by ball bearings 128A and 128B, respectively. The eccentric body shaft 114 is supported at both ends by the pair of first and second carriers 124A and 124B via angular ball bearings 134A and 134B.

  These angular ball bearings 134A and 134B are assembled in a so-called “front-facing” state, and the angular ball bearing 134B on the non-motor side is interposed between the stepped portion 124B1 of the second carrier 124B and the stepped portion 114B of the eccentric body shaft 114. The angular ball bearing 134A on the motor M side is sandwiched between the stepped portion 114A of the eccentric body shaft 114 and the retaining ring 140 implanted in the first carrier 124A.

  As shown in FIG. 4, a shim 142 is interposed between the retaining ring 140 and the outer ring 134A1 of the angular ball bearing 134A, and the thickness d of the shim 142 (including zero, that is, an embodiment without shim) is set. By appropriately selecting, the degree of pressure applied to the eccentric body shaft 114 by the angular ball bearings 134A and 134B can be adjusted, and the thickness d of the shim 142 serves to adjust the pressure.

  Further, the needle bearings 132A and 132B interposed between the eccentric bodies 116A and 116B and the external gears 118A and 118A are disposed with a gap δ1 or δ2 between the angular ball bearings 134A and 134B, Its axial movement is restricted. In other words, the needle bearings 132A and 132B can move in the axial direction within the range of the gap δ1 or δ2.

  Next, the operation of the eccentric rocking speed reduction device 110 according to this embodiment will be described.

  When the motor shaft 154 of the motor M rotates, the input shaft 112 of the speed reducer 111 rotates via the spline 156. Accordingly, the eccentric body shaft 114 integrated with the input shaft 112 rotates, and the eccentric bodies 116A and 116B rotate integrally. When the eccentric bodies 116A and 116B rotate, the external gears 118A and 118B also try to swing and rotate around the eccentric bodies 116A and 116B, but the rotation of the external gears is restricted by the internal gear 122. The gears 118 </ b> A and 118 </ b> B almost only swing while inscribed in the internal gear 122.

  In this embodiment, the number of teeth of the external teeth 127 of the external gears 118A and 118B is 34, the number of teeth of the internal teeth (external pin 129) of the internal gear 122 is 36, and the difference in the number of teeth is 2. Each time the input shaft 112 (eccentric body shaft 114) rotates, the external gears 118A and 118B are shifted (rotated) by two teeth with respect to the internal gear 122 fixed to the casing 120. This means that one rotation of the input shaft 112 (eccentric body shaft 114) has been reduced to −2/34 of the external gears 118A and 118B. Note that the sign of-indicates that the rotation direction is reversed.

  The rotation of the external gears 118A and 118B is absorbed by the clearance between the inner pin 126 (inner rollers 138A and 138B) and the inner pin holes 136A and 136B, and only the rotation component is transmitted through the inner pin 126. It is transmitted to the second carrier 124B, and further transmitted to the connecting member 150 connected to the second carrier 124B via the spline 160.

  A pinion 196 (see FIG. 3) of the above-described shovel car 180 is integrally formed at the distal end of the connecting member 150. The pinion 196 is connected to an internal gear 194 provided on the base side of the shovel car 180. By meshing, the vehicle body 186 turns about the axis 198.

  Here, in this embodiment, since the driven side connecting member 150 is supported via a pair of self-aligning roller bearings 162 and 164, the connecting member 150 itself is movable with respect to the casing. In addition, the second carrier 124B is connected to the connecting member 150 by a spline having a gap in the radial direction. Therefore, even if a load in the radial direction or the thrust direction is applied from the driven side, the load is difficult to be transmitted to the carrier side (second carrier 124B side). That is, it is possible to basically form a state in which the speed reducer 111 is hardly affected from the load side in the first place.

  Even if these disturbance elements are transmitted to the speed reducer 111 side, the external gears 118A and 118B can start smooth rotation and maintain the smooth rotation by the following actions. be able to.

  That is, in the present embodiment, the first and second carriers 124A and 124B provided as a pair on both sides in the axial direction of the external gears 118A and 118B are firmly connected via the inner pins (connectors) 126. In addition, the eccentric body shaft 114 is supported by both the first and second carriers 124A and 124B that are firmly connected to each other in a state in which a pressure is applied to the angular ball bearings 134A and 134B. . Therefore, the first and second carriers 124A and 124B and the eccentric body shaft 114 are integrated as a “large lump”, and the eccentric body shaft 114 does not rattle with respect to the first and second carriers 124A and 124B.

  The degree of pressurization of the eccentric body shaft 114 is adjusted by appropriately selecting the thickness d of the shim 142 interposed between the outer ring 134A1 and the retaining ring 140 of the angular ball bearing 134A on the motor M side. Therefore, even if there is a manufacturing error or assembly error of each member, a predetermined pressurization can always be generated.

  Further, the eccentric bodies 116A, 116B and the external gears 118A, 118B are fitted via the needle bearings 132A, 132B. The needle bearings 132A, 132B are axially arranged due to the presence of the gap δ1 or δ2. Therefore, the external gears 118A and 118B are also movable in the axial direction with respect to the eccentric bodies 116A and 116B.

  Therefore, even if a large lump including the first and second carriers 124A and 124B and the eccentric body shaft 114 moves in the horizontal direction by the gap between the ball bearings 128A and 128B as a whole, the external gears 118A and 118B Since it does not receive an axial load, it can automatically move in a direction in which rotation is smoother, and smooth rotation can always be performed. However, in the present invention, the fact that the external gear can move in the axial direction with respect to the eccentric body is not necessarily an essential requirement at least in a completed product. However, when fitting the eccentric body shaft between the bearings that are face-to-face aligned, it is essential that the external gear can move in the axial direction with respect to the eccentric body shaft. Therefore, support with a needle bearing that ensures this is effective in this respect. After the eccentric body shaft is fitted and fixed to the carrier, the axial movement of the external gear does not necessarily have to be guaranteed (for example, when the gap disappears as a result, it may not be present). .

  The pair of pressurizable bearings that support the eccentric body shaft may be tapered roller bearings in addition to the angular ball bearings as in this example. Further, the eccentric body shaft supported by the pressurization includes a “structure composed of one eccentric body shaft at the center in the radial direction of the speed reducer” as in this example, as well as a known “multiple rotating in the same phase”. It may be a “structure constituted by an eccentric body axis”.

  For example, it is most suitable for an eccentric oscillating speed reduction device that is applied in a scene in which an eccentric load is applied in the radial direction from the load side, such as a swing device of an excavator.

The longitudinal cross-sectional view which shows an example of the eccentric rocking | fluctuation reduction device which concerns on this invention Sectional view along arrow II-II in FIG. Overall schematic perspective view of an excavator to which the eccentric swing reduction device is applied Partial enlarged view showing the shim being deployed to adjust the pressure of the angular ball bearing A longitudinal sectional view showing an example of a conventional eccentric oscillating speed reducer Sectional view along line VI-VI in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 110 ... Eccentric oscillation reduction device 111 ... Reduction gear 112 ... Input shaft 114 ... Eccentric body shaft 116A, 116B ... Eccentric body 118A, 118B ... External gear 120 ... Casing 122 ... Internal gear 124A, 124B ... 1st, 2nd Carrier 126 ... Inner pin 128A, 128B ... Ball bearing 132A, 132B ... Needle bearing 134A, 134B ... Angular ball bearing 136A, 136B ... Inner pin hole 138A, 138B ... Inner roller 140 ... Retaining ring 142 ... Shim 150 ... Connecting member 162, 164: Automatic center roller bearing 180 ... Excavator 194 ... Internal gear 196 ... Pinion

Claims (4)

In the eccentric oscillating speed reduction device in which the external gear is eccentrically oscillated radially inward of the internal gear by the eccentric body provided on the eccentric body shaft,
A pair of carriers disposed on both sides in the axial direction of the external gear and connected by a connecting body penetrating the external gear and synchronized with a rotation component of the external gear;
A pair of bearings that are respectively incorporated in the pair of carriers and support the eccentric body shaft at both ends;
The pair of bearings are configured to be front-to-front with each other and are configured to be capable of applying pressure to restrict axial movement of the eccentric body shaft with respect to the carrier, and one of the carriers is a connecting member on a driven side An eccentric oscillating speed reducer characterized in that it can be connected with a gap in the radial direction. In claim 1,
The eccentric oscillating speed reduction device, wherein the external gear is fitted to the eccentric body via a needle bearing so as to be axially movable. In claim 1 or 2,
An eccentric oscillating speed reducer comprising an adjustment mechanism capable of adjusting a degree of the pressurization. In any one of Claims 1-3,
The eccentric oscillating speed reducing device, wherein the driven side connecting member is supported by a casing via a self-aligning roller bearing.

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