JP2006046664A - Gear unit with drive motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size of the entire apparatus and reduce the manufacturing cost.
In an eccentric differential reducer 56, the rotation of an output shaft 59 of a drive motor 58 is transmitted to one of the two or more crankshafts 50a for rotation, and the remaining crank Since the shaft 50b is rotated in synchronization with the one crankshaft 50a, the axial length of the entire apparatus can be shortened, the size can be reduced, and the manufacturing cost can be reduced. You can also.
[Selection] Figure 1

Description

This invention relates to a driving motor with gearing having an eccentric differential speed reducer which rotates eccentrically pinion by rotating the crank shaft.

As a conventional gear device with a drive motor , for example, those described in Patent Documents 1 and 2 below are known.
Japanese Utility Model Publication No. 64-38352 Japanese Patent Publication No. 5-13794

This patent document 1 describes an internal gear having a large number of pins provided on the inner periphery, and a tooth profile that has a slightly smaller number of teeth on the outer periphery than the pins of the internal gear and meshes with the pins of the internal gear. 1st and 2nd support that rotatably supports the camshaft, the camshaft disposed at a position eccentric from the eccentric motion center of the external gear An eccentric differential reduction gear having an input external gear consisting of a carrier made of members and a spur gear fixed to the camshaft, a first external gear fixed to the output shaft of the motor, and the first external gear meshing with each other And an input shaft to which a third external gear comprising a spur gear meshing with the second external gear and the input external gear is mounted, and the motor is in a radial direction from the center of eccentric motion of the external gear of the eccentric differential reduction gear Arranged on the outside and the bias Center of the central portion and the input shaft of the differential speed reducer is configured hollow. In this configuration, the first and second external gears are both constituted by bevel gears, so that their rotation axes are orthogonal to each other and the cam shaft extends in the axial direction, while the motor and the output shaft have a radius. Extending in the direction. In addition, the diameter of the first external gear is equal to the diameter of the second external gear. Further, Patent Document 2 discloses a basic structure of an eccentric differential reduction mechanism type gear device.

However, in such a conventional driving motor with gearing, the rotation of the drive motor for that to be transmitted to the crankshaft preparative via external teeth wheel, that the whole apparatus becomes longer in the axial direction There is a problem.

An object of this invention is to provide the gear apparatus with a drive motor which can reduce the whole apparatus in size and can reduce manufacturing cost.

These objects, internal number of teeth provided to case a circumferential, teeth than teeth of the casing to the outer circumference slightly less and pinion down the external teeth are provided which mesh with the teeth of the case, pinion to the crank portion is inserted, eccentric motion center click disposed at a position offset from Rankushafu bets pinion eccentric difference with the input outer gear fixed to the carrier and the crank shaft for rotatably supporting the crankshaft A speed reducer , a first external gear fixed to the output shaft of the drive motor, a second external gear meshing with the first external gear, and a rotating body attached with a third external gear meshing with the input external gear. The drive motor is disposed radially outward from the eccentric motion center of the pinion of the eccentric differential reducer, and the central portion of the eccentric differential reducer and the central portion of the rotating body are In the gear device with a drive motor configured to be empty, the drive motor is arranged so that an output shaft of the drive motor is parallel to a rotation axis of the crankshaft, and a rotation axis of the second external gear is set to the first This can be achieved by arranging it parallel to the rotation axis of the external gear .

According to this gear device with a drive motor, the drive motor is arranged so that the output shaft of the drive motor is parallel to the rotation axis of the crankshaft, and the rotation axis of the second external gear is connected to the rotation of the first external gear. Having arranged parallel to the axis of rotation, the manufacturing operation costs can be expensive.

In FIGS. 1, 2, and 3, reference numeral 29 denotes a flange member (not shown) fixed to an apparatus body such as an industrial robot body or an index device. In the hole (passage) provided near the center of the flange member 29, Cylindrical bodies 32 and 33 are inserted and fixed. These cylinders 32 and 33 have holes 32a and 33a in the vicinity of the center, and these holes 32a and 33a are used as passages 30 through which piping and wiring are passed. The flange member 29 and the cylinders 32 and 33 described above constitute a fixing member 31 having a passage near the center as a whole.

  A rotating case 36 that is cylindrical and coaxial with the fixing member 31 is loosely fitted on the outer side of the fixing member 31, and a plurality of pin teeth that are cylindrical in the axially central portion of the inner periphery of the rotating case 36. 37 is provided with almost half buried. These pin teeth 37 extend in the axial direction and are spaced equidistantly in the circumferential direction. Reference numeral 39 denotes two disk-shaped pinions, and a through hole 40 having a diameter larger than that of the cylindrical body 32 is formed at the center of these pinions 39. These pinions 39 are provided between the fixing member 31 and the rotating case 36 in the state where the cylindrical body 32 is loosely fitted in the through hole 40, here, inside the rotating case 36 and outside the cylindrical body 32. ing. In addition, external teeth 41 having a slightly smaller number of teeth than the pin teeth 37 of the rotating case 36 are formed on the outer periphery of the pinion 39, and these external teeth 41 are composed of cycloidal teeth, and all the teeth are connected to the pin teeth 37. Are engaged. 44 is a carrier provided between the fixing member 31 and the rotating case 36 and attached to the fixing member 31. The carrier 44 includes a one-side flange 45 disposed on one side in the axial direction of the pinion 39, and a pinion 39. The other side flange 46 disposed on the other side in the axial direction, and a plurality of connecting rods 47 extending in the axial direction loosely fitted in the pinion 39 and connecting the one side, the other side flanges 45, 46 to each other, It is composed of One end portion of the cylindrical body 32 is attached to one side flange 45 of the carrier 44, and the flange member 29 is attached to the other side flange 46. Reference numeral 49 denotes a pair of bearings interposed between the one-side and other-side flanges 45 and 46 and the rotating case 36, and these bearings 49 enable the carrier 44 and the rotating case 36 to be relatively rotated. Reference numeral 50 denotes two or more, in this case, two crankshafts, which are arranged at equal distances in the circumferential direction and extend in the axial direction. Each crankshaft 50 has one end connected to one flange 45 via a bearing 51 and the other. The end portion is rotatably supported by the other flange 46 via the bearing 52. Each crankshaft 50 has two crank portions 53 eccentric to the center, and each crank portion 53 is inserted into a through hole 54 formed in the pinion 39 with a needle bearing 55 interposed therebetween. Yes. The rotating case 36, the pinion 39, the carrier 44, and the crankshaft 50 described above constitute an eccentric differential reducer 56 that can decelerate the input rotation at a high ratio.

  58 is arranged outside the fixing member 31 on the other side of the other flange 46, more specifically, one drive motor (servo motor) fixed to the outer periphery of the cylindrical body 33. This drive motor 58 is shown in FIG. As shown, one of the crankshafts 50a is disposed on the rotational axis, and one end of the output shaft 59 is directly connected to the other end of the one crankshaft 50a via a joint 60. As a result, when the driving motor 58 is operated and a driving force is directly applied from the output shaft 59 to the crankshaft 50a, the crankshaft 50a rotates and the pinion 39 rotates eccentrically (revolves). 61 is disposed outside the fixing member 31 on the other side of the other flange 46, more specifically, is fixed to the outer periphery of the cylindrical body 33, and overlaps with the drive motor 58 (the axial position coincides and is arranged in parallel). The encoder 61 is disposed 180 degrees away from the drive motor 58, and the detection shaft 62 has a joint 63 at one of the remaining crankshafts 50, that is, the other end of the crankshaft 50b. Are connected through. The encoder 61 detects the amount of rotation of the crankshaft 50 that rotates in synchronization, and controls the drive motor 58 based on the detection result. 65 is a bottomed cylindrical cover that is connected to the flange member 29 and the other end of the cylinder 33 and covers the drive motor 58 and the encoder 61, and 66 is between the rotating case 36 and the one-side flange 45 and rotates. Oil seals interposed between the case 36 and the flange member 29, respectively.

    Now, the drive motor 58 is activated and the rotation of the output shaft 59 is transmitted to the crankshaft 50a. As a result, the pinion 39 rotates eccentrically (revolves) at the same rotational speed as the crankshaft 50a. Suppose that they are rotating at the same rotation speed. At this time, the external teeth 41 of the pinion 39 are slightly smaller in number of teeth than the pin teeth 37 of the rotating case 36, and are engaged with the pin teeth 37 of the rotating case 36 with all teeth, and the carrier 44 cannot be rotated. Since it is fixed to the fixing member 31, the rotation of the drive motor 58 is decelerated to a high ratio and taken out from the rotating case 36. At this time, the rotation of the output shaft 59 of the drive motor 58 is transmitted to one of the two or more crankshafts 50a for rotation, and the remaining crankshaft 50b is transferred to the one crankshaft. Since it is made to rotate in synchronization with 50a, the axial length of the entire apparatus can be shortened, and the production cost can be reduced.

  Here, as described above, the output shaft 59 of the drive motor 58 is directly connected to the crankshaft 50a, and the driving force from the drive motor 58 is directly applied to the crankshaft 50a without using a gear as in the prior art. Therefore, there is no backlash or noise due to the meshing of the gears, and the rotating case 36 can be rotated at a reduced speed with high accuracy while reducing noise. Moreover, as described above, by omitting the gears and directly connecting the output shaft 59 of the drive motor 58 and the crankshaft 50a, the drive motor 58 is brought close to the crankshaft 50a and the encoder 61 is separated from the drive motor 58. Since it is connected to another crankshaft 50b distant from the drive motor 58, the drive motor 58 and the encoder 61 are arranged so as to overlap each other (a side-by-side arrangement in which the axial positions are matched). As a result, the axial length of the entire apparatus can be drastically shortened. Further, as described above, the encoder 61 is disposed apart from the drive motor 58 that generates heat, thereby reducing the thermal influence from the drive motor 58 on the encoder 61 and preventing the detection accuracy of the encoder 61 from being lowered. Further, since the gear is omitted as described above, the manufacturing cost can be reduced.

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIGS. 4 and 5 , the eccentric differential reducer has a rotating case 14 provided with a large number of teeth 13 on the inner periphery . Wherein the rotating case 14, a pinion 16 which outer teeth 15 are provided teeth than teeth 13 meshing with teeth 13 of slightly smaller and the rotating case 14 of the rotary case 14 is provided on the outer periphery, the pinion 16 The crank portions 18 of two or more crankshafts 19 disposed at positions eccentric from the eccentric motion center of the pinion 16 are inserted . The crankshaft 19 is rotatably supported by the carrier 17 , and two external gears 23 as input external gears are fixed to the other end of the crankshaft 19.

Reference numeral 20 denotes an external gear 21 as a third external gear whose outer diameter is larger than the diameter of the external gear 23 and a second external gear whose diameter is larger than the diameter of an external gear 25 described later. The external gear 22 is a rotating body to which the external gear 22 is attached . The external gear 21 meshes with the external gear 23. And the center part of this rotary body 20 and the center part of the said eccentric differential reduction gear are comprised hollow. A drive motor 26 is arranged radially outward from the eccentric motion center of the pinion 16 of the eccentric differential reduction gear. A first external gear meshing with the external gear 22 is connected to one end of an output shaft 24 of the drive motor 26. The external gear 25 is fixed . The drive motor 26 is arranged so that its output shaft 24 is parallel to the rotation axis of the crankshaft 19, and so that the rotation axis of the external gear 25 and the rotation axis of the external gear 22 are parallel. Has been.

The present invention can be applied to a gear device with a drive motor having an eccentric differential reduction gear .

It is front sectional drawing which shows the gear apparatus with a drive motor . It is II sectional view taken on the line of FIG. It is a front sectional view explaining the outline. It is front sectional drawing which shows the Example of this invention . It is sectional drawing similar to the FIG.

Explanation of symbols

31 ... Fixing member 36 ... Rotating case
37 ... Teeth 39 ... Pinion
41 ... external teeth 44 ... carrier
50 ... Crankshaft 53 ... Crank part
58 ... Drive motor 59 ... Output shaft

Claims (2)

    A rotating case having a large number of teeth on the inner periphery, a pinion provided in the rotating case, the outer periphery having slightly fewer teeth than the teeth of the rotating case, and external teeth that mesh with the teeth of the rotating case, and a pinion In an eccentric differential reduction gear having two or more crankshafts having crank portions inserted therein and a carrier that rotatably supports the crankshaft, the rotation of the output shaft of the drive motor is controlled by the two or more crankshafts. An eccentric differential speed reducer characterized in that it is transmitted to any one of the shafts and rotated, and the remaining crankshaft is rotated in synchronism with the one crankshaft.     The eccentric differential reduction gear according to claim 1, wherein a drive motor is arranged on a rotation axis of any one of the crankshafts, and the one crankshaft and an output shaft of the drive motor are directly connected.

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