Harmonic drive gears and industrial robots

Abstract

To provide a wave gear device which can restrict movement of a bearing in a rotation axis direction to prevent damage to the bearing, and to provide an industrial robot.SOLUTION: A wave gear device of an embodiment includes an internal gear 3, an external gear 5, and a wave generator 6. The wave generator 6 has: a cam 31 having a non-circular outer peripheral surface 31a; and a fourth bearing 32 positioned between an inner peripheral surface 21a of the external gear 5 and an outer peripheral surface 31a of the cam 31. The fourth bearing 32 has an outer ring 33, an inner ring 34, a plurality of balls 35, and a retainer 36. The wave gear device includes a restricting portion 37 which is provided in such a way as to avoid contact with the retainer 36 and restricts the fourth bearing 32 from moving in a direction of a rotation axis C.SELECTED DRAWING: Figure 2

Claims

1. Internal gears and An external gear, which is positioned radially inward of the internal gear, partially meshes with the internal gear, rotates relative to the internal gear about its axis of rotation, and is elastic, A wave generator that contacts the inner circumferential surface of the external gear and moves the meshing position between the internal gear and the external gear in the circumferential direction around the rotation axis, A shaft supporting the wave generator, A housing that rotatably supports the aforementioned shaft, Equipped with, The aforementioned wave generator is, A cam having a non-circular outer surface and supported by the shaft, A bearing is disposed between the inner circumferential surface of the external gear and the outer circumferential surface of the cam, Equipped with, The aforementioned bearing is The outer ring that contacts the inner circumferential surface of the external gear, An inner ring that contacts the outer circumferential surface of the cam, A plurality of rolling elements are arranged between the outer ring and the inner ring, A retainer that holds the plurality of rolling elements, Equipped with, The housing is provided to avoid contact with the retainer and includes a restricting portion that restricts the movement of the bearing in the direction of the rotation axis, The restricting portion is formed to protrude radially outward from the outer circumferential surface of the cam, The radially outer end of the regulating portion faces the retainer radially with a gap in between. The outer circumferential surface of the cam is formed in an elliptical or oblong shape having a major axis and a minor axis when viewed from the direction of the rotation axis. Harsh drive gear system.

2. The regulating portion is formed in a circular shape when viewed from the direction of the rotation axis, When the length of the short shaft of the cam is d1, the wall thickness of the inner ring is t, and the diameter of the restricting portion is Φd, D1 = d1 + 2 * t D1 ≥ Φd > d1 satisfies The wave drive gear apparatus according to claim 1.

3. The regulating portion is formed in a circular shape when viewed from the direction of the rotation axis, When the length of the major axis of the cam is d2, the wall thickness of the inner ring is t, and the diameter of the regulating portion is Φd, D2 = d2 + 2 * t Φd ≤ D2 satisfies The wave drive gear apparatus according to claim 1.

4. A power generation unit that generates rotational force, A harmonic drive gear device having an input unit to which the rotational force of the power generation unit is input, and an output unit that changes the speed of the rotation of the input unit and outputs it, The wave drive gear device comprises a mating member attached to the output section, The aforementioned wave drive gear device, Internal gears and An external gear, which is positioned radially inward of the internal gear, partially meshes with the internal gear, rotates relative to the internal gear about its axis of rotation, and is elastic, A wave generator that contacts the inner circumferential surface of the external gear and moves the meshing position between the internal gear and the external gear in the circumferential direction around the rotation axis, A shaft supporting the wave generator, A housing that rotatably supports the aforementioned shaft, Equipped with, The external gear functions as either the input unit or the output unit. The aforementioned wave generator is, A cam having a non-circular outer surface and supported by the shaft, which functions as the other of either the input or output section, A bearing is disposed between the inner circumferential surface of the external gear and the outer circumferential surface of the cam, Equipped with, The aforementioned bearing is The outer ring that contacts the inner circumferential surface of the external gear, An inner ring that contacts the outer circumferential surface of the cam, A plurality of rolling elements are arranged between the outer ring and the inner ring, A retainer that holds the plurality of rolling elements, Equipped with, The housing is provided to avoid contact with the retainer and includes a restricting portion that restricts the movement of the bearing in the direction of the rotation axis, The restricting portion is formed to protrude radially outward from the outer circumferential surface of the cam, The radially outer end of the regulating portion faces the retainer radially with a gap in between. The outer circumferential surface of the cam is formed in an elliptical or oblong shape having a major axis and a minor axis when viewed from the direction of the rotation axis. Industrial robots.

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