Search

US-12624745-B2 - Eccentric oscillation type speed reducer

US12624745B2US 12624745 B2US12624745 B2US 12624745B2US-12624745-B2

Abstract

An eccentric oscillation type speed reducer includes: an eccentric body; an external gear capable of being oscillated by the eccentric body; an internal gear that meshes with the external gear; and a carrier capable of being synchronized with an axial rotation component of the external gear, in which one of the internal gear and the carrier configures at least a part of a fixed body that is fixed to an external member, the fixed body includes a first ring portion, a second ring portion that is provided to be separated from the first ring portion in a radial direction and is fixed to the external member, and a distortion generating portion provided between the first ring portion and the second ring portion, and a strain sensor is installed in the distortion generating portion.

Inventors

  • Sebastian Markert

Assignees

  • SUMITOMO HEAVY INDUSTRIES, LTD.

Dates

Publication Date
20260512
Application Date
20241210
Priority Date
20231211

Claims (7)

  1. 1 . An eccentric oscillation type speed reducer comprising: an eccentric body; an external gear capable of being oscillated by the eccentric body; an internal gear that meshes with the external gear; a carrier capable of being synchronized with an axial rotation component of the external gear; and a circuit board to which a strain sensor is electrically connected, wherein one of the internal gear and the carrier configures at least a part of a fixed body that is fixed to an external member, the fixed body includes a first ring portion, a second ring portion that is provided to be separated from the first ring portion in a radial direction and is fixed to the external member, and a distortion generating portion provided between the first ring portion and the second ring portion, the strain sensor is installed in the distortion generating portion, the distortion generating portion includes a first recessed portion that accommodates the strain sensor, and the circuit board includes a first protrusion portion that protrudes into the first recessed portion and is connected to the strain sensor.
  2. 2 . The eccentric oscillation type speed reducer according to claim 1 , wherein the first protrusion portion and the strain sensor are electrically connected to each other via a conductive connection material, and the first protrusion portion is configured by a flexible substrate.
  3. 3 . An eccentric oscillation type speed reducer comprising: an eccentric body; an external gear capable of being oscillated by the eccentric body; an internal gear that meshes with the external gear; a carrier capable of being synchronized with an axial rotation component of the external gear; and a circuit board to which a strain sensor is electrically connected, wherein one of the internal gear and the carrier configures at least a part of a fixed body that is fixed to an external member, the fixed body includes a first ring portion, a second ring portion that is provided to be separated from the first ring portion in a radial direction and is fixed to the external member, and a distortion generating portion provided between the first ring portion and the second ring portion, the strain sensor is installed in the distortion generating portion, and one of the first ring portion and the second ring portion includes a second recessed portion that accommodates at least a part of the circuit board.
  4. 4 . An eccentric oscillation type speed reducer comprising: an eccentric body; an external gear capable of being oscillated by the eccentric body; an internal gear that meshes with the external gear; a carrier capable of being synchronized with an axial rotation component of the external gear; and a circuit board to which a strain sensor is electrically connected, wherein one of the internal gear and the carrier configures at least a part of a fixed body that is fixed to an external member, the fixed body includes a first ring portion, a second ring portion that is provided to be separated from the first ring portion in a radial direction and is fixed to the external member, and a distortion generating portion provided between the first ring portion and the second ring portion, the strain sensor is installed in the distortion generating portion, and the circuit board includes an annular portion that faces one of the first ring portion and the second ring portion in an axial direction, and a first protrusion portion that protrudes in the radial direction from the annular portion and is electrically connected to the strain sensor.
  5. 5 . An eccentric oscillation type speed reducer comprising: an eccentric body; an external gear capable of being oscillated by the eccentric body; an internal gear that meshes with the external gear; a carrier capable of being synchronized with an axial rotation component of the external gear; and a circuit board to which a strain sensor is electrically connected, wherein one of the internal gear and the carrier configures at least a part of a fixed body that is fixed to an external member, the fixed body includes a first ring portion, a second ring portion that is provided to be separated from the first ring portion in a radial direction and is fixed to the external member, and a distortion generating portion provided between the first ring portion and the second ring portion, the strain sensor is installed in the distortion generating portion, the distortion generating portion includes a plurality of pillar portions provided at intervals in a circumferential direction, and the circuit board includes a second protrusion portion that protrudes to be located between the pillar portions adjacent to each other when viewed in an axial direction.
  6. 6 . The eccentric oscillation type speed reducer according to claim 5 , wherein the fixed body includes an axial through-hole formed between the pillar portions adjacent to each other, and a pair of reinforcement portions each provided at each of a pair of circumferential side portions of the axial through-hole, one of the first ring portion and the second ring portion includes a second recessed portion that accommodates at least a part of the circuit board, and the pair of reinforcement portions are interrupted in a radial side portion of the axial through-hole, which is located on a second recessed portion side with respect to the axial through-hole in the radial direction.
  7. 7 . An eccentric oscillation type speed reducer comprising: an eccentric body; an external gear capable of being oscillated by the eccentric body; an internal gear that meshes with the external gear; a carrier capable of being synchronized with an axial rotation component of the external gear; and a casing provided outside the external gear in a radial direction, wherein one of the internal gear and the carrier configures at least a part of a fixed body that is fixed to an external member, the fixed body includes a first ring portion, a second ring portion that is provided to be separated from the first ring portion in the radial direction and is fixed to the external member, and a distortion generating portion provided between the first ring portion and the second ring portion, a strain sensor is installed in the distortion generating portion, the other of the internal gear and the carrier configures at least a part of an output body that outputs rotation, a main bearing is disposed between the output body and the fixed body, the distortion generating portion is provided at a location different from a load transmission pathway extending from the output body to the external member via the main bearing and the fixed body, at least a part of the fixed body is configured by the casing and the carrier, and the distortion generating portion is provided in the carrier.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to Japanese Patent Application No. 2023-208428, filed on Dec. 11, 2023, which is incorporated by reference herein in its entirety. BACKGROUND Technical Field Certain embodiments of the present invention relate to an eccentric oscillation type speed reducer. Description of Related Art The related art discloses an eccentric oscillation type speed reducer that includes an eccentric body, an external gear that is oscillated by the eccentric body, an internal gear that meshes with the external gear, and a carrier that is synchronized with an axial rotation component of the external gear. SUMMARY According to an embodiment of the present invention, there is provided an eccentric oscillation type speed reducer including: an eccentric body; an external gear that is oscillated by the eccentric body; an internal gear that meshes with the external gear; and a carrier that is synchronized with an axial rotation component of the external gear, in which one of the internal gear and the carrier configures at least a part of a fixed body that is fixed to an external member, the fixed body includes a first ring portion, a second ring portion that is provided to be separated from the first ring portion in a radial direction and is fixed to the external member, and a distortion generating portion provided between the first ring portion and the second ring portion, and a strain sensor is installed in the distortion generating portion. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side sectional view showing an eccentric oscillation type speed reducer according to one embodiment. FIG. 2 is an exploded perspective view showing a synchronous carrier of one embodiment together with a peripheral structure. FIG. 3 is a front view showing the synchronous carrier of one embodiment. FIG. 4 is a front view showing the synchronous carrier of one embodiment together with the peripheral structure. FIG. 5 is an enlarged view showing a strain sensor of FIG. 1. FIG. 6 is an enlarged view showing the strain sensor of FIG. 4. FIG. 7 is a side sectional view showing an eccentric oscillation type speed reducer according to another embodiment. FIG. 8 is a view showing the eccentric oscillation type speed reducer of another embodiment as viewed from the same viewpoint as that in FIG. 4. FIG. 9 is a view showing an eccentric oscillation type speed reducer of further embodiment as viewed from the same viewpoint as that in FIG. 6. DETAILED DESCRIPTION In the eccentric oscillation type speed reducer, there is a case where it is required to detect torque that acts on a constituent member thereof. It is desirable to provide an eccentric oscillation type speed reducer capable of detecting torque that acts on a constituent member. Embodiments for implementing an eccentric oscillation type speed reducer (hereinafter, also referred to as a speed reducer) of the present disclosure will be described. Identical or equivalent elements will be denoted by the same reference numerals and the repeated description thereof will be omitted. In each drawing, for convenience of description, the components are appropriately omitted, enlarged, or reduced. The drawings shall be viewed according to the directions of the symbols. One Embodiment FIG. 1 is referred to. A speed reducer 10 includes a crankshaft 14 having at least one eccentric body 12, an external gear 16 capable of being oscillated by the eccentric body 12, an internal gear 18 that meshes with the external gear 16, a synchronous carrier 20 capable of being synchronized with an axial rotation component of the external gear 16, a casing 22 that is disposed outside the external gear 16 in a radial direction, and an asynchronous carrier 24 provided on a side opposite to the synchronous carrier 20 in an axial direction with respect to the external gear 16. In the present embodiment, a center crank type eccentric oscillation type speed reducer 10 will be described. In the speed reducer 10 of this type, the crankshaft 14 is disposed on an oscillation center C16a of the external gear 16. Hereinafter, the direction along the oscillation center C16a of the external gear 16 will be referred to as an axial direction, and the radial direction and the circumferential direction centered on the oscillation center C16a will be referred to as a radial direction and a circumferential direction. The speed reducer 10 includes a fixed body 28 that is fixed to an external member 26, and an output body 32 that outputs rotation to an external driven member 30. Here, an example in which the synchronous carrier 20 and the casing 22 configure the fixed body 28 and the internal gear 18 and the asynchronous carrier 24 configure the output body 32 will be described. The external member 26 is provided outside the speed reducer 10 and supports the speed reducer 10. The driven member 30 is provided outside the speed reducer 10 and is driven by the output of the output body