US 12,097,610 B2 · Torsional series elastic actuator

Abstract

A rotary-type series elastic actuator (SEA) for use in robotic applications. The SEA including a motor, gear transmission assembly, spring assembly, and sensors. In one example, a robotic joint may include the SEA as well as two links coupled with each other at the joint assembly. The two links may be designated as input and output links. Each link may have a joint housing body which may be concentrically connected via a joint bearing so that they freely rotate against each other. The housing frame of the SEA may be fixed at the joint housing body of the input link while the output mount of the spring assembly of the SEA may be concentrically coupled with the joint housing body of the output link. The rotation of the motor rotor causes the rotation of the output link with respect to the input link plus spring deflection of the spring assembly. When an external force or torque are applied between the two links, a control action of a control loop may cause a rotation and motive force of the motor that lead to the deflection of the spring assembly to balance with the external force/torque and inertial force from body masses moving together with the links.

Claims20

Dependent claims

A disc-shaped torsional spring of a spring assembly for a rotary series elastic actuator comprising:

a circular inner mount;
a circular outer mount;
and
a set of elastically deformable spirals, each of the elastically deformable spirals including an inner thick segment coupled to the circular inner mount, an outer thick segment coupled to the circular outer mount, and a middle thin section connected between the inner thick segment and the outer thick segment;
and
wherein a relative thickness of the inner thick segment to the middle thin section is at a ratio between 11:1 and 8:1 and a relative thickness of the middle thin section to the outer thick segment is at a ratio between 1:10 and 1:7.

3 more elements

A spring assembly for a rotary series elastic actuator comprising:

a first torsional spring including a first set of elastically deformable spirals, a first circular inner mount, and a first circular outer mount, wherein:
a first spiral of the first set of elastically deformable spirals includes an inner thick segment coupled to the inner mount, an outer thick segment coupled to the outer mount, and a middle thin section connected between the inner thick segment and the outer thick segment, and
a relative thickness of the inner thick segment to the middle thin section is at a ratio between 11:1 and 8:1 and a relative thickness of the middle thin section to the outer thick segment is at a ratio between 1:10 and 1:7;
a second torsional spring including a second set of elastically deformable spirals a second circular inner mount, and a second circular outer mount, the first circular outer mount coupled to the second circular out mount via a spacer;
and
an internal mechanism residing between the first torsional spring and the second torsional spring, the internal mechanism including a sensor to detect a rotational deflection of the spring assembly and provide the rotational deflection as a measured torque input value to a motor controller.

3 more elements

A torsional spring comprising:

a inner mount;
a outer mount;
and
a first elastically deformable spiral, the first elastically deformable spiral including an inner thick segment coupled to the inner mount, an outer thick segment coupled to the outer mount, and a middle thin section connected between the inner thick segment and the outer thick segment, wherein a relative thickness of the inner thick segment of the first elastically deformable spiral to the middle thin section of the first elastically deformable spiral is at a ratio between 11:1 and 8:1 and a relative thickness of the middle thin section of the first elastically deformable spiral to the outer thick segment of the first elastically deformable spiral is at a ratio between 1:10 and 1:7;
and
a second elastically deformable spiral, the second elastically deformable spiral including an inner thick segment coupled to the inner mount, an outer thick segment coupled to the outer mount, and a middle thin section connected between the inner thick segment and the outer thick segment.

3 more elements

Dependencies are inferred from the claim text.

Torsional series elastic actuator

Life of this patent

Torsional series elastic actuator

Life of this patent

Abstract

Claims20