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.

A spring assembly for 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.

A loudspeaker includes an acoustic diaphragm, an oscillatory force source, a lever coupling the oscillatory force source to the acoustic diaphragm, and a pivot coupled to the lever such that the lever moves in an arcuate path about the pivot when the oscillatory force source applies a force to the lever. The pivot includes at least one torsion bushing. The at least one torsion bushing includes a first member, a second member coupled to the lever and movable relative to the first member, and an elastomeric member coupling the first member to the second member. Either the first member or the second member is coupled to and moves with the lever. An outer surface of the elastomeric member is coupled to the second member via mechanical compression.

A torsion spring adjuster for a rolling shutter is provided. A support plate has a first flange with a hole. A wheel is rotatably mountable on the support plate. The wheel has: a drive recess shaped to engage an end of a torsion spring; a first set of recesses around a circumference of the wheel, the first set of recesses being a first lateral distance from a first end of the wheel; a second set of recesses around a circumference of the wheel, the second set of recesses being a second lateral distance from the first end of the wheel. When the wheel is mounted on the support plate the first lateral distance aligns the first set of recesses with the hole of the first flange of the support plate, and the second lateral distance aligns the second set of recess past the first flange of the support plate.

An annular cantilever beam spring is capable of exhibiting low friction and hysteresis and stiffness and specifically stiffness/volume far exceeding currently available COTS springs. The spring includes first and second sets of N stand-offs evenly positioned around opposing top and bottom surfaces of a flat annular beam at 360/N degree intervals and angularly offset with respect to each other by 360/2N degrees such that each said stand-off is evenly spaced between adjacent pairs of stand-offs on the opposing surface. The first and second sets of stand-offs are responsive to opposing axial loads to deflect the flat annular beam axially at each stand-off in opposing directions to induce a curvature to the annular beam and store energy in the beam. The spring stiffness is determined by the elastic material properties of the flat annular beam, not the initial geometry as is common with the COTS springs.

A rotary damper including: an oil chamber (4); a rotor (2); a first surface (4a) occluding an end of the oil chamber (4); a second surface (4b) occluding another end of the oil chamber (4); and a valve (3) including: a first end surface (3a) facing the first surface (4a); a second end surface (3b) facing the second surface (4b); a back surface (3c) facing a curved surface (4c) of the oil chamber (4); a valve part (3d) to shut an oil path (5) formed between the rotor (2) and the valve (3) to prevent oil injected in the oil chamber (4) from flowing back through the oil path (5); and an uneven part (3k, 3l) on the back surface (3c), the uneven part (3k, 3l) including a recess (3k) and a projection (3l), the recess (3k) forming a gap (6) between the curved surface (4c) and the uneven part (3k, 3l).

A torsion spring adjuster for a rolling shutter is provided. A support plate has a first flange with a hole. A wheel is rotatably mountable on the support plate. The wheel has: a drive recess shaped to engage an end of a torsion spring; a first set of recesses around a circumference of the wheel, the first set of recesses being a first lateral distance from a first end of the wheel; a second set of recesses around a circumference of the wheel, the second set of recesses being a second lateral distance from the first end of the wheel. When the wheel is mounted on the support plate the first lateral distance aligns the first set of recesses with the hole of the first flange of the support plate, and the second lateral distance aligns the second set of recess past the first flange of the support plate.