Apparatus utilizing planetary gearset coupled to a constant torsion spring
AssigneeRiekor Corporation
InventorsRyan Heiraas, Timothy A. Erhart, John Russell Kingery
Life of this patent
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Abstract
A gearbox includes a planetary gearset, an input shaft coupled to a sun gear of the planetary gearset, and an output shaft coupled to planet gears of the planetary gearset via a carrier. A constant torsion spring is coupled to a ring gear of the planetary gearset. The constant torsion spring is capable of preventing the ring gear from moving when a torque at the output shaft is below a threshold. The ring gear winds the constant torsion spring in response to the torque exceeding the threshold.
Claims8
An apparatus comprising:
- a. a planetary gearset, the gearset including:
- i. a sun gear;
- ii. a rotatable ring gear;
- iii. planet gears operatively supported together by a carrier and interposed between the sun gear and ring gear,
- iv. an input shaft connected to the sun gear;
- and
- v. an output shaft connected to the carrier;
- b. an idler gear rotatably engaged with the ring gear;
- c. a rotatable spring shaft having a first end and a second end;
- d. a spring shaft gear mounted on the spring shaft at the first end and rotatably engaged with the idler gear;
- e. a first spool mounted on the spring shaft at the second end;
- f. a rotatable parallel shaft to the spring shaft, the rotatable parallel shaft having a second spool mounted thereon;
- and
- g. a metal band wrapped about the first and second spools, the metal band having a rotational range of movement between the first and second spools, whereby winding the metal band on one of the spools stores spring energy;
- wherein the metal band imparts an approximately constant torque to the spring shaft and, via the spring shaft gear and the idler gear, the ring gear through the rotational range of movement of the metal band between the two spools;
- and wherein the ring gear winds the metal band about the first spool when the torque level at the output shaft exceeds a threshold.
An apparatus for selectively limiting output shaft torque or returning the output shaft to a home position, comprising:
- a planetary gearset comprising a sun gear, planet gears, and a rotatable ring gear;
- an input shaft coupled to the sun gear of the planetary gearset;
- an output shaft coupled to the planet gears of the planetary gearset via a carrier;
- and
- a constant torsion spring coupled to the ring gear of the planetary gearset;
- and
- wherein the apparatus selectively:
- a) in a first mode prevents the ring gear from moving when a torque at the output shaft is below a threshold, the ring gear winding the constant torsion spring in response to the torque exceeding the threshold, or
- b) in a second mode winds the constant torsion spring, via the ring gear, using a first brake and a second brake coupled to the ring gear and the input shaft, respectively, during an initiation phase and the first and second brakes arranged and configured in a power loss to return the output shaft to the home position as the constant torsion spring unwinds.
Dependencies are inferred from the claim text.