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US 9,447,853 B2Granted
Coaxial rotary shaft feedthrough with backlash reduction
AssigneeTechnetics Group LLC
InventorsBradley DiMarco, Aaron Glafenhein
Life of this patent
Estimating the term…
Abstract
A sealed dual coaxial rotary shaft feedthrough device is provide. The device includes an inner shaft and a hollow outer shaft that is coaxial to encompass the inner shaft. The shafts include coupled drive and driven shafts. The coupling, which may be referred to as an eccentric coupling, causes the driven shaft to rotate with the drive shaft. The rotation is transmitted without breaking the seal by an eccentric portion of either the drive or driven shaft being nutatingly coupled to either a transition cap or transition cup. Nutatingly coupled means rotation of the shaft causes the transition cap or cup to orbit, but not spin, about the longitudinal axis. The nutation is transmitted by the transition cap or cup to the other of the shafts, which rotates.
Claims15
A coaxial rotary feedthrough apparatus, comprising:
- a housing comprising a first end, a second end opposite the first end, and at least one sidewall between the first end and the second end defining an interior, a first bore in the first end and a second bore in the second end;
- an inner shaft comprising:
- an inner drive shaft, the inner drive shaft extending from the second bore;
- an inner driven shaft, the inner driven shaft extending from the first bore and comprising an inner normal portion having a longitudinal axis and an inner eccentric portion having an inner eccentric longitudinal axis offset from the longitudinal axis;
- and
- an inner coupling residing in the interior connecting the inner drive shaft and the inner driven shaft wherein the inner driven shaft rotates with the inner drive shaft, the inner coupling comprising an inner transition cup coupled to the inner drive shaft, and an inner transition cap coupled to the inner driven shaft such that the inner drive shaft is nutatingly coupled to the inner driven shaft;
- an outer shaft comprising:
- a hollow outer drive shaft coaxial to and encompassing the inner drive shaft, the hollow outer drive shaft extending from the second bore;
- a hollow outer driven shaft coaxial to and encompassing the inner driven shaft, the outer driven shaft extending from the first bore and comprising an outer normal portion having the longitudinal axis and an outer eccentric portion having an outer eccentric longitudinal axis;
- and
- an outer coupling residing in the interior connecting the outer drive shaft and the outer driven shaft wherein the outer driven shaft rotates with the outer drive shaft, the outer coupling comprising an outer transition cup coupled to the outer drive shaft, and an outer transition cap coupled to the outer driven shaft such that the outer drive shaft is nutatingly coupled to the outer driven shaft;
- and
- a barrier separating the first bore from the second bore wherein the barrier comprises a first bellows operationally coupled to the inner transition cup and the outer transition cap and a second bellows operationally coupled to the outer transition cap and the first end.
10 more elements
A coaxial rotary feedthrough apparatus, comprising:
- a housing comprising a first end, a second end opposite the first end, and at least one sidewall extending between the first end and the second end defining an interior, a first bore in the first end and a second bore in the second end;
- an inner shaft comprising:
- an inner drive shaft, the inner drive shaft extending from the second bore and comprising an inner normal portion having a longitudinal axis and an inner eccentric portion having an inner eccentric longitudinal axis offset from the longitudinal axis;
- an inner driven shaft, the inner driven shaft extending from the first bore;
- and
- an inner coupling residing in the interior connecting the inner drive shaft and the inner driven shaft wherein the inner driven shaft rotates with the inner drive shaft, the inner coupling comprising an inner transition cup coupled to the inner driven shaft, and an inner transition cap coupled to the inner drive shaft such that the inner transition cup is nutatingly coupled to the inner transition cap;
- an outer shaft comprising:
- a hollow outer drive shaft coaxial and encompassing the inner drive shaft, the hollow outer drive shaft extending from the second bore and comprising an outer normal portion having the longitudinal axis and an outer eccentric portion having an outer eccentric longitudinal axis;
- a hollow outer driven shaft coaxial and encompassing the inner driven shaft, the outer driven shaft extending from the first bore;
- an outer coupling residing in the interior connecting the outer drive shaft and the outer driven shaft wherein the outer driven shaft rotates with the outer driven shaft, the outer coupling comprising an outer transition cup coupled to the outer driven shaft, and an outer transition cap coupled to the outer drive shaft such that the outer transition cup is nutatingly coupled to the outer transition cap;
- and
- a barrier separating the first bore from the second bore, the barrier comprising at least a first bellows encompassing the hollow outer driven shaft and coupled to the second end and the outer transition cap and a second bellows encompassing the inner driven shaft and coupled to the outer transition cap and the inner transition cap.
9 more elements
Dependencies are inferred from the claim text.