COAXIAL ROTARY SHAFT FEEDTHROUGH WITH BACKLASH REDUCTION

摘要

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.

主权项

1. 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; andan 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 coupling comprising an inner transition cup coupled to the inner drive shaft, 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; andan 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 coupling comprising an outer transition cup coupled to the outer drive shaft, an outer transition cap coupled to the outer driven shaft such that the outer drive shaft is nutatingly coupled to the outer driven shaft.