Offset compound gear inline two-speed drive
AssigneeThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration
InventorsMark A. Stevens, Robert F. Handschuh, David G. Lewicki
Life of this patent
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Abstract
A two-speed transmission having an input shaft and an output shaft, the transmission being capable of transitioning between fixed ratios, the high-range ratio being direct 1:1 and the low-range ratio being about 2:1. The transmission is a simple lightweight, yet robust, configuration utilizing only two gear meshes, being comprised of an input gear, a cluster gear, and an output gear. The transmission is controlled with a clutch and a sprag and with the input and output shafts turning in the same direction.
Claims21
A transmission having a gear arrangement for transmitting torque from an input shaft to an output shaft, the gear arrangement comprising:
- the input shaft rotating about a first rotational axis and having a first gear coupled thereto;
- an elongated, hollow, cylindrical shaft rotating about a second rotational axis that is offset from the first rotational axis, the hollow cylindrical shaft having a second gear at one end thereof which engages the first gear and a third gear at an opposite end thereof;
- a fourth gear mounted to one end of a hollow drive shaft, the fourth gear and the hollow drive shaft rotating about the first rotational axis, the fourth gear being meshed with the third gear of the hollow, cylindrical shaft, the hollow drive shaft having a cylindrical end portion at an opposite end thereof;
- the output shaft rotating about the first rotational axis and having a flange portion attached thereto;
- a sprag clutch having an input side mounted to the cylindrical end portion of the hollow drive shaft and an output side mounted to the flange portion of the output shaft;
- a clutch attached to an end portion of input shaft and to the output shaft;
- and
- means for coupling and uncoupling the input shaft with the output shaft whereby the transmission operates in first or second modes.
The method of transmitting torque from an input shaft to an output shaft, comprising:
- rotating the input shaft having a first gear coupled thereto about a first rotational axis;
- rotating an elongated, hollow, cylindrical shaft about a second rotational axis that is offset from the first rotational axis, the hollow cylindrical shaft having a second gear at one end thereof which meshes with the first gear and a third gear at an opposite end thereof;
- rotating a fourth gear mounted to one end of a hollow drive shaft with a cylindrical end portion at an opposite end thereof about the first rotational axis whereby the fourth gear meshes with the third gear of the hollow, cylindrical shaft;
- rotating the output shaft with a flange portion attached thereto about the first rotational axis;
- mounting an input side of a sprag clutch to the cylindrical end portion of the hollow drive shaft and an output side of the sprag clutch to the flange portion of the output shaft;
- attaching a clutch to an end portion of input shaft and to the output shaft;
- and
- coupling the input shaft with the output shaft whereby the transmission operates in either a first or a second mode.
Dependencies are inferred from the claim text.