Multiple gear range transmission
AssigneeQinetiq Limited
InventorRobert William Thompson
Life of this patent
Estimating the term…
Abstract
Some embodiments are directed to a transmission including a plurality of shafts, each carrying a plurality of drive members, the drive members on each shaft arranged to operatively cooperate with those carried by at least one other shaft for transferring load between a torque input and a torque output of the transmission in use, the transmission being configured such that respective resultant gear ratios between the torque input and the torque output can be selected in use from each of a plurality of groups thereof by changing a load path between the torque input and the torque output, wherein each group of selectable resultant gear ratios has a load path feature for transferring load between a pair of the shafts which is common to the selectable resultant gear ratios within that group.
Claims24
A multiple gear range transmission for use with a torque input and a torque output, comprising:
- an input shaft;
- an output shaft;
- and
- only one bridging shaft arranged in a triangular arrangement, each carrying a plurality of drive members, the bridging shaft not being connected to the torque input or the output;
- wherein drive members on the bridging shaft operatively cooperate with those carried on either the input shaft and/or output shaft so as to transfer load between the input shaft and the output shaft via a plurality of selectable load paths corresponding to a plurality of respective resultant gear ratios grouped in at least two gear ranges;
- wherein each shaft has one or more drive members capable of being selectively rotationally fixed to the shaft;
- wherein successive gear ratios up or down a gear range are selectable, using load paths that include different respective drive members from one of either the input or output shafts;
- wherein successive gear ranges are selectable using load paths that include different respective drive members from the other of either the input or output shafts;
- and
- wherein a transition from a selected gear at the top or bottom of a selected gear range to the next available gear in the next available gear range involves selection of a new load path comprising drive members from the input and output shaft that are not involved in the load path for the currently selected gear.
A transmission for use with a torque input and a torque output, comprising:
- a plurality of shafts, each carrying a plurality of drive members, the drive members on each said shaft configured to operatively cooperate with those carried by at least one other said shaft for transferring load between the torque input and the torque output in use, the transmission being configured such that respective resultant gear ratios between the torque input and the torque output can be selected in use from each of a plurality of groups thereof by changing a load path between the torque input and the torque output,
- wherein each said group of selectable resultant gear ratios has a load path feature for transferring load between a pair of the shafts which is common to the selectable resultant gear ratios within that group,
- wherein any of the drive members which are not permanently rotationally fixed to one of the shafts can be selectively rotationally fixed to the shaft carrying it by engaging dog hubs rotationally fixed to the shaft with either side of the drive member, and wherein for one of the shafts a forward driving dog hub for one said drive member is mechanically coupled to a reverse driving dog hub for another said drive member such that these two dog hubs cannot be caused to engage such drive members simultaneously.
Dependencies are inferred from the claim text.