Transmission
First Claim
1. A constant mesh gearbox providing a plurality of forward speed ratios, said gearbox comprising a casing defining a plurality of parallel shaft axes having shafts rotatable thereon, and between which gear wheel pairs associated with each speed ratio are arranged to transmit torque, said casing defining a support plane substantially orthogonal to said axes and containing a support bearing for a shaft on each of said axes, said gearbox providing four or more forward speed ratios, the gear wheel pairs associated with odd forward speed ratios being provided on one side of said support plane, and the gear wheel pairs associated with even forward speed ratios being provided on the other side of said support plane, the arrangement of speed ratios being at least partially symmetrical about the support plane and wherein on the one side of said support plane the gear wheels of an input shaft decrease progressively in diameter toward said support plane, and on the other side of said support plane the gear wheels of an input shaft increase progressively in diameter away from said support plane,said gearbox including two reverse speed ratios, the gear wheel pairs associated with one of said reverse speed ratios being provided on the one side of said support plane, and the gear wheel pairs associated with the other of said reverse speed ratios being provided on the other side of said support plane.
1 Assignment
0 Petitions
Accused Products
Abstract
A constant mesh gear transmission has an input shaft (21, 22), two layshafts (31, 35) and an output shaft (23). Gear wheels are selectively connectable to shafts to provide forward and reverse speed ratios. A common central web (39) provides central support bearings for the shafts. The transmission is stiffened, and allows assembly of components from either end to the middle.
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Citations
20 Claims
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1. A constant mesh gearbox providing a plurality of forward speed ratios, said gearbox comprising a casing defining a plurality of parallel shaft axes having shafts rotatable thereon, and between which gear wheel pairs associated with each speed ratio are arranged to transmit torque, said casing defining a support plane substantially orthogonal to said axes and containing a support bearing for a shaft on each of said axes, said gearbox providing four or more forward speed ratios, the gear wheel pairs associated with odd forward speed ratios being provided on one side of said support plane, and the gear wheel pairs associated with even forward speed ratios being provided on the other side of said support plane, the arrangement of speed ratios being at least partially symmetrical about the support plane and wherein on the one side of said support plane the gear wheels of an input shaft decrease progressively in diameter toward said support plane, and on the other side of said support plane the gear wheels of an input shaft increase progressively in diameter away from said support plane,
said gearbox including two reverse speed ratios, the gear wheel pairs associated with one of said reverse speed ratios being provided on the one side of said support plane, and the gear wheel pairs associated with the other of said reverse speed ratios being provided on the other side of said support plane.
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20. A constant mesh gearbox providing a plurality of forward speed ratios, said gearbox comprising a casing defining a plurality of parallel shaft axes having shafts rotatable thereon, and between which gear wheel pairs associated with each speed ratio are arranged to transmit torque, said casing further defining a support plane substantially orthogonal to said axes and containing a support bearing for a shaft on each of said axes, said gearbox providing four or more forward speed ratios, the gear wheel pairs associated with odd forward speed ratios being provided on one side of said support plane as a first series of gear wheel pairs, and the gear wheel pairs associated with even forward speed ratios being provided on an opposite side of said support plane as a second series of gear wheel pairs, and wherein on the one side of said support plane the gear wheels of an input shaft belonging to the first series of gear wheel pairs decrease progressively in diameter toward said support plane, and on the opposite side of said support plane the gear wheels of an input shaft belonging to the second series of gear wheel pairs increase progressively in diameter away from said support plane, said gearbox having two reverse speed ratios, gear wheel pairs associated with one of said reverse speed ratios being provided on the one side of said support plane, and gear wheel pairs associated with the other of said reverse speed ratios being provided on the opposite side of said support plane.
Specification