摘要 |
A CVVL system including a self-locking helical gear pair with, optionally, a transmission to increase output torque of the actuator. The self-locking helical gear pair provides high forward efficiency and a fully mechanically self-locking feature. The actuator therefore requires a smaller motor to perform the same actuation as a prior art worm-gear system. The CVVL system comprises two helical gears having a radial pressure angle {acute over (alpha)} between 45° and 75° and a helix angle beta between 60° and 80°. An asymmetric tooth profile is presently preferred, reducing contact stress and permitting higher torque density. Preferably, the helical gears are discontinuous and comprise laminated spur gear slices and hence are less costly to produce than continuous helical gears. Configurations are possible within the scope of the present invention include a single stage gear system; a multiple stage gear system; a planetary gear system; and an internal or external gear system.
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