Transfer case input shaft brake system
AssigneeBorgWarner Inc.
InventorsLarry Pritchard, Christopher V. Kurmaniak
Life of this patent
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Abstract
A two-speed transfer case includes a planetary gear assembly, and a shift sleeve that is used for selecting either the reduced speed gear ratio, in which the torque from the input is transferred though the planetary gears, or the direct drive speed ratio, in which the input and output shafts are coupled directly together. The carrier of the planetary gear assembly is equipped with a surface that is capable of receiving a band brake that is disposed thereabout. A lever composed to two pieces, a brake apply arm and a cam follower, applies the brake band, and in doing so controls retardation of the planet carrier, controlling the speed of the carrier, and thus, controlling the output of the planetary gear assembly.
Claims16
A planetary gear carrier brake assembly comprising, in combination,
- an input member having a sun gear,
- a planet carrier disposed about said sun gear and having a brake surface,
- at least two planet gears rotatably disposed in said planet carrier,
- a ring gear disposed about and engaged by said planet gears,
- a brake band disposed about said brake surface and having a pair of ends,
- a rotary actuator driving a cam
- a cam follower, and
- a lever having a first end engaging one of said pair of ends of said brake band and a second end for receiving said cam follower,
- wherein rotation of said cam tightens said brake band.
A method of restricting drag torque input into a two-speed transfer case, allowing for synchronized shifts between separate input and output members, comprising the steps of:
- providing an input member featuring a sun gear,
- providing a planet carrier featuring a brake surface,
- providing at least two planet gears, operably disposed about said planet carrier,
- providing a ring gear, operably disposed about and engaged by said plant gears, providing a brake band operably disposed about said brake surface, featuring a pair of ends,
- providing a cam driven by a rotary actuator,
- providing a cam follower, and,
- providing a lever having a first end engaging one of said pair of ends of said brake band and a second end for receiving said cam follower,
- providing that wherein rotation of said cam tightens said brake band.
Dependencies are inferred from the claim text.