Two-speed automatic transmission
AssigneeSundstrand Corporation
InventorRobert C. White
Life of this patent
Estimating the term…
Abstract
A two-speed centrifugally shifted automatic transmission provides an overdrive output shaft rotational speed that may be three times the rotational speed of the input shaft (12). A shift point at a partial speed may provide a direct drive through an overrunning clutch (33). A spline mounted shift engagement ring (46) is adapted to slide axially within housing (10) to restrain planet carrier ring (36) from rotating at start-up. After reaching a predetermined input shaft rotational speed, the shift engagement ring (46) moves to its extreme left position (FIG. 1), thereby allowing the planet carrier ring (36) to rotate and the rotational speed of the output shaft (14) to be driven by the overrunning clutch (33).
Claims12
A two speed transmission comprising:
- an input shaft having a drive sun gear adapted to rotate about an axis;
- an output shaft having a driven sun gear;
- a planetary gear assembly having a planet carrier supporting a shaft containing a plurality of gears for engagement with said drive and driven sun gears respectively;
- a clutch which prevents the output shaft from rotating at a rotational speed less than the instantaneous rotational speed of the input shaft;
- and
- a speed change mechanism including a non-rotating slide member which axially shifts in response to input shaft speed between a first axial position and a second axial position, said first axial position being effective to engage the planet gear carrier to prevent rotation of the planet gear carrier thereby to drive the output shaft at a rotational speed greater than the rotational speed of the input shaft, and said second axial position being effective to allow said planet gear carrier to rotate freely and the clutch to drive the output shaft at the rotational speed of the input shaft.
In an automatic transmission adapted when shifting to engage and disengage facing gear teeth on respective parts of an axially fixed rotating member and of an axially movable non-rotating slide member,
- a housing in which said members are mounted and supporting axially aligned input and output shafts;
- a hub that is spline mounted on said input shaft and that supports flyweights and a radially extending member having an end for controlling the axial position of said non-rotating member;
- a collar secured at a fixed axial position on said drive shaft;
- a compression spring positioned to separate said collar said drive shaft;
- said axially movable non-rotating slide member having a plurality of radially outwardly extending projections with each projection having opposed sloping sidewall surfaces facing the direction of axial movement;
- a plurality of separate ball and spring assemblies positioned in said housing to engage both sloping side wall surfaces of said projections as the projections are moved axially by movement of said hub;
- and
- means associated with said flyweights to produce a force directed in opposition to the force of said compression spring in response to input shaft rotational speeds above a predetermined value, said flyweight force being sufficient to overcome the combined forces of said compression spring and said ball and spring assemblies to effect disengagement of said facing gear teeth.
Dependencies are inferred from the claim text.