Planetary gear transmission system

A planetary gear transmission system, comprising:

• a main planetary gear train composed of a main sun gear, a main ring gear coaxial with said main sun gear, and main planet gears meshing with said main sun gear and said main ring gear, said main sun gear adapted in use to be connected to an input rotary shaft to be driven thereby to rotate;
• a sub planetary gear train composed of a sub sun gear, a sub ring gear coaxial with said sub sun gear, and sub planet gears meshing with said sub sun gear and said sub ring gear and having a different gear ratio than said main planetary gear train, said sub sun gear connected to said main sun gear to rotate together therewith;
• a common carrier supporting said main and sub planet gears and rotatable about a common center axis of said main and sub sun gears, said common carrier adapted in use to be drivingly connected to an output shaft;
• lock means for releasably fixing said main ring gear;
• first one-way clutch means, connected to said sub ring gear for permitting said sub ring gear to rotate in a first direction and for preventing said sub ring gear from rotating in a second direction opposite to said first direction, said first direction being selected to be a direction in which said sub ring gear is permitted to rotate during said common carrier rotation with said main ring gear fixed by said lock means, such that said sub ring gear is locked in said second direction after said main ring gear is released to thereby permit said common carrier to continue rotating at a speed reduction ratio different than when said main ring gear is fixed;
• an additional sub ring gear meshing with said sub planet gears in a coaxial relation with said sub ring gear;
• and
• second one-way clutch means which is connectable to said additional sub ring gear to permit said additional sub ring to rotate only in the second direction, wherein selector means is provided to selectively actuate said first and second one-way clutch means.

A planetary gear transmission system, comprising:

• a main planetary gear train composed of a main sun gear, a main ring gear coaxial with said main sun gear, and main planet gears meshing with said main sun gear and said main ring gear, said main sun gear adapted in use to be connected to an input rotary shaft to be driven thereby to rotate;
• a sub planetary gear train composed of a sub sun gear, a sub ring gear coaxial with said sub sun gear, and sub planet gears meshing with said sub sun gear and said sub ring gear and having a different gear ratio than said main planetary gear train, said sub sun gear connected to said main sun gear to rotate together therewith;
• a common carrier supporting said main and sub planet gears and rotatable about a common center axis of said main and sub sun gears, said common carrier adapted in use to be drivingly connected to an output shaft;
• lock means for releasably fixing said main ring gear;
• and
• first one-way clutch means, connected to said sub ring gear for permitting said sub ring gear to rotate in a first direction and for preventing said sub ring gear from rotating in a second direction opposite to said first direction, said first direction being selected to be a direction in which said sub ring gear is permitted to rotate during said common carrier rotation with said main ring gear fixed by said lock means, such that said sub ring gear is locked in said second direction after said main ring gear is released to thereby permit said common carrier to continue rotating at a speed reduction ratio different than when said main ring gear is fixed,
• wherein said lock means is movable from a lock position of fixing said main ring gear to a release position of releasing said main ring gear, said lock means being actuated to move into said release position in response to said main ring gear receiving a load which exceeds a predetermined level.

A planetary gear transmission system, comprising:

• a main planetary gear train composed of a main sun gear, a main ring gear coaxial with said main sun gear, and main planet gears meshing with said main sun gear and said main ring gear, said main sun gear adapted in use to be connected to an input rotary shaft to be driven thereby to rotate;
• a sub planetary gear train composed of a sub sun gear, a sub ring gear coaxial with said sub sun gear, and sub planet gears meshing with said sub sun gear and said sub ring gear and having a different gear ratio than said main planetary gear train, said sub sun gear connected to said main sun gear to rotate together therewith;
• a common carrier supporting said main and sub planet gears and rotatable about a common center axis of said main and sub sun gears, said common carrier adapted in use to be drivingly connected to an output shaft;
• lock means for releasably fixing said main ring gear;
• and
• first one-way clutch means, connected to said sub ring gear for permitting said sub ring gear to rotate in a first direction and for preventing said sub ring gear from rotating in a second direction opposite to said first direction, said first direction being selected to be a direction in which said sub ring gear is permitted to rotate during said common carrier rotation with said main ring gear fixed by said lock means, such that said sub ring gear is locked in said second direction after said main ring gear is released to thereby permit said common carrier to continue rotating at a speed reduction ratio different than when said main ring gear is fixed,
• wherein said lock means is movable from a lock position of fixing said main ring gear to a release position of releasing said main ring gear, and release handle is connected to manually move said lock means into said release position.

A planetary gear transmission system, comprising:

• a main planetary gear train composed of a main sun gear, a main ring gear coaxial with said main sun gear, and main planet gears meshing with said main sun gear and said main ring gear, said main sun gear adapted in use to be connected to an input rotary shaft to be driven thereby to rotate;
• a sub planetary gear train composed of a sub sun gear, a sub ring gear coaxial with said sub sun gear, and sub planet gears meshing with said sub sun gear and said sub ring gear and having a different gear ratio than said main planetary gear train, said sub sun gear connected to said main sun gear to route together therewith;
• a common carrier supporting said main and sub planet gears and rotatable about a common center axis of said main and sub sun gears, said common carrier adapted in use to be drivingly connected to an output shaft;
• lock means for releasably fixing said main ring gear;
• and
• first one-way clutch means, connected to said sub ring gear for permitting said sub ring gear to rotate in a first direction and for preventing said sub ring gear from routing in a second direction opposite to said first direction, said first direction being selected to be a direction in which said sub ring gear is permitted to rotate during said common carrier rotation with said main ring gear fixed by said lock means, such that said sub ring gear is locked in said second direction after said main ring gear is released to thereby permit said common carrier to continue rotating at a speed reduction ratio different than when said main ring gear is fixed,
• wherein said lock means is movable from a lock position of fixing said main ring gear to a release position of releasing said main ring gear, and an electromagnetic actuator is connected to move said lock means into said release position in response to an electric signal.

A planetary gear transmission system, comprising:

• a main planetary gear train composed of a main sun gear, a main ring gear coaxial with said main sun gear, and main planet gears meshing with said main sun gear and said main ring gear, said main sun gear adapted in use to be connected to an input rotary shaft to be driven thereby to rotate;
• a sub planetary gear train composed of a sub sun gear, a sub ring gear coaxial with said sub sun gear, and sub planet gears meshing with said sub sun gear and said sub ring gear and having a different gear ratio than said main planetary gear train, said sub sun gear connected to said main sun gear to rotate together therewith;
• a common carrier supporting said main and sub planet gears and rotatable about a common center axis of said main and sub sun gears, said common carrier adapted in use to be drivingly connected to an output shaft;
• lock means for releasably fixing said main ring gear;
• and
• first one-way clutch means, connected to said sub ring gear for permitting said sub ring gear to rotate in a first direction and for preventing said sub ring gear from rotating in a second direction opposite to said first direction, said first direction being selected to be a direction in which said sub ring gear is permitted to rotate during said common carrier rotation with said main ring gear fixed by said lock means, such that said sub ring gear is locked in said second direction after said main ring gear is released to thereby permit said common carrier to continue rotating at a speed reduction ratio different than when said main ring gear is fixed,
• wherein said one-way clutch means comprises a fixed outer race, an inner race integral with said sub ring gear, and a roller held between said outer and inner races to allow said inner race to rotate only in said first direction, said outer race being formed as part of a gear casing incorporating said main and sub planetary gear trains, and said inner race defining itself said sub ring gear.

A planetary gear transmission system, comprising:

• a main planetary gear train composed of a main sun gear, a main ring gear coaxial with said main sun gear, and main planet gears meshing with said main sun gear and said main ring gear, said main sun gear adapted in use to be connected to an input rotary shaft to be driven thereby to rotate;
• a sub planetary gear train composed of a sub sun gear, a sub ring gear coaxial with said sub sun gear, and sub planet gears meshing with said sub sun gear and said sub ring gear having a different gear ratio than said main planetary gear train, said sub sun gear connected to said main sun gear to rotate together therewith;
• a common carrier supporting said main and sub planet gears and rotatable about a common center axis of said main and sub sun gears, said common carrier adapted in use to be drivingly connected to an output shaft;
• lock means for releasably fixing said main ring gear;
• and
• first one-way clutch means, connected to said sub ring gear for permitting said sub ring gear to rotate in a first direction and for preventing said sub ring gear from rotating in a second direction opposite to said first direction, said first direction being selected to be a direction in which said sub ring gear is permitted to rotate during said common carrier rotation with said main ring gear fixed by said lock means, such that said sub ring gear is locked in said second direction after said main ring gear is released to thereby permit said common carrier to continue rotating at a speed reduction ratio different than when said main ring gear is fixed,
• wherein said one-way clutch means includes direction switch means for switching said first and second directions, and
• wherein said one-way clutch means comprises a fixed outer race, an inner race integral with said sub ring gear, and a roller received in each one of first and second compartments formed to extend circumferentially between said outer and inner races, and wherein said direction switch means comprises a switch member for displacing said rollers circumferentially in said first and second compartments between a first position and a second position, said first and second compartments having varying gap between said inner and outer races to define a lock end in one of circumferential ends of each compartment and a release end in the other circumferential end thereof, said lock ends of said first and second compartments opposing to each other in the circumferential direction, said lock end having a gap smaller than the diameter of said roller and said release end having a gap greater than the diameter of said roller, said roller movable circumferentially in each compartment and urged towards said lock end such that said roller in said first compartments is displaced into said lock end to permit said inner race to rotate only in said first direction when said switch member is moved to said first position, and that said roller in said second compartment is displaced into said lock end to permit said inner face to rotate only in said second direction when said switch member is moved to said second position.