Speed changing mechanism including planet gears and one-way clutch

A speed changing mechanism, comprising:

• a plurality of planet gears;
• a first planet gear support plate integrally formed with a first internal gear and provided with a first fitting member formed radially outwardly of said first internal gear, said plurality of planet gears being adapted to engage said first internal gear;
• a second planet gear support plate mounted on a driven shaft and integrally formed with a second fitting member and rotatably supporting said plurality of planet gears engaged with said first internal gear;
• a cylindrical member including a mechanism for being slidably and selectively fitted either with only said first fitting member or with both said first and second fitting members formed on said first and second planet gear support plates;
• and
• a one-way clutch which is mounted with a sun gear engageable with said plurality of planet gears, said one-way clutch being rotatable in one direction exclusively,
• wherein said mechanism for being slidably and selectively fitted comprises a third internal gear,
• said speed changing mechanism being adapted for use with an eccentric shaft of a hydraulic pump, wherein said eccentric shaft is rotated with said second planet gear support plate, a magnitude of torque transmitted from said speed changing mechanism to said eccentric shaft being adjustable by sliding said internal gear in first and second directions.

A speed changing mechanism, comprising:

• a plurality of planet gears;
• a first planet gear support plate integrally formed with a first internal gear and provided with a first fitting member formed radially outwardly of said first internal gear, said plurality of planet gears being adapted to engage said first internal gear;
• a second planet gear support plate mounted on a driven shaft and integrally formed with a second fitting member and rotatably supporting said plurality of planet gears engaged with said first internal gear;
• a cylindrical member including a mechanism for being slidably and selectively fitted either with only said first fitting member or with both said first and second fitting members formed on said first and second planet gear support plates;
• a one-way clutch which is mounted with a sun gear engageable with said plurality of planet gears, said one-way clutch being rotatable in one direction exclusively, wherein said mechanism for being slidably and selectively fitted comprises a third internal gear;
• and
• a shift lever having first and second ends coupled to said third internal gear and extending in a circumferential direction thereof.

A speed changing mechanism, comprising:

• a rotatable member having an internal gear;
• a planet gear carrier coaxially provided with said rotatable member and securely fixed to an output shaft;
• a plurality of planet gears rotatably supported on said planet gear carrier and meshed with said internal gear;
• a sun gear coaxially provided with said rotatable member and meshed with said plurality of planet gears;
• a one-way clutch for enabling said sun gear to rotate in one direction exclusively;
• and
• a coupling member for selectively coupling said rotatable member to said planet gear carrier to rotate said rotatable member and said planet gear carrier together,
• wherein a rotational torque transmitted to said rotatable member is directly transmitted from said rotatable member to said planet gear carrier when said rotatable member is coupled to said planet gear carrier by said coupling member, and
• wherein a rotational torque transmitted to said rotatable member is increased and transmitted from said rotatable member to said planet gear carrier through said plurality of planet gears meshed with said sun gear prevented by said one-way clutch from being rotated when said rotatable member is not coupled to said planet gear carrier by said coupling member.