Multistage transmission
AssigneeHonda Motor Co., Ltd.
InventorShinya MATSUMOTO
Life of this patent
Estimating the term…
Abstract
A multistage transmission is provided that smoothly operates with a small force without the necessity of a shift clutch, that does not cause a loss of switching time during shifting, and that does not cause escape of a driving force as well as provides a small shift shock. When shift drive means executes upshift to a one-step-upper speed-change stage reduced in reduction ratio by one stage, normal rotation odd-numbered stage cam rods Cao and normal rotation even-numbered stage cam rods Cae alternately operate normal rotation odd-numbered stage engaging members Rao and the normal rotation odd-numbered stage engaging members Rae for shifting.
Claims15
A multistage transmission in which a plurality of drive gears and driven gears are rotatably supported by respective parallel gear shafts in a constant-mesh state for each speed-change stage, one of the plurality of drive gears and driven gears is secured to a gear shaft and engaging means provided between the other of the plurality of drive gears and driven gears and the gear shaft to establish engagement therebetween is switchably driven by shift drive means to execute shifting,
- the engaging means comprising:
- normal rotation odd-numbered engaging members each adapted to bring an odd-numbered stage gear of an odd-numbered speed-change stage into engageable abutment against a gear shaft in a normal rotation direction of the gear to simultaneously rotate the odd-numbered stage gear and the gear shaft;
- normal rotation even-numbered engaging members each adapted to bring an even-numbered stage gear of an even-numbered speed-change stage into engageable abutment against the gear shaft in a normal rotation direction of the gear to simultaneously rotate the even-numbered stage gear and the gear shaft;
- a normal rotation odd-numbered cam rod adapted to come into axially movably slidable contact with a hollow inner circumferential surface of the gear shaft, formed with a plurality of odd-numbered stage cam grooves on a slidable contact surface at desired axial positions, and operating the normal rotation odd-numbered engaging members;
- and
- a normal rotation even-numbered stage cam rod adapted to come into axially movably slidable contact with the hollow inner circumferential surface of the gear shaft, formed with a plurality of even-numbered stage cam grooves on a slidable contact surface at desired axial positions, and operating the normal rotation even-numbered engaging members,
- wherein when the shift drive means executes upshift to a one-step-upper speed-change stage reduced in reduction ratio by one stage, the normal rotation odd-numbered stage cam rod and the normal rotation even-numbered stage cam rod alternately operate the normal rotation odd-numbered stage engaging members and the normal rotation even-numbered stage engaging members for shifting.
The multistage transmission according to claim 6, wherein the control rod is formed at two, axially right and left, positions with outer circumferential recessed sections and each is reduced in diameter and extends by a predetermined length.
A multistage transmission in which a plurality of drive gears and driven gears are rotatably supported by respective parallel gear shafts in a constant-mesh state for each speed-change stage, one of the plurality of drive gears and driven gears is secured to a gear shaft and engaging means provided between the other of the plurality of drive gears and driven gears to establish engagement therebetween is switchably driven to execute shifting,
- the engaging means comprising:
- an engaging portion circumferentially formed with an engaging surface at a desired circumferential position of an inner circumferential surface of each gear;
- an engaging member provided in the gear shaft to engage with the engaging portion of the gear;
- and
- a cam member brought into axially movably slidable contact with the hollow inner circumferential surface of the gear shaft, formed with a cam surface on a slidable contact surface and moved to operate the engaging member;
- wherein the gear shaft is formed with, on the hollow inner circumferential surface, a cam guide groove extending toward an axial direction to axially guide the cam member, and
- the cam member is an axially elongated prismatic bar member rectangular in cross-section and is slidably fitted into the cam guide groove.
A multistage transmission in which a plurality of drive gears and driven gears are rotatably supported by respective parallel gear shafts in a constant-mesh state for each speed-change stage, one of the plurality of drive gears and driven gears is secured to a gear shaft and engaging means provided between the other of the plurality of drive gears and driven gears and the gear shaft to establish engagement therebetween is switchably driven to execute shifting by shift drive means,
- the engaging means comprising:
- an engaging portion circumferentially formed with engaging surfaces at a plurality of desired circumferential positions of an inner circumferential surface of each gear;
- an engaging member provided in the gear shaft to disengageably engage with the engaging portion of each gear;
- and
- a plurality of cam rods adapted to come into axially movably slidable contact with a hollow inner circumferential surface of the gear shaft, formed with a plurality of cam surfaces on a slidable contact surface at desired axial positions, and be moved to operate the engaging members;
- wherein the shift drive means includes
- a control rod provided inside the plurality of cam rods at the hollow central axis of the gear shaft;
- and
- a lost motion mechanism interposed between the outer circumferential surface of the control rod and the inner surfaces of the cam rods to simultaneously move the control rod and the cam rods via axially acting springs.
Dependencies are inferred from the claim text.