Abstract:
In a traveling transmission in which an auxiliary transmission is interposed between a main clutch and a mechanical transmission, the auxiliary transmission is configured such that power transmission is cut out interlockingly with the disengagement operation of the main clutch. For example, the auxiliary transmission is configured as a high-low speed selector device including a hydraulic-operated first hydraulic clutch and a spring-operated second hydraulic clutch. Preferably, there should be provided a controller for changing the position of a direction switching valve for the first and second hydraulic clutches based on the operation of an operating member such as a pedal for disengaging the main clutch. According to the present invention, it is possible to shorten a time required for a speed change operation by the mechanical transmission and, also, to achieve a smooth operation by the mechanical transmission.
Abstract:
In a traveling transmission in which an auxiliary transmission is interposed between a main clutch and a mechanical transmission, the auxiliary transmission is configured such that power transmission is cut out interlockingly with the disengagement operation of the main clutch. For example, the auxiliary transmission is configured as a high-low speed selector device including a hydraulic-operated first hydraulic clutch and a spring-operated second hydraulic clutch. Preferably, there should be provided a controller for changing the position of a direction switching valve for the first and second hydraulic clutches based on the operation of an operating member such as a pedal for disengaging the main clutch. According to the present invention, it is possible to shorten a time required for a speed change operation by the mechanical transmission and, also, to achieve a smooth operation by the mechanical transmission.
Abstract:
A hydraulic clutch assembly is equipped with a spring-drive hydraulic clutch, which includes a gear rotatably mounted on a transmission shaft and a clutch cylinder fixedly mounted on the transmission shaft, first and second friction elements respectively supported on the gear and the clutch cylinder in such a manner as to be slidable along an axis of the clutch (hereinafter sometimes referred to a clutch axis) and relatively non-rotatable thereto, a pressure disk disposed opposite to the friction elements, and a spring for moving the pressure disk towards the friction elements to bring the first friction element into engagement with the second friction element, in which the pressure disk is moved away from the friction elements by an effect of hydraulic pressure, thereby withdrawing the friction elements from engagement with each other.
Abstract:
A slidable and rotatable first control shaft (61) and a slidable and rotatable second control shaft (67) for respectively shifting main and auxiliary speed change mechanisms (26, 29) project outwardly to one side of a vehicle housing (2) and are connected respectively to a main change lever (74) and an auxiliary change lever (75) which are pivotally supported by a support member (70) fixedly provided at one side of the vehicle housing. Preferably, the main change lever is disposed at a location where an operator on a seat (76) can operate the lever easily whereas the auxiliary change lever is disposed at a location where the operator is hard to operate the lever. The support member is preferably composed of a cover member which surrounds the control shafts, lower portions of the change levers, and connecting members (80, 87) therebetween. An opening (70b) provided to the cover member for assembling the connecting members is closed by a closure member (70c).
Abstract:
A drive gear (37) having integral drive teeth (37a) is rotatably mounted on a transmission shaft (36) for transmitting power to front wheels, and a movable clutch member (52) having integral driven teeth (52a) engageable with the drive teeth is slidably but non-rotatably mounted on the transmission shaft. A spring (54; 54A) for biasing the movable clutch member into a direction of causing engagement of the driven teeth with the drive teeth is inserted at a part thereof into an axial bore (52b) in the clutch member. A piston (54) is slidably fitted in a cylinder member (55) which is fixedly mounted on the transmission shaft at a radially inward location of the drive and driven teeth. The transmission shaft includes a fluid passage (60) which applies fluid pressure to the piston such that the piston is moved so as to move the movable clutch member into a direction of causing disengagement of the driven teeth from the drive teeth. The front wheel drive clutch of this structure is small in the number of parts, is compact in its axial length, and is rich in durability.
Abstract:
Two fluid-operated supplementary speed change mechanisms (9, 10), one of which is formed into a direction-reversing mechanism and the other of which is formed into a high/low speed-selecting mechanism, are provided in a front housing 1 at locations before and behind a bearing support wall (4) which divides the inside of the front housing into front and rear chambers. Two transmission shafts (8, 12), on which fluid-operated clutches (38F, 38R, 45, 46) of the supplementary speed change mechanisms are mounted, are disposed non-coaxially and are supported by the bearing support wall, and rotary joints (54F, 54R, 54L, 55H, 55L) for connecting fluid passages (51F, 51R, 51L, 52H, 52L) in the transmission shafts, which passages are in fluid communication with the fluid-operated clutches, to stationary fluid passages are formed in outer circumferences of the transmission shafts within an inside of the single bearing support wall.
Abstract:
A baffle plate used for a transmission that has a transmission mechanism including a rotating body operatably connected to a drive source and has a housing receiving the transmission mechanism and having a storage space where oil can be stored. The baffle plate is installed in the housing so as to separate the storage space of the housing in a liquid sealing manner into a surrounding space surrounding at least the lowermost end portion of the rotating body and into a main space other than the surrounding space. In the state installed in the housing, oil in the surrounding space is moved to the main space by pump effect induced by rotating motion of the rotating body. The baffle plate can effectively prevent, with a sufficient amount of oil stored in the housing, the lowering of transmission efficiency of the transmission mechanism caused by the stored oil.
Abstract:
A speed change mechanism (1) constructed by connecting in tandem a hydraulic type speed change unit (17) having a plurality of hydraulic clutches (57, 58, 59) to be alternatively engaged and a hydraulic type speed change unit (20) having a plurality of hydraulic clutches (66, 67, 68) to be alternatively engaged, wherein a time-varying region (common slip region) is secured in which the two clutches slip in common such that during speed change, when the working hydraulic pressure in a clutch to be engaged is on its way to gradual increase, the working hydraulic pressure in a clutch to be disengaged lowers. This common slip region is made smaller during shift-down than during shift-up by a change in time-difference between the pressure increase start time for the clutch to be engaged and the pressure decrease start time for the clutch to be disengaged or by a change in the pressure decrease property of the clutch to be disengaged, and is maintained constant irrespective of whether one or two hydraulic clutches are engaged and disengaged during speed change respectively or irrespective of a difference in engine rpm.
Abstract:
In a front housing (1) including at a front end portion thereof an engine flywheel (6), there are provided a primary drive shaft (8) which is co-axial with the flywheel, a transmission shaft (11) which is parallel to the drive shaft, and an output shaft (13) which is co-axial with the drive shaft. The output shaft is connected to a speed change mechanism (17, 20) in a transmission case (2) succeeding to the front housing. A first supplemetary speed charge mechanism (12) is disposed between the drive shaft and the transmission shaft, and a second supplementary speed change mechanism (14) is disposed between the transmission shaft and the output shaft. One of these supplementary change mechanisms is formed into a direction-reversing mechanism, and the other change mechanism is formed into a high/low speed-selecting mechanism. Preferably, the front housing includes a first bearing support wall (1a) disposed before the first supplementary change mechanism, a second bearing support wall (4) disposed between the first and second supplementary change mechanisms, and a third bearing support wall (5) disposed behind the second supplementary change mechanism. The second and third bearing support walls are removably secured. Preferably, the second supplementary change mechanism comprises a fluid-actuated clutch (45) and a spring-actuated clutch (46) which are supplied with fluid pressure through a single fluid passage (61) in the transmission shaft.
Abstract:
A direction-reversing mechanism (20) is disposed between a primary shaft (17) and output shaft (19) which are arranged in parallel with each other with the output shaft being arranged at a level lower than that of the primary shaft. A first fluid-operated speed change mechanism (23) is disposed between a first drive shaft (21), arranged co-axially with and coupled to the output shaft, and a first driven shaft (22) arranged in parallel with the drive shaft. The drive shaft is arranged at a level lower than that of the driven shaft, and plural fluid-actuated clutches (63, 64, 65) are mounted on the drive shaft. A second fluid-operated speed change mechanism (24) is disposed between a second drive shaft (26), arranged co-axially with and coupled to the first driven shaft, and a second driven shaft (27) arranged in parallel with the second drive shaft. The second driven shaft is arranged at a level lower than that of the second drive shaft, and plural fluid-actuated clutches (75, 76, 77) are mounted on the second driven shaft. The fluid-actuated clutches mounted on the transmission shafts (21, 27) of low levels do not highten the level of an upper surface of the vehicle body and allows to arrange valve means for the first and second change mechanisms concentratedly on an outer surface of the vehicle body.