摘要:
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.
摘要:
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.
摘要:
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.
摘要:
Within a rear half of a tractor front housing (1) which includes an internal partition wall (1a) and an open rear end, a fluid-operated first speed cleanse mechanism (12) is disposed and is supported, at its rear side, by a bearing support frame (4) which is in turn supported by the front housing. Within a transmission casing (2) which includes an open front end and is fastened to the rear of the front housing, a second speed change mechanism (15) is disposed and is supported, at its front side, by the support frame. A fluid pump (72) for supplying fluid to the first change mechanism is mounted on the partition wall. The support frame includes therein a fluid passage (162) which is adapted to function as a fluid passage for supplying fluid from a fluid sump within the vehicle body to the pump. The passage has first and second open ends (162a, 162b) at front and rear surfaces of the frame for connecting the passage to a pump suction passage (160) and to a fluid sump filter (165), preferably through internal pipes (166, 167).
摘要:
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.
摘要:
The present invention is so designed that a housing of a transmission which can drive front wheels and rear wheels and a power take-off shaft is constructed having a first chamber and a second chamber. A hydrostatic transmission is housed in the first chamber. A gear-type speed changing unit is housed in the second chamber. A hydraulic pump and a hydraulic motor are separately disposed on the inner and outer surfaces of the front wall of the first chamber. A clutch mechanism for engaging or disengaging with or from the front wheels for supplying power thereto is also provided. On the housing is provided a restraint mechanism for restraining rearward acceleration more than a predetermined speed by a speed control lever of the hydrostatic transmission when the gear-type speed changing unit is switched to the high speed setting. Left and right running brake units provided on the vehicle are made independently operable by treading left and right turn brake pedals on a first brake pedal shaft and made simultaneously operable by treading a master brake pedal on a second brake pedal shaft.
摘要:
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).
摘要:
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.
摘要:
A four-wheel drive vehicle includes a first transmission system for transmitting power from an engine to a left and a right first driving wheel provided with a braking unit, and a second transmission system branching off from the first transmission system to transmit power to a second pair of driving wheels serving as steerable wheels. The second transmission system is provided therein with a frictional transmission passage having a frictional torque, which is smaller than that between the second driving wheels and a road surface, and a direct transmission passage disposed in parallel with the frictional transmission passage, so that either passage can be selected. The frictional transmission passage is selected when a speed-changing operating tool is set to its high speed position or when a steering device is operated beyond a predetermined angle, and the direct transmission passage is selected in all other cases.
摘要:
A transmission for a working vehicle like a tractor of the invention is housed in a transmission housing 1 interposed between an engine and a rear axle housing 2. An interior of transmission housing 1 is divided into a front chamber A and a rear chamber B through a partition wall 1a. In front chamber A is disposed a main-clutch system partition centering a traveling-input shaft 7. In rear chamber B is disposed a speed-changing system as a combination of reversing arrangement and multi-speed-changing arrangement. In a rear opening of housing 1 is disposed a bearing plate 3. In rear chamber B, a first speed-changing shaft 8, a second speed-changing shaft 9 and a front transmission output shaft 10 are supported in parallel between wall 1a and plate 3. A regular speed-reduction gear train and a reversing speed-reduction gear train are interposed between shafts 8 and 9, so that shafts 8 and 9 can be connected with each other through one of the gear trains by a first clutch device C1 on shaft 8. A second clutch device C2 is on shaft 9 so as to selectively connect shafts 7 and 9 directly. A plurality of gear trains for multi-speed stages are interposed between shafts 9 and 10, so that shafts 9 and 10 are connected with each other through one of the gear trans by a third clutch device C3 on shaft 10. A cover 51 is settled on housing 1. A main (second) speed-changing lever 52 and a sub (first) speed-changing lever 52 are disposed respectively at both lateral sides of cover 51. Third clutch device C3 is operated by lever 52. First and second clutch devices C1 and C2 are selectively operated by lever 55.