摘要:
A control system for the control of a fluid pressure-operated clutch (12) is provided. It includes a fluid pressure-operated clutch actuator (14) and a source of pressurized fluid (15). A fluid flow control valve (18) controls the flow of pressurized fluid to and exhaust of fluid from the actuator. A manually operable clutch control member (19) (e.g. a pedal) is connected via a linkage (20) to the valve (18) to enable engagement/disengagement of the clutch by operation of the control member. An electrical actuator (33) is also provided for operation of the valve, and hence clutch, independently of the manually operable clutch control member. The system further includes a sensor (19a) for sensing the position of the clutch control member and an electrical control circuit (21) for independent control of the valve in response to predetermined vehicle operating criteria. The electrical control circuit is capable of commanding complete disengagement of the clutch irrespective of the position of the clutch control member but is only capable of commanding a level of clutch engagement up to that set by the clutch control member position.
摘要:
A selector mechanism for a gearbox in which speed change couplers (28, 29) and a range change coupler (34) are operated by the same selector lever (47). Lever (47) operates the speed change couplers to engage a plurality of drive speeds when moved from a neutral plane to speed selection positions (1, 2, 3, 4) in a speed change gate and operates the range change couplers when moved to discrete range change positions (H,L). The selector mechanism is arranged so that on movement of the selector lever (47) out of the speed change gate towards a desired range change position (H, L) the range change coupler (34) is moved towards an engaged position for the desired range and on movement of the selector lever back towards the speed change gate from the desired range change position the movement of the range change coupler (34) is completed to engage the desired range.
摘要:
A power take-off drive unit for use at the front of a tractor, in which a housing supports input and output shafts for rotation with the input shaft above the output shaft and a gear train connecting the two shafts. An oil-cooled clutch is provided within the housing which is mounted concentrically with the higher input shaft. Coolant oil is supplied to cool the clutch and a scavenging pump is driven from the input shaft for scavenging coolant oil from within the housing to ensure an oil level within the housing below the clutch to minimize the power losses due to churning of the clutch within the coolant oil while still immersing at least part of the gear train. A bearing support for a pivot of a front axle of the tractor is also carried by the housing.
摘要:
A transmission ratio selecting mechanism including a ratio selector means (typically a hand lever), first and second ratio coupling members (36b,37 ) movable to select a number of ratios in the forward and reverse drive directions of an associated transmission, and linkage means (65,63,54,61,62,59,57,60,65,63,64,70,71,68,67,69) for moving the ratio coupling members in response to movement of the ratio selector means. The ratio selecting mechanism includes disconnecting means (72,73,63,64) for disconnecting one (37) of the ratio coupling members from the selector means during selection of the reverse ratios of the transmission. During selection of any reverse ratio both the gear coupling means are initially moved in synchronism in response to movement of the selector means to complete the first part of the selection of the particular reverse ratio, the disconnecting means is then operated, and selection of the reverse ratio is completed by further movement of only one (36b) of the ratio coupling means in response to further movement of the selector means. The selector means is arranged to return the ratio coupling members to synchronism on movement of the selector means to disengage the reverse ratio.
摘要:
A tractor draft sensing apparatus in which a shaft (14) is supported at laterally spaced locations (15) on a tractor and carries at locations (22) outboard of the shaft supports a pair of lower draft links (10) so that the imposition of a draft link (10) to monitor the deflection of the shaft (14) (or an extension (28) thereof) to provide a signal indicative of the draft force being imposed on each draft link. In a form of the sensing system for use on a tractor in which the draft links are raised by external piston and cylinder assemblies whose lower ends are secured to the tractor at locations outboard of the draft links and in alignment with the longitudinal axis of the shaft, the lower ends (36) of the cylinders (32) are connected with the tractor by hollow pins (33) through which the shaft (14) (or an extension (28) thereof) extends. Each sensing unit (42) is located outboard of the associated hollow pin (33) and the clearance between the hollow pin (33) and the shaft (14) (or its extension (28)) allows the shaft (or its extension) unrestricted freedom to deflect in response to draft forces within the designed operating range of the tractor.
摘要:
A tractor draft sensing apparatus in which an elongated sensing shaft is supported in spaced fulcrum supports and carries a pair of draft links on its end portions located outward of the supports. Draft force signals are provided by an elongate member which is attached at one end to the shaft, extends generally parallel to the shaft, and carries at its other end a follower which engages a cam and pivots the cam to give a signal proportional to shaft bending and hence to the draft forces applied to the shaft. The elongate member also carries a separate follower which engages a guide surface on a guidance member to ensure that the elongate member moves relative to the shaft generally in a horizontal plane only during shaft bending. The shaft may also be shaped so that its neutral axis between the fulcrum supports is displaced transversely of the shaft, generally in the direction of application of the draft force, relative to its neutral axis location within the supports.
摘要:
A combined powershift transmission and main clutch assembly for a vehicle includes a casing containing an input shaft and an output shaft. A planetary transmission is disposed within the casing and is co-axially mounted around the input shaft. The planetary powershift unit includes a sun gear and an annulus gear interconnected by one or more planet gears carded on a planet carder. A first one of the sun gear, the annulus gear, and the planet carder is connected to the input shaft, while a second one of the sun gear, the annulus gear, and the planet carder acts as an output member of the planetary powershift unit. A first clutch is disposed within the casing and co-axially surrounds the output shaft for drivingly connecting the output member of the planetary powershift unit with the output shaft. A second clutch is disposed within the casing and co-axially surrounds the input shaft for selectively clutching a third one of the sun gear, the annulus gear, and the planet carder for co-rotation with one of the first element of the planetary powershift unit, the second element of the planetary powershift unit, and the casing so as to select an operative gear ratio of the powershift unit. A power-take off shaft is connected to the input shaft and extends co-axially therefrom within the output shaft.
摘要:
A transmission selector mechanism including two selector members (50, 51) connected with two coupling members (6, 7) each coupling member being axially slidable in both directions either side of a neutral position to couple a selected one of a pair of gears (10, 12: 11, 13) to an associated shaft (4, 5). The coupling members are connected with the selector members via an epicyclic gear train (56, 55, 54, 52). A first element (52) of the epicyclic is connected with one selector member (50), a second element (56) of the epicyclic is connected with one coupling member (6), and a third element (55) of the epicyclic is connected with the other selector member (5) and the other coupling member (7). The arrangement is such that by appropriate movement of the two selector members (50, 51) both coupling members (6, 7) can be positioned either on the same or opposite sides of their respective neutral positions. The other selector member (51) may operate in a control gate (51' ) in part of which the other selector member (51) is disconnected from the other coupling member (7) and selects operative ratios of an additional transmission stage or stages.
摘要:
A transmission ratio selector mechanism for a transmission having two ratio selector couplers both of which must be engaged to provide drive through the transmission. The selector mechanism includes a selector shaft which is rotatable about its longitudinal axis and also axially moveable parallel to its longitudinal axis. Rotation of the selector shaft is arranged to operate one of the couplers via a mechanical linkage including a twin-armed member and a pivoted lever while axial movement of the shaft operates the other coupler via a fluid pressure-operated actuator and an associated control valve mechanism. An interlock is provided to ensure that the fluid pressure-operated coupler is always engaged before the mechanically operated coupler. The interlock comprises a formation which is movable with the shaft and cooperates with a formation movable with the coupler which is to be engaged first.
摘要:
A transmission ratio selector mechanism having an upper manually operable gear lever (120) which is mounted (139, 250) intermediate its ends for pivoting about two perpendicular axes and a lower lever member (134) which is pivoted in a fixed mount (136) at its lower end (135) and is connected at its upper end (137) with the lower end (138) of the gear lever (120). The lower lever (134) is interconnected (133) intermediate its ends with a ratio selector shaft (112) whose longitudinal axis passes through the fixed mount (136). Pivoting of the gear lever (120) about one of the perpendicular axis causes axial displacement (W1, W2) of the selector shaft (112) in a direction parallel to its longitudinal axis and pivoting of the gear lever about the other perpendicular axis causes turning of the selector shaft about its longitudinal axis to move one or more ratio selector forks (101, 102). The gear lever (120) also has a range change position (H/L) which can only be reached when the associated transmission is in a neutral condition. The mounting (400) of the upper lever (120) may also vibrationally isolate the upper lever relative to the lowr lever (134).