GB2129385A - A vehicle drive apparatus - Google Patents

A vehicle drive apparatus Download PDF

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Publication number
GB2129385A
GB2129385A GB08315043A GB8315043A GB2129385A GB 2129385 A GB2129385 A GB 2129385A GB 08315043 A GB08315043 A GB 08315043A GB 8315043 A GB8315043 A GB 8315043A GB 2129385 A GB2129385 A GB 2129385A
Authority
GB
United Kingdom
Prior art keywords
plunger
drive apparatus
change speed
power
clutch
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB08315043A
Other versions
GB2129385B (en
GB8315043D0 (en
Inventor
Shigekazu Hasegawa
Tetsu Fukui
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kubota Corp
Original Assignee
Kubota Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP57194400A external-priority patent/JPS5983852A/en
Priority claimed from JP57195133A external-priority patent/JPS5983853A/en
Application filed by Kubota Corp filed Critical Kubota Corp
Publication of GB8315043D0 publication Critical patent/GB8315043D0/en
Publication of GB2129385A publication Critical patent/GB2129385A/en
Application granted granted Critical
Publication of GB2129385B publication Critical patent/GB2129385B/en
Expired legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W30/00—Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units
    • B60W30/18—Propelling the vehicle
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K17/00—Arrangement or mounting of transmissions in vehicles
    • B60K17/02—Arrangement or mounting of transmissions in vehicles characterised by arrangement, location, or kind of clutch
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K17/00—Arrangement or mounting of transmissions in vehicles
    • B60K17/04—Arrangement or mounting of transmissions in vehicles characterised by arrangement, location, or kind of gearing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K17/00—Arrangement or mounting of transmissions in vehicles
    • B60K17/04—Arrangement or mounting of transmissions in vehicles characterised by arrangement, location, or kind of gearing
    • B60K17/06—Arrangement or mounting of transmissions in vehicles characterised by arrangement, location, or kind of gearing of change-speed gearing
    • B60K17/08—Arrangement or mounting of transmissions in vehicles characterised by arrangement, location, or kind of gearing of change-speed gearing of mechanical type
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K17/00—Arrangement or mounting of transmissions in vehicles
    • B60K17/28—Arrangement or mounting of transmissions in vehicles characterised by arrangement, location, or type of power take-off
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
    • B60W10/02—Conjoint control of vehicle sub-units of different type or different function including control of driveline clutches
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
    • B60W10/10—Conjoint control of vehicle sub-units of different type or different function including control of change-speed gearings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H3/00—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion
    • F16H3/02—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion without gears having orbital motion
    • F16H3/08—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion without gears having orbital motion exclusively or essentially with continuously meshing gears, that can be disengaged from their shafts
    • F16H3/085—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion without gears having orbital motion exclusively or essentially with continuously meshing gears, that can be disengaged from their shafts with more than one output shaft
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H37/00—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00
    • F16H37/02—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00 comprising essentially only toothed or friction gearings
    • F16H37/04—Combinations of toothed gearings only
    • F16H37/042—Combinations of toothed gearings only change gear transmissions in group arrangement
    • F16H37/043—Combinations of toothed gearings only change gear transmissions in group arrangement without gears having orbital motion
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/70—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing specially adapted for change-speed gearing in group arrangement, i.e. with separate change-speed gear trains arranged in series, e.g. range or overdrive-type gearing arrangements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H63/00—Control outputs from the control unit to change-speed- or reversing-gearings for conveying rotary motion or to other devices than the final output mechanism
    • F16H63/02—Final output mechanisms therefor; Actuating means for the final output mechanisms
    • F16H63/30—Constructional features of the final output mechanisms
    • F16H63/3023—Constructional features of the final output mechanisms the final output mechanisms comprising elements moved by fluid pressure

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Transportation (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • General Engineering & Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Control Of Transmission Device (AREA)
  • Gear-Shifting Mechanisms (AREA)

Abstract

The drive apparatus of a tractor comprises an engine (E), a main clutch (2) and a power shift change-speed transmission (1). The main clutch (2) is mounted downstream of the power shift transmission (1). Owing to the lower inertia involved in changing the speed ratio of the transmission (1) with the clutch (2) so disposed, a lower change-speed shift force is necessary. This allows the power shift means of the transmission (1) to be made smaller. The drive apparatus further comprises an auxiliary change- speed mechanism 3 incorporating a reversing means, and a super- reduction mechanism 4. The clutch 2 is automatically operated, and two or four wheel drive is possible. A power take-off shaft 12 is driven through a change speed mechanism 10 and a clutch 11. <IMAGE>

Description

SPECIFICATION A drive apparatus This invention relates to a drive apparatus comprising an engine, a main clutch and a power shift transmission.
Referring to Fig. 6 of the accompanying drawings (the figures of which are listed hereinafter), a drive apparatus according to the prior art has a main clutch 2 interposed between an engine E and a power shift transmission (gear assembly or the like) 1. This construction has a problem of requiring a change speed power shift means 1 3 having a great shifting force, which results in the shift means 13 itself being of large size, and the power shift transmission 1 and a hydraulic change speed mechanism therefor having to be of large size also.
More particularly, in effecting a speed change operation with the prior art construction after the main clutch 2 and the shift means 13 are disengaged, one of freely rotatable driven gears Gb is rigidly connected by operating the shift means 13 to a driven shaft S2 rotating at a different speed by inertia to the driven gear Gb. At this time the shift means 1 3 has to be operated against mass inertia of all of an input shaft S1, a plurality of drive gears Ga fixedly mounted thereon, and the driven gear Gb in constant mesh with the drive gears Ga, respectively, and therefore the shift means 1 3 needs a great shifting force.
This invention enables us to provide a drive apparatus in which an essential function of the power shift means, discussed further below, is utilized to enable a compact shift means to be employed.
Broadly stated, the present invention provides a drive apparatus comprising an engine, a main clutch and a power shift transmission wherein the main clutch is mounted downstream of the power shift transmission operatively connected to the engine.
The preferred practice of the invention, described in detail hereinafter, is based on the fact that the power shift means is, by nature, operable even when maintaining power transmission from the engine to an input shaft of the power shift transmission, and provides a simple improvement consisting in disposition of the main clutch downstream of the power shift transmission. This construction permits a change speed operation to be carried out by putting in the shift means, after the main clutch and the shift means are put out, with a small force just enough to resist mass inertia of the driven shaft (or an output shaft of the power shift transmission upstream of the clutch) in order to rigidly connect one of the driven gears to the driven shaft rotating at a different speed thereto.The shift means can be made, therefore, far smaller than that of the prior art which is shifted against mass inertia of the input shaft and the plurality of gears. As a result, the hydraulic mechanism for actuating the shift means and the power shift transmission in its entirety can also be made compact.
The invention and its practice will be further described with reference to the accompanying drawings, in which: Fig. 1 is a sectional view of a drive apparatus according to this invention; Fig. 2 is a schematic view of the drive apparatus; Fig. 3 is a schematic view of a hydraulic drive circuitry: Fig. 4 is an enlarged view in vertical section of a principal part of the drive apparatus showing a relationship between a change speed means and a hydraulic clutch in neutral position; Fig. 5 is a view similar to Fig. 4 and showing the change speed means in one speed position; and Fig. 6 is a schematic view of a prior art construction already referred to above.
Referring to Figs. 1 and 2 showing a drive apparatus for a four wheel drive working vehicle such as a tractor, power of an engine E is transmitted to a main change speed mechanism 1, then a hydraulic clutch 2, an auxiliary change speed mechanism 3 and to a super-reduction mechanism 4, all housed in a transmission case N.
From the super reduction mechanism 4 power is transmitted to rear wheels 5 through a rear differential 7 and to front wheels 6 through a drive shaft 8 and a front differentiai 9.
The transmission case M also houses a power take-off change speed mechanism 10 which takes power from an upstream side of the main change speed mechanism 1 and passes it through a hydraulic multidisc clutch 11 on to a power takeoff shaft 12 for actuating an attached implement.
Each of the change speed mechanisms 1, 3, 4 and 10 is particularly described hereinafter.
The main change speed mechanism 1 comprises an input shaft S1 carrying four drive gears G I -G4 having varied numbers of teeth and rotatable together with the input shaft Si, and a driven shaft S2 of a travelling system carrying four driven gears G5-G8 to be freely rotatable thereon and in constant mesh with the drive gears G 1-G4, respectively. Two synchromesh shift means 1 3a and 1 3b are provided between adjacent pairs of driven gears G5-G8, respectively, to selectively bring one of each pair of driven gears G5 or G6 and G7 or G8 into rigid connection with the driven shaft S2, thereby to provide four speeds.
The auxiliary change speed mechanism 3 comprises a third shaft S3 which receives power from the main change speed mechanism 1 through the clutch 2 and carries, for free rotation thereon, a ninth gear G9 in constant mesh with a backing relay gear GB and a first gear joint GG1 rigidly interconnecting two gears G10 and G 11 having different numbers of teeth, and a fourth shaft S4 carrying, for free rotation thereon, a second gear joint GG2 rigidly interconnecting a gear G12 in constant mesh with the backing relay gear GB and a gear G13 in constant mesh with one of the gears G 10 of the first gear joint GG 1, and a gear G 14 in constant mesh with the other gear G 11 of the first gear joint GG 1.Synchromesh shift means 14 and 15 are provided between the ninth gear G9 and the first gear joint GG 1 and between the second gear joint GG2 and the fourteenth gear G 14, respectively, to selectively bring the gears G9 and G 14 and the gear joints GG1 and GG2 into rigid connection with the third shaft S3 is operable to switch between backward drive and forward drive, and the shift means 1 5 on the fourth shaft S4 is operable to switch between a high speed and a low speed.
The super reduction mechanism 4 comprises a fifth shaft S5, a final output shaft S6 coaxial with the fourth shaft S4, and a shift means 1 6. The shift means 1 6 is operable to switch between an ordinary change speed position in which the fourth shaft S4 is directly connected to the final output shaft S6 and a super reduction position in which power from the fourth shaft S4 is transmitted by a roundabout route, i.e. to the fifth shaft S5 via a super reduction gearing 4a and to the final output shaft S5.
The main change speed mechanism 1, the auxiliary change speed mechanism 3 and the super reduction mechanism 4 as described above provide, in combination, sixteen forward speeds and sixteen backward speeds. Power is transmitted from the final output shaft S6 to the front wheel drive shaft 8 via a relay gear GF freely rotatably mounted on a power take-off output shaft S8. A gear GF1 is provided to mesh with the relay gear GF at a downstream side thereof, the gear GF1 being shiftable between a four wheel drive position and a two wheel drive position.
The power take-off change speed mechanism 10, like the main change speed mechanism 1, comprises a driven shaft S9 of a power take-off system carrying, for free rotation thereon, gears G1 18 in constant mesh with the four drive gears G1-G4, respectively. Two synchromesh shift means 1 7a and 1 7b are provided between adjacent pairs of free rotation gears G 1 5-G 1 8, respectively, to selectively bring one of each pair offree rotation gearsG15 and G17 orG18 into rigid connection with the power take-off driven shaft S9, thereby to provide four speeds for the power take-off system.
To shift each of the synchromesh shift means 13a, 13b, 14,15, and 17b, a common plunger 1 9 is provided slidably between a coaxially opposed pair of pilot cylinders 18, and each of the shafts S carries a shift element 20 to be rotatable with the shaft S and slidable thereon, the shift element 20 being engaged by a shift fork 21 connected to an intermediate position of the plunger 19. The plunger 19 is slidable by flowing pressure fluid in and out of the cylinder 18.
A hydraulic drive construction for the change speed mechanisms 1,3 and 10 is particularly described hereinafter with reference to Figs. 2 and 3.
For actuating the main change speed mechanism 1 and the auxiliary change speed mechanism 3, the respective pilot cylinders 18 of the two shift means 1 3a and 1 3b of the main change speed mechanism 1 and the high speed and low speed switching shift means 1 5 of the auxiliary change speed mechanism 3 are connected parallel to one another to pressure oil feed lines 22 extending from a pressure oil pump P through a travelling speed changing valve V1.
The pilot cylinders 1 8 of the backward and forward switching shift means 14 of the auxiliary change speed mechanism 3 is connected, parallel to the above travelling speed changing system, to the oil feed lines 22 extending through a backward and forward switching valve V2.
The travelling speed changing valve V1 comprises a switch valve having nine positions N and F1-F8 including neutral position N, which is operable to provide eight speeds by a combination in eight ways of the three shift means 1 3a, 1 3b and 1 5 connected thereto. The backward and forward switching valve V2 is operable to switch the eight speeds between backward and forward directions.
The shift means ? 3a, 13b, 14 and 15 also constitute three-way switch valves v1-v4 receiving pressure oil from the valves V1 and V2 and utilizing the plungers 1 9 as slide spools. The three-way switch valve vl is connected to a hydraulic operator section of the travelling system clutch 2 by an oil line 23 which includes a series of two-way switch valve v'2-v'4 operable by pilot pressures provided by the remaining threeway switch valves v2-v3, respectively.This construction permits the travelling system clutch to be "in" only when both the backward and forward switching shift means 14 and the high speed and low speed switching shift means 1 5 are out of their neutral position and one of the two shift means 1 3a and 1 3b of the main change speed mechanism 1 is out of its neutral position.
In operating the travelling speed switching valve V1 or the backward and forward switching valve V2 from one change speed position to another, the travelling system clutch 2 automatically goes out when whichever shift element 20 moves from an operative position to neutral, and automatically comes in when whichever shift element 20 moves from neutral to an operative position.
For actuating the power take-off change speed mechanism 10, the pilot cylinders 1 8 of the two shift means 1 7a and 1 7b are connected parallel to each otherto the pump P through a power takeoff speed changing valve V3. The power take-off speed changing valve V3 comprises a five-way switch valve having five positions N, f1-f4 including a neutral position n, and operable to provide four power take-off speeds by a combination in four ways of the two shift means 17a and 17b.
The shift means 1 7a and 1 7b constitute two three-way switch valves v5 and v6 utiiizing the plungers 1 9 as slide spools. Two-way switch valves V'5 and V'6 operable by pilot pressures from the three way valves V5 and r6, respectively, are mounted in series on an oil line 24 connecting the pump P to a hydraulic operator section of the power take-off clutch 11. The power take-off clutch 11 automatically goes out only when the two shift means 1 7a and 1 7b both move to neutral by operating the power take-off speed changing valve V3.In other words, the shift means 1 7a and 1 7b are shiftable to the "in" position with a small force just enough to resist mass inertia of the power take-off driven shaft S7 which is out of operative connection with the attached implement, whereby each of the shift means 1 7a and 1 7b and the hydraulic construction therefor may be small.
Each of the change speed mechanisms 1, 3, 4 and 10 may be modified in varied ways in the number of speeds it provides, in the arrangement of gears and so forth. The shift means 1 3a and 1 3b of the synchromesh type too may be replaced by known power shift means of varied types.
With the use of different type shift means 13a, 13b, the change speed mechanism 1 and clutch 2 may also be modified by employing a hydraulic or electric construction.
The drive apparatus described above is applicable to various working vehicles such as for use in agriculture or construction. In accordance with the type of vehicle, the auxiliary change speed mechanism, the super reduction mechanism, or the power take-off change speed mechanism, for example, may be disposed with as desired or may be arranged in a different order of power transmission to the described order. In short, the most salient feature lies in that the main clutch 2 is mounted downstream of the power shift transmission represented by the main change speed mechanism 1.
Referring to Figs. 4 and 5, the high speed and low speed switching shift means 1 3b of the main change speed mechanism 1 and the valve v4 are constructed as follows. The plunger 1 9 of the shift means 1 3b acts also as a slide spool of the valve v4. The plunger 19 is slidably mounted in the pilot cylinders 18 provided in a portion of the transmission case M. A shift fork 125 is rigidly connected to a mid-point axially of the plunger 1 9.
The plunger 1 9 includes axial bores at respective ends thereof to house springs 1 04a and 104b.
Each of the springs 1 04a and 1 04b has one end supported at a bottom of the bore and the other end supported by a plug 1 80a or 1 80b of the cylinder 18, whereby the plunger 1 9 is constantly urged to place the shift fork 125 in neutral. The plunger 19 defines annular grooves 136a and 136b having a relatively large width in its axial direction adjacent the respective ends thereof. The pilot cylinders 18 include output ports 135a and 135b which are constantly in communication with the annular grooves, respectively, regardless of the sliding movements of the plunger 19. The ports 135a and 135b conjoin into a pilot line PL1 leading to the valve v4'.Number 1 28a and 1 28b denote cylinder chambers, and numbers P5 and P6 denote oil lines connected to the travelling speed changing valve V1.
When the pressure oil is supplied to the oil lines P5 and P6 of the valve v4, the two ports 135a and 135b are in communication with a drain space 1 37 defined centrally of the transmission case M through the annular grooves 136a and 136b, respectively as shown in Fig. 4.
When the valve V1 is switched to supply pressure oil to the oil line P5, the plunger 1 9 of the valve v2 moves to a righthand end as shown in Fig. 5. In this position one of the ports 135a is in communication with the cylinder chamber 1 28a and the other port 135b is shut within the transmission case M, whereby oil pressure of the oil line P5 is applied to the pilot oil line PL1. This pilot pressure opens the valve v4t, and oil pressure acting on the valve v4' through the other valve V2' is applied to the oil line for the main clutch 2 to put in the main clutch 2.
When the valve V1 is operated to switch from one speed position, with the main clutch 2 put in, to another speed position, the supply of pressure oil to the oil line P5 stops and the plunger 1 9 returns toward neutral (i.e., leftward in the drawings) by the force of the spring 104b. As the plunger 1 9 moves slightly and the righthand end of the plunger 1 9 departs from a deep end face of the cylinder 128b, bringing the port 1 35b into communication with the cylinder chamber 1 28b and the oil line P6 through the annular groove 136b, the pressure in the pilot oil line PL1 begins to lower.As the plunger 19 makes a further slight movement, the lefthand end of the annular groove 136a begins to interfere with the- port 135a, bringing the pilot oil line PL1 into communication with the drain space 137 through the port 135a and the annular groove 136a. The resulting release of the pilot pressure causes the valve V4' to make a return movement thereby allowing the pressure in the oil line for the main clutch 2 to escape and putting out the main clutch 2 immediately.
To obtain one speed by supplying pressure oil to the oil line P6 of the valve v4, pilot pressure is applied to the pilot oil line PL1 through the other port 135b, putting in the main clutch 2. When switching from this speed position, the pilot pressure is released also through the annular grooves 136a and 136b in the above case.
The described interlocking construction between the shift means 1 3b and the valve 1n4 is used also for the other shift means and the valves corresponding thereto, as shown in Fig. 3.
The described construction in which the piston rod of the pilot valve which acts also as hydraulic change speed means is provided with the wide annular grooves for releasing the pilot pressure, the pressure release action starting with a slight departure of the piston rod from one speed position at a stroke end thereby to put the hydraulic clutch, is effective to put out the hydraulic clutch at a position intermediate between change speed positions promptly and reliably, thereby maintaining a good synchronous relationship between a gear-changing operation and a clutch operation, and assuring a smooth change speed operation.

Claims (7)

1. A drive apparatus comprising an engine (E), a main clutch (2) and a power shift transmission (1), said main clutch (2) being mounted downstream of said power shift transmission (1) operatively connected to said engine (E).
2. A drive apparatus as defined in Claim 1 further comprising an auxiliary change speed mechanism (3) receiving power from said main clutch (2) and having a backward and forward switching function.
3. A drive apparatus as defined in Claim 2 further comprising a super reduction mechanism (4) receiving power from said auxiliary change speed mechanism (3).
4. A drive apparatus as defined in Claim 3 wherein said auxiliary change speed mechanism (3) includes a hydraulically operable backward and forward switching shift means (14) in order to carry out the backward and forward switching function.
5. A drive apparatus as defined in Claim 2 wherein said power shift transmission (1) has a synchromesh gear meshing function, power shifting thereof being effected by hydraulic pressure.
6. A drive apparatus as defined in Claim 1 wherein said power shift transmission (1) includes hydraulic operator means to drive a shift fork (125) of a synchromesh change speed speed gearing (18) by shifting a plunger (19) back and forth, oil supply to said hydraulic operator means being variable by switching a change speed selection control valve (V1), said main clutch (2) mounted in series with a gear transmission system being controlled by a pilot type oil line switch valve (V4), said hydraulic operator means constituting a pilot valve (V3) for controlling application of pilot pressure of said switch valve (V4), said plunger (1 9) being supported at respective ends thereof in cylinder chambers (128a, 128b) defined in a transmission case (M) which further defines ports (135a, 135b) connected to a pilot oil line (PL1) for controlling said hydraulic clutch, said plunger (19) defining pilot pressure releasing annular grooves (136a, 136b) peripherally and adjacent the respective ends thereof, said grooves (136a, 136b) being brought into and out of communication with said ports (135a,135b) by shifting movements of said plunger (19), said annular grooves (136a, 136b) having a large width axially of said plunger to establish communication between one of the cylinder chambers (128a, 128b) and one of the ports (135a, 135b) to which pressure oil has been supplied to shift said plunger and close the other port (135a or 135b) when said plunger (19) is at a stroke end, and to establish communication between said ports(l35a. 135b) and a drain space (137) provided outwardly of the cylinder chambers (1 28a, 1 28b) through said annular grooves (136a, 136b) when said plunger (19) departs from said stroke end.
7. A drive apparatus substantially as hereinbefore described with reference to Figs. 1 to 5 of the accompanying drawings.
GB08315043A 1982-11-04 1983-06-01 A vehicle drive apparatus Expired GB2129385B (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP57194400A JPS5983852A (en) 1982-11-04 1982-11-04 Driving device
JP57195133A JPS5983853A (en) 1982-11-05 1982-11-05 Driving device

Publications (3)

Publication Number Publication Date
GB8315043D0 GB8315043D0 (en) 1983-07-06
GB2129385A true GB2129385A (en) 1984-05-16
GB2129385B GB2129385B (en) 1986-09-24

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Family Applications (1)

Application Number Title Priority Date Filing Date
GB08315043A Expired GB2129385B (en) 1982-11-04 1983-06-01 A vehicle drive apparatus

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Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2556661A1 (en) * 1983-12-20 1985-06-21 Kubota Ltd TRANSMISSION FOR TRACTOR WITH PTO SHAFT
WO1987000254A1 (en) * 1985-07-06 1987-01-15 Zahnradfabrik Friedrichshafen Ag Transmission
DE3931175A1 (en) * 1988-09-21 1990-03-22 Kubota Ltd WORK VEHICLE WITH A MAIN OIL CLUTCH
US4938085A (en) * 1987-06-30 1990-07-03 Honda Giken Kogyo Kabushiki Kaisha Power transmission system in a tractor
GB2358049A (en) * 1999-11-04 2001-07-11 Kubota Kk Tractor transmission with super-reduction and overdrive operated by a single switching device
US6889569B2 (en) * 2001-08-09 2005-05-10 Kubota Corporation Change speed apparatus for a working vehicle that engages in an operation while moving forward and backward
GB2444367A (en) * 2006-11-28 2008-06-04 Ford Global Tech Llc Hybrid vehicle with forward and underdriven reverse drive unit
CN102537268A (en) * 2012-01-13 2012-07-04 杭州祥龙钻探设备有限公司 Hydraulic clutching and gear-shifting transmission case of coal mine gallery drilling machine
CN104070996A (en) * 2013-03-28 2014-10-01 株式会社久保田 Power transmission apparatus
US8984973B1 (en) * 2013-11-07 2015-03-24 Agco International Gmbh Multiple speed power take off

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GB367876A (en) * 1930-11-13 1932-02-15 Edward Henry James Cecil Gille Improvements in or relating to power transmission systems
GB691547A (en) * 1949-01-22 1953-05-13 Bela Barenyi Improvements in motor vehicle driving arrangements
GB999210A (en) * 1963-12-30 1965-07-21 Fritz Buhrer Power transmission arrangement
GB1061380A (en) * 1964-09-11 1967-03-08 Axel Wickerman Transmissions L Motor vehicle transmission system

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB367876A (en) * 1930-11-13 1932-02-15 Edward Henry James Cecil Gille Improvements in or relating to power transmission systems
GB691547A (en) * 1949-01-22 1953-05-13 Bela Barenyi Improvements in motor vehicle driving arrangements
GB999210A (en) * 1963-12-30 1965-07-21 Fritz Buhrer Power transmission arrangement
GB1061380A (en) * 1964-09-11 1967-03-08 Axel Wickerman Transmissions L Motor vehicle transmission system

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2556661A1 (en) * 1983-12-20 1985-06-21 Kubota Ltd TRANSMISSION FOR TRACTOR WITH PTO SHAFT
WO1987000254A1 (en) * 1985-07-06 1987-01-15 Zahnradfabrik Friedrichshafen Ag Transmission
US4938085A (en) * 1987-06-30 1990-07-03 Honda Giken Kogyo Kabushiki Kaisha Power transmission system in a tractor
DE3931175A1 (en) * 1988-09-21 1990-03-22 Kubota Ltd WORK VEHICLE WITH A MAIN OIL CLUTCH
GB2358049A (en) * 1999-11-04 2001-07-11 Kubota Kk Tractor transmission with super-reduction and overdrive operated by a single switching device
GB2358049B (en) * 1999-11-04 2001-12-19 Kubota Kk Tractor transmission
US6446521B1 (en) 1999-11-04 2002-09-10 Kubota Corporation Tractor transmission
US6889569B2 (en) * 2001-08-09 2005-05-10 Kubota Corporation Change speed apparatus for a working vehicle that engages in an operation while moving forward and backward
GB2444367A (en) * 2006-11-28 2008-06-04 Ford Global Tech Llc Hybrid vehicle with forward and underdriven reverse drive unit
US7703353B2 (en) 2006-11-28 2010-04-27 Ford Global Technologies, Llc Drive unit connected to a transmission output for producing forward and reverse device
US7918757B2 (en) 2006-11-28 2011-04-05 Ford Global Technologies, Llc Drive unit connected to a transmission output for producing forward and reverse drive
GB2444367B (en) * 2006-11-28 2011-08-10 Ford Global Tech Llc A drive unit for a motor vehicle
CN101191533B (en) * 2006-11-28 2012-12-26 福特全球技术公司 Drive unit connecting with gear box output end for producing forward and reverse drive
CN102537268A (en) * 2012-01-13 2012-07-04 杭州祥龙钻探设备有限公司 Hydraulic clutching and gear-shifting transmission case of coal mine gallery drilling machine
US20150090056A1 (en) * 2012-11-07 2015-04-02 Agco International Gmbh Multiple Speed Power Take Off
CN104070996A (en) * 2013-03-28 2014-10-01 株式会社久保田 Power transmission apparatus
CN104070996B (en) * 2013-03-28 2016-07-20 株式会社久保田 Power transmission
US8984973B1 (en) * 2013-11-07 2015-03-24 Agco International Gmbh Multiple speed power take off

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GB8315043D0 (en) 1983-07-06

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