GB2057987A - Vehicle transmission - Google Patents

Vehicle transmission Download PDF

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Publication number
GB2057987A
GB2057987A GB7926152A GB7926152A GB2057987A GB 2057987 A GB2057987 A GB 2057987A GB 7926152 A GB7926152 A GB 7926152A GB 7926152 A GB7926152 A GB 7926152A GB 2057987 A GB2057987 A GB 2057987A
Authority
GB
United Kingdom
Prior art keywords
drive
shaft
differential unit
drive shaft
transmission
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
GB7926152A
Other versions
GB2057987B (en
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.)
SCHULER PRESSES Ltd
Original Assignee
SCHULER PRESSES Ltd
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
Application filed by SCHULER PRESSES Ltd filed Critical SCHULER PRESSES Ltd
Priority to GB7926152A priority Critical patent/GB2057987B/en
Publication of GB2057987A publication Critical patent/GB2057987A/en
Application granted granted Critical
Publication of GB2057987B publication Critical patent/GB2057987B/en
Expired legal-status Critical Current

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Classifications

    • 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
    • B60K17/34—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles
    • B60K17/344—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles having a transfer gear
    • B60K17/346—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles having a transfer gear the transfer gear being a differential gear
    • B60K17/3467—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles having a transfer gear the transfer gear being a differential gear combined with a change speed gearing, e.g. range gear
    • 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
    • B60K17/34—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles
    • B60K17/344—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles having a transfer gear
    • B60K17/346—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles having a transfer gear the transfer gear being a differential gear
    • B60K17/3462—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles having a transfer gear the transfer gear being a differential gear with means for changing distribution of torque between front and rear wheels
    • B60K17/3465—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles having a transfer gear the transfer gear being a differential gear with means for changing distribution of torque between front and rear wheels self-actuated means, e.g. differential locked automatically by difference of speed
    • 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
    • F16H3/44—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion using gears having orbital motion
    • F16H3/62—Gearings having three or more central gears
    • F16H3/64—Gearings having three or more central gears composed of a number of gear trains, the drive always passing through all the trains, each train having not more than one connection for driving another train

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Arrangement And Driving Of Transmission Devices (AREA)

Abstract

A four wheel drive transmission can be coupled to a manual or automatic gear box of a traditional engine or even to an engine of a mid-engine car, and incorporates a twin-chain drive 13 from the output shaft of the gear box which drives a first drive shaft 16, there being a high/low range change mechanism 17 supported on the first drive shaft 16, a Ferguson (Registered Trade Mark) Formula epicyclic differential unit 33 incorporating a viscous coupling acting between the first shaft 16 and a second shaft 35, and there being a Ferguson Formula/Mullard (Registered Trade Mark) antiskid braking system associated with the differential unit, the toothed disc of the Ferguson Formula/Mullard system being mounted on the planetary carrier 31 of the differential unit and its sensor being mounted on the casing of the differential unit. <IMAGE>

Description

SPECIFICATION Vehicle transmission This invention relates to a four wheel drive transmission for motor vehicles.
With safety being a principal requirement for all present day motor vehicles, there is now a demand for vehicles to be fitted with a permanent four wheel drive transmission. The Range Rover has such a transmission, but this has its limitations, and only has a manual gear box. The present invention seeks to provide an improved four wheel drive transmission, which, when fitted to a vehicle, will give the vehicle optimum handling characteristics, make it extremely difficult for skidding to occur in an emergency, allow cornering at high speed without danger, will generally improve road holding, and yet will allow the vehicle to operate not only at high speed on the open road, but also at low speed on rough terrain.Furthermore, it is an aim of the invention that a vehicle fitted with the transmission can pull heavy loads, and at all times the transmission will operate without undue noise.
According to the present invention, we provide a four wheel drive transmission for a motor vehicle comprising an input shaft, at least one drive sprocket rotatable with the input shaft, endless entrainment means for transmitting drive from the said at last one drive sprocket to at least one driven sprocket rotatably supported on a first drive shaft, a high/ low range change mechanism supported on said first drive shaft, a Ferguson (Registered Trade Mark) Formula epicyclic differential unit incorporating a viscous coupling supported on said first drive shaft to split the torque delivered between said first drive shaft and a second drive shaft in a predetermined ratio, said first drive shaft being keyed to the sun gear of the epicyclic differential unit and the second drive shaft being driven by the annulus of the unit with the viscous coupling acting between the said two drive shaft to prevent substantial relative rotation between the two shafts,and a Ferguson Formula/Mullard (Registered Trade Mark) anti-skid braking system associated with the differential unit, with its toothed disc mounted on the planetary carrier of the differential unit and its sensor mounted on the casing of the differential unit.
The input shaft of the transmission may be connected to an automatic or a manual gear box, and if desired, a power take-off may be taken from the other end of the input shaft.
A four wheel drive according to the invention is now described by way of example with reference to the accompanying drawings, in which: Figure 1 is a section showing the input drive assembly, and Figure 2 is a section showing the assembly of the outputs.
Referring to Fig. 1 of the drawings, a vehicle gear box (manual or automatic) is shown at 1. An adaptor casing 3, the shape and size of which depends on whether the gear box 1 is manual or automatic, is connected to the gear box 1, and a further casing 5 is connected to casing 3 An input shaft 7, which is either the output shaft or an extension of the output shaft of the gear box 1 extends axially within casings 3, 5, the shaft being supported at its end in bearings 8. The end of the casing 3 is closed off by a cover plate 9; this can be removed and replaced by a different casing if a p.t.o. drive is to be taken off the end of the shaft 7.
A double drive sprocket 11 is keyed to the end of the input shaft 7, and entrained around the double sprocket 11 are two drive chains 1 3, by means of which drive is taken to a double driven sprocket 1 5 (see Fig. 2) about which the chains 1 3 are also entrained.
The input sprocket 1 5 is rotatably mounted on a first shaft 1 6 and is connected to an epicyclic high/low range change mechanism 1 7 by a suitable clutch. The range change mechanism 1 7 is of known construction and includes an epicyclic gear train 19 which can be arranged to give a high drive ratio from the sprocket 1 5 by locking an annulus 21 and a sun gear 23 together in known manner (see Fig. 2) or a lower range can be obtained by locking the annulus 21 to "earth", i.e. to the casing 5, so that the carrier will rotate at a higher output speed.The epicyclic range change mechanism has its ratio changed in known manner by axially sliding a sleeve 25 so that it either locks a drive gear 27 and inner hub 29 together (high range) or the hub 29 and casing 5, and hence the annulus 21 are locked together (low range).
The output from the range change mecha prism is the carrier 31 of the mechanism 1 9 and the carrier 31 has further planetary gear wheels 32 mounted thereon which form part of a known Ferguson Formula epicyclic centre differential gear mechanism 33 distributing power to the front and rear axles of a vehicle by means of the first output shaft 1 6 and a second output shaft 35. The output shaft 35 is driven by means of the annulus 37 of the differential 31 and the first output shaft 1 6 is driven from the sun gear 39 of the differential gear mechanism 31. The gear ratios can of course be changed, but in the arrangement shown (for a Range Rover) 40% of the total power is transmitted to the drive shat 1 6 (front) and 60% to the drive shaft 35 (rear).
The mechanism 33 (which is the subject of U.K. Patent Specification No. 1412583) incorporates a viscous coupling. This coupling has a first set of clutch plates (not shown) keyed to a shaft 39 driving the shaft 16, which plates are alternately arranged between the plates of a second set of clutch plates (not shown) rotatable with the shaft 35. Under normal driving conditions wherein front and rear output shafts 1 6 and 35 are rotating at the same speed, the two sets of clutch plates will rotate at the same speed. The clutch plates form part of a self-energising or automatic, viscostatic clutch, or coupling, and rotate in a housing filled with a liquid which, under normal circumstances, is a liquid but which, when agitated, undergoes a molecular change and becomes more viscous.It will thus be appreciated that if there is substantial relative movement between the sets of clutch plates and, for example, when the wheels on the axle associated with one of the shafts 1 6 or 35 begin to slip, then the liquid will become agitated and will, due to its increased viscosity (it becomes almost like a tacky gum), cause the sets of clutch plates to become locked together.
In accordance with the present invention the transmission also incorporates a Ferguson Formula/Mullard Ltd. anti-skidd device. Such a device is well known and is the subject of U.K. Patent Specification No. 1511254. Although the centre differential with viscous coupling gives a substantial measure of skid prevention in emergency braking situations, it also makes possible the provision of a complete anti-lock system.
The Ferguson Formula/Muilard anti-skid system is based on a single sensor and a single electronic module and the principle of the system is to reduce hydraulic brake line pressure during an anti-skid operation. This is effected simply by reversing the vacuum within a substantially standard brake booster by means of a solenoid operated valve. This in turn produces a mild pulsation of the brake pedal which informs the driver that the system is operating and serves as a warning of treacherous road conditions. Because the system is a known one, it will not be described in detail but the system does include a toothed disc and a sensor associated therewith which is sensitive to changes in speed of the disc.
Regardless of whether the transmission is in high or low range, it is the carrier 31 of the differential 33 which effectively acts as the input for the two drive shafts 16, 35 and accordingly the toothed disc is mounted on the carrier and the sensor is mounted on the casing 5 immediately adjacent the disc. (These items are not shown in the drawings).
The above described transmission has been specifically designed for the Range Rover motor vehicle and it will fit into the space between either a manual gear box or an automatic gear box and the traditional transmission brake 41 on the vehicle. On a test vehicle fitted with the transmission, considerably improved cornering speeds and stopping speeds were achieved on various different running surfaces and it was found that these improvements could be improved even further by fitting special wheels and tyres giving a wider track to the vehicle.
It is even possible to fit the transmission on a mid-engined car and in this case, drive from the gear box would be taken to the input shaft 7 from the opposite end to that shown in Fig.
1 merely by removing the cover plate 9 and making a suitable attachment of the casing to the gear box at this location. In this case, of course, the high/low range transfer box would be run in the opposite rotation.
As can be seen from the drawings, drive from the input shaft 7 to the output shafts is by means of a pair of chains 13. We have found that by incorporating two chains rather than a single chain, optimum drive character aspics are obtained and there is a minimum of vibration and noise. It will of course be appreciated that because the drive from the input shaft to both output shafts, which are axially aligned, is through the chains, both the output shafts are off-set relative to the input shaft.

Claims (6)

1. A four wheel drive transmission for a motor vehicle comprising an input shaft, at least one drive sprocket rotatable with the input shaft, endless entrainment means for transmitting drive from the said at least one drive sprocket to at least one driven sprocket rotatably supported on a first drive shaft, a high/low range change mechanism supported on said first drive shaft, a Ferguson (Registered Trade Mark) Formula epicyclic differential unit incorporating a viscous coupling supported on said first drive shaft to split the torque delivered between said first drive shaft and a second drive shaft in a predetermined ratio, said first drive shaft being keyed to the sun gear of the epicyclic differential unit and the second drive shaft being driven by the annulus of the unit with the viscous coupling acting between the said two drive shafts to prevent substantial relative rotation between the two shafts, and a Ferguson Formula/Mullard (Registered Trade Mark) anti-skid braking system associated with the differential unit, with its toothed disc mounted on the planetary carrier of the differential unit and its sensor mounted on the casing of the differential unit.
2. A transmission according to claim 1 wherein the input shaft of the transmission is connected to an automatic gea7 box.
3. A transmission according to claim 1 or 2 wherein a power take-off is taken from the other end of the input shaft.
4. A transmission according to claim 1, 2 or 3 wherein the input shaft is located at the front end of the gear box od a mid-engined car.
5. A transmission according to any one ot the preceding claims wherein said endless entrainment means comprises a pair of chains.
6. A four wheel drive transmission substantially as hereinbefore described with reference to the accompanying drawings.
GB7926152A 1979-07-26 1979-07-26 Vehicle transmission Expired GB2057987B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB7926152A GB2057987B (en) 1979-07-26 1979-07-26 Vehicle transmission

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB7926152A GB2057987B (en) 1979-07-26 1979-07-26 Vehicle transmission

Publications (2)

Publication Number Publication Date
GB2057987A true GB2057987A (en) 1981-04-08
GB2057987B GB2057987B (en) 1983-05-18

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2551004A1 (en) * 1983-08-22 1985-03-01 Peugeot COMPACT TRANSMISSION ASSEMBLY FOR A TWO-AXLE VEHICLE
FR2593754A1 (en) * 1986-01-31 1987-08-07 Renault FOUR-WHEEL DRIVE TRANSMISSION DEVICE
US4747643A (en) * 1986-04-29 1988-05-31 Steyr-Daimler-Puch Aktiengesellschaft Motor vehicle having two driven axles and brake system
US4750382A (en) * 1985-09-03 1988-06-14 Regie Nationale Des Usines Renault Four-wheel drive transmission device
EP0290201A1 (en) * 1987-04-30 1988-11-09 Fuji Jukogyo Kabushiki Kaisha Power transmitting system for a four-wheel drive vehicle
US4784236A (en) * 1986-04-03 1988-11-15 General Motors Corporation Four-wheel drive vehicle
EP0377310A1 (en) * 1988-12-22 1990-07-11 Isuzu Motors Limited Transfer differential gear lock controller
US5083478A (en) * 1981-08-20 1992-01-28 Nissan Motor Company, Limited Four-wheel vehicle drive system

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102062199B (en) * 2011-01-21 2013-01-23 力帆实业(集团)股份有限公司 Transmission gear for comprehensive test bed of pure electric vehicle

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5083478A (en) * 1981-08-20 1992-01-28 Nissan Motor Company, Limited Four-wheel vehicle drive system
FR2551004A1 (en) * 1983-08-22 1985-03-01 Peugeot COMPACT TRANSMISSION ASSEMBLY FOR A TWO-AXLE VEHICLE
EP0135421A1 (en) * 1983-08-22 1985-03-27 Automobiles Peugeot Compact transmission aggregate for a vehicle with two driving shafts
US4750382A (en) * 1985-09-03 1988-06-14 Regie Nationale Des Usines Renault Four-wheel drive transmission device
FR2593754A1 (en) * 1986-01-31 1987-08-07 Renault FOUR-WHEEL DRIVE TRANSMISSION DEVICE
EP0236178A1 (en) * 1986-01-31 1987-09-09 Regie Nationale Des Usines Renault Four-wheel drive transmission device
US4756381A (en) * 1986-01-31 1988-07-12 Regie Nationale Des Usines Renault Four-wheel drive transmission device
US4784236A (en) * 1986-04-03 1988-11-15 General Motors Corporation Four-wheel drive vehicle
US4747643A (en) * 1986-04-29 1988-05-31 Steyr-Daimler-Puch Aktiengesellschaft Motor vehicle having two driven axles and brake system
AT390410B (en) * 1986-04-29 1990-05-10 Steyr Daimler Puch Ag DRIVE ARRANGEMENT FOR MOTOR VEHICLES WITH AT LEAST TWO DRIVE AXLES
EP0290201A1 (en) * 1987-04-30 1988-11-09 Fuji Jukogyo Kabushiki Kaisha Power transmitting system for a four-wheel drive vehicle
EP0377310A1 (en) * 1988-12-22 1990-07-11 Isuzu Motors Limited Transfer differential gear lock controller

Also Published As

Publication number Publication date
GB2057987B (en) 1983-05-18

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Legal Events

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PCNP Patent ceased through non-payment of renewal fee