WO2010123436A1

WO2010123436A1 - Vehicle comprising a transmission device with pto shaft

Info

Publication number: WO2010123436A1
Application number: PCT/SE2010/050418
Authority: WO
Inventors: Anders BRÄNNSTRÖM
Original assignee: Scania Cv Ab
Priority date: 2009-04-20
Filing date: 2010-04-19
Publication date: 2010-10-28
Also published as: SE0950254A1; SE533695C2

Abstract

A motor vehicle (101) with wheels (101, 104) and an engine (118) is described. The vehicle (101) comprises a transmission device (1) comprising an input shaft (6), a primary shaft (7) coupled to the wheels (103, 104), a countershaft (16) adapted to rotating with the input shaft (6), a PTO shaft (32) adapted to rotating with the countershaft (16), a first locking means (14), a clutch device (102) and a control device (34). Upon demand for the clutch device (102) to be opened, the control device (34) is adapted to causing the clutch device (102) to disconnect the engine (118) and to moving the first locking means (14) to a first position so that the speed of the countershaft (16) is synchronised with the speed of the primary shaft (7). A method for controlling such synchronisation is also described.

Description

Vehicle comprising a transmission device with PTQ shaft

Technical field

The present invention relates to a motor vehicle comprising a transmission device with a PTO (power take-off) arranged on a PTO shaft.

Description of prior art

Motor vehicles have an engine connected to a transmission device to propel the vehicle. Motor vehicles are in certain cases provided with a PTO connected to the engine. The PTO may be intended to drive some external machine such as a winch, a generator, a sweeping machine or some agricultural implement. The PTO may alternatively be intended for internal use within the vehicle, e.g. to run, for example, a crane, a tilting device or a cooling unit. In certain cases it is desired to be able to connect the external machine while the vehicle is in motion, whereas in other cases it is only desired to be able to engage the PTO when the vehicle is stationary. The PTO may be adapted to being driven directly by the engine, via the gearbox or via a driveshaft.

The PTO shaft and the PTO are usually arranged on the transmission device so that the same engine can be used for motor vehicles with PTO as for motor vehicles without PTO, but it is also possible to have the PTO shaft connected directly to the engine. Engaging the PTO involves some form of clutch device between the engine and the PTO. If the PTO is driven via a transmission device, the clutch device is usually so arranged that the main clutch has to be used when engaging the PTO, since the PTO is always connected to the input shaft of the gearbox.

Automated gearboxes with fixed steps have become increasingly usual for heavy vehicles. Such a gearbox works in principle like an ordinary manual gearbox but with the difference that gear changing is automated. Such a gearbox may be combined with engine control whereby the engine's torque and speed are controlled at the time of gear changing so that the latter can take place without the engine being disconnected. Alternatively, such a gearbox may be combined with an automatic clutch which disconnects the engine at the time of gear changing.

A problem with PTOs which are engaged and disengaged by means of the main clutch is that the PTO may continue to rotate for a time after the engine has been disconnected. This means having to wait a while after disconnecting the engine before trying to connect anything to the PTO. For the driver him/herself to be able to connect equipment to the PTO, this also entails either the driver switching off the engine or the motor vehicle being equipped with an automatic clutch. Before connecting equipment to the PTO, however, the driver still has to wait until the PTO has stopped even if the vehicle is equipped with an automatic clutch.

American patent US 7,357,745 B2 describes an engine arrangement with a PTO which can be engaged and disengaged with a separate clutch and refers to the problem of the PTO continuing to rotate despite having been disengaged by the separate clutch. To prevent this, it describes the provision of a brake device which is automatically applied as soon as the separate clutch is disengaged.

American patent US 5,947,218 describes a PTO transmission for a utility vehicle and refers to the provision of a brake for halting the rotation of a PTO.

American patent 7,318,788 describes a gearchange procedure for vehicles with clutch- dependent PTOs and proposes to provide a vehicle with such a PTO whereby it is possible to use the PTO while the vehicle is in motion and to change gear between all the gears in the gearbox with the PTO engaged. The vehicle has a brake for an intermediate shaft which is connected to the PTO, which brake can therefore be used for braking the PTO.

Japanese patent publication JP 2000-177418 describes a hydrodynamic transmission with an engine stop means which halts the rotation of an engine shaft.

American patent application US 2008/0092676 Al describes a toothed brake device for a manual transmission with a number of speeds.

Summary of the invention

An object of the present invention is to propose a motor vehicle with an engine and a transmission device with a clutch-controlled PTO shaft, the rotation of which PTO shaft is halted when the transmission device is disconnected, which motor vehicle is an alternative to known motor vehicles which function similarly. Another object of the present invention is to propose a method for halting the rotation of the PTO shaft when the transmission device is disconnected, which method is an alternative to known methods.

A basic concept of the present invention is to prevent a clutch-controlled PTO shaft on a motor vehicle from rotating when the vehicle is stationary, by synchronising the speed of the PTO shaft with the output shaft from the transmission device.

A first aspect of the present invention is a proposed motor vehicle with wheels which comprises an engine, a transmission device comprising an input shaft, a primary shaft intended to power the vehicle's wheels, a countershaft adapted to rotating when the input shaft rotates, a PTO shaft adapted to rotating when the countershaft rotates, and a first locking means which can be placed in at least a first position to synchronise the speed of the countershaft with the speed of the primary shaft. The vehicle comprises also a clutch device connected between the engine and the input shaft of the transmission device, and a control device adapted to controlling the first locking means and the clutch device. The vehicle is characterised in that, upon demand, the control device is adapted to causing the clutch device to disconnect the engine, and to moving the first locking means to the first position so that the speed of the countershaft is synchronised with the speed of the primary shaft.

The primary shaft being intended to power the motor vehicle's wheels means that the primary shaft either is connected to the vehicle's wheels or is connectable to the vehicle's wheels. In the latter case it is of advantage to provide a brake device adapted to braking the primary shaft when the primary shaft is not connected to the vehicle's wheels.

The demand may take various forms, e.g. requiring the clutch device to open or the rotation of the PTO to stop.

A motor vehicle according to the invention provides a simple way of synchronising the speed of the PTO shaft with the speed of the output shaft, whereby the PTO shaft will stop because the output shaft is motionless. The first locking means may be the same means as used for synchronising and locking a gear in the transmission device. There may be at least a first primary gearwheel on the primary shaft and at least a first countershaft gearwheel firmly mounted on the countershaft and in engagement with the first primary gearwheel, the first locking means in the first position being adapted to synchronising the speed of the first primary gearwheel with the speed of the primary shaft. Such a locking means will with advantage be movable from the first position to a second position in which the first primary gearwheel is locked relative to the primary shaft. Such a locking means may also be used to lock a certain gear in the transmission device and is present in transmission devices in today's motor vehicles.

Today's transmission devices have a plurality of primary gearwheels and a plurality of locking means for selecting a gear. In such a transmission device the locking means and the primary gearwheel corresponding to the lowest forward gear are with advantage used for synchronising the speed of the countershaft with the speed of the primary shaft. It is of course possible to use also second primary gearwheels and second locking means for the synchronisation.

The motor vehicle may comprise a gearshift device, in which case the control device will be adapted to moving the first locking means by operating the gearshift device. This is advantageous in that gearshift devices are already present in transmission devices in today's motor vehicles.

The transmission device may comprise electric actuators for operating the gearshift device, which actuators are adapted to being controlled by the control device. Electric actuators means electromechanical actuators, i.e. actuators in which electrical energy is converted to mechanical movement.

The transmission device may alternatively or additionally comprise hydraulic actuators for operating the gearshift device, which actuators will be adapted to being controlled by the control device. Hydraulic actuators means actuators in which hydraulic pressure is used to control mechanical movement. The hydraulic pressure may come from a hydraulic pump driven by the vehicle's engine or by an electric motor.

The transmission device may also comprise a second locking means, in which case the gearshift device will comprise a first movement means for moving the first locking means and a second movement means for moving the second locking means. The clutch device may comprise actuators for operating the clutch device, which actuators are adapted to being controlled by the control device. Like the actuators for operating the gearshift device, the actuators for operating the clutch device may be electric or hydraulic actuators.

A second aspect of the present invention is a proposed method for control of a transmission device which comprises an input shaft, a primary shaft intended to power the motor vehicle's wheels, a countershaft adapted to rotating when the input shaft rotates, a PTO shaft adapted to rotating when the countershaft rotates, and a first locking means which can be placed in at least a first position to synchronise the speed of the countershaft with the speed of the primary shaft, and for control of a clutch device which is connected between an engine and the input shaft of the transmission device. The method is characterised in that it comprises the steps of causing the clutch device to disconnect the engine and of moving the first locking means to the first position so that the speed of the countershaft is synchronised with the speed of the primary shaft. A method according to this second aspect of the present invention is relatively easy to implement in certain vehicles according to the state of the art without making any major modifications to the vehicle.

The primary shaft being intended to power the motor vehicle's wheels means that the primary shaft either is connected to the vehicle's wheels or is connectable to the vehicle's wheels. La the latter case the method comprises also the step of braking the primary shaft when the primary shaft is not connected to the vehicle's wheels.

A method according to the second aspect of the invention provides a simple way of synchronising the speed of the PTO shaft with the speed of the output shaft, resulting in the PTO shaft stopping. The first locking means may be the same means as used for synchronising and locking a gear in the transmission device.

Further advantages are achieved with the features in the dependent method claims. Where applicable, the features described in relation to the first aspect of the present invention may also be combined with a method according to the second aspect of the present invention.

Preferred embodiments of the invention are described below with reference to the appended drawings.

Brief description of the drawings

Fig. 1 depicts a motor vehicle with a transmission device according to an embodiment of the present invention.

Fig. 2 depicts in cross-section a transmission device according to a first embodiment of the invention.

Description of preferred embodiments

In the following description of preferred embodiments of the invention, similar features in the various drawings are designated by the same reference notation.

Fig. 1 depicts a vehicle 101 according to an embodiment of the present invention. The vehicle 101 comprises a first powered wheel 103 and a second powered wheel 104 which are adapted to being driven by a differential gear 112. The vehicle 101 further comprises an engine 118, a transmission device 1 with an input shaft 6 (Fig. 2), and a clutch device 102 which is connected between the engine 118 and the input shaft 6 (fig. 2) of the transmission device 1. The motor vehicle comprises also a universal shaft 106 arranged between the transmission device 1 and the differential gear 112. A PTO

(power take-off) 3 is provided from a transmission device 1. The vehicle 101 comprises also a control device 34 adapted to controlling the clutch device and the transmission device 1, and a driving cab 107 in which there is an operating device 108 connected to the control device 34 to engage and disengage the clutch device 102 and to manoeuvre the transmission device 1.

Fig. 2 depicts in cross-section a transmission device 1 according to a first embodiment of the invention, which transmission device 1 comprises a casing 2. A mainshaft 5 is supported in the casing 2. The mainshaft 5 comprises an input shaft 6 and a primary shaft 7 which are rotatable relative to one another. The transmission device 1 comprises also a countershaft 16 supported in the casing 2. The engine 118 is adapted to being coupled to the input shaft 6. On the input shaft 6 there is an input gearwheel 8 in engagement with a countershaft input gearwheel 9 on the countershaft 16. On the primary shaft 7 there are a first primary gearwheel 10, a second primary gearwheel 11, a third primary gearwheel 12 and a fourth primary gearwheel 13. On the countershaft 16 there are a first countershaft gearwheel 17 in engagement with the first primary gearwheel 10, a second countershaft gearwheel 18 in engagement with the second primary gearwheel 11, a third countershaft gearwheel 19 in engagement with the third primary gearwheel 12 and a fourth countershaft gearwheel 20 in engagement with the fourth primary gearwheel 13. All of the countershaft gearwheels 17, 18, 19, 20 are locked relative to the countershaft 16. The transmission ratio between the input shaft 6 and the primary shaft 7 depends on which of the primary gearwheels 10, 11, 12, 13 is locked relative to the primary shaft 7.

On the primary shaft 7 there is a first locking means 14 adapted to synchronising or locking the first primary gearwheel 10 or the second primary gearwheel 11 relative to the primary shaft 7. The first locking means 14 is movable between various positions along the primary shaft 7. hi a first position of the first locking means, the locking means is adapted to synchronising the speed of the first primary gearwheel 10 with the speed of the primary shaft 7 and thereby synchronising the speed of the countershaft 16 with the speed of the primary shaft 7. The first locking means 14 can be moved from the first position to a second position in which the first primary gearwheel 10 is locked relative to the primary shaft 7. The first locking means 14 can also be moved to a third position in which the locking means is adapted to synchronising the speed of the second primary gearwheel 11 with the speed of the primary shaft 7 and thereby synchronising the speed of the countershaft 16 with the speed of the primary shaft 7, and to a fourth position in which the second primary gearwheel 11 is locked relative to the primary shaft 7. On the primary shaft 7 there is also a second locking means 15 which, similarly to the first locking means 14, is movable between various positions to synchronise the speed of the countershaft 16 with the speed of the third primary gearwheel 12 or the speed of the fourth primary gearwheel 13 or to lock the third primary gearwheel 12 or the fourth primary gearwheel 13 to the primary shaft.

In the transmission device 1 there is also a PTO shaft 32 on which there is a PTO 33 to which an external machine can be connected. The transmission device 1 comprises a first PTO gearwheel 29 arranged on the countershaft 16 and a second PTO gearwheel 30 arranged on the PTO shaft 32. The transmission ratio between the countershaft 16 and the PTO shafl 32 is determined by the size relationship between the first PTO gearwheel 29 and the second PTO gearwheel 30. As an alternative, the PTO gearwheels 29, 30 may be replaced by driving wheels with a driving belt or chain running between them. The driving belt may be any desired type of belt, e.g. a V-belt or a toothed belt.

The transmission device 1 comprises a tag axle 31 and a first movement means 21 arranged on, and movable along, the tag axle 31. The first movement means 21 comprises a protrusion 22 which is in engagement with the first locking means 14. A first actuator 27 in the form of a hydraulic actuator is arranged between the casing 2 and the movement means 21 and is adapted to moving the first actions means 21 along the tag axle 31. The transmission device 1 comprises also a second movement means 23 arranged on the first movement means 21 and movable along the tag axle 31. The second movement means 23 comprises a protrusion 24 in engagement with the second locking means 15. A second actuator 28 in the form of a hydraulic actuator is arranged between the casing 2 and the second movement means 23 and is adapted to moving the second movement means 23 along the tag axle 31. The movement means 21 , 23 , the actuators 27, 28 and the tag axle 31 constitute a gearshift device 35.

The operating device 108 is connected to the control device 34 which is adapted to controlling the clutch device 102 in response to the operating device. The control device 34 is also adapted to controlling the gearshift device by controlling the actuators 27, 28 in response to the operating device 108.

The function of a motor vehicle 101 and a transmission device 1 and a method according to the invention will now be described. When a driver of the vehicle 101 has stopped the vehicle 101 and wishes to connect power to the PTO 33, he/she uses the operating device 108 to cause the clutch device 102 to disconnect the engine 118. The control device then causes the clutch device 102 to disconnect the engine 118 by means of a hydraulic or electric actuator 36 which is connected to the clutch device 102. When the clutch device 102 has disconnected the engine 118, the control device causes title first actuator 27 to move the first movement means 21 and hence the first locking means 14 so that the first locking means 14 assumes the first position. The speed of the first primary gearwheel 10 will then be synchronised with the speed of the primary shaft 7, thereby synchronising the speed of the countershaft 16 with the speed of the primary shaft 7. As the PTO shaft is coupled to the countershaft 16, the speed of the PTO shaft 32 will also be synchronised with the speed of the primary shaft 7. The primary shaft 7 is coupled to the wheels 103, 104 via the differential gear 112. As the vehicle 101 is stationary, the primary shaft 7 will also be motionless. Thus the synchronisation of the speed of the countershaft 16 with the speed of the primary shaft 7 will lead to the countershaft 16 stopping and hence also to the PTO shaft 32 stopping.

As the locking means 14, 15 are provided to control the selected transmission ratio, no components are required solely for the purpose of stopping the PTO shaft.

An alternative embodiment has a wheel engaging device 37 between the primary shaft 7 and the motor vehicle's wheels 103, 104, and a brake device adapted to braking the rotation of the primary shaft 7. When the wheels 103, 104 are not coupled to the primary shaft 7, the motion of the primary shaft can be braked by the brake device 38.

The embodiments described may be modified in many ways without departing from the spirit and scope of the invention, which is only limited by the claims.

In the embodiments described, the first locking means is moved to the first position to halt the PTO shaft, but it is possible for the first locking means 14 to be moved to the third position or for the second locking means 15 to be moved to the first or third position in order to halt the PTO shaft 32.

The actuators 27, 28 may alternatively be electric actuators.

Claims

1. A motor vehicle (101) with wheels (103, 104) comprising an engine (118), a transmission device (1) which comprises an input shaft (6), a primary shaft (7) intended to power the wheels (103, 104) of the vehicle (101), a countershaft (16) adapted to rotating when the input shaft (6) rotates, a PTO shaft (32) adapted to rotating when the countershaft (16) rotates, and a first locking means (14) which can be placed in at least a first position to synchronise the speed of the countershaft (16) with the speed of the primary shaft (7), a clutch device (102) connected between the engine (118) and the input shaft (6) of the transmission device (1) , and a control device (34) adapted to controlling the first locking means (14) and the clutch device (102), characterised in that, upon demand when the vehicle (101) is stationary, the control device (34) is adapted to causing the clutch device (102) to disconnect the engine (118), and to moving the first locking means (14) to the first position so that the speed of the countershaft (16) is synchronised with the speed of the primary shaft (7).

2. A motor vehicle (101) according to claim 1, in which there are at least a first primary gearwheel (10) on the primary shaft (7) and at least a first countershaft gearwheel (17) firmly mounted on the countershaft (16) and in engagement with the first primary gearwheel (10), and in which the first locking means (14) in the first position is adapted to synchronising the speed of the first primary gearwheel (10) with the speed of the primary shaft.

3. A motor vehicle (101) according to claim 2, in which the first locking means is movable from the first position to a second position in which the first primary gearwheel (10) is locked relative to the primary shaft (7).

4. A motor vehicle (101) according to any one of the foregoing claims comprising a gearshift device (35), in which the control device (34) is adapted to controlling the first locking means (14) by operating the gearshift device (35).

5. A motor vehicle (101) according to claim 4, in which the transmission device (118) comprises electric actuators (27, 28) for operating the gearshift device, which actuators (27, 28) are adapted to being controlled by the control device (34).

6. A motor vehicle (101) according to claim 4, in which the transmission device (118) comprises hydraulic actuators (27, 28) for operating the gearshift device (35), which actuators (27, 28) are adapted to being controlled by the control device (34).

7. A motor vehicle (101) according to any one of claims 4, 5 and 6, in which the transmission device (118) comprises also a second locking means (15) and in which the gearshift device (35) comprises a first movement means (21) for moving the first locking means (14) and a second movement means (23) for moving the second locking means (15).

8. A motor vehicle (101) according to any one of the foregoing claims, in which the clutch device (102) comprises electric actuators (36) for operating the clutch device (102), which actuators (36) are adapted to being controlled by the control device (34).

9. A motor vehicle (101) according to any one of the foregoing claims, in which the clutch device (102) comprises hydraulic actuators (36) for operating the clutch device

(102), which actuators (36) are adapted to being controlled by the control device (34).

10. A motor vehicle according to any one of the foregoing claims, which comprises also a wheel engagement device (37) arranged between the primary shaft (7) and the vehicle's wheels (103, 104) , and a brake device (38) adapted to braking the rotation of the primary shaft (7).

11. A method for controlling a transmission device (1) in a motor vehicle (101) with an engine (118) and wheels (103, 104), which transmission device comprises an input shaft (6), a primary shaft (7) intended to power the wheels (103, 104) of the vehicle (101), a countershaft (16) adapted to rotating when the input shaft (6) rotates, a PTO shaft (32) adapted to rotating when the countershaft (16) rotates, and a first locking means (14) which can be placed in at least a first position to synchronise the speed of the countershaft (16) with the speed of the primary shaft (7), and a clutch device (102) connected between the engine (118) and the input shaft (6) of the transmission device (1), characterised in that, when the motor vehicle (101) is stationary, the method comprises the steps of causing the clutch device (102) to disconnect the engine (118), and moving the first locking means (14) to the first position so that the speed of the countershaft (16) is synchronised with the speed of the primary shaft (7).

12. A method according to claim 11, which comprise also the step of braking the rotation of the primary shaft (7).

13. A method according to claim 11 or 12, in which the first locking means (14) is controlled by operating the gearshift device (35).

14. A method according to claim 13, in which the gearshift device (35) is operated by electrical actuators (27, 28).

15. A method according to claim 13, in which the gearshift device (35) is operated by hydraulic actuators (27, 28).