SE1451597A1

SE1451597A1 - Motor vehicle

Info

Publication number: SE1451597A1
Application number: SE1451597A
Authority: SE
Inventors: Hällqvist Thomas; Kardos Zoltan
Original assignee: Scania Cv Ab
Priority date: 2014-12-19
Filing date: 2014-12-19
Publication date: 2016-06-20
Also published as: SE538997C2

Abstract

16 ABSTRACT A motor vehicle (1) comprising: - a drive engine (4) for propelling the motor vehicle; - a power steering pump (21) operatively connectable to anoutput shaft (22) of the drive engine to allow the pump to bedriven by the drive engine; - a turbine (23) operatively connected to the power steeringpump (21) to allow the pump to be driven by the turbineindependently of the drive engine; - an air compressor (11) capable of producing compressed airunder the effect of the kinetic energy of the motor vehicle whenthe motor vehicle is rolling with the drive engine turned off andoperatively disconnected from the drive shaft; and - a compressed air tank (17) for storing compressed air producedby the air compressor and connected to the turbine to allow theturbine to be driven by compressed air supplied from the compressed air tank. (Fi9 1)

Description

Motor vehicle FIELD OF THE INVENTION AND PRIOR ART The present invention relates to a motor vehicle according to the preamble of claim 1.

A motor vehicle, such as for instance a lorry or a bus, is oftenprovided with a hydraulically actuated power steering system forassisting the driver in the steering of the vehicle by strengtheningthe manual steering forces exerted by the driver on the steeringwheel of the vehicle. A hydraulic power steering systemcomprises a power steering pump which provides and maintainsthe required working pressure of the hydraulic fluid in thehydraulic circuit of the power steering system. lf the powersteering pump is turned off, the power steering system will not becapable of operating and the power steering assistance is lost,which might be dangerous if occurring when the vehicle is rolling.lt is therefore important that the power steering pump is alwayssupplied with driving power when the vehicle is in operation. Thepower steering pump is normally driven by an output shaft of thecombustion engine of the vehicle. ln such a case, it is notappropriate to turn off the combustion engine when the vehicle isrolling, because that would result in a loss of the power steeringassistance, even though it might be favourable with respect tothe fuel disconnect it from the drive shaft of the vehicle in a situation economy to turn off the combustion engine and when the vehicle is capable of rolling at a sufficient speed without any power input from the combustion engine, such as for instance when driving downhill or when decelerating before coming to a halt. lt is previously known, for instance from US 5 549174A andUS 2011/0023509 A1, to produce compressed air by means of anair Compressor under the effect of the kinetic energy of a motorvehicle when the vehicle is braking to thereby recover energyand save fuel, wherein the compressed air is stored in acompressed air tank for later use, for instance in order to drive a pneumatic motor.

OBJECT OF THE INVENTION The object of the present invention is to provide a motor vehicle which offers improved possibilities for a fuel economic driving.

SUMMARY OF THE INVENTION According to the present invention, the above-mentioned objectis achieved by a motor vehicle having the features defined in claim 1.

The motor vehicle of the present invention comprises:- a drive engine for propelling the motor vehicle; - a hydraulic power steering pump which is operativelyconnectable to an output shaft of the drive engine so as to allowthe power steering pump to be driven by the drive engine; - a drive shaft connected to two or more driving wheels of the motor vehicle; - a transmission for transmitting driving torque from the driveengine to the drive shaft; - a turbine which is operatively connected or connectable to thepower steering pump so as to allow the power steering pump tobe driven by the turbine independently of the drive engine; - an air compressor capable of producing compressed air underthe effect of the kinetic energy of the motor vehicle when themotor vehicle is ro||ing with the drive engine turned off andoperatively disconnected from the drive shaft; and - a compressed air tank connected to the air compressor forstoring compressed air produced by the air compressor, whereinthe compressed air tank is connected to the turbine to allow theturbine to be driven by compressed air supplied from the compressed air tank.

Thus, the power steering pump may be driven by the drive enginewhen the drive engine is in operation and by the turbine when thedrive engine is turned off. Hereby, the drive engine may beturned off without losing the power steering assistance and it isthereby possible to turn off the drive engine in order to save fuelwhen the motor vehicle is capable of ro||ing at a sufficient speedwithout any power input from the drive engine, such as forinstance when driving downhill or when decelerating beforecoming to a halt. With the motor vehicle of the present invention,it will also be possible to take advantage of the kinetic energy ofthe motor vehicle in order to produce compressed air by meansof the air compressor, for instance when driving downhill andThe compressed air may be stored in the compressed air tank and when decelerating with the drive engine turned off. used in order to drive the power steering pump by means of the turbine when so appropriate. Thus, the motor vehicle of the present invention offers improved possibilities for a fueleconomic driving. Another advantage of the invention is that aturbine driven by compressed air is capable, when so needed, ofrapidly delivering a high driving power for driving the powersteering pump and any other apparatus that may be operatively connected to the turbine.

Further advantageous features of the motor vehicle of thepresent invention will appear from the following description and the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS With reference to the appended drawings, a specific descriptionof embodiments of the invention cited as examples follows below.ln the drawings: Fig 1 is an outline diagram of a motor vehicle according to afirst embodiment of the present invention, Fig 2 is an outline diagram of a motor vehicle according to asecond embodiment of the invention, Fig 3 is an outline diagram of parts included in a motor vehicle according to a third embodiment of the invenüon, Fig4 is an outline diagram of parts included in a motorvehicle according to a fourth embodiment of theinvenüon,and Fig 5 is an outline diagram of a motor vehicle according to a fifth embodiment of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THEINVENTION Different embodiments of a motor vehicle 1 according to thepresent invention are very schematically illustrated in Figs 1-5.The motor vehicle 1 comprises two or more driving wheels 2, adrive shaft 3 connected to the driving wheels 2, a drive engine 4for propelling the motor vehicle and a transmission 5 fortransmitting driving torque from the drive engine 4 to the driveshaft 3. ln the illustrated embodiments, the motor vehicle 1 alsocomprises a set of non-driven wheels 6. By means of a clutchdevice 7 provided between the drive engine 4 and thetransmission 5, an output shaft 8 of the drive engine 4 may beoperatively connected to and operatively disconnected from aninput shaft 9 of the transmission 5 at the choice of the driver ofthe motor vehicle 1 or automatically under the control of an electronic control system. ln the embodiment illustrated in Fig 1, the drive engine 4 is theonly power source for propelling the motor vehicle 1. ln this case,the drive engine 4 may for instance be an electric motor or a combustion engine, for instance in the form of a diesel engine. ln the embodiment illustrated in Figs 2-4, the motor vehicle 1 is ahybrid vehicle provided with an additional power source in theform of an electric motor 10, which may be used independently ofthe drive engine 4 for propelling the motor vehicle 1 when thedrive engine 4 is turned off or together with the drive engine 4 forpropelling the motor vehicle 1 in co-operation with the drive engine. ln this case, the drive engine 4 is preferably a combustion engine, for instance in the form of a diesel engine.

The motor vehicle 1 comprises an air compressor 11 which iscapable of producing compressed air under the effect of thekinetic energy of the motor vehicle 1 when the motor vehicle isrolling with the drive engine 4 turned off and operativelydisconnected from the drive shaft 3. The motor vehicle 1 mayalso be provided with two or more such air compressors. ln theillustrated embodiments, the air compressor 11 is operativelyconnectable to the drive shaft 3 via a clutch device 12 and via a13 which torque from the drive shaft 3 to the air The clutch device 12hydraulically actuated clutch and the torquea belt transmission or a chain transmission. As an alternative, the air torque transmission mechanism is configured totransmit drivingcompressor 11. is with advantage anelectrically ortransmission mechanism 13 may be a gear train,compressor may be operatively connected or connectable to arotary shaft of the transmission 5, to one of the wheel axles 14,15 of the motor vehicle 1 or to one of the driving wheels 2 ornon-driven wheels 6 of the motor vehicle. The air compressor 11is supplied with ambient air though an air supply conduit 16,which with advantage is connected to the air intake of the drive engine 4 downstream of an air filter arranged in this air intake.

The compressed air produced by the air Compressor 11 or aircompressors is stored in at least one compressed air tank 17,which is connected to the air compressor 11 through a conduit18. A non-return valve 19 is arranged in the conduit 18 betweenthe air compressor 11 and the compressed air tank 17 in order toprevent compressed air from flowing from the compressed air tank 17 back towards the air compressor11.

A hydraulic power steering pump 21 is operatively connectable toan output shaft 22 of the drive engine 4 so as to allow the powersteering pump 21 to be driven by the drive engine 4. The powersteering pump 21 forms part of a hydraulic power steering systemof conventional type (not shown) and is configured to supply pressurized hydraulic fluid to the power steering system.

The motor vehicle 1 further comprises a turbine 23 which isoperatively connected or connectable to the power steering pump21 so as to allow the power steering pump 21 to be driven by theturbine 23 independently of the drive engine 4. The compressedair tank 17 is connected to the turbine 23 through a supplyconduit 24 to allow the turbine 23 to be driven by compressed airproduced by the air compressor 11 and stored in the compressedair tank 17. The supply of compressed air to the turbine 23 isregulated by means of a regulating valve 25 arranged in the supply conduit 24.

The motor vehicle 1 comprises a rotary shaft 26 which isoperatively connectable to the above-mentioned output shaft 22 of the drive engine 4 via a clutch device 27 or a freewheel mechanism so as to allow the rotary shaft 26 to be driven inrotation by the drive engine 4 when the drive engine is inoperation and the output shaft 22 rotates under the effect of thedrive engine and also allow the rotary shaft 26 to rotateindependently of the output shaft 22 when the drive engine 4 isturned off. The clutch device 27 is with advantage an electricallyor hydraulically actuated clutch. The turbine 23 comprises aturbine wheel 28 which is operatively connected to the rotaryshaft 26 so as to allow the rotary shaft 26 to be driven in rotationby the turbine 23. The above-mentioned clutch device 27 orfreewheel mechanism makes it possible to prevent torque frombeing transmitted from the rotary shaft 26 to the output shaft 22of the drive engine 4 when the rotary shaft is rotated under theeffect of the turbine 23. ln the embodiments illustrated in Figs 1-3 and 5, the turbine wheel 28 is fixed to the rotary shaft 26. Asan alternative, the turbine wheel 28 may be operativelyconnected to the rotary shaft 26 via a torque transmissionmechanism 29 configured to transmit driving torque from theturbine wheel 28 to the rotary shaft 26, as illustrated in Fig 4.This torque transmission mechanism 29 may be a gear train, a belt transmission or a chain transmission.

The power steering pump 21 comprises a pump rotor 30 which isoperatively connected to the rotary shaft 26. ln the embodimentsillustrated in Figs 1, 2 and 5, the pump rotor 30 is fixed to therotary shaft 26. As an alternative, the pump rotor 30 may beoperatively connected to the rotary shaft 26 via a torquetransmission mechanism 31 configured to transmit driving torque from the rotary shaft 26 to the pump rotor 30, as illustrated in Figs 3 and 4. This torque transmission mechanism 31 may be a gear train, a belt transmission or a chain transmission. ln the embodiment illustrated in Figs 2-5, also a pump rotor 33 ofa coolant pump 34 is operatively connected to the rotary shaft 26so as to allow this pump rotor 33 to be driven in rotation by thedrive engine 4 and also by the turbine 23 independently of thedrive engine 4. The coolant pump 34 forms part of a coolingcircuit of conventional type (not shown) and is configured tocirculate coolant in the cooling circuit. The cooling circuit may forinstance be used for cooling the drive engine 4. ln theembodiments illustrated in Figs 2 and 5, the pump rotor 33 isfixed to the rotary shaft 26. As an alternative, the pump rotor 33may be operatively connected to the rotary shaft 26 via a torquetransmission mechanism 35 configured to transmit driving torquefrom the rotary shaft 26 to the pump rotor 33, as illustrated inFigs 3 and 4. This torque transmission mechanism 35 may be a gear train, a belt transmission or a chain transmission. ln the embodiment illustrated in Fig 5, also an air conditioningcompressor 36 is operatively connectable to the rotary shaft 26so as to allow the air conditioning compressor 36 to be driven bythe drive engine 4 and also allow the air conditioning compressor36 to be driven by the turbine 23 independently of the driveengine 4. The air conditioning compressor 36 forms part of an airconditioning system of conventional type (not shown) and isconfigured to compress a working medium of the air conditioningsystem. The air conditioning compressor 36 is preferablyoperatively connectable to the rotary shaft 26 via a clutch device 37 in order to allow the air conditioning compressor to be operatively disconnected from the turbine 23 and the output shaft22 of the drive engine 4 in a situation when no air-conditioningeffect is required. The clutch device 37 is with advantage an electrically or hydraulically actuated clutch. ln the illustrated embodiments, the motor vehicle 1 comprises abelt transmission 39 for transmitting driving torque from theoutput shaft 22 of the drive engine 4 to the rotary shaft 26. As analternative to a belt transmission, a gear train or a chaintransmission could be used for transmitting driving torque from the output shaft 22 of the drive engine 4 to the rotary shaft 26.

The motor vehicle 1 further comprises an electronic controldevice 40 for controlling the above-mentioned clutch devices 7,12, 27, 37, the drive engine 4, the air compressor 11 and theregulating valve 25. The electronic control device 40 may beimplemented by one single electronic control unit of the motorvehicle 1, as illustrated in Figs 1-5. However, the electroniccontrol device 40 could as an alternative be implemented by twoor more mutually co-operating electronic control units of the motor vehicle.

The motor vehicle according to the invention is particularly aheavy motor vehicle, such as for instance a bus, a tractor truck or a lorry.

The clutch device 12 between the drive shaft 3 and the aircompressor 11 is intended to be engaged particularly when themotor vehicle 1 is running downhill or decelerating, so as to thereby allow the air compressor 11 to take advantage of the 11 kinetic energy of the rolling motor vehicle 11 in order to producecompressed air for storing in the compressed air tank 17. Thecompressed air may then be used for driving the power steeringpump 21 and possibly also the coolant pump 34 and the airconditioning Compressor 36 when the drive engine 4 is turned offand also in any appropriate situation when the drive engine 4 isrunning. The clutch device 27 between the turbine 23 and thedrive engine 4 is disengaged when compressed air is used for driving the power steering pump 21 by means of the turbine 23.

The invention is of course not in any way restricted to the embodiments described above. On the contrary, many possibilities to modifications thereof will be apparent to a personwith ordinary skill in the art without departing from the basic idea of the invention such as defined in the appended claims.

Claims

1. _ A motor vehicle comprising: - a drive engine (4) for propelling the motor vehicle (1); - a hydraulic power steering pump (21) which is operativelyconnectable to an output shaft (22) of the drive engine (4) soas to allow the power steering pump (21) to be driven by thedrive engine (4); - a drive shaft (3) connected to two or more driving wheels (2)of the motor vehicle (1); and - a transmission (5) for transmitting driving torque from thedrive engine (4) to the drive shaft (3); characterized in that the motor vehicle (1) further comprises:- a turbine (23) which is operatively connected or connectableto the power steering pump (21) so as to allow the powersteering pump (21) to be driven by the turbine (23)independently of the drive engine (4); - an air compressor (11) capable of producing compressed airunder the effect of the kinetic energy of the motor vehicle (1)when the motor vehicle is rolling with the drive engine (4)turned off and operatively disconnected from the drive shaft(3); and - a compressed air tank (17) connected to the air compressor(11) for compressor (11), wherein the compressed air tank (17) is storing compressed air produced by the airconnected to the turbine (23) to allow the turbine to be drivenby compressed air supplied from the compressed air tank (17).

2. A motor vehicle according to claim 1, characterized in: 13 - that the motor vehicle (1) comprises a rotary shaft (26)which is operatively connectable to said output shaft (22) ofthe drive engine (4) via a clutch device (27) or a freewheelmechanism so as to allow the rotary shaft (26) to be driven inrotation by the drive engine (4); - that the turbine (23) comprises a turbine wheel (28) which isoperatively connected to the rotary shaft (26) so as to allowthe rotary shaft (26) to be driven in rotation by the turbine(23); and - that the power steering pump (21) comprises a pump rotor (30) which is operatively connected to the rotary shaft (26). _ A motor vehicle according to claim 2, characterized in that the turbine wheel (28) is fixed to the rotary shaft (26). _ A motor vehicle according to claim 2, characterized in that the turbine wheel (28) is operatively connected to the rotaryshaft (26) via a torque transmission mechanism (29) which isconfigured to transmit driving torque from the turbine wheel(28) to the rotary shaft (26). _ A motor vehicle according to any of claims 2-4, characterized in that the pump rotor (30) of the power steering pump (21) isfixed to the rotary shaft (26). _ A motor vehicle according to any of claim 2-4, characterized in that the pump rotor (30) of the power steering pump (21) isoperatively connected to the rotary shaft (26) via a torque transmission mechanism (31) which is configured to transmit 10. 14 driving torque from the rotary shaft (26) to the pump rotor(30). A motor vehicle according to any of claims 2-6, characterized in that the motor vehicle (1) comprises a coolant pump (34)for circulating coolant in a cooling circuit of the motor vehicle,wherein the coolant pump (34) comprises a pump rotor (33)which is operatively connected or connectable to said rotaryshaft (26) so as to allow the coolant pump (34) to be driven bythe drive engine (4) and also allow the coolant pump (34) tobe driven by the turbine (23) independently of the driveengine (4). A motor vehicle according to claim 7, characterized in thatthe pump rotor (33) of the coolant pump (34) is fixed to therotary shaft (26). A motor vehicle according to claim 7, characterized in thatthe pump rotor (33) of the coolant pump (34) is operativelyconnected to the rotary shaft (26) via a torque transmissionmechanism (35) which is configured to transmit driving torque from the rotary shaft (26) to this pump rotor (33). A motor vehicle according to any of claims 2-9, characterized in that the motor vehicle (1) comprises an air conditioningcompressor (36) which is operatively connectable to said(26) compressor (36) to be driven by the drive engine (4) and also rotary shaft so as to allow the air conditioning allow the air conditioning compressor (36) to be driven by the turbine (23) independently of the drive engine (4). 11.A motor vehicle according to claim 10, characterized in that the air conditioning compressor (36) is operatively connectable to the rotary shaft (26) via a clutch device (37). 12.A motor vehicle according to any of claims 2-11, characterized in that the motor vehicle (1) comprises a belttransmission (39) for transmitting driving torque from saidoutput shaft (22) of the drive engine (4) to said rotary shaft(26). 13.A motor vehicle according to any of claims 1-12, characterized in that the air compressor (11) is operativelyconnectable to the drive shaft (3) via a clutch device (12) andvia a torque transmission mechanism (13) which is configuredto transmit driving torque from the drive shaft (3) to the air compressor (11). 14.A motor vehicle according to any of claims 1-13, characterized in that the drive engine (4) is a combustion engine. 15.A motor vehicle according to any of claims 1-14, characterized in that the motor vehicle (1) is a hybrid vehicleand also comprises an electric motor (10) for propelling the motor vehicle (1).