Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C14/00—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations
  • F04C14/24—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valves
  • F04C14/26—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valves using bypass channels
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C2/00—Rotary-piston machines or pumps
  • F04C2/08—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
  • F04C2/12—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type
  • F04C2/14—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons
  • F04C2/20—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons with dissimilar tooth forms

Definitions

• This invention relates to means for transmitting power from a prime mover to a load.
• An example is a motor vehicle having an internal combustion engine as prime mover and propelling the vehicle as load.
• the vehicle is provided with a gear box between the engine and the load to provide torque conversion enabling the engine to run in a power output range and at a speed of revolution range in which the engine operates efficiently, notwithstanding load variation, for example when the vehicle travels up a hill.
• Embodiments of the present invention provide means of operating such a motor at a more nearly constant fuel consumption and at close to optimum engine efficiency, while permitting periods of vehicle acceleration at a rate which is independent from engine speed of revolution.
• embodiments of the invention provide a more or less continuously variable torque conversion in transmission of power from a prime mover to a load and may be used in substitution for a gear box.
• the invention consists in apparatus for use in a drive transmission system comprising: a pump adapted to be driven to perform work on a medium, and means repetitively and automatically to unload the pump .
• the invention consists in apparatus for use in a driven transmission system comprising: a flywheel driven by a prime mover a pump driven by the flywheel to perform work on a medium and means repetitively to unload the pump whereby to permit acceleration of the flywheel.
• the invention consists in drive transmission means for transmitting power from a prime mover to a load comprising: a flywheel driven by the prime mover, a pump driven by the flywheel, a hydraulic motor powered by the pump, means repetitively to unload the pump thereby permitting the prime mover repetitively to accelerate the flywheel; and compensation means to power the hydraulic motor while said pump is unloaded.
• the pump is a positive displacement pump, and more preferably a rotary positive displacement pump, provided with relief galleries which eliminate the seal between ' pumping elements during a part of each stroke or revolution, whereby the pump is repetitively unloaded.
• Figure 1 is a schematic diagram showing a drive transmission system according to the invention.
• Figure 2 shows in sectional elevation an embodiment of apparatus useful as a hydraulic motor or pump in drive transmission systems of the invention.
• Figure 3 shows a part sectional view of the apparatus of Figure 2.
• Figure 4 shows in part section the apparatus of Figure 2 with its rotors at a different position.
• Figures 5 to 7 show an embodiment of a pump having means repetitively to unload the pump.
• FIG. 1 there is shown schematically an embodiment of drive transmission means according to the invention.
• the apparatus is intended to deliver power from a conventional engine (not shown) from which torque is to be transmitted to an output shaft 2 for driving a load (not shown in Figure 1) .
• a main shaft 3 supported by bearings 1 is coupled at one end for example by inter-engageable splines 4 with the engine whereby main shaft 3 may be driven in axial rotation.
• pump 5 is a rotary positive displacement pump of a type to be described in more
• Pump 5 is mounted in a sump 10 and the high pressure pump outlet port 8 communicates via a high pressure manifold 11 with the inlet side 12 of a hydraulic motor indicated generally at 13 whereby output shaft 2 is driven in rotation. Oil from the outlet side 14 of motor 13 is returned to sump 10.
• a valve may be provided whereby the direction of flow' of hydraulic fliud from manifold 11 through motor 13 may be reversed permitting the motor and consequently output shaft 2 to be driven in clockwise or anticlockwise rotation.
• the torque delivered by motor 13 is controlled by the bleed of fluid from manifold 11 via a valve having a valve orifice 20 communicating with a bypass return line 21 which returns oil to sump 10.
• the ratio of the amount of oil returning to the sump by motor 13 to the amount bypassing motor 13 through return line 21, that is to say the pressure of oil supplied to motor 13, is controlled by valve rod 22 which is actuatable to open or close valve orifice 20.
• High pressure oil manifold 11 also communicates with a high pressure oil stabiliser indicated generally at 23.
• Oil stabiliser 23 comprises a large diameter control air cylinder 24 fitted with an air piston 25 movable slidably therein and providing a seal with the walls of cylinder 24 so that air piston 25 divides cylinder 24 into a high pressure side 26 and a low pressure side'27.
• a piston rod 28 is connected at one end to the low pressure side of air piston 25 and, at the other end, to a small diameter oil piston 29 slidable within oil cylinder 30 and providing a seal therewith, valve rod 22 has one end connected on the side of oil piston 29 opposite the side of connection of piston rod 28 thereto and is co-axial with piston rod 28.
• the other end of valve rod 22 is slidable ' in a valve seating so as to control oil flow from manifold 11 via valve inlet 16 and valve orifice 20 to oil bypass return pipe 21 which has a diameter greater than that of valve rod 22.
• a compressor 30, in the present example driven by inter-engaging gears 31 and 32 from main shaft 3 provides compressed air via a line 33 to the high pressure side 27 of air piston 25.
• the air pressure in the high pressure side of air piston 25 that is to say S £
• valve means indicated generally at 34 connected between orifice 35 of the cylinder head and an air return line 36 communicating with the low pressure side of cylinder 26.
• the low pressure side cylinder 26 is provided with an air inlet 37 having a filter 38 communicating with atmosphere and an outlet 35 communicating via air line 40 with the inlet side of compressor 30 whereby air is provided to compressor 30.
• Valve rod 22 is arranged so that when air pressure on the high pressure side of air piston 25 is at atmospheric pressure and oil manifold 11 is pressurised, oil pressure in manifold 11 drives oil piston 29 and air piston 28 to fully extended positions in which valve rod 18 opens valve orifice 20 fully, thereby permitting flow of oil to bypass line 21. Increase of air pressure can be used to drive valve rod 22 progressively to close off oil bypass of motor 13 at orifice 20, or close it • completely.
• a flywheel 50 is fixedly mounted to shaft 3.
• the engine may be operated for example at a constant throttle and thereby turns shaft 3 and flywheel 50.
• shaft 3 pump 5 is driven, supplying high pressure oil to manifold 11.
• a proportion of the oil is used to drive hydraulic motor 13 and the balance is returned via valve orifice 20 and bypass 21 to sump 10.
• the pressure of oil admitted to motor 13, and hence the torque delivered by the motor may be varied according to the torque requirements at output shaft 2 by control of. air pressure at the high pressure side of piston 25 by means of valve 34 and thereby control of valve rod 22,
• the torque transmitted from the couple of engine and flywheel 50 to shaft 2 can be varied continuously and that this is achieved by simple control means. Moreover more energy can be supplied for periods to drive shaft 2 than is supplied during that period by the motor by virtue of the kinetic energy stored in the flywheel. In that event the flywheel is decelerated but can be again accelerated during following second and fourth quarter revolutions of shaft 3 occurring during periods when energy demand at output shaft 2 is less than the average supplied by the engine. It is therefore possible to drive the engine for example at optimum efficiency with respect to fuel consumption and to store the energy produced in flywheel 50. If energy supplied to the load exactly equals the output of the motor (ignoring losses which are minor) the flywheel will on average be neither accelerated nor decelerated.
• the surplus will be stored in the flywheel by acceleration thereof, and the stored energy will be available for subsequent consumption at a rate greater than the average output of the motor by deceleration of the flywheel.
• the system as a whole therefore performs at an optimum efficiency notwithstanding variations in load demand.
• the pump comprises a housing 100 having a first port 101 which in the present example is an inlet port and a second port 102 which in the present example is an outlet port, a first rotor 103 fixedly mounted to a shaft 104 and a second rotor 105 fixedly mounted to a
• Shafts 104 and 106 are parallel and are supported by bearings 108 mounted to parallel end walls 109 and 110 of housing 100.
• Shafts 104 and 106 project through end wall 109, high pressure oil seals 117 being provided to prevent escape of oil from the housing interior, and shaft 106 is driven synchronously with but in opposite sense to, shaft 104 by means of intermeshing gears 111 and 112 mounted respectively to the shaft 104 and 109 externally of the pump and adjacent wall 109.
• Rotors 103 and 105 are of generally cylindrical shape and equal radii and are effectively in rolling line contact. However rotor 103 is provided with two protruding lobes 113 and 114 each of which in cross-section is shaped in the arc of a circle centred on the circumference of rotor 103, at diametrically opposite points thereof, and is adapted during rotation of the rotor to sweep fluid admitted at the inlet through a volume defined between rotor 103 and housing 100 to port 102.
• the peripheries of lobes 113 and 114 are in close tolerance clearance with housing 100 between port 101 and port 102 in the direction of rotation of rotor 103.
• Rotor 105 is provided with depressions 115 and 116 which in cross-section are shaped in the arc of a circle
• Inlet port 101 and outlet ' port 102 are centred on the chord of intersection of the circles of pump housing 100 at opposite ends of the chord.
• outlet port is slot-shaped and extends longitudinally in the axial direction.
• lobes 113 and 114 may pass through the seal line while maintaining the seal.
• some fluid from inlet 101 is carried in depressions of rotor 105 towards exit
• the apparatus When used as an air pump the apparatus may be submerged in oil within a sealed sump. Fitered air is provided from outside the sump at atmospheric pressure via an air inlet line to the pump inlet. Air is ejected from the pump outlet into the surrounding oil and passes to a space above the oil level. A high pressure air outlet connection communicates with the space.
• a baffle is provided in the oil above the pump outlet port and further baffles may be provided to prevent oil from being entrained with high pressure air drawn from the sump outlet connection.
• a hydraulic fluid under pressure may be admitted at one port whereby the rotors are driven and spent fluid at a lower pressure exits from the other port.
• shaft 104 or 105 is extended externally of housing 100 to provide a drive shaft.
• the pump is in most respects similar to the apparatus shown in Figures 2-4 and the same numerals are used in Figures 5 to 7 to identify parts corresponding to those of Figures 2-4.
• circumferential pressure relief recesses 120 extending over an arc subtending an angle of 90O at the rotor axis and each located along ah edge of the rotor cylindrical portion and intermediate the lobes.
• the rotor has a width in the axial direction of 90 mm and the recesses have a radial depth of 10 mm and an axial width of 10 mm.
• pressure relief recesses 120 is that during operation of the apparatus as a pump in the manner described in relation to the apparatus of Figures 2 to 4, the pump of Figures 5 to 7 provides positive displacement during a first and third quarter cycle of rotor 103 while during a second and fourth quarter cycle the seal between inlet and outlet sides of the pump is broken by virtue of communication therebetween via pressure relief recesses 120 as shown in Figure 7.
• the pump thus produces a pulsating output achieving high peak pressures during a first and third quarter cycle and is freely rotatable during a second and fourth cycle.
• apparatus according to the invention may be adapted to replace the clutch and gear box of a vehicle by being mounted in the transmission housing of the vehicle in substitution for the clutch and gear box.
• the transmission output shaft is connected, for example by a spline coupling, to a universal joint connected to the vehicle tail shaft and thereby to the load, in this case the vehicle, while the input shaft is connected via a splined coupling to the flywheel of the vehicle engine.
• shaft 3 is then supported by bearings from the transmission housing of the vehicle.
• Pump 5 and motor 13 are housed within the transmission housing which acts as an oil sump.
• Main shaft 3 is in fact an extension of shaft 104 of pump 5.
• the external synchronising gears 111 and 112 of pump 5 and motor 13 are lubricated by the oil in the sump.
• the prime mover may be of any kind, for example, an internal combustion engine, electric motor, a waterwheel or a man-powered pedal arrangement.
• flywheel dimensions and weight should be selected having regard to the power output of the motor, the power requirements of the load and the storage capacity required.
• Any pump may be used if means ' are provided for relieving the load repetitively so that the flywheel can be accelerated.
• gear pump could be employed having grooves cut in certain gear teeth.
• a reciprocating piston pump can be provided with longitudinal grooves along the cylinder wall over a part of the piston stroke.
• a pump may be arranged with a bypass line connecting the outlet to the inlet, the bypass line
• valve could be a rotary valve controlled from the main drive shaft or could for example be a solenoid valve electrically opened and closed repetitively.
• the pump be relieved by some means to permit energy storage in the flywheel. Furthermore it is not essential that the periods of no load be of equal duration with the periods of load.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Rotary Pumps (AREA)
• Vehicle Body Suspensions (AREA)
• Auxiliary Devices For And Details Of Packaging Control (AREA)
• Surgical Instruments (AREA)
• Pretreatment Of Seeds And Plants (AREA)
• Adjustment And Processing Of Grains (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=3768379

Family Applications (1)

Country Status (10)

Cited By (1)

Families Citing this family (4)

Citations (7)

Family Cites Families (9)

• 1980
  • 1980-12-09 ZA ZA00807701A patent/ZA807701B/xx unknown
  • 1980-12-09 IT IT8083479A patent/IT8083479A0/it unknown
  • 1980-12-09 IT IT8083478A patent/IT8083478A0/it unknown
  • 1980-12-10 JP JP50012080A patent/JPS56501687A/ja active Pending
  • 1980-12-10 EP EP19800902363 patent/EP0041518A4/en not_active Withdrawn
  • 1980-12-10 AU AU65758/80A patent/AU541373B2/en not_active Expired - Fee Related
  • 1980-12-10 NZ NZ195799A patent/NZ195799A/en unknown
  • 1980-12-10 BR BR8008972A patent/BR8008972A/pt unknown
  • 1980-12-10 CA CA000366479A patent/CA1166933A/en not_active Expired
  • 1980-12-10 WO PCT/AU1980/000107 patent/WO1981001729A1/en not_active Application Discontinuation
  • 1980-12-10 US US06/287,748 patent/US4493188A/en not_active Expired - Lifetime

Patent Citations (7)

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