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
• • 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
  • F04C2/10—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member
• • 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
  • F04C11/00—Combinations of two or more machines or pumps, each being of rotary-piston or oscillating-piston type; Pumping installations
• • 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
  • F04C14/08—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by varying the rotational speed
• • 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
  • F04C14/28—Safety arrangements; Monitoring
• • 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
  • F04C15/00—Component parts, details or accessories of machines, pumps or pumping installations, not provided for in groups F04C2/00 - F04C14/00
  • F04C15/0003—Sealing arrangements in rotary-piston machines or pumps
  • F04C15/0023—Axial sealings for working fluid
  • F04C15/0026—Elements specially adapted for sealing of the lateral faces of intermeshing-engagement type machines or pumps, e.g. gear machines or pumps

Definitions

• the invention concerns a motor pump unit comprising a rotary electric motor driving a pump.
• the pump comprises a first rotating or orbiting displacement element, which performs a relative movement in relation to a second displacement element.
• the displacement elements are arranged between a first and a second side plate, of which at least one comprises commutation channels with connections to an inlet and a pressure outlet, respectively.
• Pumps used for oil burners are often driven by e.g. electric motors, which drive both an oil pump and a fan supplying air.
• the motor is provided with a shaft extending outwards at either end of the rotor of the motor. One end of the shaft is connected with the pump shaft, while the other end of the shaft drives the fan. Pump and fan get the same rotation speed, with no opportunity of individual regulation.
• a reduction gear has a negative influence on the efficiency of the high-pressure cleaner, and the gear requires lubrication by a lubricant, e.g. oil.
• a lubricant e.g. oil.
• gear and lubricant also contribute to an increase of the weight of the high- pressure cleaner, which is a disadvantage, if it has to be portable.
• the use of a gear influences the price of the high-pressure cleaner.
• connection motor and pump both motor and pump are aligned by the common flange, securing a very exact control of the pump in relation to the motor during fitting, and the perfect assembling causes a minimum load on shaft and bearings, as the deflection of the shaft is very small.
• a possible application of the motor pump unit is a fuel pump for an oil burner.
• the separation of fan and pump involves the opportunity of independent regulation. Further, an optimum dimensioning of the motor of the pump in relation to the actual requirement is possible, and at the same time, a fan having its own motor can be opti- mised.
• the motor pump unit is a high pressure cleaner, which can be made without using a gear between motor and pump. This increases the effi- ciency, and the motor pump unit can work without needing oil. The weight of the motor pump unit can become so low that the unit can be particularly suited for use in a portable high pressure cleaner.
• the pump may comprise an inner, externally toothed gear wheel, which rotates around a first centre, where the first gear wheel co-operates with a second outer, internally toothed gear wheel, which rotates around a second centre.
• the invention can be made with a gerotor pump, which is suited for rotation at high speed.
• the common flange may comprise a first bore for admission of the common shaft and a second concentric bore for admission of the common bearing.
• the bearing may be a ball bearing, but roller or needle bearings can also be used. Further, slide bearings in the shape of a bushing can be used.
• the common flange can be made with a recess for admission of one of the side plates of the pump. Thus, the placing of the side plate is determined by the common flange.
• the common bearing of the shaft can also be formed in the common flange.
• the bore of the flange can be used as bearing, and the flange can be made of a suitable bearing material.
• the common bearing can secure optimum positioning of the first, inner, externally toothed gear wheel of the pump. An optimum placing of the inner gear wheel will reduce frictional losses and the risk of jamming.
• the common bearing can also secure optimum positioning of the common flange, which guides the placing of the channel discs and the outer ring of the pump, which again secure the positioning of the second, outer, internally toothed gear wheel of the pump.
• the gear wheels of the pump can be arranged between side plates comprising commutation channels with connection to the inlet and the pressure outlet, respectively, which side plates are made of ceramics with an addition of wear and friction reducing materials.
• side plates can contribute to reducing the frictional losses of the pump. A long life can also be obtained.
• the gear wheels of the pump can be made of a powder, which is sintered together, to which powder are added materials with corrosion, wear and friction reducing properties. This implies that the gear wheels can be produced so accurately that jamming is avoided and the intermeshing of the inner and outer gear wheels can take place with very small frictional losses.
• the common flange can form the basis of the stator of the electric motor, and at the same time the common flange forms the basis of a connection flange.
• motor and pump are assembled with common bolts, extending from the stator of the motor, through the common flange and fi- nally through the connection flange of the motor.
• the common flange may comprise a number of channels creating a connection between commutation channels of the side plates and an inlet and/or an outlet, whose connec- tion branch (es) is/are inserted in the common flange.
• connection to the pump can be made via the common flange, which forms the basis of at least one connection branch.
• the common flange can comprise means for flow regulation with connection to the channels of the common flange.
• the common flange can form the basis of one or more valves .
• the channels of the common flange can be provided with at least one heating element.
• an oil preheater can be built into the motor pump unit, which will be advantageous for oil burner applications.
• the channels of the common flange can be connected with a filter, which is fitted in the common flange.
• a filter which is fitted in the common flange.
• the flange of the motor pump unit can comprise means for ventilating the pump.
• the pump can be ventilated, which may be necessary in connection with the first start of the pump.
• connection flange can form a connection between an inlet and at least one of the channel discs, and also between at least one of the channel discs and the pressure outlet of the motor pump unit.
• the motor pump unit can be connected e.g. to an oil tank or a water supply, and the outlet can be connected to a nozzle in an oil burner, or to a hose, which forms connection to the handle of a high pressure cleaner.
• the connection flange can be made with valves for regulation of pressure or flow.
• the motor pump unit can have a connection flange, which creates a connection between an inlet and at least one of the channel discs, and between at least one of the channel discs and the pressure outlet of the motor pump unit.
• connection flange surrounds the pump, and between connection flange and pump there is a chamber, which is connected with the inlet or the outlet of the pump.
• the motor pump unit can comprise a pressure regulation valve. This secures a constant pressure level on the outlet of the motor pump unit.
• the pressure regulation valve can be made with a by-pass connection, which returns medium to the low pressure side of the pump, when the fixed pressure level has been reached.
• the pressure regulation valve can be made with a setting element for setting of the desired pressure level .
• the motor pump unit may also comprise a flow regulation valve.
• the motor pump unit can set the outlet pressure in relation to a flow value, e.g. 5 1 per min- ute. If the motor pump unit is used for a high pressure cleaner, a connected flow restriction will automatically receive the pressure, which is built up by the fixed flow over the restriction.
• the pump comprises an overflow valve, which connects the pressure outlet of the pump with its inlet, if the outlet pressure of the pump exceeds a fixed value.
• an overflow valve which connects the pressure outlet of the pump with its inlet, if the outlet pressure of the pump exceeds a fixed value.
• the motor pump unit may comprise a pressure switch, which disconnects the electrical connection to the motor, if an upper limit pressure is exceeded. This provides a security function, which starts working before the motor pump unit or the environment are damaged.
• the motor can be provided with a thermal switch, which disconnects the electrical connection to the motor, if the thermal switch exceeds a fixed temperature. This protects the motor against damages, which may occur on overheating of the motor windings.
• the motor pump unit is used for a high pressure cleaner, it is advantageous for the motor to be a highspeed electric motor, which drives the pump directly. Thus, even a small pump can obtain a sufficient displace- ment for high pressure cleaning.
• the speed of the electric motor can be controlled by a frequency converter.
• the pressure or the displacement of the pump can be regulated by means of the fre- quency converter. Measured values of pressure, flow and temperature can be used for regulation of the frequency converter.
• An operation panel can be equipped with means for setting of desired pressure, flow or temperature.
• the electric motor can be a series motor, in which the current first passes a stator winding, and then a rotor winding via a commutator.
• a cheap and well-known motor can be used.
• the invention can be made with a synchronous motor.
• This is a motor with a permanently magnetic rotor, and, if operated with high-frequency AC, the motor has a fixed relation between speed and frequency.
• the electric motor can be an asynchronous motor. This is a simple and cheap motor, whose torque is automatically adapted to the actual requirement.
• the invention can also be made with a reluctance motor.
• This motor is particularly suited for high speed, by which the motor is supplied from a frequency converter.
• the common flange can have a bore from the motor side for adoption of a sealing element.
• the medium lubricates the common bearing, which is advantageous, if the medium is oil.
• the sealing element can be made of a flexible material, e.g. rubber, and have the shape of a lip sealing, which bears on the common shaft.
• the pump can have means for sealing, to prevent medium from getting in touch with the bearings of the motor pump unit. If the medium is water, or any other medium, which can damage the bearing, it is advantageous to prevent medium from getting to the bearing.
• Means for sealing can be embedded in a ring-shaped recess, arranged concentrically around the shaft in the inner gear wheel or in the opposite side plate, where a resilient element presses a wearing ring against the opposite surface. This gives a simple and cheap sealing of the pump.
• Fig. 1 a possible embodiment of the invention
• FIG. 2 an enlarged section of a possible sealing arrangement
• Fig. 5 a section through the embodiment shown in fig. 4
• Fig. 6 a fourth possible embodiment of the invention
• Fig. 1 shows a motor-pump unit 1, comprising an electric motor 2 and a pump unit 3, in which the motor 2 is connected with the pump 3 by means of a shaft 4. Between the electric motor 2 and the pump unit 3 there is a common flange 5, which contains a common bearing 6.
• the pump unit consists of two channel discs 7 and 8, between which there is an inner, externally toothed gear wheel 9, which is connected with the shaft 4 by means of a driver 10.
• the inner gear wheel 9 co-operates with an outer, internally toothed gear wheel 11, which rotates freely in a spacing ring 12.
• a connection flange 13 contains an inlet 15 and an outlet 14, which are connected with the gear wheel set through the channel disc 8.
• the pump unit 3 is sealed by means of a number of O-rings 16. Further, the shaft 4 is supported by a bearing 19.
• the motor pump unit as shown in fig. 1 is extremely easy to produce, as during assembling the motor shaft and the bearing 6 control the placing of the common flange 5, which forms the basis of the channel discs 7 and 8, which again guide the spacing ring 12. At the same time, the shaft 4 is guiding the inner gear wheel 9. This gives a pump, which is easy to assemble, and which can work very precisely.
• the motor 2 drives first the inner gear wheel 9, and by means of the inner gear wheel 9 also the outer gear wheel 11 to perform a rotary movement.
• a gerotor pump occurs, which is commu- tated by means of channels in the channel discs 7 and 8.
• the electric motor 2 is a high-speed motor, which drives the gerotor pump at a speed of up to 24,000 r.p.m. This gives a very large displacement capacity with a very small pump.
• the pump is able to supply 8 to 10 1 per minute at a pressure of more than 60 bar, which makes the motor pump unit particularly suited for a high pressure cleaner.
• the channel discs 7 and 8 are made of ceramics, and plane ground on the side surfaces. Together with the collector ring 18 and the resilient elements 17, this provides an efficient and cheap sealing, which protects the rotating shaft against liquid leakage.
• Fig. 2 showing an enlarged section of part of fig. 1, shows a possible embodiment of a sealing between working chambers of the gear wheel set and the driving shaft.
• a first resilient element 17 which can be an 0-ring.
• a collector ring 18 is yieldingly fixed, and pressed against the surrounding channel discs 7 and 8.
• Fig. 3 shows an alternative embodiment of the invention, in which common reference numbers have been maintained. Fig. 3 deviates in that the bearing 19 is omitted, so that the shaft 4 is only supported by the common bearing 6.
• fig. 3 shows an alternative connection flange 21 with an inlet 15 and an outlet 14.
• the inlet 15 of the flange 21 is connected with a surrounding chamber 22, which surrounds the whole pump unit.
• the surrounding chamber is sealed towards the surroundings by means of 0- rings 16. This saves O-rings in the pump unit itself, as any leakage between the channel disc 7 or 8 and the spacing ring 12 will end in the chamber 22, from which there is a direct access to the suction connection.
• the surrounding chamber 22 also offers the opportunity of cooling the pump unit.
• Fig. 4 shows a section through an alternative embodiment of a liquid pump according to the invention.
• the liquid pump shown in fig. 4 is particularly suited for media with lubricating properties, e.g. oil.
• the motor pump unit 1 comprises an electric motor 2 and a pump 3 driven by the motor.
• the electric motor comprises a stator 25 and a rotor 26.
• the rotor is fixed on a shaft 4, which is embedded rotatably in a bearing 27.
• the bearing 27 is fixed on the stator 26 by means of bolts 28, which pass through both the stator 25, the common flange 5 and a connection flange 23. Further, the motor is provided with a fan 29 for cooling of the motor.
• the bolts 28 are arranged in bushings 30 at the passage between the stator 25 and the common flange 5, where the bushings create a positioning between the flange 5 and the stator 25.
• the sealing element 24 is arranged in a first bore in the flange 5 and bearingly retained against the bottom of the bore by means of a locking ring 31.
• the ball bearing 6 is also fitted around the shaft 4.
• the ball bearing 6 is arranged in a second bore in the flange 5 and retained in relation to the shaft 4 by means of locking rings 32.
• a first side plate 7 is also fitted around the shaft 4.
• the side plate 7 is arranged in a third bore in the flange 5.
• An outer ring 12 is bearingly arranged on the side plate 7 and forms a stationary element in the pump.
• the outer ring 12 is retained in relation to the side plate 7 by means of a pin 33.
• a second side plate 8 is bearingly arranged on the outer ring 12.
• An outer gear wheel 11 is arranged between the first side plate 7 and the second side plate 8 inside the outer ring 12.
• the gear wheel 11 rotates freely inside the outer ring 12.
• An inner gear wheel 9 is arranged between the first side plate 7 and the second side plate 8 inside the outer gear wheel 11.
• the inner gear wheel 9 is retained on the shaft 4 by means of a spring 10.
• the ball bearing 6 is fitted in a second bore in the flange 5, and the ball bearing 6 forms the basis of the side plate 7 in the pump.
• the side plate 7 forms the basis of the outer ring 12 and the gear wheel 11.
• the ball bearing 6 also forms the basis of the shaft 4 in the flange 5.
• the shaft 4 guides the inner gear wheel 9 in relation to the outer gear wheel 11.
• a filter holder 34 is shown between the inlet 15 and the gear wheels 9, 11 of the pump. This filter holder 34 is arranged between the second side plate 8 and a cover 23. The filter holder 34 is provided with a sleeve, which supports a mechanical filter 35.
• Sealings 16 being O-rings in the embodiment shown, are arranged between the first side plate 7 and the flange 5 and form the sealing of an outlet from the pump.
• Another sealing 16 in the embodiment shown also an O-ring, is arranged between the cover 23 and the flange 5 and forms the sealing of the inlet 15 in the cover 23.
• the cover 23 is fixed to the flange 5 by means of the bolts 28.
• An additional sealing 16, in the embodiment shown also an 0- ring, is arranged between the cover 23 and the filter 35, and seals so that the medium, in the embodiment shown fuel, must pass the filter 35 before being led to the gear wheel 11 and the gear wheel 9.
• Fig. 5 is a section through the oil pump at right angles to the section shown in fig. 1.
• the section shows various elements, which could not be seen in fig. 4.
• a ventilation plug 36 is fitted in a first threaded hole in the flange 5.
• a sealing 37 is formed by arranging an O-ring between the ventilation plug 36 and the bottom of the first threaded hole.
• a regulation screw 38 is fixed in a second threaded hole in the flange 5.
• a sealing 39 in the embodiment shown an O-ring, is arranged between the flange 5 and the regulation screw 38.
• the regulation screw 38 comprises a spring element 40, in the embodiment shown a helical spring, a spring guide 41, forming the bearing of the spring element 40, and also of a regulation cone 42, which forms a regulation element.
• a pressure controlled valve 43 is fixed in a third threaded hole in the flange 5, which valve only opens after exceeding a fixed first pressure level, and closes as soon as a second fixed pressure level has been reached.
• a sealing 44 in the embodiment shown an O-ring, is arranged between the flange 5 and valve 43.
• the valve 43 comprises a diaphragm 45, which bears on a spring retainer 46.
• a spring element 47 in the embodiment shown a helical spring, bears on the spring retainer 46 and is bearingly retained on the spring retainer 41 by means of a jacket 48.
• Fig. 6 is a section through a fourth possible embodiment of the invention.
• the common flange 49 forms the bearing 50 of the shaft 4.
• the flange 49 replaces both the ball bearing 6 and the first side plate 7.
• the shaft 4 is embedded in the flange 5 and the gear wheel 11 and the gear wheel 9 of the pump bear direct on an outer surface of the flange 5.
• the bore, through which the shaft ex- tends is preferably provided with a coating or a bushing (not shown), which is made of a bearing material.
• the flange 5 is made of a material, which is a suitable bearing material for the shaft 4.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Rotary Pumps (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)
• Compressor (AREA)
• Lubrication Of Internal Combustion Engines (AREA)
• Control Of Electric Motors In General (AREA)
• Control Of The Air-Fuel Ratio Of Carburetors (AREA)
• Reciprocating Pumps (AREA)
• Details And Applications Of Rotary Liquid Pumps (AREA)

Applications Claiming Priority (5)

Publications (2)

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ID=26063213

Family Applications (1)

Country Status (6)

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Family Cites Families (6)

• 1997
  • 1997-12-02 AU AU51873/98A patent/AU5187398A/en not_active Abandoned
  • 1997-12-02 AT AT97946743T patent/ATE247777T1/de not_active IP Right Cessation
  • 1997-12-02 KR KR10-1999-7004876A patent/KR100391007B1/ko not_active IP Right Cessation
  • 1997-12-02 WO PCT/DK1997/000551 patent/WO1998025029A1/en active IP Right Grant
  • 1997-12-02 DE DE69724271T patent/DE69724271T2/de not_active Expired - Lifetime
  • 1997-12-02 EP EP97946743A patent/EP0943056B1/de not_active Revoked

Non-Patent Citations (1)

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