Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
  • F04B49/10—Other safety measures
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
  • F01B11/00—Reciprocating-piston machines or engines without rotary main shaft, e.g. of free-piston type
  • F01B11/007—Reciprocating-piston machines or engines without rotary main shaft, e.g. of free-piston type in which the movement in only one direction is obtained by a single acting piston motor, e.g. with actuation in the other direction by spring means
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
  • F01B11/00—Reciprocating-piston machines or engines without rotary main shaft, e.g. of free-piston type
  • F01B11/04—Engines combined with reciprocatory driven devices, e.g. hammers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B19/00—Machines or pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B1/00 - F04B17/00
  • F04B19/20—Other positive-displacement pumps
  • F04B19/22—Other positive-displacement pumps of reciprocating-piston type
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B9/00—Piston machines or pumps characterised by the driving or driven means to or from their working members
  • F04B9/08—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid
  • F04B9/12—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being elastic, e.g. steam or air
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B9/00—Piston machines or pumps characterised by the driving or driven means to or from their working members
  • F04B9/08—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid
  • F04B9/12—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being elastic, e.g. steam or air
  • F04B9/123—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being elastic, e.g. steam or air having only one pumping chamber
  • F04B9/125—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being elastic, e.g. steam or air having only one pumping chamber reciprocating movement of the pumping member being obtained by a double-acting elastic-fluid motor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B2203/00—Motor parameters
  • F04B2203/10—Motor parameters of linear elastic fluid motors

Definitions

• the present invention relates to an air-driven hydraulic pump, comprising an air motor which is operatively connected with an oil pump, wherein the air motor comprises a cylinder element in which an air piston is arranged movable in a reciprocating manner along an axis.
• the air piston is connected with an oil piston of the oil pump for transmitting the reciprocating movement of the air piston to the oil piston.
• Air-driven hydraulic pumps of this kind are used to set oil under a
• the hydraulic pump is suitable for applications such as bolt tensioning, injecting oil for overcoming interference fits and pressurizing large hydraulic nuts.
• the use of air-driven oil pumps can save considerable time and effort.
• the oil pump itself is driven by an air motor which allows to carry out a reciprocating movement of a piston within a respective cylinder.
• the piston of the air motor moves the piston of the oil pump.
• An air motor of this kind is known for example from US 2 765 804.
• the air motor comprises a cylinder in which the air piston is arranged.
• the piston can carry out a reciprocating movement in the cylinder.
• the air piston separates two cylinder chambers in the cylinder.
• the cylinder chambers are periodically charged with pressurized air from a pressurized air source, wherein the periodical charging of the chambers with air is controlled by a control valve element.
• an air-driven hydraulic pump comprising an air motor, and an oil pump, which is operatively connected with the air motor.
• the air motor comprises a cylinder element in which an air piston is arranged movable in a reciprocating manner along a centre axis.
• the air piston is connected with an oil piston of the oil pump for transmitting the reciprocating movement of the air piston to the oil piston.
• the air piston separates a first cylinder chamber from a second cylinder chamber within the cylinder element.
• a control valve element is arranged to control the application of pressurized air from a source of pressurized air to the cylinder element.
• At least one pressure control valve is arranged in the air motor, allowing an air flow from one of the cylinder chambers to the other cylinder chamber when the pressure difference between the two cylinder chambers exceeds a
• a single pressure control valve is employed.
• the at least one pressure control valve is arranged in the air piston.
• the pressure control valve can then penetrate the air piston in the direction of the axis of the cylinder.
• the at least one pressure control valve is a check valve.
• This check valve can comprise a housing in which a valve element is elastically biased, or biased, against a seat by means of a spring element.
• the valve element is preferably a ball.
• the spring element is preferably a helical spring.
• the housing can have a substantial hollow cylindrical form. The axis of the housing is mostly parallel to the axis of the cylinder element. Thereby, the axis of the housing and the axis of the cylinder element are preferably radially distanced from another.
• the at least one pressure control valve comprises means for adjusting the pressure difference between the two cylinder chambers at which the pressure control valve opens.
• the means for adjusting the pressure difference can comprise a screw element which is screwed into a thread in the housing of the valve element.
• the screw element can have a hexagon socket in one of its face sides for easy adjustment of the applied spring force.
• the air piston and the oil piston are arranged coaxially.
• an air pressure limiter device is incorporated into the air-driven hydraulic pump.
• the oil pressure that the pump is able to produce is limited, since the oil pressure is directly depending on the air pressure used for powering the air motor.
• Fig. 1 shows a perspective view of en embodiment of the hydraulic pump according to this invention, consisting of an air motor and an oil pump;
• Fig. 2 shows a top plan view of the hydraulic pump according Fig. 1 ;
• Fig. 3 shows a cross sectional view along to the cut C-D according to Fig. 2;
• Fig. 4 shows the detail "X" according to Fig. 3.
• Fig. 5 shows an enlarged view of the valve element as shown in Fig. 4.
• the hydraulic pump 1 has a carrying handle 25. In the region of this handle an oil inlet 21 is arranged which leads to the oil pump 3. The oil is set under pressure by the oil pump 3 and leaves it via a connection nipple 22. An oil return is denoted with reference numeral 23. A release valve 24 allows releasing the pressure from the oil pump 3. The pressure of the oil which is created by the oil pump 3 can be monitored with the pressure gauge 26.
• the air motor 2 has a cylinder element 4 in which an air piston 5 is arranged movable in a reciprocating manner.
• the air piston 5 is connected with an oil piston 6 of the oil pump 3.
• the cylinder element 4 and the air piston 5 at one hand and the oil piston 6 at the other hand are arranged coaxially around a centre axis a of the cylinder element 4.
• a pressure control valve 1 1 is arranged in the air motor 2.
• the pressure control valve 1 1 allows an air flow from one of the cylinder chambers 7, 8 to the other when the pressure difference between the two cylinder chambers 7, 8 exceeds a predetermined value.
• a pressure control valve 1 1 being a check valve is mounted into the air piston 5. Details of the pressure control valve 1 1 are apparent from Fig. 4 and Fig. 5.
• the pressure control valve 1 1 has a housing 12 which has a substantial hollow cylindrical shape, i.e. a tube shape.
• the housing 12 has a centre axis b, which is parallel to the centre axis a of the cylinder element 4 but is radially spaced from it.
• a conical seat 14 is machined.
• a valve element 13, being a ball in the shown embodiment, is biased against the seat 14 by a helical spring 15.
• the pressure control valve 1 1 is shown in an opened state, i.e. a gap between the ball 13 and the seat 14 allows an air flow between the cylinder chambers 7, 8.
• means 16, 17 are arranged for adjusting this pressure difference.
• the means comprise a screw element 16 which is screwed into a thread 17 which is machined in one of the axial end regions of the housing, as apparent from Fig. 5.
• the screw element 16 has a hexagon socket 18 in its right face side. The screw element 16 can thus be moved axially relative to the housing.
• the screw element 16 is moved to the left side in Fig. 5 the helical spring 15 is elastically biased with a higher force.
• the pressure difference between the cylinder chambers 7, 8 must be higher before the pressure control valves 1 1 opens.
• the pressure control valve(s) can be arranged in a different way, while still being in the air motor, and while still letting air pass between the first and second chambers above a maximum pressure difference.
• the shown arrangement in the air piston is however presently preferred.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Reciprocating Pumps (AREA)

Priority Applications (5)

Applications Claiming Priority (1)

Publications (1)

Family

ID=50071611

Family Applications (1)

Country Status (5)

Cited By (2)

Families Citing this family (3)

Citations (3)

Family Cites Families (33)

• 2014
  • 2014-02-07 BR BR112016016502-0A patent/BR112016016502B1/pt active IP Right Grant
  • 2014-02-07 DE DE112014006342.8T patent/DE112014006342T5/de active Pending
  • 2014-02-07 CN CN201480074237.2A patent/CN105934582B/zh active Active
  • 2014-02-07 US US15/112,591 patent/US20160341192A1/en not_active Abandoned
  • 2014-02-07 WO PCT/EP2014/052456 patent/WO2015117666A1/en active Application Filing

Patent Citations (3)

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