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
  • F04B7/00—Piston machines or pumps characterised by having positively-driven valving
  • F04B7/0042—Piston machines or pumps characterised by having positively-driven valving with specific kinematics of the distribution member
  • F04B7/0053—Piston machines or pumps characterised by having positively-driven valving with specific kinematics of the distribution member for reciprocating distribution members

Definitions

• the invention relates to a piston pump with a pump housing and a piston, which limits the working space in a pump cylinder by stroke movements, according to the preamble of claim 1.
• the invention preferably relates to a piston pump for conveying or metering liquid media of various types.
• Piston pumps are generally known in a large number of design variants and serve the most varied of conveying or drive tasks (hydraulics).
• the piston pumps known from process engineering only use one end face of the piston for filling and ejecting the pump medium. This results in the undesired pulsation, which is sinusoidal in the case of a crank drive for the sowing or working stroke, with its negative consequences on the shark pressure level NPSH (Net Positive Inlet Head) or the cavitation.
• NPSH Net Positive Inlet Head
• the valve work on these piston pumps is purely automatic, i.e. the suction vacuum or the pressure of the working stroke opens or closes the check valves.
• the kinematics of the valve work (closing delay angle) are only well under control with pure and clean fluids.
• the invention has for its object to make a piston pump of the type described available, the pulsation with only one piston and works efficiently, has positively controlled suction and pressure valves and has a simple, compact structure.
• the piston with its upper and lower piston end faces delimits the working space in the pump cylinder on two sides and in that the working space is connected via a positively controlled inlet valve and a positively controlled outlet valve, which alternately each when the two end positions of the Open or close the piston for filling or ejecting the working volume.
• a positively controlled inlet valve and a positively controlled outlet valve which alternately each when the two end positions of the Open or close the piston for filling or ejecting the working volume.
• valve rods pierce the valves, the pump housing and the valve cover on one side and are connected at the end by means of a rocker, one end of which is extended and the valve rods are movably connected to the feed lever via a bracket ,
• a cylinder with a loaded piston, the piston rod of which penetrates the cylinder is connected to the pump cover via a drive lever, and that this drive lever movably receives a drive rod in the area between its finite pivot points, which at the other end also the conveyor lever is movably connected.
• the drive is preferably carried out with a pneumatic cylinder which is equipped with an automatic switchover device in the two end positions of the piston.
• the piston pump can also be used in Ex zones.
• the pump housing has three bores lying in one axis, one bore forming the working space and the other two bores, each with a transverse bore, forming the inlet and outlet channels, such that in pump operation the inlet valves or outlet valves alternately shut off or open the bores on one side to the stroke movement of the piston.
• the drive lever comes to rest in the center of the longitudinal axis of the pump, which makes the structure simple and space-saving.
• the forced actuation of the valves is designed according to the invention in such a way that the valve rods on the side facing the pump cover finally have a thread with a nut, with the screwing or unscrewing of which the distances of the mirror-image pairs of valves for adjusting the play are reduced or enlarged.
• the valve seats can be flat, conical or conical be trained. The smallest stroke with the required valve opening cross-section is achieved with flat seat valves.
• the valves can be designed with an elastic coating to ensure a secure seal with particle-laden fluids and / or to reduce the accuracy of the fits.
• the construction of the piston pump enables two or a larger number of piston pumps to be operated synchronously by coupling their drive levers to a common piston rod.
• the pumps to be coupled are preferably arranged vertically one above the other in such a way that the drive rods can be coupled directly to the cylinder underneath, as a result of which all pumps have a common drive.
• two or more pumps can also be arranged side by side and operated synchronously via a common connection between their piston rods.
• a pneumatic cylinder with a flip-flop circuit is preferably proposed as the drive.
• any type of liner drive or crank drive can be connected. With crank drives, however, the flow rate becomes sinusoidal with a negative impact on the shark head NPSH.
• FIG. 1 shows the longitudinal section through the piston pump
• FIG. 2 shows the section AA through the piston pump
• Fig. 3 shows the elevation of two coupled piston pumps.
• 1 shows a pump housing 1, 2, 3 with a pump cylinder 5, in which a pump piston 4 with a piston rod 7, which is sealed with an O-ring 6, is guided.
• the piston rod 7 is sealed by an O-ring 6 and a packing 9 with its end facing away from the pump piston 4, the pump housing 3 and the valve cover 8 and is finally connected via a rocker 19, one end of which is extended and the valve rods via a tab 22 11, 15 movably connects to the conveyor lever 25.
• the Conveyor lever 25 is rotatably connected to sliding bushes 23, 26, 27 via a drive rod 28 and connected to the drive lever 31.
• the drive lever 31 is locked in the center, so that the feed lever 25 can be changed with a removable bolt 32 in its point of application.
• the stroke of the pump piston 4 can thus be increased or decreased.
• the drive lever 31 is connected at one end to the pump cover 2 and at its other end to the piston rod 35 in an articulated manner with bolts 33, 34.
• the piston rod 35 leads from a pneumatic cylinder 36, which is controlled in such a way that it moves automatically back and forth (flip-flop circuit). This is preferably done via two magnetic switches and two pneumatic valves for both piston end positions.
• the valve cover 8 is spaced from the base plate 29 with four spacer bars 30.
• the rocker 19 is mounted in the center of the two valve rods 11, 15 on the elevation of the valve cover 8 with a slide bush 21.
• the rocker 19 is somewhat extended and pivotally connected to a bracket 22 via slide bushes 23, 24.
• This extension of the rocker 19, ie the distance between the force exerted by the tab 22 and the pivot point 21 of the rocker 19, is to be selected such that the force required to actuate the valve rods 11, 15 via the pivot points 18, 20 is significantly less than the force required for the movement of the pump piston. Otherwise, the conveyor lever 25 would only rotate at the pivot point 23 without moving the valve rods 11, 15.
• 2 shows the section AA through the piston pump in the middle of the inlet valves 14, 16. In particular, this section shows the inlet channel c, which is open or closed at the top or bottom, depending on the position of the two valves 14, 16 arranged in mirror image.
• FIG. 3 shows the elevation of two piston pumps according to FIG. 1 coupled one above the other with a common pneumatic cylinder 36 as the drive.
• the piston rod 35 of this pneumatic cylinder 36 drives an extension rod 38 via a rotatable pin connection 37, which in turn drives the drive lever 40 of the second piston pump via a rotatable pin connection 39.
• the drive lever 40 here has a recess between its pivot points 39, 45, which contains a spindle with a spindle nut 43, to which the drive rod 44 is fixed in an articulated manner.
• By turning the handwheel 42 runs the spindle nut 43 and with it the drive rod 44 in the direction of the piston pump or in the direction of the handwheel 42.
• the stroke of the piston of the coupled second pump changes, as a result of which a delivery quantity changed to the first pump can be set with the same bore in the delivery cylinder.

Landscapes

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

Applications Claiming Priority (2)

Publications (1)

Family

ID=33557709

Family Applications (1)

Country Status (6)

Families Citing this family (4)

Family Cites Families (12)

• 2004
  • 2004-06-01 US US10/561,978 patent/US20060159574A1/en not_active Abandoned
  • 2004-06-01 EP EP04735548A patent/EP1680597A1/de not_active Withdrawn
  • 2004-06-01 JP JP2006517924A patent/JP2007506895A/ja not_active Withdrawn
  • 2004-06-01 WO PCT/CH2004/000327 patent/WO2005003559A1/de not_active Application Discontinuation
  • 2004-06-01 CN CNB2004800183168A patent/CN100406723C/zh not_active Expired - Fee Related
  • 2004-06-01 EA EA200600151A patent/EA007695B1/ru not_active IP Right Cessation

Non-Patent Citations (1)

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