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
  • F04B35/00—Piston pumps specially adapted for elastic fluids and characterised by the driving means to their working members, or by combination with, or adaptation to, specific driving engines or motors, not otherwise provided for
  • F04B35/04—Piston pumps specially adapted for elastic fluids and characterised by the driving means to their working members, or by combination with, or adaptation to, specific driving engines or motors, not otherwise provided for the means being electric
  • F04B35/045—Piston pumps specially adapted for elastic fluids and characterised by the driving means to their working members, or by combination with, or adaptation to, specific driving engines or motors, not otherwise provided for the means being electric using solenoids
• • 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
  • F04B2201/00—Pump parameters
  • F04B2201/02—Piston parameters
  • F04B2201/0201—Position of the piston
• • 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
  • F04B2203/04—Motor parameters of linear electric motors
  • F04B2203/0401—Current

Definitions

• the invention relates to an oscillating piston drive for a vacuum pump with a piston, which has two piston sections and a central area equipped with a drive magnet, with cylinder sections assigned to the piston sections, with an annular recess arranged between the cylinder sections and located at the level of a central yoke. which forms the movement space of the / drive magnet, and with an electromagnetic drive surrounding the piston with yoke components and coils located to the side of the central yoke.
• the invention also relates to operating methods for the drive.
• the aim of the developers and designers concerned here is to improve the pumping power or effect (suction capacity, compression) of a vacuum pump, if possible with a constant, preferably even smaller, construction volume and / or reduced energy consumption.
• This goal is synonymous with the fact that measures that become necessary in the course of the further development or design of a pump of the type concerned must not be associated with impairments of the pump performance.
• the present invention is based on the object of proposing a vibrating piston drive for a vacuum pump in which impairments to the pump performance are reduced.
• a vibrating piston drive of the type mentioned at the outset is known from WO 00/63 556, FIG. 8. It has a number of components (coils, pole components, cylinders, etc.) that adjoin the range of motion of the drive magnet and influence the pump power. There is a risk that the movement space is connected to the external environment via gaps between the components or current feedthroughs. Air penetrates into the movement space via such gaps and increases the negative pressure which forms in the movement space during operation of the pump. Measures to seal this gap (e.g. layers of adhesive or sealant) can impair the efficiency of the electromagnetic drive since they increase the distance between the individual components.
• a canned tube limit the outer recess peripherally.
• a pipe section that peripherally delimits the movement space of the drive magnet reduces the number of gaps opening into the movement space, so that the risk of undesirable pressure increases in this space is largely eliminated.
• the wall thickness the tube can be very small, e.g. B. less than 1 mm, so that impairments in the efficiency of the electromagnetic drive are negligible.
• the can are those that have good sliding properties, such as plastic, aluminum, stainless steel or the like. the like (Not - or only weakly ferromagnetic.
• the canned tube can be made of a more ferro-magnetic material and its wall thickness can be selected at least in the area of sections outside the central yoke so that the drive magnet magnetizes the respective section to saturation when it is in the areas This design of the can has the effect that it becomes part of the drive. The saturated section is practically no longer available for the magnetic field of the associated coil.
• the input signal for the phase control can z. B.
• the stroke frequency of the piston results in all cases from the frequency of the alternating current supplied.
• FIG. 1 shows a section through a piston vacuum pump with a drive according to the invention
• Figure 2 is a partial section at the level of the can
• Figure 3 is a schematic representation of a pump according to the invention with means for powering the drive coils.
• the figures each show a piston vacuum pump 1 with a piston 2: This has piston sections 3 and 4, the free end faces of which are each assigned a cylindrical pump chamber 5 or 6.
• the piston 2 and the scoops 5, 6 are located in a housing 7 with cylinder sections 8, 9 for the piston sections 3, -4.
• the materials of the cylinder sliding surfaces and the associated piston surfaces are selected in a manner known per se so that the pump can be operated dry, ie without lubricants.
• a linear drive is assigned to the piston 2. It comprises a permanent magnet ring 11 on the piston side, which surrounds the piston 2 in its central region. The permanent magnet ring 11 moves in an annular space surrounding the piston 2 (recess 12). On the stator side, the permanent magnet 12 on the piston side is assigned further permanent magnet rings 13, 14, which each form the axial delimitation of the annular recess 12. The cylinder sections 8, 9 also end at the level of these permanent magnet rings.
• the stator-side components of the linear drive are also the coils 15 and 16. They are partially surrounded by yoke components 17, 18 and, together with these yoke components, surround the cylinder sections 8 and 9, respectively. Between the coils 15, 16 and the yoke components 17, 18 there is a annular center yoke 19, the inner surface of which faces the annular space 12. The coils 15, 16 are energized such that the magnetic fields generated by them and guided by the yoke components 17 to 19 interact with the magnetic fields of the permanent magnet rings 11, 13 and 14 in the desired manner.
• the piston 2 should swing about its central position so that the piston faces can perform their pumping function during this movement.
• the compression spaces 5, 6 are each equipped with an inlet valve and an outlet valve (only shown in FIG. 1).
• Each of the inlet valves has an inlet opening 21 or 22, which is located between an outer inlet chamber 23 or 24 and the respective scooping chamber 5 or 6.
• the inlet openings 21, 22 are designed as slot-shaped, radially extending openings in the respective cylinder wall 8 or 9.
• the piston sections 3 and 4 release the respective inlet opening when they assume one of their two dead center positions (each position retracted into the cylinder section).
• the outlet valves 26, 27 are each arranged on the end face. Their closure elements 28, 29 separate the respective compression space 5 or 6 from an outlet space 31, 32 until they are opened by the respective piston section 3 or 4 - at high pressure differences also from the pressure generated.
• the closure elements 28, 29 are designed as flexible plates which extend over the entire cross section of the cylinder sections 3, 4 and which are fastened centrally to the housing 7 and are actuated peripherally by the pressure generated or by the end faces of the piston 2.
• the piston faces are concave.
• the end faces of the components which form the cylinder sections 8, 9 have the function of the valve seats.
• the canned tube is designated 34. It surrounds the annular space or the recess 12 and extends into the area of the stator permanent magnet rings 13, 14.
• FIG. 2 shows that the can 34 has two lateral sections 35, 36 with a relatively small wall thickness and a central section with a larger wall thickness.
• the wall thickness of the lateral sections 35, 36 is less than 1 mm, preferably 0.7 mm. With these wall thicknesses, the desired saturation occurs through the drive magnet 11 when it is in the vicinity of the sections 35, 36.
• the larger wall thickness in the central area is only required if the can has to have sufficient mechanical strength.
• FIG. 3 shows the vacuum pump 1 with its linear drive only very schematically.
• an embodiment for the power supply of the coils 15, 16 according to the invention is shown.
• alternating current preferably the mains current at 50 Hz
• the actuator 42 only allows the positive, the actuator 43 only the negative half-wave of the alternating current.
• the current / time diagrams 44, 45, 46 shown in the area of the power supply and between the actuators 42, 43 and the coils 15, 16 show the power supply of the coils according to the invention.
• the coils 15, 16 are expediently switched into the respective supply circuit in such a way that they exert repulsive forces on the drive magnet 11. As a result, the piston swings around its central position at the frequency of the alternating current supplied.
• the permanent magnets 13, 14 are expediently magnetized in such a way that they exert a repulsive effect on the drive magnets. This solution has the advantage that mechanical springs that move the piston back to its central position can be eliminated.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Reciprocating, Oscillating Or Vibrating Motors (AREA)
• Compressors, Vaccum Pumps And Other Relevant Systems (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=7701745

Family Applications (1)

Country Status (6)

Families Citing this family (11)

Family Cites Families (10)

• 2001
  • 2001-10-06 DE DE10149506A patent/DE10149506A1/de not_active Withdrawn
• 2002
  • 2002-09-28 WO PCT/EP2002/010921 patent/WO2003031818A1/de not_active Application Discontinuation
  • 2002-09-28 CN CN02819814.XA patent/CN1564911A/zh active Pending
  • 2002-09-28 EP EP02777257A patent/EP1432912A1/de not_active Withdrawn
  • 2002-09-28 US US10/491,770 patent/US20050053490A1/en not_active Abandoned
  • 2002-09-28 JP JP2003534768A patent/JP2005504928A/ja active Pending

Non-Patent Citations (1)

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