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
  • F04C18/00—Rotary-piston pumps specially adapted for elastic fluids
  • F04C18/30—Rotary-piston pumps specially adapted for elastic fluids having the characteristics covered by two or more of groups F04C18/02, F04C18/08, F04C18/22, F04C18/24, F04C18/48, or having the characteristics covered by one of these groups together with some other type of movement between co-operating members
  • F04C18/34—Rotary-piston pumps specially adapted for elastic fluids having the characteristics covered by two or more of groups F04C18/02, F04C18/08, F04C18/22, F04C18/24, F04C18/48, or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in group F04C18/08 or F04C18/22 and relative reciprocation between the co-operating members
  • F04C18/344—Rotary-piston pumps specially adapted for elastic fluids having the characteristics covered by two or more of groups F04C18/02, F04C18/08, F04C18/22, F04C18/24, F04C18/48, or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in group F04C18/08 or F04C18/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the inner member
  • F04C18/3441—Rotary-piston pumps specially adapted for elastic fluids having the characteristics covered by two or more of groups F04C18/02, F04C18/08, F04C18/22, F04C18/24, F04C18/48, or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in group F04C18/08 or F04C18/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the inner member the inner and outer member being in contact along one line or continuous surface substantially parallel to the axis of rotation
• • 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
  • F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
  • F04C29/12—Arrangements for admission or discharge of the working fluid, e.g. constructional features of the inlet or outlet
  • F04C29/124—Arrangements for admission or discharge of the working fluid, e.g. constructional features of the inlet or outlet with inlet and outlet valves specially adapted for rotary or oscillating piston pumps
  • F04C29/126—Arrangements for admission or discharge of the working fluid, e.g. constructional features of the inlet or outlet with inlet and outlet valves specially adapted for rotary or oscillating piston pumps of the non-return type
  • F04C29/128—Arrangements for admission or discharge of the working fluid, e.g. constructional features of the inlet or outlet with inlet and outlet valves specially adapted for rotary or oscillating piston pumps of the non-return type of the elastic type, e.g. reed 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
  • F04C2220/00—Application
  • F04C2220/10—Vacuum

Definitions

• the invention relates to a vacuum pump with a cup-shaped housing, a rotor rotatably mounted eccentrically in the housing, a rotatably mounted in the rotor orthogonal to the axis of rotation, which abuts with its wing tips on a working space bounding inner peripheral surface of the housing while the working space in a suction chamber and a Pressure chamber divided, and the suction chamber with an air inlet opening and the pressure chamber are provided with an air outlet opening, wherein the
• Air outlet opening is provided with an outlet valve and the outlet valve as a closing member has a cantilevered leaf spring.
• Vacuum pumps with such a structure are known, for example, from DE 10 2004 034 926 B3. They usually have a housing in which a rotor is rotatably mounted, wherein the rotor is located in a working space. Such vacuum pumps are used inter alia in vehicles, where, for example, the motor of the motor vehicle rotates the rotor. These vacuum pumps are lubricated with oil, which also serves to seal the sealing gap between the wing and working space in order to achieve high efficiency.
• an outlet valve is provided, which is designed in the manner of a leaf spring.
• This leaf spring presses on the outside of the air outlet and closes it.
• the leaf spring can be bent over the prevailing pressure in the pressure chamber to the outside. Thereby the compressed air is expelled from the pressure space into the pressure line.
• Such a device is known for example from DE 40 19 854 B4. With this vacuum pump it has been found that with leaf springs closed air outlet openings, which are not completely covered when sweeping the wing, relatively high losses occur.
• the invention is therefore based on the object to provide a vacuum pump, wherein it is ensured that the air compressed in the pressure chamber is completely discharged into the pressure line and is not transferred to the pressure chamber located behind the wing.
• the outlet valve has a leaf spring which does not consist, as in the prior art, of a leaf spring having a constant spring constant. Rather, the leaf spring according to the invention has one starting from the clamping point changing spring constant. This means that the free end of the leaf spring can be lifted off the outlet opening with a relatively small force, whereas for the further lifting of the leaf spring the force required for this increases disproportionately. As a result, the advantage is achieved that only the portion of the leaf spring is lifted from the outlet opening, which is required for the outlet of the compressed fluid. Too large an opening of the exhaust valve is effectively prevented by the clamping force of the leaf spring towards growing force required to lift the leaf spring.
• a change in the spring characteristic or the spring constant can take place, for example, by virtue of the fact that the leaf spring has changing spring properties over its length, which can be achieved, for example, by targeted hardening of different regions of the leaf spring.
• the leaf spring is designed as a rectangular spring, triangular spring or trapezoidal spring. Already by the shape of the spring can be specifically acted on the stiffness. It should only be noted that the outlet opening is completely covered by the leaf spring.
• a further variant according to the invention provides that the leaf spring is a simple or layered leaf spring.
• a layered leaf spring two or more sheets are stacked on top of each other, either of equal length or graduated lengths. The leaves are attached to the clamping point and extend, with different lengths, different distances away from this. As a result, the rigidity of the free end of the leaf spring is selectively increased in the direction of the clamping point.
• the friction between the blades can be used to control the opening of the valve.
• the leaf spring has a constant or a thickness which decreases starting from the clamping point.
• the thickness of the leaf spring can change continuously, but preferably in stages. The production takes place, for example, by gradual rolling of the individual sheets.
• a variant of the invention provides that in a layered leaf spring, the thickness of the individual sheets is equal or unequal. Especially with uneven thick leaves, the thickness can be greater for shorter leaves.
• the leaf spring made of metal or plastic.
• this can also be composed of a combination of plastic and metal leaves.
• the long leaves are made of plastic, whereas the short leaves are made of metal.
• a further variant of the invention provides that in a layered leaf spring, the leaves are blasted with decreasing length. This means that the leaves are curved in the direction of the longer leaf. Also by this measure, the rigidity of the leaf spring is increased in the direction of the clamping point.
• the leaf spring in the sealing plane is partially circular or kidney-shaped bent. This is especially the case when the outlet opening is located in the bottom of the housing. If the outlet opening is located in the peripheral wall of the housing, then the above-mentioned measures are respectively adapted with regard to the curvature of the peripheral wall. This means that the leaf spring from the outset has the curvature of the peripheral wall or the outlet opening.
• Figure 1 is a vacuum pump with removed housing cover
• FIG. 2 shows the rear side of the vacuum pump, the drive of the rotor and the outlet valve
• Figure 3 is an enlarged view of the exhaust valve prior to assembly
• FIG. 4 shows the outlet valve according to FIG. 3 in the assembled position.
• FIG. 1 In the figure 1 is denoted by the reference numeral 10, a vacuum pump, in which the housing 12 is shown without housing cover. This housing cover can be seen beginning in Figure 2.
• the housing 12 has a suction port 14, which opens into an interior 16.
• a generally designated 18 rotor In this interior 16 is a generally designated 18 rotor, in which a wing 20 is mounted orthogonal to the axis of rotation 21 slidably.
• the rotor 18 has a rotor housing 24, with which it bears against an inner circumferential surface 22 of the working space 30.
• the rotor 18 passes through the housing 12, in particular a bottom 26 of the interior 18, via a drive opening and projects out of the housing 12 on the rear side, so that it can be rotated by means of a drive (not shown) on a coupling 28 (FIG.
• the interior 16 is divided by the wing 20 into a suction chamber 32 and a pressure chamber 34.
• the direction of rotation of the rotor 20 is indicated by an arrow 36.
• the in the pressure chamber 34 located and arranged in the bottom 26 of the housing 12 air outlet opening 38 is partially visible. This outlet opening 38 could also be provided in the peripheral surface 22.
• FIG. 2 shows the rear side of the housing 12 of the vacuum pump 10 and shows the outlet valve 40 located behind the air outlet opening 38.
• This outlet valve 40 has a valve stop 42, which limits the deflection of a leaf spring 44 designed as a closing member 46.
• this leaf spring 44 lies directly on the outside of the outlet opening 38 and closes it, as can be seen in FIG. With a screw 48, not only the valve stop 42, but also the leaf spring 44 is secured to the housing 12 at its clamping point 50.
• the leaf spring 44 consists of a total of four blades 52 to 58, each of which has a fastening opening 60 for the passage of the screw 48 at its clamping point 50 and which lie above one another starting from this fastening opening 60 and in the direction of the free end 62 of the sheet 52 extend.
• the outlet opening 38 is located in the bottom 26 of the working space 30, the outlet opening 38 and thus also the leaf spring 44 have a part-circular or kidney-shaped shape and are curved around the rotor 18.
• the blade 52 is immediately adjacent the discharge opening 38 and rests on this and closes it.
• the blade 52 is engaged behind by the blade 54, which bears against the opposite side. However, the blade 54 has a shorter length, so that the blade 52 projects beyond the blade 54 over a certain distance.
• the leaves 56 and 58 are constructed accordingly and engage behind the sheet 54 and the sheet 56th
• the free end 32 of the blade 52 is rounded and the blades 54, 56 and 58, although partially curved, but with respect to the curvature of its longitudinal axis has a rectangular shape. It is also conceivable that the leaves are directed 52 to 58 triangular with the tip to the free end 62 or trapezoidal. Further, the leaves 54 to 58 may be blasted, that is, bent or curved in the direction of the respective underlying leaves 52 to 56. In addition, there is the possibility that the respective projecting ends of the leaves 52 to 56 have a decreasing towards the free end 62 thickness.
• the material of the For example, sheet 52 may be plastic, whereas the materials of the other sheets 54-58 may be a metal. Different spring rates or stiffnesses of the individual blades 52 to 58 are also possible.
• FIG. 4 shows the leaf spring 44 in the assembled position, in which the leaves 52 to 58 lie one above the other. It is also conceivable to produce a one-piece leaf spring 44 with a stepped thickness. The thickness can also decrease continuously from the clamping point 50 in the direction of the free end 62.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Applications Or Details Of Rotary Compressors (AREA)
• Rotary Pumps (AREA)

Applications Claiming Priority (2)

Publications (2)

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ID=39204763

Family Applications (1)

Country Status (4)

Families Citing this family (8)

Family Cites Families (7)

• 2007
  • 2007-04-12 DE DE102007018247A patent/DE102007018247A1/de not_active Withdrawn
• 2008
  • 2008-01-09 EP EP08701036A patent/EP2122176B1/fr active Active
  • 2008-01-09 WO PCT/EP2008/000103 patent/WO2008125155A1/fr active Search and Examination
  • 2008-01-09 AT AT08701036T patent/ATE524655T1/de active

Non-Patent Citations (1)

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