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
  • F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
  • F04C29/0042—Driving elements, brakes, couplings, transmissions specially adapted for pumps
  • F04C29/0085—Prime movers
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K5/00—Casings; Enclosures; Supports
  • H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
  • H02K5/08—Insulating casings
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K5/00—Casings; Enclosures; Supports
  • H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
  • H02K5/12—Casings or enclosures characterised by the shape, form or construction thereof specially adapted for operating in liquid or gas
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
  • F05C2225/00—Synthetic polymers, e.g. plastics; Rubber
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
  • F05C2251/00—Material properties
  • F05C2251/04—Thermal properties
  • F05C2251/048—Heat transfer

Definitions

• the invention relates to a vacuum pump with an electric drive motor having a motor rotor and a motor stator.
• Another design solution is to isolate the motor rotor isolated by a split pot in vacuum, while the motor stator outside the gap pot is arranged outside the vacuum or in the atmosphere.
• the containment shell entails inevitable electro-technical disadvantages, namely a deteriorated efficiency and a degraded power factor, and as a result a relatively large drive motor and high heat losses.
• the object of the invention is in contrast to provide a vacuum pump with an electric drive motor with high efficiency and without shaft seal.
• the motor stator is arranged within a vacuum-tight motor housing within the vacuum. Furthermore, the motor stator is cast in a potting compound body from a suitable potting compound. In contrast to a split pot motor not only the motor rotor, but also the motor stator is arranged within the vacuum space according to the invention, that is not hermetically separated from vacuum-carrying parts of the vacuum pump. If necessary, the motor housing has only one opening through which control and supply lines for the drive motor are led outwards to the outside of the motor housing.
• the vacuum-tight sealing of non-moving parts, as they are control and supply lines, is much easier than the sealing of a moving part against a stationary part, for example by a shaft seal. With the arrangement of both the motor rotor and the motor stator in vacuum, a shaft seal is eliminated and a leak-free and reliable permanent sealing of the vacuum space of the vacuum pump is realized.
• the gap between the motor stator and the motor rotor can be reduced to a constructively required minimum.
• the efficiency or the power factor of the drive motor is significantly improved.
• smaller electric drive motors can be used to generate the same shaft power. Because of the lower electromagnetic losses and the heat generation is significantly reduced, whereby further structural simplifications are made possible.
• the motor stator is cast in a potting compound, wherein in any case the motor stator winding or windings are cast into the potting compound body. This is necessary because otherwise between the turns of the stator winding or windings in a vacuum voltage flashovers would occur.
• the potting compound is a good electrical insulator compared to the potting compound-free vacuum. Furthermore, the potting compound ensures heat removal due to its thermal conductivity.
• the laminated core of the motor stator can, but need not, be completely or partially molded into the potting compound body.
• the motor stator has a winding or a plurality of windings and a laminated core, wherein both the winding or windings and the laminated core are cast into the potting compound body.
• the potting material is an epoxy resin. Epoxy resin is a good electrical insulator, has high thermal conductivity, and is relatively easy to cast at relatively low temperatures.
• the potting compound contains fillers which have a better thermal conductivity than the potting compound material. As a result, the heat conductivity of the potting compound is increased, so that larger amounts of heat can be dissipated.
• a cable feedthrough is provided by a motor housing opening and protrudes the potting compound axially with an approach into the opening, ie along the axial of the drive motor and the pump rotor.
• the approach is formed integrally with the potting compound of the potting compound body.
• the lines for supplying the drive motor and possibly other lines are arranged axially.
• the vacuum-tight seal of the implementation may be formed between the Vergussmasse- approach and the opening edge by suitable sealing means, for example by a rubber-elastic O-ring.
• the actual vacuum-tight seal can also be effected by a separate opening cover, which in turn is sealed with respect to the edge of the motor housing opening with a rubber-elastic O-ring, and having corresponding contact pins for the implementation.
• the drive motor is a brushless DC or asynchronous motor.
• Such motors are particularly suitable as a drive motor for vacuum pumps because of their brushlessness.
• the vacuum pump is a Roots vacuum pump.
• Roots vacuum pumps is by design, the drive motor or parts of the drive motor usually on the vacuum side arranged so that the requirement of a vacuum-tight sealing of the drive motor results in particular in Roots vacuum pumps.
• Figure 1 shows a Roots vacuum pump in longitudinal section
• FIG. 2 enlarges a line bushing of the vacuum pump of FIG. 1.
• Roots vacuum pump 10 is shown in longitudinal section, the u.a. an electric drive motor 12, a first pump rotor 14 and two bearings designed as a roller bearing 16,18.
• One of the two rolling bearings 18 is arranged axially between the pump rotor 14 and the drive motor 12.
• a second pump rotor, with which the first pump rotor cooperates, is not shown.
• the housing 19 of the vacuum pump 10 essentially consists of a gear housing 20, a pump housing 22 and a motor housing 24.
• the vacuum-tight metal motor housing 24 of the drive motor 12 is arranged, which is formed by a motor stator 28 and a motor rotor 30 sitting on a wave 32.
• the drive motor 12 is a brushless DC motor, but may also be designed as a brushless asynchronous motor. In any case, the drive motor 12 is brushless.
• the entire vacuum pump housing 19 is formed vacuum-tight.
• the motor housing 24 is formed vacuum-tight. Within the motor housing 24 therefore always approximately the same gas pressure is formed, as at the adjacent end of the pump rotor 14. This is, inter alia required to prevent gas flow from the motor housing 24 in the direction of the pump rotor 14, could pass through the undesirably lubricant from the motor housing 24 in the pump area.
• a sealing arrangement 34 is provided, which is essentially a lubricant seal and prevents passage of lubricant from the motor housing 24 into the pump housing 22.
• the motor stator 28 has a plurality of windings 42 on a laminated core 40.
• the motor stator 28 formed by the laminated core 40 and the windings 42 is completely cast in a potting compound body 43 of potting compound 44.
• the potting compound body 43 forms in this way a closed ring.
• the potting compound 44 is made of epoxy resin and contains fillers which have a better thermal conductivity than the Vergussmassen- material. Particularly suitable as fillers are electromagnetically neutral materials, such as sand and the like.
• a line bushing 46 is shown enlarged by an axial motor housing opening 48.
• a potting compound 60 protrudes axially into the opening 48 over part of the opening length.
• the opening 48 and lug 60 are arranged axially, i. parallel to the drive motor axial.
• the actual vacuum-tight sealing takes place through a cover 62, which is sealed with an O-ring 64 relative to the housing 24.
• the cover 62 one or more contact pins 50 'are cast, the electrical leads 50 contact the outside.
• the electrical leads 50 are used to energize the motor stator 28, possibly serve to energize a magnetic bearing and are used to transmit sensor data.

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

Applications Claiming Priority (2)

Publications (1)

Family

ID=38515781

Family Applications (1)

Country Status (3)

Cited By (2)

Families Citing this family (3)

Citations (4)

Family Cites Families (1)

• 2006
  • 2006-07-14 DE DE200610032765 patent/DE102006032765A1/de not_active Withdrawn
• 2007
  • 2007-07-09 TW TW96124856A patent/TW200819629A/zh unknown
  • 2007-07-09 WO PCT/EP2007/056992 patent/WO2008006809A1/de active Application Filing

Patent Citations (4)

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