DE8908757U1 - Rotary vane vacuum pump - Google Patents

Description

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PATENT ATTORNEYS;:*:::

Professional representatives before the European Patent Office

DiPL-PHYS. BUSE -DiPL-PHYS. MENTZEL · di PL-ing. LUDEWIG Untardfrnan 114 · PO Box 200210 · 5800 Wuppertal 2 · Telephone (0202) 557022/23/24 - Telex 8581608 wpet ■ Taltfax 0202/571501

11 c 5600 Wuppertal 2, the

Key word: "Housing pivoting II"

Gebr. Becker GmbH Ä Co., Hölker Feld 29-31,
56oo Wuppertal 2

Rotary vane vacuum pump

The invention relates to a rotary vane vacuum pump with at least one pump housing having an inner cylinder, which is framed in the axial direction by partition walls, with a rotary piston arranged in the inner cylinder with axially extending vanes guided radially in slots, which is provided in a rotationally fixed manner on a shaft that can be driven by a motor and which is located eccentrically in the inner cylinder, with the motor being provided in a housing that accommodates the pump housing in a recess in a housing-like extension. In pumps of this type, high vacuums require tight manufacturing tolerances and/or complex adjustment work during assembly, especially in multi-stage vacuum pumps. For this, the radial play must be set in each case and the existing axial play must be determined by precisely positioning and fixing the piston. This results in a time-consuming

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assembly and, due to the tight manufacturing tolerances, cost-effective production. Furthermore, disassembly for maintenance purposes is relatively difficult, since the axial and radial clearances must then be precisely fixed and adjusted again =

The object of the invention is first of all to design a rotary vane vacuum pump of the type mentioned at the beginning in such a way that it is easy to repair and maintain, allows simple production, is easy to adjust, but nevertheless high vacuums can be generated with the vacuum pump without excessive manufacturing tolerances. Finally, simple and cost-effective production should also be guaranteed. Furthermore, a simple structure should be provided to adapt to different operating requirements with regard to the materials of the gas-carrying pump parts.

This is achieved according to the invention by making the recess of the housing-like extension larger in cross-section than the outside of the pump housing, so that the pump housing can be inserted into the recess with some play, and by making the pump housing radially adjustable relative to the shaft of the rotary piston after all parts of the vacuum pump have been assembled, the displacement direction essentially running in the direction of the eccentricity between the rotary piston and the inner cylinder of the pump housing. By inserting with play, relatively large manufacturing tolerances can be taken into account when manufacturing the individual pump parts. The swiveling ability of the pump housing now allows for precise adjustment of the minimum distance between the rotary piston and the pump housing without the individual parts seizing. Relatively high vacuums can therefore be generated. Finally, the adjustment option allows

which is only to be carried out after all parts of the vacuum pumps have been assembled, a hardening and assembly-friendly design.

In a special embodiment of the invention, the partition walls and the pump housing are provided with a hole in the motor that runs in the direction of the shaft, into which a pin can be inserted for pre-assembling the partition walls and pump housing. The hole is designed so large that the play between the pin and the hole is greater than or equal to the play between the recess and the pump housing. This measure allows the partition walls and pump housing to be aligned with one another in a simple manner, while still retaining the ability to adjust the pump housing for fine adjustment. The play between the pin and the hole also ensures that the full adjustment option, which is provided by the play between the recess of the housing-like extension and the pump housing, is retained and can be utilized.

It is particularly advantageous if the pump housing is pivoted around a pin. Such a design

allows an adjustment to be carried out in a simple manner, it is advantageous if the pump housing is protected by a

the housing-like extension is mounted and can be guided essentially radially to the shaft. This measure allows the movement of the pump housing for adjustment to be carried out easily and quickly in order to arrange the pump housing at the desired distance from the rotary piston, either the weight of the pump housing presses it against the filling screw in order to have a secure connection or the pump housing is held in place by a

_ spring-loaded counter bearing on the free end of the fixing screw is held in place by a spring. It is therefore always safe

ensures that when the pump housing moves, it remains in contact with the filling screw.

In a special embodiment of the invention, the vacuum pump is constructed in several stages and each pump stage has its own pump housing, with an intermediate disk between each pump housing. This measure allows the pump housing to be adjusted safely while being easy to assemble. In addition, such an arrangement is also easy to maintain, since the parts lying on top of one another can be easily separated from one another.

What is particularly advantageous about this design is that each pump housing can be moved separately from one another in the housing-like extension radially to the shaft using a fixing screw. The optimal operating point can therefore be set separately for each stage.

It is advisable for the individual pump housings to be designed identically and for two adjacent pump housings to be mirror-symmetrical to one another with respect to a plane passing through the motor shaft, whereby the intermediate disk preferably has holes that directly connect the outlet of the pump chamber of the first stage with the inlet of the second pump stage. This design results in a simple arrangement, in particular the bridging lines from one stage to another are designed to be relatively short. Furthermore, production is relatively simple, since the same components can be used for each stage. By using the same components, such a vacuum pump is also easy to maintain.

It is particularly advantageous if the intermediate discs, pump housing and rotary

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alloy covers are held together in a clamped manner in the axial direction of the motor shaft, as this measure makes assembly and maintenance relatively easy, as the fastening and fixing of the parts is completed by arranging the individual parts in the recess and then clamping them using the cover. It is recommended that the cover holds the intermediate disks, pump housing and rotary piston together in a spring-loaded axial manner using compression springs, as this means that any thermal expansion caused by displacement of the cover can be easily absorbed during operation without the thermal expansion leading to clamping in the cover or in the vacuum pump. In addition, even if the pump housing or the pressure rotary piston is not positioned exactly perpendicular to the shaft due to dimensional inaccuracies, secure fastening is possible, as the cover can compensate for any slight inclination of the intermediate disks, pump housing and rotary piston. There is also the further advantage that, for example, after the pump has been run in, any tolerances in the axial direction that arise as a result are compensated for by the spring-loaded cover.

The main advantage of the cover is that only a pre-positioning of the individual pump parts needs to take place, while a further final securing of the position is only carried out later after adjustment by the side cover.

In a special embodiment of the invention, the rotary piston arranged in the pump housing is coupled to the motor shaft via an elastically flexible key. This elastic design makes it easy to drive the rotary piston, while the shape and bearing tolerances

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The elastic key also acts as a noise dampener when the vacuum pump is in operation, as any shocks during operation can be compensated for. Such an elastic key can be made from an elastomer.

In order to make the manufacture of the vacuum pump cost-effective, pump housing pistons, intermediate disks and/or slides can be manufactured as molded parts, whereby the use of the molded parts in the vacuum pump is possible without major post-treatment, since these parts do not need to have tight tolerance limits in their dimensions for the pump described. It is recommended to use a material made of plastic-bonded carbon as the material for pistons, intermediate disks and/or slides. On the one hand, this material allows the molded parts to be manufactured safely, and on the other hand, this material also has the lubricating properties required during operation.

In order to ensure that any condensate can collect at the outlet or inlet of the vacuum pump during pump operation, it is recommended that the intermediate disks, pump housing, rotary piston as a unit and the cover that seals the individual parts together can be rotated in 90-degree increments and secured to the housing-like extension, so that depending on the type of installation, it is ensured that, for example, the inlet is located at the lowest point of the vacuum pump.

To make installation easier, the recess of the housing-like extension has a pre-formed exhaust air ring channel on the front side on the drive side. The exhaust air can be easily and safely discharged through this ring channel in every individual position of the other pump parts.

In addition, a resonance chamber is created to dampen sound, and it is also ensured that any condensate can only collect in the lower area.

It is more advantageous if the bore or the recess in the housing is located on an axis that runs radially through the center of the piston and perpendicular to the radial connection between the top and bottom dead center of the pump. This means that in a multi-stage pump design, the same pistons can be used for the individual stages, which only need to be inserted in the housing in a mirror image, whereby they are pushed onto the pin.

can be.

The invention is shown in several embodiments in the drawings, namely:

Fig. 1 a cross section through a step
a rotary vane vacuum pump,

Fig. 2 a longitudinal section through a two-stage rotary vane vacuum pump with
drive motor,

Fig. 3 in cross view the individual components

another rotary vane vacuum pump.

The drive Io of the rotary vane vacuum pump 11 is only shown schematically. The drive is arranged in a housing 12, it has an electric motor which has a stator 13 fixed in the housing 12 and a

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ner Yelle 14 attached rotor 15« In addition, the motor can be provided with cooling fins 16 on its housing 12.

The shaft 14 is supported several times in the housing 12 or in the extension 18, whereby a bearing 17 is shown in Fig. 2. The motor housing 12 and the extension 18 can be formed as one piece.

The motor housing 12 is equipped with a housing-like extension IS, which is attached to the motor housing 12 by means of a screw fastening. The housing-like extension 13 has a recess 19 in its interior, which

from the side opposite the engine is closed by a cover 2o.

The drive shaft 14 projects, as shown in Fig. 2, into the recess 19.

The two-stage rotary vane vacuum pump 11 is arranged in the recess 19. It consists of a pump housing 21 in which a rotary piston 22 is arranged eccentrically. The size of the eccentricity 46 determines the delivery volume. The pump also has an intermediate disk 2? and a / further pump housing 24, inside which a rotary piston

26 is provided. Finally, a further intermediate disk 25 is provided. As can be seen from Fig. 2, the pump housing 24 is axially limited by the two intermediate disks 23 and 25.

From Fig. 2 it can also be seen that the pump housing 21 and 24 and the intermediate disks 23 and 25 are provided with a bore 27 into which a pin 28 engages. This pin lies with a clearance 29 in the bore 27. The pin itself is in the cover 20 or in one end face

3o of the housing-like extension 18.

The pump housing 21 and 24 has a small outer diameter, so that the housing is arranged with a clearance 31 in the recess 19 of the housing-like extension 18. This clearance is at least 1/1 μm. The pump housing is thus radially movable - depending on the size - in the space between the two disks.

The individual pump parts, such as the pump housing 21, ^rotary piston 22, intermediate disk 23, pump housing 24, intermediate disk 25 and pressure piston Zo are spring-loaded via the cover 20 to the front side 30 of the housing-like extension 18, so that they are axially clamped on the shaft. For spring-loaded mounting, the shaft is equipped with springs 32, which press the cover against the housing 21 via the screws 33 arranged in the housing-like extension 18.

Ib it should also be noted here that the cover 2o has an inlet opening and that the intermediate disks are provided with bores 35 and that finally the front side 3o of the housing-like extension 18 is provided with an annular channel 36.

The air is sucked in via the inlet opening 34, then passes through the pump chamber 37 of the first stage into the holes 35 of the intermediate disk 23 to the pump chamber of the second stage of the vacuum pump and from there via the holes of the intermediate disk 25 to the annular channel and is discharged from there.

To pivot the pump housings 21 and 24, a fixing screw 39 is mounted in the housing-like extension 18. The fixing screw 39 engages with one end

the pump housing 21. When the fixing screw 39 moves inwards, the pump housing 21 is excited against the rotary piston 22, so that the distance between the piston and the housing, as shown in Fig. 1, is reduced, so that vacuums of less than 10 mbar can be generated in the multi-stage pump.

When the fixing screw 39 moves outward, the housing 21 is moved away from the rotary piston 22 via a spring-loaded, adjustable counter bearing 40. This measure now allows the narrow distance between the rotary piston and the pump housing to be precisely adjusted.

It should be noted here that the pump housing is pivoted about the pin 28 during the radial movement caused by the fixing screw 39.

This pivoting movement makes it easy to compensate for any tolerances in the external diameter of the rotary piston or in the diameter of the inner cylinder 41 of the pump housings 21 and 24, so that large vacuums can be generated with such pumps.

It should also be added here that the rotary piston is mounted on the shaft 14 of the drive motor via a key 42 made of an elastic material, such as an elastomer, in a rotationally fixed manner in the radial direction and floating in the axial direction.

As can be seen from Fig. 1, the rotary piston 22 is provided with radial slots 43. Slides 44 are arranged in these slots. Due to the rotary movement of the rotary piston during operation, the slides are pressed against the inner cylinder 41 due to the radial force.

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In the embodiment according to Fig. 3, the individual pump parts are shown in a transverse view. In this embodiment, in contrast to the first embodiment, an intermediate disk 45 is arranged between the cover 20 and the pump housing 21. This intermediate disk is connected to the inlet opening 34 of the cover 20 via holes 35. As can also be seen from Fig. 3, the pump housing 21 is arranged in a mirror image with respect to the pump housing 24, i.e. the same rotary pistons can be used during installation, one housing is rotated by 180 degrees with respect to a plane passing through the axis of the shaft and inserted into the recess 19 of the extension 18 with respect to the other housing.

The vacuum pump is now assembled by inserting the pin 28 into the front side 3o of the housing-like extension. The intermediate disk 2\ is then pushed onto the shaft 14. The pump housing 24 is then pushed onto the pin 28 in the housing-like extension, the rotary piston 26 with the slides is then pushed into the inner cylinder 41 of the pump housing on the shaft 14, the key 42 connecting the piston to the shaft in a rotationally fixed manner. The further intermediate disk 23 is then inserted onto the pin and into the recess 19. The further pump housing 21 and the rotary piston 22 are then inserted into the recesses. Finally, the further intermediate disk 45 is inserted into the recess, then the cover 20 is loosely fastened to the housing-like extension with the screws 33.

As soon as the pump is adjusted and the rotary piston is rotating, the pump housing 21 or 24 can be moved radially against the rotary piston until an optimal distance is achieved between the rotary piston and the inner cylinder of the pump housing.

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ben let. As soon as the optimal distance is reached, the pump has the maximum suction power. The lid is then screwed on tightly.

The second pump housing can also be optimally adjusted using an additional fixing screw (not shown). It should also be mentioned here that in the event of any thermal expansion, the cover 20 can move in the axial direction using the springs 32. In the radial direction, expansion is possible using the two clearances 31 and 29. It should also be added that for optimal adjustment, the two pump housings are adjusted one after the other to generate the vacuum.

It should also be added that if the pin 28 is not fixed in the front side of the housing, a structural unit consisting of pump parts and the cover could also be inserted into the recess. In this case, the pin again provides a rough alignment of the individual pump parts. Once the individual pump housings can be optimally adjusted, the pump parts can be further axially braced by further tightening the screws 33, which are evenly distributed on the front side of the cover.

As already mentioned, the embodiments shown are only examples of implementation of the invention and are not limited to them. Rather, many other modifications and applications are possible. For example, instead of the two-stage version shown, the vacuum pump could also be designed as a three-stage or single-stage version, with the individual stages being constructed in a modular manner. Furthermore, instead of one spring-loaded counter bearing, two spring-loaded counter bearings could be provided, which engage the outer circumference of the pump housing. The pump housing could then be secured via the fixing screw.

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hMure in turn can be moved radially against the counter bearings. 807 ¹ HeBIiCh eei also stated that the holes in the intermediate disks can be arranged radially in such a way that the individual holes run spirally with respect to the outer circumference of the intermediate disk, depending on the pump space inside the vacuum pump. Furthermore, the inventive features can also be transferred analogously to single- or multi-stage compressors, whereby the piston widths can be graduated according to the desired compression ratio (as with the multi-stage vacuum pump). It should also be added that the inventive features can also be used with oil-lubricated and dry-running vacuum pumps or compressors. It should also be stated that the hole in the housing which receives the pin could be designed as a recess in the edge area of the pump housing.

PATENT ATTORNEYS

Authorized representatives before the European

DiPL-PHYS. BUSE -DiPL-PHYS. MENfZEL r biPL-iNei,^UDEWIG Unttrdörnen 114- Portfach 200210 5600 Wuppt'ta! 2 ■ Telefon (0202) 657022/23/24 · Telex 86&THgr;1 606 wpat'· Telefax 0202/571501

11 C

5600 Wuppertal 2, the

Password: "Housing pivot II"

Gebr. Becker GmbH Ä Co., Hölker Feld 29-31, 56oo Wuppertal 2

List of reference symbols:

1o drive 38 Pump room 1 1 Rotary vane vacuum pump 3P Fixing screw 12 Engine housing 4o spring loadeda 13 stator Counter bearing 14 Wave 41 Inner cylinder of 15 rotor 21 ,24 16 Cooling fins 42 adjusting spring 17 camp 43 radial slot 18 housing-like extension in 22.26 19 Recess 44 slider in 43 20 Lid 45 Intermediate disc 21 Pump housing 46 eccentricity 22 Rotary piston 23 Intermediate disc 24 Pump housing 25 Intermediate disc 26 Rotary piston 27 drilling 28 Pen 29 Game 3o Front side 31 Game 32 feathers 33 Screws 54 Inlet opening 35 Drilling 36 Ring channel 37 Pump room

Claims (1)

PATENT ATTORNEYS: ··: Authorized representative at the European Patent Office DiPL-PHYS. BUSE - DiPL-PHYS. MENTZEL · dipl-ing. LUDEWIG Unterdörnen 114- PO Box 200210 · 5600 Wuppertal 2 · Telephone (0202) 557022/23/24 · Telex 8591606 wpat · Fax 0202/571501 5600 Wuppertal 2, the 1C Password: "Housing pivoting II ¹ Gebr. Becker GmbH 4 Co.KG, Hölker Feld 29-31,
^ 56oo Wuppertal 2 Expectations : . Rotary vane vacuum pump with at least one pump housing having an inner cylinder, which is framed in the axial direction by intermediate walls, with a rotary piston arranged in the inner cylinder with axially extending slides guided radially in slots, which is provided in a rotationally fixed manner on a shaft that can be driven by a motor and which is located eccentrically in the inner cylinder, wherein the motor is provided in a housing that accommodates the pump housing in a recess of a housing-like extension. f characterized by #1 ( t Il
* I » * Il e el·· that in cross-section the recess (19) of the housing-like extension (18) is larger than the
Exterior of the pump housing (21,24)» so that the pump gshSase (Si ,24·} with play (51) in the Aassshmtms (19)
can be used and that after assembling all Tnwvsn parts (21 to 26,23,42,44“45) the pump housing (21,
24) regarding the shaft (14) of the Brshlr-nlbeae (22,26)
is radially adjustable, the direction of movement being essentially in the direction of the eccentricity (46) between the piston &ngr; (22,26) and the inner cylinder (41) of the pump housing (21,24). 2. Rotary vane vacuum pump according to claim 1, characterized
characterized in that the intermediate disk (23,25,45) and the pump housing (21,24) are provided with a bore (27) running in the direction of the motor shaft, into which a pin (28) can be inserted for pre-assembly of intermediate walls and pump housing, the bore (27) being designed so large that the clearance (29) between the pin (28) and the bore (27) is greater than or equal to the clearance (31) between the recess (19) and the pump housing / (21,24) iet. 3. Rotary vane vacuum pump according to claim 1 or 2,
characterized in that the pump housing (21,24) is pivotally mounted about a pin (28). 4« Rotary vane vacuum pump according to one of claims 1 to 3» characterized in that the pump housing
(21,24) is movable by means of a fixing screw (59) mounted in the housing-like extension (18). ·· 1 « I I 5· Rotary vane vacuum pump according to one of claims 1 to 4, characterized in that the pump housing (21,24) rests resiliently against the free end of the fillet screw (39) by means of a spring-loaded counter bearing (4o). 6. Rotary vane vacuum pump according to one of the claims 1 to 5, characterized in that the vacuum pump is constructed in several stages, in that each pump stage has its own pump housing (21,24), in which case between the pump housing (21,24) there is an intermediate disk (2?), 7. Rotary vane vacuum pump according to any one of claims 1 to 6, characterized in that each pump housing (21,24) is radially movable separately from one another in the housing-like extension via a fixing screw (39) . P ■- Rotary vane vacuum pump according to one of claims 1 to 7, characterized in that the individual lamp housings (21,24) are of identical design and that two adjacent pump housings (21,24) are mirror-symmetrical to one another with respect to an axial plane of the motor shaft and that the intermediate disk (23,25,45) has bores (35) which directly connect the outlet of the pump chamber (37) of a first stage with the inlet of the pump housing (38) of a second pump stage. 9· Rotary vane vacuum pump according to one of claims 1 to 8, characterized in that the pump parts (21, 24) and rotary pistons (22, 26) loosely assembled in the recess (19) are secured by a cover (20) which can be fixed to the housing-like extension (18) on one side. It (III II·· 1 1 · I III · are held together in a clamped manner in the axial direction of the motor shaft (4o). f& 1o. Rotary vane vacuum pump according to claim 9, characterized $ characterized in that the cover (2o) via springs the £■ Pump part© is held together by spring tension. ':.■■ 11. Rotary vane vacuum pump according to one of the claims 1 to 10, characterized in that the rotary piston (22, 24) arranged in the pump housing (21, 24) is connected to the motor via an elastically flexible key (42). ■'·* shaft (14) is coupled. 12. Rotary vane vacuum pump according to one of the claims 1 to 11, characterized in that the pump housing (21,24), rotary pistons (22,26), intermediate disks (23,25,45) and/or slides (44) can be manufactured as pointed parts. 13· Rotary disc vacuum pump according to one of the claims 1 to 12, characterized in that rotary piston (22,26), intermediate disc (23,25,45) and/or slide • (44) on a material made of plastic-bonded carbon can be produced. 14· Rotary vane vacuum pump according to one of the claims 1 to 13, characterized in that intermediate disks (23, 25, 45), pump housing (21, 24), rotary piston (22, 26) as a unit and the cover axially bracing the individual parts can be fixed in angular sections of 90 degrees each to the housing-like extension (18). 15· Rotary vane vacuum pump according to one of claims 1 to 14, characterized in that the recess f ( f
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&iacgr; ( 18) S ti rnseitig rtigen renewal ( rge fo red ab- (19) the housing page (30) a VO on the drive having* air ring channel (36) 16. Rotary vane vacuum pump according to one of the claims 1 to 15, characterized in that in cross section
the bore or recess (27) of the housing (21,24)
on an axis running radially through the piston center and perpendicular to the radial connection between the top and bottom dead center of the piston.