EP3482078B1 - Oil-lubricated rotary vane vacuum pump - Google Patents

Description

field of technology

The invention relates to an oil-lubricated rotary vane vacuum pump with a rotary vane unit, having a rotary vane chamber and a rotary vane rotor, and with an oil separation and reprocessing device, wherein in the oil separation and reprocessing device there is a separation of oil and gas that has passed through the rotary vane unit , by a separation device, which is preferably formed by a filter element and / or by a gravity and / or impact separator and / or a fine separator, preferably together with an oil foam reduction device, and / or with an oil cooler, for the devices mentioned one or several monitoring and/or maintenance devices are provided and the oil separation and reprocessing device is housed in an oil separation and reprocessing housing, with side walls, a bottom wall, a top wall and end walls, the side walls extending transversely to a plane of rotation of the rotary valve rotor and a longitudinal extension of the oil separation and reprocessing housing.

State of the art

Oil-lubricated rotary vane vacuum pumps of the type in question are known. This is usually a rotary vane blower with a rotary vane housing forming a rotary vane space, which rotary vane space is designed in the form of a cylindrical bore. The rotary vane rotor is usually cylindrical, with vanes that are displaceably arranged in slots in the rotor. The slots in the rotor can be strictly related to a cross section through the rotor be aligned radially or run at an acute angle to a radial. According to the prior art, the rotor is preferably mounted in the area of the side cover that closes the end of the rotary valve housing.

When the vacuum pump is in operation, the rotor rotates radially offset from the central axis of the rotary valve housing. This results in closed chambers, separated by the essentially radially displaceable slides, the size of which changes during one revolution of the rotor. The change in size results in pressure differences between the individual chambers and thus between the inlet side and the outlet side of the pump.

In oil-lubricated rotary vane vacuum pumps, oil is introduced into the rotary vane housing. This creates gaps between the different components. This also hinders the gas exchange between the chambers between the slides. In this way, higher vacuums are achieved during operation than with so-called dry-running rotary vane vacuum pumps.

Due to the design, the oil is pumped from the last chamber into the outlet together with the pumped gas. In addition, the oil is heated due to the enthalpy of compression in the system. The oil can also become dirty due to contact with the pumped medium or change as a result of possible chemical reactions. This results in preferential treatment of the oil after it leaves the blower area. In this regard, it is known to let the oil run through the device in a circular process.

It is also known that the oil treatment process can essentially be carried out in three sub-processes. Oil and gas are initially separated, possibly in several stages. A coarse separation of large oil drops can be provided by a corresponding filter element, as well as alternatively or in combination with gravity and/or impact separation by redirecting the gas-oil mixture and alternatively or in combination by slowing down the flow. A fine separation can also be provided to separate oil and gas, with the gas stream being passed through a special filter mat, for example. The breakdown of oil foam can be provided in a further sub-process. Air bubbles trapped in the oil can enter the rotary vane chamber in the form of foam and impair the function of the pump.

One or more monitoring and/or maintenance devices can be provided, for example an electrical oil level sensor and/or an oil sight glass and/or an oil temperature monitor.

In addition, it is known to accommodate the oil separation and reprocessing device in an oil separation and reprocessing housing that is separate from the rotary valve housing but may be coupled to it. The side walls of such a housing extend transversely to the direction of rotation of the rotary vane rotor and thus preferably essentially in the axial direction of the rotary vane rotor.
From the WO 2006/036598 A2 An oil-lubricated rotary vane vacuum pump is known, in which an oil separation and reprocessing device is arranged with a corresponding housing and a side wall. The facility consists of a free mirror area and a from this outlet tube extending vertically upwards, in which a separating device is accommodated.

Summary of the invention

With regard to the prior art presented, the invention is concerned with the task of designing a rotary vane vacuum pump of the type in question in terms of handling and/or maintenance and/or manufacturing technology favorable design, especially with regard to oil separation, to be further improved.

This object is achieved in the subject matter of claim 1, the aim being that the gas flows through two separating devices one after the other within the oil separation and reprocessing housing, both of which are accessible for maintenance from an end wall.

According to the invention, (at least) two separating devices for separating oil and gas are provided in the gas flow direction. This results in improved oil separation overall. The first separation device viewed in the flow direction can be a fine separation device, the second separation device in the flow direction a secondary separation device for separating fine to very fine oil particles from the gas stream.

Both separation devices are arranged inside the oil separation and reprocessing housing. Any interfaces on the housing for connecting an external, additionally assignable separating device are not necessary. Such interfaces, as well as lines leading from them, such as hoses to an external separation device, represent potential risks for operation.

The joint arrangement of both separating devices within the same oil separation and reprocessing housing makes it possible to internally ground both components together with the other components accommodated in this housing. Static discharges and flying sparks can be safely avoided.

The separating devices connected in series in the direction of flow offer a step-like separation.

The accessibility of both separating devices via an end wall of the oil separation and reprocessing housing proves to be convenient in terms of handling, especially with a preferred arrangement of the separating devices one behind the other, with the one separating device being arranged at least partially concealed behind the separating device, which is initially visible from the end wall, when viewed from the end wall.

In one possible embodiment, the two separating devices can be used and removed individually. The insertion or removal can, as preferred, be carried out in a predetermined order. In addition, in order to remove a separating device, the removal of the other separating device may first be a prerequisite.

In an alternative embodiment, the two separating devices can also be connected to one another in combination for joint insertion and removal. Such a connection can be canceled after removal, for example to replace only one separating device. (Continue on page 6 , above WO 2018/007443 A1 taking into account the attached amended pages 30 and 31.)

The insertion and removal can each refer to the entire separating device (first and/or second separating device). In this regard, it is also possible to simply remove or insert filter elements from the separation devices. These filter elements alone can also be accessible via one end wall. The arrangement can also be chosen such that a separating device can be completely removed from the housing for maintenance or replacement, while in the second separating device preferably only the associated filter element can be removed as part of normal maintenance.

The gas path between the first separating device in the gas flow direction and the second separating device in the gas flow direction can, as is also preferred, be designed to be valve-free. This preferably results in a pressure loss-free transition from the first separating device into the second separating device, with the line section defining the gas path between the separating devices being provided through the oil separator and reprocessing housing in a preferred embodiment.

The length of the gas path between the gas flow direction of the first separating device and the gas flow direction of the second separating device, viewed in the gas flow direction, can correspond to a diameter dimension or less of the first separating device. The length of the gas path can tend to zero, if the two separating devices are in direct (linear) succession. The diameter dimension of the first separating device preferably refers to a largest extension dimension in a cross section transverse to the longitudinal extent or transverse to the gas flow direction within the separating device, in this case based on the filter material used for oil separation. In a preferred circular cylindrical design of the first separating device or its separating filter The maximum extension dimension in the cross section results from the diameter dimension. In the case of an exemplary rectangular cross section of the filter material, the aforementioned diameter dimension corresponds, for example, to the longest extension dimension in the cross-sectional area.

The separating devices are fine separator or air separator elements, also known as oil mist separators, with the second separating device connected downstream in the gas flow direction having, in a preferred embodiment, a higher degree of separation than the first separating device and thus a higher particle filter class.

Also, as is preferred, the one or more monitoring and/or maintenance devices can only be arranged in three cover parts which are attached to the two end walls of the oil separation and reprocessing housing, the oil separation and reprocessing housing also having side walls, a bottom wall, a Ceiling wall and end walls can be designed without a design for a monitoring and / or maintenance device.

The cover parts can be assigned to the end walls of the oil separation and reprocessing housing. For example, an end wall can be designed as a rear side cover and a service cover can be assigned to a front end wall that is common in operation. In addition, a removable maintenance cover can be arranged in particular on the service cover for maintenance purposes.

In addition, the monitoring and/or maintenance devices, more preferably all monitoring and/or maintenance devices relevant to the normal operation of the vacuum pump, can be in or on the three cover parts be provided. Furthermore, frequently used monitoring and/or maintenance devices can be provided in the service cover or in the maintenance cover that can be arranged on the service cover or can be accessed via these.

Essential functions are preferably located in the area of the three cover parts or can be carried out in the area of these. These are in particular filling with oil and/or checking oil and/or monitoring oil and/or draining oil and/or attaching one or both separating devices and/or creating access for maintenance of one or both separating devices and/or attaching a float device and/ or create access to the float device and/or create space for separated oil and/or create return flow for collected oil and/or receptacle for the maintenance cover and/or divide into upper and lower spaces of the oil separation and reprocessing housing and/or connect an oil bath heater and /or connection of water cooling and/or connection for filters and/or connection for elements connected downstream of the vacuum pump and/or direct blown-out air in a defined direction.

The actual oil separation and reprocessing housing without the aforementioned cover parts is preferably without a relevant function, at least regarding the user interface. This housing can therefore be easily implemented. In particular, the top wall and the bottom wall, more preferably at least one external side wall, can be designed without preparation for the arrangement of relevant devices.

The float device is, in general terms, a control for the flow from the upper to the lower chamber. It is particularly influenced by an oil level that arises in the upper chamber. A Exceeding a certain specified oil level should be avoided. You can also call it a so-called valve. For the sake of simplicity, this device is always referred to below as a float device. The separated oil from both separating devices is returned to the oil circuit via this floating device.

In a further embodiment, the one or more monitoring and/or maintenance devices can be arranged on a removable maintenance cover of the oil separation and reprocessing device, with one or both separating devices and/or a float device being accessible for maintenance when the maintenance cover is removed.

The one or more monitoring and/or maintenance devices can be assigned to a housing area of the oil separation and reprocessing device, in which area a removable maintenance cover can be formed. The monitoring and/or maintenance devices can be arranged or formed directly on the maintenance cover, but if necessary also in the immediate vicinity of the maintenance cover in the surrounding housing area. This reduces the space required for the rotary vane vacuum pump in the installation and use area. By removing the maintenance cover from the oil separation and reprocessing housing, access to components of the oil separation and reprocessing device can be made possible, in particular access to one or both separating devices and/or to a float device. Such a float device may be necessary in order to allow the gas stream to flow in a targeted manner through the one or more separating devices due to given pressure differences in the area of the oil separation and reprocessing device during operation of the vacuum pump. Here, separated oil is preferably formed in a cavity collected in a service cover forming an end wall of the oil separation and reprocessing housing. A hollow body is arranged in the cavity, which can also be referred to as an oil collecting space, connected to a joint, preferably a swivel joint, and a seal. The seal blocks the oil return. If the oil level rises, the hollow body floats and the seal is raised over the joint, revealing an opening for the oil return.

The maintenance cover can be designed and arranged in such a way that the oil located behind it in the oil separation and reprocessing housing cannot escape when the maintenance cover is removed, the maintenance cover being able to be arranged in the area of an end wall of the oil separation and reprocessing housing. The maintenance cover can also be arranged on a service cover assigned to an end wall of the oil separation and reprocessing housing.
The oil separation and reprocessing housing can consist of a profile with the same cross-section in terms of its longitudinal extent. Such a profile can be an extruded profile, in particular an extruded aluminum profile. This means that the housing of the oil separation and reprocessing system in particular can be produced cheaply. The contour is preferably identical at every point on the longitudinal axis of the housing part. In relation to an extruded profile, a wrought aluminum alloy is pressed through a two-dimensional die to create an elongated profile which can be cut to the preferred length. This enables the production of such a housing with dimensionally stable contours over the entire length.

The outer surfaces can be visually clean and uniform. Further work steps, in particular surface processing steps, can be omitted, particularly when producing from an extruded profile. In addition, according to the proposed design of the housing, the surface of the housing can be represented as a design element.

The profile of the same cross-section, preferably the extruded profile, offers the possibility of changing the volume of the oil separation and reprocessing device and adapting it to the application needs.

As far as reference is made above and below to an extruded profile, this is always to be understood in a more general version as a profile with the same cross-section.
Furthermore, it can be provided that the maintenance cover forms part of an end wall of the oil separation and reprocessing housing or the end wall as a whole. When the vacuum pump is in the use position, the front wall can be oriented towards an operator or control person. In a preferred embodiment, the maintenance cover sealingly covers an opening provided in the end wall of the housing, through which, for example, one or both separating devices and/or the float device are accessible for maintenance. The maintenance cover can have a size in terms of its top surface that corresponds to 0.25 to 0.5 times the outward-facing end face of the end wall.

The separating devices can be arranged in the longitudinal direction of the oil separation and reprocessing device with respect to the flow direction. Further preferably, the arrangement of the separating devices is selected with respect to the flow direction in the longitudinal direction of the extruded housing profile.

The maintenance cover is preferably arranged in the extension of at least one of the separating devices in the area of the end wall. A longitudinal central axis of the separating device can extend through the maintenance cover in the area of its broad side surfaces.

After removing the maintenance cover, the filter element, preferably in the form of a special filter mat, can be removed, for example, from the separating device formed as a fine separation device. This means, for example, that it can easily be replaced with a new filter element.

A side wall is provided between the rotary valve unit and the oil separation and reprocessing device. This can be the side wall of the oil separation and reprocessing housing. The side wall can have a passage opening through which compressed gas with an oil content from the rotary valve unit can enter the oil separation and reprocessing device.

The incoming gas with oil content can flow in a first section of the oil separation and reprocessing device in countercurrent to a second section, in which second section the oil separation, for example fine separation, takes place. The flow direction can, as is also preferred, be given in the longitudinal extent of the oil separation and reprocessing housing, and thus more preferably in the longitudinal extent of the extruded profile. This is an essential flow direction from one end region of the housing along its longitudinal extent to the other end region of the housing, deviations from a strictly linear flow direction can be provided within this flow from one end of the housing to the other.

Below the passage opening, a housing section can be formed as a flow path, into which oil separated from the gas flows as a result of gravity and/or centrifugal force. The housing section can serve to accommodate an oil sump and can therefore be designed in the form of an oil pan. A preferably first separation of gas and oil takes place via gravity and/or centrifugal separation.

In order to allow an oil change, possibly also a connection to an oil cooling circuit, the housing section has at least one oil outlet opening. This can, as is also preferred, be formed in a vertically lowest area of the housing section when the vacuum pump is in the set-up and use state, more preferably close to the bottom of the housing section. More preferably, the oil outlet opening can be closed.

The oil outlet opening can also be accessible from an end wall of the oil separation and reprocessing housing. In a preferred embodiment, the oil outlet opening is assigned to the end wall, on which the maintenance cover is also arranged.

In particular, in order to separate particles from the oil separated from the gas, an oil filter can be provided in the housing section or associated therewith, through which the oil located in the housing section can be conducted. As preferred, it can be a replaceable oil filter.

The oil passed through the oil filter can preferably be introduced into the rotary valve chamber. For this purpose, a pump can be provided which sucks the oil collecting in the housing section through the oil filter and conveys it into the rotary valve chamber of the rotary valve unit. Is preferred a design without a pump, in which the pressure difference between the oil collecting chamber and the working chamber of the vacuum pump is used to pump oil.

A filter mat can be provided in the fine separation device (first separation device). This filter mat is preferably replaceable, with such a change taking place in a preferred embodiment from the one end wall having the maintenance cover after removing the maintenance cover.

The filter mat can be tubular with an internal flow path for the gas/oil mixture. In a preferred embodiment, oil separated in the fine separation device flows via the secondary separator (second separation device) and via the float device into the housing section having the oil collecting space.

The flow resistance of the filter elements (filter mat) in the separating devices results in a pressure difference before and after the fine separation device. Depending on the volume flow that the pump is currently delivering, this can be up to 400 mbar.

The float device can be formed directly on the maintenance cover or, as preferred, can be accessible after removing the maintenance cover. This also offers an improvement in maintenance.

A level indicator can also be provided on the front wall, possibly in or on the maintenance cover. The oil level of the vacuum pump can be read here. This can be a standard sight glass, alternatively an analogue or digital measurement display.

A pressure relief valve or a rupture disk can also be arranged in the front wall, possibly in the maintenance cover. Such a pressure relief valve or a rupture disk serves as protection against sudden overpressure in the device. With a possible arrangement of a burst protection in the maintenance cover, the safe operating state can be restored after an event in a simple manner, for example by changing the maintenance cover as a whole.

In a further embodiment, a temperature monitoring element can be arranged in the end wall, possibly in the maintenance cover or assigned to the maintenance cover. This is used in particular to monitor the oil temperature.

In one possible embodiment, the gas separated from the oil can exit through the front wall, for example through the maintenance cover. For this purpose, the end wall, in particular the maintenance cover, has a corresponding outlet opening.

In one possible embodiment, the maintenance cover has a gas outlet connection. This can be designed to connect a silencer or a continuation element. In a first embodiment of the maintenance cover, the gas outlet connection can also be equipped with a thread. An outlet piping can be connected to this. The thread can also be used to connect a burst valve. If necessary, the burst valve can also be arranged and secured in the outlet piping. If necessary, a pipeline, a silencer or other gas routing elements can be connected. By changing the maintenance cover, an appropriately equipped maintenance cover can be arranged even when the device is in use.

In a further embodiment, the gas outlet connection can be provided with an optionally removable deflection cap, in which the emerging gas is deflected by at least 60° with respect to its exit direction given at the gas outlet connection. The deflection is preferably chosen so that the emerging gas flows out in a downward direction. This reduces the noise level during operation of the vacuum pump because the sound is directed in a direction towards the floor. The gas outlet connection can also be arranged rotatably on the maintenance cover, so that, for example, deflection to the side or upwards is also possible.

The oil separation and reprocessing housing can have an integrally formed chamber with a lower and an upper chamber in terms of gravity in the set-up state, with an end wall can be connected to the front and rear in the longitudinal direction of the oil separation and reprocessing housing. The integral formation of chambers can be formed in the course of the preferred production of the housing from an extruded profile. In a preferred embodiment, the upper chamber serves in particular to accommodate the separating devices, while the lower chamber during operation of the vacuum pump forms the housing section described above. The end walls to be connected each form an end closure of the oil separation and reprocessing housing. One of the end walls can have an opening covered by the maintenance cover described above.

At least one end wall preferably forms a connection between the chambers. With a preferred opposite flow within the chambers, at least one end wall can form gas deflection areas.

In a preferred embodiment, the passage opening from the rotary valve unit or from the rotary valve chamber to the oil separation and reprocessing device opens into the lower chamber of the oil separation and reprocessing housing. Viewed in the direction of flow, the gravity and/or impact separator preferably adjoins this passage opening.

Furthermore, in a preferred embodiment, the lower chamber forms an oil collecting container.

One or more cooling lines, preferably integrated into the extruded profile, can be provided associated with the oil collecting container. Inlets and outlets for cooling the oil by means of an external cooler can also be provided in the area of the oil collecting container.

Brief description of the drawings

Fig. 1

eine ölgeschmierte Drehschieber-Vakuumpumpe in perspektivischer Darstellung;

Fig. 2

die Draufsicht hierzu;

Fig. 3

die Vakuumpumpe in einer Seitenansicht mit Blick auf eine Stirnwand mit einem Wartungsdeckel;

Fig. 4

den Schnitt gemäß der Linie IV-IV in Figur 3;

Fig. 5

den Schnitt gemäß der Linie V-V in Figur 2;

Fig. 6

das Ölabscheide- und Wiederaufbereitungsgehäuse in perspektivischer Einzeldarstellung;

Fig. 7

in perspektivischer Einzeldarstellung die Stirnwand mit zugeordnetem Wartungsdeckel und einem an dem Wartungsdeckel festlegbaren Gasaustrittstutzen;

Fig. 8

eine weitere perspektivische Darstellung des Wartungsdeckels mit Blick auf die im Nutzungszustand innere Fläche;

Fig. 9

das Ölabscheide- und Wiederaufbereitungsgehäuse in einer Schnittdarstellung;

Fig. 10

den Schnitt gemäß der Linie X - X in Figur 2.

The invention is explained in more detail below with reference to the accompanying drawing, which only represents an exemplary embodiment. It shows:

Fig. 1

an oil-lubricated rotary vane vacuum pump in a perspective view;

Fig. 2

the top view of this;

Fig. 3

the vacuum pump in a side view with a view of an end wall with a maintenance cover;

Fig. 4

the cut according to line IV-IV in Figure 3 ;

Fig. 5

the cut according to the line VV in Figure 2 ;

Fig. 6

the oil separation and reprocessing housing in a perspective individual view;

Fig. 7

in a perspective individual view, the front wall with an assigned maintenance cover and a gas outlet connection that can be fixed to the maintenance cover;

Fig. 8

another perspective view of the maintenance cover with a view of the inner surface when in use;

Fig. 9

the oil separation and reprocessing housing in a sectional view;

Fig. 10

the cut according to the line X - X in Figure 2 .

Description of the embodiments

It is shown and described, initially with reference to Figure 1 , an oil-lubricated rotary vane vacuum pump 1 with a rotary vane unit and an oil separation and reprocessing device 3.

The rotary vane unit 2 has an aggregate housing in which a rotary vane chamber 5 with a rotary vane rotor 6 are arranged. The unit housing is covered by a hood 4 and by side covers 11 and 12 arranged at the ends with respect to a longitudinal axis.

The rotary valve chamber 5 is designed in the form of a cylindrical bore in the unit housing. The rotary valve chamber 5 has a longitudinal extension which is oriented on the bore axis of the rotary valve chamber 5.

The cylindrical rotary vane rotor 6 is arranged eccentrically relative to the rotary vane space 5. Accordingly, the rotor axis x runs parallel but offset from the spatial axis.

The rotary slide rotor 6 has several, in the exemplary embodiment three slides 7. These are arranged so that they can slide in slots 8 of the rotor 6 that are approximately radially aligned in cross section. The slides 7 are pressed against the wall delimiting the rotary slide chamber 5 by the rotation of the rotary slide rotor 6 due to centrifugal force.

During operation of the vacuum pump 1, the rotary vane rotor 6 rotates radially offset from the central axis of the rotary vane space 5, which is driven by a motor, in particular an electric motor 9, which rotates on the rotor shaft. This results in closed chambers 10, separated by the radially displaceable slides 7 , the size of which changes during one revolution of the rotary valve rotor 6.

The rotary slide chamber 5 is closed at each end with respect to its longitudinal axis by rotary slide side covers 46 and 47 (see Figure 10).

Outside the unit housing, for example assigned to the side cover 12, the electric motor 9 is preferably attached to the unit housing. The shaft of the rotary valve rotor 6 can pass through the relevant side cover 12 for rotationally fixed attack of the electric motor 9.

The change in size of the chambers 10 during operation of the vacuum pump 1 results in pressure differences between the individual chambers 10 and thus between the inlet side and the outlet side of the blower thus formed.

The drive via the electric motor 9 can be arranged directly on the rotor shaft or, as is further preferred, via a clutch.

Oil-lubricated rotary valve units 2 are characterized by the fact that oil is introduced into the rotary valve chamber 5. This oil creates gaps between the various components, in particular between the slides 7 and the wall of the rotary slide chamber 5. The gas exchange between the different chambers 10 is thus hindered. In this way, higher vacuums are achieved during operation than is possible with dry-running rotary vane pumps.

Due to the design, the oil is pumped out of the last chamber 10 of the rotary valve unit 2 together with the pumped gas. In addition, the oil is heated due to the enthalpy of compression in the system. As the oil comes into contact with the pumped medium (gas), it can become dirty or change as a result of possible chemical reactions.

The oil runs through the vacuum pump 1 in a circular process. This means that it has to be treated after it has left the rotary vane unit 2. The oil separation and reprocessing device 3 is used for this purpose.

The device 3 is connected to the rotary valve unit 2, so that a unit is formed, consisting of the rotary valve unit 2, oil separation and reprocessing device 3 and electric motor 9.

The oil separation and reprocessing device 3 initially has an oil separation and reprocessing housing 13, with side walls 14, 15, a bottom wall 16, a top wall 17 and end walls 18, 19.

The end walls 18 and 19 are viewed in the longitudinal extent of the housing 13, which longitudinal extent corresponds to the longitudinal extent of the rotary valve space 5 of the rotary valve unit 2, each arranged at the end of the housing which integrally forms the side walls 14 and 15, the bottom wall 16 and the top wall 17, in particular with screw connected to the housing. The front wall 18 is preferably formed by a service cover and the front wall 19 by a rear side cover.

With respect to its longitudinal extent, the housing 13 can consist of an extruded profile 20, in particular an extruded aluminum profile. The oil separation and reprocessing housing 13 has a substantially constant cross-section over its length, viewed over the longitudinal extent while maintaining a dimensionally stable contour. In addition, when the housing 13 is manufactured using the extrusion process, the outer surfaces are visually uniform and clean, so that surface processing steps to visually enhance the surface can be omitted. Only necessary processing steps, such as openings in the side walls and/or bottom wall and/or top wall, can be provided.

The production of the housing 13 using the extrusion process can also be used in such a way that, in addition to the surface, the shape of the housing can also be designed in such a way that it ultimately represents the design element.

The side walls 14 and 15 extend transversely to a plane of rotation of the rotary valve rotor 6, with the side wall 14 in the illustrated embodiment also representing the fastening plane for fastening the oil separation and reprocessing housing 13 to the unit housing.

In one possible embodiment, the end wall 18 arranged at the end closes on the outside of the wall with the adjacent side cover 11, as also, more preferably, the top wall 17 and the bottom wall 16 with the adjoining adjacent wall sections of the unit housing. This results in a compact and visually appealing unit.

The outer surface of the side wall 15 facing away from the rotary valve unit 2 and thus facing outwards is corrugated with respect to a cross section in the plane of rotation of the rotary valve rotor 6 (cf. in particular Figure 9 ). There are 15 uniform, rounded elevations over the length of the side wall viewed in cross section, which are connected to one another via valleys. This results in an increase in the surface area in the area of the side wall 15 and thus an improvement in heat dissipation during operation of the vacuum pump 1.

In a preferred embodiment, the wave surface continues in the facing surface areas of the end walls 18 and 19.

The oil separation and reprocessing housing 13 has a preferably integrally formed chamber. With reference to an installation state as shown, there is a lower chamber 21 and an upper chamber 22 with regard to gravity. The separation of the chambers 21 and 22 is achieved by a cross section according to Figure 9 Divider 23 running transversely to the side walls 14 and 15.

In the oil separation and reprocessing device, oil and gas are particularly separated during operation of the vacuum pump 1.

For this purpose, a gravity and/or impact separator 24 and a two-stage separation device connected downstream in the gas flow direction are initially provided, which is composed of a first separation device T ₁ in the form of a fine separation device 25 and a downstream second separation device T ₂ in the form of a secondary separation device 43.

The oil/gas mixture enters the oil separation and reprocessing device 3 from the rotary valve unit 2 via a passage opening 26 in the area of the side wall 14.

When entering the device 3, large oil drops are preferably first roughly separated by the gravity and/or impact separator 24 by redirecting the gas-oil mixture and slowing down the flow.

The oil-gas mixture enters the device 3 due to the corresponding arrangement of the passage opening 26 in the area of the lower chamber 21, in which there is a separating device T ₃ , for example Form of a gravity and/or impact separator 24, can be arranged.

The housing section 27 which results under the passage opening 26 in the area of the lower chamber 21 serves in the manner of an oil pan in which an oil sump collects. An oil collecting container is thus formed in the lower chamber 21.

The lower chamber 21 further forms a flow path with a flow a that is oriented towards the longitudinal orientation of the housing. This flow a is directed towards the rear end wall 19.

To prevent the oil collecting in the oil sump from being stirred up by the gas flow, the area of the oil pan is covered by a recessed filter plate 44.

The inside of the end wall 19 is designed to redirect the flow from the lower chamber 21 into the upper chamber 22, in which the flow path formed in the upper chamber 22 allows a flow b opposite to the flow a of the lower chamber 21.

In the upper chamber 22, the separating devices T ₁ and T ₂ are provided in a linear arrangement one behind the other.

The fine separation device 25 (separation device T ₁ ) has a tubular filter mat 42, the tube axis of which is preferably aligned with the rotor axis x of the rotary valve rotor 6. The fine separation device 25 is also arranged oriented essentially in the longitudinal direction of the oil separation and reprocessing housing 13.

In the gas flow direction b, a post-separation device 43 is provided downstream of the fine separation device 25 in the upper chamber 22. The gas emerging from the fine separation device 25 is inevitably guided through the secondary separation device 43. The length c of the gas path between the first separation device T ₁ (fine separation device 25) in the gas flow direction b and the second separation device T ₂ (post-separation device 43) in the gas flow direction b corresponds to approximately a quarter to a third of the diameter of the first separation device T ₁ (based on the largest Cross-sectional extent of the filter-effective element).

The oil-gas mixture diverted from the lower chamber 21 into the upper chamber 22 is directed specifically and successively through the two separating devices T ₁ and T ₂ , whereby a pressure difference results in front of the first separating device T ₁ and behind the second separating device T ₂ , which can be up to 400 mbar depending on the delivery pressure of the rotary valve unit 2.

Furthermore, an oil foam removal device can be provided in the oil separation and reprocessing device 3.

An oil filter 28 is also provided. This can be arranged assigned to the bottom area of the oil separation and reprocessing housing 13, more preferably the rear end wall 19. The oil in the oil sump is sucked through the oil filter 28 and, in particular, freed from solid particles.

Using the pressure difference between the lower chamber 21 and the chamber 10 in the rotary valve unit 2, the oil filtered in the oil filter 28 is conveyed into the rotary valve unit 2 via a suction line 29.

The particularly filtered oil can be cooled using an external cooler, not shown. For this purpose, corresponding entrances and exits are provided in the area of the lower chamber 21.

Cooling paths can also be provided in the profile of the housing 13, for example in the area of the bottom wall 16 and/or the side walls 15 (assigned to the lower chamber 21).

The end wall 18, which in the state of use preferably faces an operator, leaves a passage on the inside of the wall for connecting the upper chamber 22 with the lower chamber 21, which passage is formed by a float device 30. Oil separated at the two separating devices T ₁ and T ₂ is returned to the reservoir in the area of the lower chamber 21, this through the float device 30. Due to the above-described pressure difference in front of and behind the separating devices T ₁ and T ₂ , this prevents a short-circuit-like flow of the gas entering the lower chamber 21 through the passage opening 26 directly to the gas outlet 31.

In addition, an oil bath heater can be provided to heat the oil before starting the vacuum pump 1.

Additional water cooling can also be provided.

The oil bath heating and/or the water cooling can be arranged on the end wall 19.

In the end wall 18 facing away from the electric motor 9 and forming a front side during operation, at least one is assigned to the upper chamber 22 Window-like opening 32 extending approximately over the entire cross-sectional area of the upper chamber 22 is provided. This is closed by a maintenance cover 33 during operation of the vacuum pump 1. The maintenance cover 33 can be screwed to the end wall 18, preferably with the interposition of a seal.

The gas outlet 31 is provided in the maintenance cover 33. For this purpose, the maintenance cover 33 has a passage opening 34, to which a gas outlet connection 35 can be connected on the outside of the wall of the maintenance cover 33.

The gas outlet connection 35 can be designed in the form of a removable deflection cap 36, in which the emerging gas is at least 60 °, preferably up to, with respect to its orientation given on the gas outlet connection - which is essentially in the same direction as the flow b in the upper chamber 22 is deflected 90 ° downwards towards the plane given by the bottom wall 16. This directs the sound towards the floor, which leads to a reduction in noise pollution.

The gas outlet connection 35 is preferably rotatably arranged on the maintenance cover 33, so that the exhaust air can also be deflected either to the side or upwards, for example.

The deflection cap 36 can be exchanged, for example with a gas outlet connection for connecting a silencer or a continuation element.

In addition, a maintenance cover 33 with deflection cap 36 can be exchanged for a maintenance cover 33 for connecting external piping, for example.

The oil separation and reprocessing device 3 has several monitoring and/or maintenance devices 37. A fill level indicator 38 for determining the amount of oil can be provided in the end wall 18, assigned to the lower chamber 21. The level indicator 38 can be formed by an oil sight glass and/or by an electric oil level sensor.

A possible oil temperature display can also be arranged in the area of the end wall 18.

Furthermore, both the inlet and the outlet for changing the oil in the oil separation and reprocessing device 3 can be provided in the end wall 18. For this purpose, in one embodiment, an oil outlet opening 39 and a filler neck 40 are provided in the end wall 18.

After removing the maintenance cover 33 assigned to the end wall 18, both separating devices T ₁ and T ₂ and the float device 30 are accessible for maintenance and, if necessary, replacement from the operating side of the vacuum pump 1.

After removing the end wall 18, the second separating device T ₂ (post-separation device 43) is exposed. This can be removed from the upper chamber 22 accordingly. The post-separation device 43 can be attached to a slide-like frame 45, for example. In one embodiment, the post-separation device 43 can be removed from the upper chamber 22 together with the frame 45, after which the Filter mat 42 of the fine separation device 25 is also exposed for removal or the filter mat 42 can be accessed for maintenance purposes.

The gas path between the two separating devices T ₁ and T ₂ is designed to be valve-free and, in the exemplary embodiment shown, is surrounded solely by the material of the oil separation and reprocessing housing 13 in the area of the upper chamber 22 with respect to a cross section.

The post-separation device 43 can have a filter mat or the like that can be passed through essentially in the flow direction b.

In addition, a pressure relief valve can be arranged in the maintenance cover 33.

The pressure relief valve serves as protection against sudden overpressure in the oil separation and reprocessing device 3; is therefore preferably part of the monitoring device.

The end walls 18 and 19 as well as the maintenance cover 33 are assigned as cover parts A, B and C to the oil separation and reprocessing housing 31 directly or indirectly (cover part C or maintenance cover 33).

As a result of the above-described arrangement of the monitoring and/or maintenance devices 37 and the design of the cover parts A, B and C, all interfaces relevant to the operator are preferably accommodated in the area of the end walls 18, 19 in an easily accessible manner, which reduces the space required for the device, increases ease of maintenance and the manufacturability of the oil separation and reprocessing housing is simplified. List of reference symbols 1 vacuum pump 26 Passage opening 2 Rotary vane unit 27 Housing section 3 Oil separation and reprocessing facility 28 Oil filter 29 suction line 4 Hood 30 Float facility 5 Rotary valve room 31 Gas outlet 6 Rotary vane rotor 32 opening 7 Slider 33 Maintenance cover 8th slot 34 Passage opening 9 Electric motor 35 Gas outlet connection 10 chamber 36 deflection cap 11 Side cover 37 Monitoring and maintenance facility 12 Side cover 13 Oil separation and recycling 38 Level indicator preparation housing 39 Drain opening 14 Side wall 40 Filler neck 15 Side wall 42 Filter mat 16 floor wall 43 Post-separation device 17 ceiling wall 44 Filter plate 18 Front wall 45 frame 19 Front wall 46 Rotary slide side cover 20 Extruded profile 47 Rotary slide side cover 21 lower chamber 22 upper chamber 23 Divider 24 Gravity and/or impact separators 25 Fine separation device a flow b flow c length x Rotor axis A Lid part b Lid part C Lid part _T1 Separation device _T2 Separation device _T3 Separation device

Claims (6)

1. An oil-lubricated rotary vane vacuum pump (1) with a rotary vane power unit (2), comprising a rotary vane chamber (5) and a rotary vane rotor (6), and with an oil separating and recycling unit (3), wherein in the oil separation and recycling unit (3) a separation of oil and gas takes place, which has passed through the rotary vane power unit (2), by means of a first separating device (T₁, T₂), which is preferably formed by a filter element and/or by a gravity and/or impact separator (24) and/or a fine separator (25), preferably together with an oil foam degradation device, and/or with an oil cooler and/or with an oil pump, wherein one or more monitoring and/or maintenance units (37) are provided for said devices and the oil separating and recycling unit (3) is accommodated in an oil separating and recycling housing (13), with sidewalls (14, 15), a bottom wall (16), a ceiling wall (17) and face walls (18, 19), wherein the sidewalls (14, 15) extend transversely to a plane of rotation of the rotary vane rotor (6) and define a longitudinal extent of the oil separation and recycling housing (13), characterised in that the gas flows successively within the oil separation and recycling housing (13) through the first separating device (T₁) and a second separating device (T₂), both of which are accessible for maintenance from an face wall (18).
2. The rotary vane vacuum pump according to claim 1, characterised in that both separating devices (T₁, T₂) are singly insertable and removable.
3. The rotary vane vacuum pump according to one of the preceding claims, characterised in that both separating devices (T₁, T₂) are connected to each other, combined for joint insertion and removal.
4. The rotary vane vacuum pump according to one of the preceding claims, characterised in that a gas path between the first separating device (T₁) in the gas flow direction (b) and the second separating device (T₂) in the gas flow direction (b) is designed to be valve-free.
5. The rotary vane vacuum pump according to claim 4, characterised in that the length (c) of the gas path between the first separating device (T₁) in the air flow direction (b) and the second separating device (T₂) in the air flow direction (b) corresponds to a diameter dimension or less of the first separating device (T₁).
6. The rotary vane vacuum pump according to one of the preceding claims, characterised in that a further separating device (T₃) is provided, for example in the form of a gravity and/or impact separator (24).

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