Improved rotary vane pump

Abstract

A rotary vane pump (1) for conveying a fluid has a housing (2) with a rotor receiving chamber (3) and a lubricant chamber (14). An eccentrically arranged rotor (4) is arranged in the rotor receiving chamber (3) such that at least one conveying chamber (11) is produced, the volume of which varies cyclically during rotation of the rotor (4). Furthermore, the rotary vane pump (1) has an inlet passage (12) for supplying the fluid to be conveyed into the conveying chamber (11) and a discharge passage (13) for discharging the fluid to be conveyed out of the conveying chamber (11) in the direction of the lubricant chamber (14), in which a valve device (21) is provided between the discharge passage (13) and the lubricant chamber (14) to prevent backflow of the fluid entering the conveying chamber (11) from the lubricant chamber (14). The discharge channel (13) is also arranged to lead to the lubricant chamber (14). Furthermore, the rotary vane pump (1) has: at least one ventilation channel (26) which is fluidly connected to the delivery chamber (11) by means of a delivery chamber end (28) and to a chamber outside the delivery chamber (11) by means of a ventilation end (27); and at least one compensation channel (29) fluidly connected to the delivery chamber (11) via a delivery chamber end (31) and fluidly connected to the lubricant chamber (14) via a compensation end (30). In this manner, the compensation end (30) opens into the lubricant chamber (14) below a lubricant level (24) in an operating state of the rotary vane pump (1) and opens into the lubricant chamber (14) above a lubricant level (34) in a stationary state of the rotary vane pump (1).

Description

[0001] The invention relates to a rotary vane pump for conveying a fluid to be conveyed.

[0002] A rotary vane pump has a housing with a chamber in which a rotatable rotor is eccentrically arranged. In general, a groove-shaped recess (often referred to as a slide) is formed in the rotor, in which a wall assembly (so-called slide) is movably, in particular slidably, arranged. In a large number of designs, the wall assembly / slide is pressed against the inner wall of the housing chamber (rotor receiving chamber) during the rotation of the rotor due to centrifugal force. Thus, one or more conveying chambers are formed by the wall assembly, and the volume of the conveying chamber changes cyclically during the rotation of the rotor. By appropriately arranging the inlet and discharge channels, the fluid to be conveyed by the rotary vane pump can thus be conveyed from the inlet channel to the discharge channel.

[0003] The lubricant stored in the lubricant chamber of the rotary vane pump is used to lubricate the parts that mechanically move against each other. Another task of the lubricant is to provide additional sealing between the inner wall and the wall assembly inside the housing, between the wall assembly and the rotor, and between other components of the rotary vane pump.

[0004] Rotary vane pumps are well known in the prior art and are used in a wide variety of applications. Typical areas of application of such rotary vane pumps are, for example, the generation of low pressures / vacuums in scientific applications, in the latter case mostly as a link in a chain of different pump types (wherein rotary vane pumps are often used to generate so-called pre-vacuum or low vacuum).

[0005] While rotary vane pumps have proven their usefulness and are widely used, they still suffer from certain disadvantages.

[0006] A disadvantage that rotary vane pumps are often criticised for is that they produce constant noise. Understandably, a reduction in the operating noise produced would be welcomed by many users.

[0007] Another problem is the shut-down of the rotary vane pump (for which the shut-down can be planned, for example, by user intervention, or it can also occur unplanned, for example, due to a malfunction). In this case, the typical design of the rotary vane pump tends to suck lubricant into the rotor receiving chamber or delivery chamber. The volume of lubricant sucked in can then cause problems when the rotary vane pump is restarted, in particular resulting in increased operating noise, the need for increased drive torque, and / or resulting in increased mechanical resistance. In particular, the latter can lead to increased mechanical wear and, under unfavorable conditions, can even lead to damage to the rotary vane pump. It can be easily seen that due to the above-mentioned problems, and also due to other problems not described in detail here, there is still a need for improvements in the construction of rotary vane pumps. Based on this, it is not surprising that a large number of possible improvements have already been proposed in the prior art.

[0008] For example, WO 2013 / 139570 A2 proposes a vacuum rotary vane pump, wherein a valve device is arranged between the discharge channel of the delivery chamber and the lubricant chamber of the rotary vane pump to prevent the fluid from flowing back from the lubricant chamber into the delivery chamber. It is suggested to use a compensating channel, which is connected to the discharge channel and the lubricant chamber and is integrated into the valve device. It is intended to provide a rapid pressure balance in the delivery chamber when the rotary vane pump is closed, so that the delivery chamber quickly reaches atmospheric pressure, thereby preventing lubricant from filling the delivery chamber via a lubricant supply device. Different designs of the compensating channel between this delivery chamber and the lubricant chamber are proposed in WO 2007 / 006666 A1.

[0009] EP 3 470 678 A1 proposes a compensating channel between a delivery chamber and a lubricant chamber of a rotary vane pump, wherein the opening of the compensating channel is arranged in the region of an overflow partition of the lubricant chamber.

[0010] While these proposals definitely have some merit, further improvements are needed.

[0011] It is therefore an object of the present invention to provide a rotary vane pump for conveying a fluid to be conveyed, which has an improved operating behavior.

[0012] This object is achieved by a rotary vane pump for conveying a fluid to be conveyed having the features of claim 1 .

[0013] A rotary vane pump for conveying a fluid to be conveyed is proposed, comprising: a housing having a rotor receiving chamber and a lubricant chamber; a rotor eccentrically arranged in the rotor receiving chamber; an inlet channel for supplying the fluid to be conveyed into the conveying chamber and a discharge channel for discharging the fluid to be conveyed from the conveying chamber in the direction of the lubricant chamber. The rotor is eccentrically arranged in the rotor receiving chamber so as to have at least one conveying chamber, the volume of which changes cyclically during the rotation of the rotor. A valve device is arranged between the discharge channel and the lubricant chamber to prevent the fluid (especially lubricant and / or the fluid to be conveyed) from flowing back from the lubricant chamber into the conveying chamber. The rotary vane pump is designed and equipped so that the discharge channel leads to the lubricant chamber. The rotary vane pump has at least one ventilation channel, which is fluidically connected to the conveying chamber by means of a conveying chamber end, and is fluidically connected to the space outside the conveying chamber by means of the ventilation end. In addition, the rotary vane pump has at least one compensation channel, which is fluidically connected to the conveying chamber by means of a conveying chamber end, and is fluidically connected to the lubricant chamber by means of the compensation end. The rotary vane pump is designed and equipped so that the compensation end of the compensation channel opens into the lubricant chamber below the lubricant level in the operating state of the rotary vane pump. In the stationary state (or closed state) of the rotary vane pump, the compensation end of the compensation channel opens into the lubricant chamber above the lubricant level.

[0014] At first glance, the design of a rotary vane pump with separate discharge, ventilation and compensation channels appears unnecessarily complex. However, the increased manufacturing costs (which are indeed the case) are usually more than compensated by the associated advantages. This is because the separate design of the different channels (discharge channel, ventilation channel, compensation channel) makes it possible to optimize the relevant channels for the functionality to be achieved in each case, without usually having any significant adverse effects on the other functionality of the rotary vane pump, in particular the functionality of the other channels.

[0015] For example, the ventilation channel can be designed in particular with respect to the placement and / or size of its conveying chamber end, with respect to the placement and / or size of its ventilation end, and / or with respect to other geometric dimensions (in particular cross-sectional shape, cross-sectional dimensions, fluid throttling device, position, channel routing, etc.) so that it can (to a large extent) optimally perform the ventilation function associated with it. Due to its at least partially separated design, this usually has no or at most only a slight adverse effect on other functionalities. In the case of the ventilation function, it must be ensured in particular that on the one hand the best possible noise reduction is achieved, but on the other hand the pumping behavior of the rotary vane pump is not excessively adversely affected (in particular with respect to the low pressure that can be achieved, efficiency losses due to the inflowing fluid, etc.). In this context, it should be noted that, for the sake of completeness, it may be necessary to find a compromise between optimizing the noise reduction and minimizing the pumping efficiency losses as much as possible. However, this compromise largely only relates to the ventilation functionality itself / ventilation channel itself, and not to the remaining channels and their functionality.

[0016] What has been said above about the ventilation channel can also be applied in an analogous manner to other channels, in particular the discharge channel and / or the compensation channel. In particular, the discharge channel generally requires particularly effective pumping performance with respect to the fluid to be conveyed (in particular when the fluid to be conveyed is discharged from the conveying chamber). In this case, a sufficiently large cross-sectional area must be selected for good conveying performance. However, an excessively large discharge channel can be disadvantageous, since it can reduce the achievable vacuum quality.

[0017] In particular, with regard to the compensation channel, the main concern is usually to achieve the best possible sealing effect in the operating state of the rotary vane pump, combined with the fastest possible ventilation of the delivery chamber / rotor receiving chamber when the rotary vane pump is switched off or after being switched off, and / or a sufficiently small lubricant volume flowing into the delivery chamber / rotor receiving chamber when the rotary vane pump is switched off or after being switched off. In principle, the ventilation end of the ventilation channel can be in fluid contact with essentially any area. In particular, these areas can be areas that are largely under atmospheric pressure. The fluid communication can take place with the environment (i.e. the outside) and also with certain (internal) areas of the rotary vane pump, in particular with these (internal) areas of the rotary vane pump that are essentially under ambient pressure / atmospheric pressure (in particular in the operating state of the rotary vane pump). For example, it can be an area of ​​a lubricant chamber (or, if applicable, a lubricant groove and / or a lubricant supply chamber) that is (substantially) filled with gas, or an area of ​​a lubricant chamber (or, if applicable, a lubricant groove and / or a lubricant supply chamber) that is (substantially) filled with a gaseous fluid (or, if applicable, a lubricant groove and / or a lubricant supply chamber).

[0018] For the sake of completeness, it is pointed out that an excess of lubricant flowing into the delivery chamber / rotor receiving chamber may result in a (too) high torque being required when restarting the rotary vane pump. Additionally or alternatively, damage to the rotary vane pump or at least increased wear may occur, which is inherently undesirable. An excess of lubricant flowing into the rotor receiving chamber may also result in lubricant leaking into the inlet channel of the rotary vane pump, which may cause the vacuum region or the vacuum device (if applicable) to be oiled.

[0019] In principle, any type of valve design is conceivable. In particular, passive valves, non-return valves, disk valves, seat valves, etc. come into consideration. When designing the valve arrangement, consideration should be given to a combination of low-cost construction, the highest possible sealing effect, a long service life, and a high maximum possible switching frequency.

[0020] In particular, it is possible to arrange the compensating end of the compensating channel, and / or the ventilation end of the ventilation channel, and / or the discharge end of the discharge channel in a region of the lubricant chamber substantially adjacent to the rotor receiving chamber or the conveying chamber. In particular, the relevant ends can be formed in the wall that separates the lubricant chamber from the rotor receiving chamber or the conveying chamber. In this way, a compensating channel, ventilation channel, or discharge channel that is mostly straight and / or relatively short can be achieved. This can in particular facilitate a simple construction and can also be functionally advantageous.

[0021] In particular, the conveying chamber end of the ventilation channel of the rotary vane pump and / or the conveying chamber end of the compensation channel can directly lead to the conveying chamber of the rotary vane pump. In other words, separate openings (separate openings from each other) are provided for the separate channels (ventilation channel, compensation channel and / or discharge channel) towards the conveying chamber, that is, in other words, non-overlapping openings are provided or channels that are not gathered together are provided, and there is a common conveying chamber opening / end and a common channel portion towards the conveying chamber. The same situation also applies to the conveying chamber end of the discharge channel adjacent to the conveying chamber. The separate design makes it possible to optimize the corresponding conveying chamber end for the corresponding purpose, in particular its placement, cross-sectional shape and cross-sectional size. In initial tests, for example, it has been shown that it is advantageous if the corresponding conveying chamber end is placed at different (that is, in particular slightly offset) positions, in particular along the circumferential direction of the rotor receiving chamber / conveying chamber. For example, placing the conveying chamber end of the ventilation channel close to the dead point in combination with a highly efficient rotary vane pump can achieve particularly effective noise reduction, while the conveying chamber end of the compensation channel is preferably placed at a place farther away from the dead point. First tests have shown that in particular the conveyor chamber ends of the ventilation channels (and, if necessary, additionally or alternatively, the conveyor chamber ends of the compensation channels) should be located in the last third, preferably in the last quarter, of the angular extent of the respective conveyor chamber, which results when one side of the respective conveyor chamber encounters a dead point. For example, if there are three conveyor chambers in the rotor receiving region and the conveyor chamber ends of the relevant channels are positioned in the last third, the conveyor chamber ends should be arranged in an angular extent of 360°·1 / 3·1 / 3=40° before the dead point. If there are four conveyor chambers, this would result in an angular extent of 360°·1 / 4·1 / 3=30° before the dead point. Additionally or alternatively, different placement positions of different conveyor chamber ends (or parts thereof) in the axial direction can be used, in particular in order to allow a separation of different conveyor chamber ends, although they have (approximately) equivalent or only slightly different placement positions in the circumferential direction of the rotor receiving chamber. Again, additionally or alternatively, it is also conceivable that at least parts of the conveyor chamber ends are arranged at (approximately) the same height when viewed in the circumferential direction and / or in the axial direction. For the sake of completeness, it should be noted that at least some of the channels can of course be designed such that the relevant channels are brought together at a certain distance from the delivery chamber / rotor receiving chamber in order to result in a common delivery chamber end / delivery chamber opening to a certain extent. In particular, the latter design form can lead to a simplified construction of the rotary vane pump in question, a smaller installation space requirement, and / or an improved functionality.

[0022] It is further proposed that in the rotary vane pump the compensating channel is arranged such that in the operating state of the rotary vane pump it opens completely into the lubricant chamber below the lubricant level of the lubricant chamber and preferably in the stationary state of the rotary vane pump it opens at least partially (preferably at least substantially completely) into the lubricant chamber above the lubricant level. Such a design makes it possible in particular to achieve a high degree of sealing of the compensating channel in the operating state of the rotary vane pump in combination with a good ventilation efficiency of the delivery chamber / rotor receiving chamber after the rotary vane pump is shut off. Furthermore, the amount of fluid (in particular lubricant, but also external fluid and / or fluid to be delivered; also a mixture of different fluids, for example a mixture of lubricant and fluid to be delivered) flowing into the delivery chamber / rotor receiving chamber can be kept as low as possible in order to maintain or even possibly increase the efficiency of the rotary vane pump. If, as is preferably proposed, in the stationary state (in particular shortly after the rotary vane pump is switched off or shut down), the compensating end of the compensating channel opens into the lubricant chamber above the lubricant level, a particularly rapid ventilation of the delivery chamber / rotor receiving chamber can be achieved and / or the amount of lubricant flowing into the delivery chamber / rotor receiving chamber can be minimized. These are generally desired features for rotary vane pumps.

[0023] It is further proposed that the rotary vane pump is designed so that the ventilation end of the ventilation channel leads to the lubricant chamber. The ventilation end of the ventilation channel can preferably lead to the lubricant chamber above the lubricant level, especially above the lubricant level in the operating state of the rotary vane pump. In other words, the ventilation end of the ventilation channel can preferably lead to the (at least substantially) gas-filled area of ​​the lubricant chamber, or the (at least substantially) gaseous liquid-filled area. This can effectively prevent the lubricant from causing unwanted contamination to the environment (external space). The loss of lubricant in the rotary vane pump can also be reduced, which is also advantageous. In this article, it should be noted that any lubricant (for example, in the form of lubricant mist) entrained from the lubricant chamber by the ventilation channel into the conveying chamber / rotor receiving chamber is generally not a problem, and in particular, it is generally negligible compared to the amount of lubricant introduced via the compensation channel (although the amount of lubricant entering the conveying chamber / rotor receiving chamber through the compensation channel is relatively low due to the design of the proposed rotary vane pump).

[0024] Furthermore, it is proposed to design the rotary vane pump such that the discharge channel is arranged such that, in the operating state of the rotary vane pump, the discharge channel opens into the lubricant chamber at least partially (preferably at least substantially completely) below the lubricant level of the lubricant chamber. This applies in particular to the operating state of the rotary vane pump; however, it can also apply to the stationary state of the rotary vane pump. In this way, the sealing of the valve device can generally be particularly high, so that the efficiency of the rotary vane pump can be increased and / or a valve device with a relatively simple structure and / or inexpensive production can be used.

[0025] It is further proposed that in the rotary vane pump, the lubricant chamber has a lubricant trough adjacent to the discharge channel and a lubricant storage area, the lubricant trough and the lubricant storage area being preferably separated from each other by a partition, preferably by an overflow partition. Due to this relatively simple further development, it is particularly possible for the lubricant level in the lubricant trough to drop particularly quickly when the rotary vane pump is shut down, and thus, in particular, the compensating end of the compensating channel can be located particularly quickly at a point where it is partially / mostly completely above the lubricant level (by lowering the lubricant level). In particular, this can significantly reduce the amount of lubricant that enters the rotor receiving chamber via the compensating channel. By providing a lubricant storage area separate from the lubricant trough, the supply volume of lubricant (which can be delivered to the relevant area of ​​the rotary vane pump via a feed pump or the like for lubricating various components) can be selected to be particularly large, so that the rotary vane pump can be operated particularly long without refilling lubricant. In particular, this can extend maintenance intervals and / or reduce the likelihood of damage due to lubricant loss. Another advantageous feature of the partition is that it defines the lubricant level in the lubricant sump to a large extent, in particular in the operating state of the rotary vane pump (excess lubricant flows through the partition into the lubricant storage area, it being noted that lubricant is usually replenished via the discharge channel). In this way, the lubricant level relative to the compensating end of the compensating channel, the venting end of the venting channel, and / or the discharge end of the discharge channel (primarily the compensating end of the compensating channel) in the operating state and in the stationary state of the rotary vane pump can be defined particularly easily and precisely. For the sake of completeness, it should be pointed out that the lubricant level in the lubricant sump is generally higher than the lubricant level in the lubricant storage area, in particular in the operating state of the rotary vane pump, but also in general in the closed state of the rotary vane pump.

[0026] It is possible that the bulkhead has at least one drainage opening and / or at least one recess in the region of the upper edge of the bulkhead. The number and size of the recesses in the region of the upper edge of the bulkhead should be selected so that the amount of lubricant discharged via these recesses / drainage openings is compensated by the lubricant that is subsequently delivered under all operating conditions that are actually expected in the operating state of the rotary vane pump. Generally, a safety margin must be taken into account. The discharge opening can be designed in particular as a through hole in the bulkhead. The proposed design can in particular promote a particularly rapid drop in the lubricant level in the region of the lubricant groove when the rotary vane pump switches from the operating state to the stationary state. This in turn can reduce the amount of lubricant that enters the rotor receiving chamber / delivery chamber when the rotary vane pump is shut down.

[0027] It is further proposed that at least one volume reduction device, in particular a bead device, is arranged in the lubricant chamber, in particular in the lubricant groove, particularly preferably in the upper filling level region of the lubricant chamber and / or the lubricant groove. In this way, for example, the cross section of the lubricant groove in the upper filling level region, in particular in the region of the upper edge of the partition wall, can be reduced. The upper level range can be understood in particular as the range between the lubricant level when the rotary vane pump is turned on and the lubricant level when the rotary vane pump is turned off. This makes it possible to further accelerate the drop in the lubricant level during the transition of the rotary vane pump from the operating state to the stationary state. Accordingly, the amount of lubricant entering the rotor receiving chamber / delivery chamber can be even further reduced. The bead device can in particular be arranged in the region of the upper edge of the partition wall on the partition wall. Additionally or alternatively, the partition wall can also be curved so that the cross section of the lubricant groove tapers towards the top.

[0028] Furthermore, it is proposed to design the rotary vane pump such that the valve device is designed at least partially as a valve tongue device. In particular, the valve device or the valve tongue device can also have several valve tongue areas. This allows a relatively simple and cost-effective design of the valve device. In particular in combination with at least partial immersion of the valve device in the lubricant chamber / lubricant trough, it generally enables a particularly high sealing effect of the valve device to be achieved.

[0029] When designing a rotary vane pump, it is possible (and usually preferred) to provide a plurality of inlet channels, discharge channels, and / or valve devices, and / or valve tongue devices, and / or ventilation channels, and / or compensation channels, and / or conveying chambers, and / or rotors, and / or rotor receiving chambers. In this way, the functionality of the rotary vane pump can be significantly increased. In particular, it is possible to improve the pumping performance, pressure, noise, and / or ventilation after the rotary vane pump is shut down / shut down. However, it should be noted that the rotary vane pump can also have exactly one rotor receiving chamber, one rotor, one conveying chamber, one inlet channel, one discharge channel, one valve device, one compensation channel, and / or one ventilation channel. However, it is also conceivable that one, more, or all of the components mentioned can appear multiple times (in particular twice, three times, four times, five times or six times). In this context, the possibility of "mixed combinations" is also mentioned, so that, for example, a rotary vane pump with a rotor and a rotor receiving chamber can have, for example, three delivery channels, two inlet channels, four discharge channels, a valve device (in particular with several valve areas, for example, in particular valve tongue areas), a ventilation channel and two compensation channels. Of course, other combinations are also conceivable.

[0030] It is further proposed that at least one ventilation channel and / or at least one compensation channel in the rotary vane pump has at least one fluid flow rate limiting device, in particular at least one throttling device. This can further increase the functionality of the channel in question. If the fluid flow rate limiting device is also designed to be variable and / or interchangeable (in each case, in particular with regard to the achievable fluid flow rate), it is also possible to adapt the rotary vane pump particularly easily to different application areas / usage situations. For example, by using different throttling devices, the rotary vane pump can be adapted for use with different lubricants (e.g., different viscosities) without requiring unduly cost-intensive adaptation work.

[0031] Another conceivable design of the rotary vane pump is when at least one valve device of the rotary vane pump is designed as a completely sealed valve device, in particular so that at least one valve tongue area of ​​the valve device is designed to be substantially free of recesses. In this way, the efficiency of the rotary vane pump can generally be further increased. In particular, pumping losses and / or reduced pressure / vacuum quality can generally be avoided. It should be noted that functionality such as ventilation during operation to reduce noise and / or ventilation of the rotor receiving chamber / delivery chamber of the rotary vane pump when the rotary vane pump is closed can be achieved by means of a device (compensation chamber / ventilation channel) specially provided and designed for this purpose, so that it can optimize the functionality to be achieved in each case. In a sense, the proposed design can also be understood as a valve device that is optimized for its intended use, or a valve device that can be optimized for its intended use, that is, it allows the fluid to flow (roughly) only in one direction.

[0032] Another embodiment of the rotary vane pump is when the dimensions of the rotary vane pump, in particular the volume of the lubricant chamber, particularly preferably the volume of the lubricant groove, are selected such that, during the transition from the operating state of the rotary vane pump to the stationary state, a reduction in the lubricant level is achieved by an initial lubricant transfer from the lubricant chamber and / or the lubricant groove to the delivery chamber / rotor receiving chamber via the compensation channel, wherein the maximum lubricant transfer into the delivery chamber (in particular with respect to volume) is dimensioned such that a restart of the rotary vane pump is not significantly affected, in particular substantially not affected, by the lubricant present in the delivery chamber. Additionally or alternatively, the maximum lubricant transfer into the delivery chamber (in particular with respect to volume) should be dimensioned such that the lubricant entering the region of the channel or entering the entry channel is reduced, in particular minimized or at least substantially prevented. In this way, when the rotary vane pump is shut down / shut down (the rotary vane pump is transferred from the operating state to the stationary state), a functionality that is ideal for the rotary vane pump can be achieved by means that are relatively simple and inexpensive to implement. In particular, the volume of lubricant transferred should be so small that when the rotary vane pump is restarted no undesirably high drive torque is required and / or no increased wear and / or no damage to mechanical parts (in particular wall components / slides etc.) occurs (at least under practically expected operating conditions).

[0033] In particular, it is proposed that the rotary vane pump is designed and arranged such that the relative arrangement of the lubricant level in the lubricant chamber and / or lubricant trough on the one hand and the compensating end of the discharge channel and / or compensating channel on the other hand is (entirely) caused by a change in the lubricant level (height / level). This change in the lubricant level can be achieved in particular by suitable dimensioning of the lubricant chamber / lubricant trough. This makes the required functionality particularly easy to implement technically. In particular, for example, no moving mechanical parts need to be provided for this purpose.

[0034] In particular, it is proposed that in a rotary vane pump, at least one conveying chamber is at least partially delimited by a wall component, which is movable and / or pivotable relative to the rotor. In particular, the displacement capability of the wall component (usually referred to as a slide) relative to the rotor can be achieved by means of the wall component, which is displaceably mounted in a correspondingly formed receiving groove (usually referred to as a slide groove) in the rotor. It is thus pointed out that mechanical wear can be reduced by the relative movement between the rotor and the wall component with the help of a lubricant. Typically, this form of construction results in 2, 3, 4, 5, 6, 7, 8, 9, 10 or more conveying chambers (in particular in each rotor receiving area), although it has been stated that it is not necessarily limited to this embodiment.

[0035] Furthermore, it is proposed that the ventilation channel of the rotary vane pump, in particular the fluid flow rate restriction device of the ventilation channel, is dimensioned such that, in the operating state of the rotary vane pump, a noise reduction is achieved without significantly impairing the delivery rate of the rotary vane pump. Generally, this is also a particularly desirable operating behavior for a rotary vane pump. Due to the design of the rotary vane pump proposed previously here, this particularly desirable operating behavior of the rotary vane pump can be achieved technically by relatively simple means.

[0036] It is further proposed that in a rotary vane pump, the compensation channel, in particular the fluid flow rate limiting device of the compensation channel, is dimensioned so that during shutdown of the rotary vane pump, sufficient ventilation of the delivery chamber is achieved without significantly impairing the operating state due to lubricant and / or fluid to be delivered flowing back through the compensation channel. This is also a particularly ideal operating behavior of the rotary vane pump. Once again, due to the design of the rotary vane pump proposed here, this ideal operating behavior of the rotary vane pump can be easily achieved by relatively simple means.

[0037] More advantages, features and functions of the present invention will be apparent from the following detailed description of the present invention in conjunction with the corresponding drawings. The drawings show:

[0038] Figure 1 is a schematic cross-sectional view of a rotary vane pump having a transversely arranged lubricant chamber;

[0039] Figure 2 for Figure 1 An enlarged detail view of the area of ​​the discharge channel, ventilation channel and compensation channel;

[0040] Figure 3 for Figure 1 A lateral top view of the region of the rotary vane pump shown having the valve tongue arrangement; and

[0041] Figure 4 for Figure 1 A lateral plan view of an overflow partition in a lubricant chamber of a rotary vane pump is shown.

[0042] Figure 1 2 shows a schematic cross-sectional view of a rotary vane pump 1. The basic structure of this rotary vane pump 1 is known in the prior art and is used in a variety of applications.

[0043] The rotary vane pump 1 has a housing 2 in which a hollow space, i.e. a rotor receiving chamber 3, is formed. Arranged in an eccentrically offset manner in the rotor receiving chamber 3 is a rotor 4 which is set to be rotationally movable along an axis of rotation 5. In the embodiment example shown, the rotor 4 has three slide grooves 6, in each of which a wall component 7 (also often referred to as a slide, a vane or a sliding vane) is arranged so as to be displaceable relative to the rotor 4, so that the wall component 7 rotates together with the rotor 4. Through the rotation of the rotor 4 about the axis of rotation 5, the wall component 7 is pressed against the inner wall 8 of the rotor receiving chamber 3 due to the centrifugal force. With the help of the lubricant 10, the mechanical friction between the front end 9 of the wall component 7 and the inner wall 8 of the rotor receiving chamber 3 is reduced, and thus the wear of the rotary vane pump 1 is significantly reduced. At the same time, the lubricant film between the front end 9 of the wall component 7 and the inner wall 8 of the rotor receiving chamber 3 produces a sealing function, so that the fluid to be conveyed cannot flow here.

[0044] The wall element 7 divides the rotor receiving chamber 3 (taking into account the rotor 4) into three conveying chambers 11, namely, conveying chambers 11a, 11b and 11c. Due to the current position of the rotor 4 and the dead point 15, the conveying chamber 11c can be further divided into two sub-conveying chambers 11c, 11c' separated by the dead point. Due to the eccentric arrangement of the rotor 4 in the rotor receiving chamber 3, the volume of the conveying chamber 11 changes cyclically during the rotation of the rotor 4 of the rotary vane pump 1, so that the fluid can be conveyed.

[0045] The fluid to be conveyed is sucked into one of the three conveyor chambers 11 (currently the conveyor chamber 11a and possibly also the conveyor chamber 11c') via the inlet opening 12. As already mentioned, the conveyor chamber 11 in question is delimited by two adjacent wall elements 7. Due to the initial expansion of the respective conveyor chamber 11, the fluid to be conveyed is sucked into the respective conveyor chamber 11 (the conveyor chamber 11a). After the respective conveyor chamber 11 is separated from the inlet opening 12 by the rotation of the rotor 4 from a specific angular position, the volume of the rotor receiving chamber 3 is reduced again due to the shape of the rotor receiving chamber 3 and the rotor 4 eccentrically arranged in the rotor receiving chamber 3, so that the fluid contained therein is compressed (the conveyor chamber 11b). From the specific angular position of the rotor 4 or the respective conveyor chamber 11, a fluid connection to the discharge channel 13 is established and the fluid to be conveyed is ejected from the conveyor chamber 11 via the discharge channel 13 into the lubricant chamber 14 (the conveyor chamber 11c). The fluid is injected into the lubricant chamber 14 via the valve flap device 21, which opens when the pressure in the delivery chamber 11 is slightly higher than the pressure in the lubricant chamber 14 (usually close to atmospheric pressure). The described cycle then starts again from the beginning. The so-called dead point 15 should be mentioned, which separates the area of ​​the rotor receiving chamber 3 adjacent to the discharge channel 13 from the area of ​​the rotor receiving chamber 3 adjacent to the inlet opening 12.

[0046] The lubricant chamber 14 is connected to the region of the housing 2 of the rotary vane pump 1 via a flange region 16, in which the rotor receiving chamber 3 and the rotor 4 are formed. In the present embodiment, the lubricant chamber 14 has two different regions. The regions are a lubricant groove 17 arranged adjacent to the discharge channel 13, and a lubricant storage region 18 designed to be separated from the lubricant groove 17. The lubricant groove 17 and the lubricant storage region 18 are separated from each other by a partition wall, which is designed as an overflow partition wall 19.

[0047] The discharge end 20 facing the lubricant groove 17 is connected to the lubricant groove 17 via a valve device, which is designed in this case as a valve tongue device 21. For example, the valve tongue device 21 is connected to the housing 2 of the rotary vane pump 1 by means of screws 22. In the embodiment example shown here, the valve tongue device 21 has four elastic valve tongue areas 23 (see also according to Figure 3 ), which cover the respective discharge ends 20 of the discharge channels 4 and which are also arranged adjacent to each other in the axial direction of the rotation axis 5 of the rotor 4. Due to the elastic valve tongue area 23, the fluid to be conveyed by the rotary vane pump 1 can only flow from the rotor receiving chamber 3 in the direction of the lubricant chamber 14, but not in the opposite direction.

[0048] In the case under consideration, the rotary vane pump 1 is designed such that, in the operating state of the rotary vane pump 1, the discharge end 20 of the discharge channel 13 opens into the lubricant groove 17 below the lubricant level 24 in the operating state of the rotary vane pump 1. This has the advantage that the lubricant 10 in the lubricant groove 17 exerts a certain fluid pressure on the elastic valve tongue area 23 and, as a result, the discharge end 20 of the discharge channel 13 is securely closed (fluid-tight) by means of the valve tongue area 23. As a result, the ambient pressure of the lubricant chamber 14 naturally exerts pressure on the lubricant 10 in the lubricant groove 17. In addition, the lubricant 10 provides a certain degree of sealing of any gaps and cracks that may be present, so that the tightness of the valve tongue device 21 is therefore also particularly high.

[0049] Especially from Figure 2 As can be seen in the enlarged view, in the present embodiment example of the rotary vane pump 1 shown, in addition to the discharge channel 13, there is also a ventilation channel 26, which in this case is completely separated from the discharge channel 13, and (in this case) also has two compensation channels 29, which are also designed to be completely separated from the discharge channel 13 and the ventilation channel 26.

[0050] The ventilation channel 26 has a ventilation end 27, which opens into the lubricant chamber 14 (or lubricant groove 17) above the lubricant level 24 in the operating state of the rotary vane pump 1. The delivery chamber end 28 of the ventilation channel 26 is arranged at a suitable position in the rotor receiving chamber 3, preferably directly adjacent to the dead center 15. Due to the ventilation channel 26, a small amount of air or a small amount of fluid (in particular a gaseous fluid) present in the lubricant chamber 14 can flow into the compression area of ​​the rotor receiving chamber 3. This leads to a reduction in the occurrence of noise, especially when the rotation speed of the rotor 4 is within a limited range. Since the ventilation opening 26 can be optimized for the purpose of noise reduction, a partially significant noise reduction can be achieved by means of relatively small construction efforts, without adversely affecting other advantageous properties of the rotary vane pump 1 to a significant extent (which will be explained in more detail below).

[0051] In particular, it is possible to provide the ventilation channel 26 with an appropriately sized throttle 32. Furthermore, it is also possible to make the throttle 32 interchangeable, so that the rotary vane pump 1 can be quickly adapted to different operating environments and for different purposes (also retroactively).

[0052] Furthermore, in the embodiment example shown here, two compensating channels 29 are provided, which are arranged at the same height but axially offset from one another (with respect to the axis of rotation 5 of the rotor 4) (see also Figure 3 Of course, a different number of compensation channels 29 is also possible (this also applies to the ventilation channels 26, by the way).

[0053] The compensation ends 30 of the compensation channels 29 are arranged such that they are located just below the lubricant level 24 of the lubricant groove 17 in the operating state of the rotary vane pump 1. Thus, a certain sealing effect is achieved by means of the lubricant 10 in the lubricant groove 17, so that during operation of the rotary vane pump 1, only a slight (net) fluid output (if any) occurs through the outlet channel 29. This applies both to the flow of the fluid to be conveyed out of the rotor receiving chamber 3 in the direction of the lubricant chamber 14 and to the flow of the fluid (in particular the lubricant 10) out of the lubricant chamber 14 or the lubricant groove 17 in the direction of the rotor receiving chamber 3.

[0054] With regard to the arrangement of the compensation ends 30 of the outlet channels 29, it is particularly noteworthy that these compensation ends are completely below the lubricant level 24 in the operating state of the rotary vane pump 1, but only just below the lubricant level 24 in the operating state of the rotary vane pump 1. This is relevant because after a shutdown of the rotary vane pump 1 (whether intentional or unintentional), the compensation channels 29 should be exposed as quickly as possible. Therefore, the lubricant level of the lubricant groove 17 should drop as quickly as possible to the level that it was when the rotary vane pump 1 was shut down (by Figures 1 to 3) is indicated by the dotted line in FIG. This will be discussed in more detail below.

[0055] In the operating state of the rotary vane pump 1, the fluid to be conveyed, which is rich in lubricant 10 (the fluid to be conveyed is sucked in via the inlet opening 12), is conveyed into the discharge channel 13 from the conveying chamber 11 (in this case the conveying chamber 11c) located adjacent to the discharge channel 13 by means of the cyclically increasing and decreasing conveying chamber 11. Due to the pressure generated, the elastic valve tongue area 23 of the valve tongue device 31 is pressed away from the wall of the flange area 16, so that the mixture of lubricant and fluid enters the lubricant groove 17 or the oil chamber 14. This continuous flow of the mixture of lubricant and fluid (and therefore also the lubricant 10) keeps the lubricant level 24 in the operating state of the rotary vane pump 1 in the upper range. The upper lubricant level 24 is substantially defined by the upper edge 35 of the overflow partition 19. The function of the optional recess 36 in the area of ​​the upper edge 35 of the overflow partition 19 and the optional drainage opening 37 in the overflow partition 19 will be discussed below. In any case, the recesses 36 and the drainage openings 37 (if present) are dimensioned with respect to number and size such that, in all practically expected operating states of the rotary vane pump 1, the lubricant level 24 in the operating state of the rotary vane pump 1 remains in the region of the upper edge 35 of the overflow partition 19, whereby the overflow 38 of the lubricant 10 (at Figure 1 and 2 The lubricant level 24 rises above the upper edge 35 of the overflow partition 19 (indicated by arrow 38 in the figure), the overflow 38 causing the lubricant 10 to flow from the lubricant groove 17 into the lubricant storage area 18 of the lubricant chamber 14.

[0056] The lubrication of the rotary vane pump 1, in particular in the region of the rotor 4 or the rotor receiving chamber 3, can be achieved by means of a lubricant pump, not shown here, which, for example, releases lubricant 10 in the region of an inlet 12 of the rotary vane pump. Such a lubricant pump and the lubrication of such a rotary vane pump 1 are as known in the prior art.

[0057] When the rotary vane pump 1 stops (e.g. due to an intentional shutdown procedure, but also due to an unintentional malfunction), air or fluid (in particular, mainly gaseous fluid) is sucked from the lubricant chamber 14 via the ventilation channel 26 into the rotor receiving chamber 3. In addition, lubricant 10 initially flows from the lubricant groove 17 via the compensation channel 29 into the rotor receiving chamber 3. Since no lubricant 10 (via the discharge channel 13) is “replenished” into the lubricant groove 17 due to the stop of the rotary vane pump 1, the initial lubricant level 24 in the operating state of the rotary vane pump 1 drops rapidly to the reduced lubricant level 34 in the closed state of the lubricant pump 1. Accordingly, the compensation end 30 of the compensation channel 29 is now exposed, so that air or a substantially gaseous fluid is now sucked from the lubricant chamber 14 into the rotor receiving chamber 3. This allows the pressure in the rotor receiving chamber 3 to be balanced particularly quickly. Since the rotor receiving chamber 3 can thus reach the ambient pressure (usually atmospheric pressure) particularly quickly, it can be ensured that only a minimum amount of lubricant enters the rotor receiving chamber 3. This is an advantageous way of preventing the rotor receiving chamber 3 from filling up with lubricant.

[0058] The rapid reduction of the lubricant level from the level 24 in the operating state to the level 34 in the closed state can be accelerated by means of optional recesses 36 in the upper edge 35 of the overflow partition 19 and / or by means of drainage openings 37 in the overflow partition 19. The number and size of the recesses 36 and / or drainage openings 37 can be selected so that the amount of lubricant drained out through these recesses / openings is compensated (usually plus a safety margin) under all practically expected operating conditions in the operating state of the rotary vane pump 1. In order to enable the rotary vane pump 1 to be adapted to different applications and / or operating conditions, the recesses 36 and / or drainage openings 37 can be designed to be reversibly closable, for example by providing an internal thread (particularly in the case of drainage openings 37) or by means of the possibility of sliding onto the discharge edge (particularly in the case of the recesses 36 being located in the region of the upper edge 35).

[0059] Furthermore, in the embodiment example shown, a bead 39 (which is also optional) is attached in the region of the upper edge 35 of the overflow partition 19. This makes the cross section ( Figure 1 and Figure 2 The bead 39 is a horizontal section in the view of FIG. 39 , which tapers so that the reduced volume of lubricant 10 is sufficient to reduce the lubricant level 24 in the operating state to the lubricant level 34 in the closed state of the rotary vane pump 1 (compared to the situation without the bead 39). The bead 39 also increases the effectiveness of the recess 36 and / or the drainage opening 37 (if any).

[0060] Furthermore, it is possible to pick out only individual components of the detailed described embodiment example of the rotary vane pump 1 described in this text (or also a certain subset of the described features) and combine them with the general description of the presently proposed rotary vane pump.

Claims

1. A rotary vane pump (1) for conveying a fluid to be conveyed, the rotary vane pump comprising: A housing (2) having a rotor receiving chamber (3) and a lubricant chamber (14); a rotor (4) which is eccentrically arranged in the rotor receiving chamber (3) so as to form at least one conveying chamber (11), the volume of which varies cyclically when the rotor (4) rotates; an inlet channel (12) for supplying the fluid to be conveyed into the at least one conveying chamber (11) and a discharge channel (13) for discharging the fluid to be conveyed outside the at least one conveying chamber (11) in the direction of the lubricant chamber (14), wherein a valve device (21) is arranged between the discharge channel (13) and the lubricant chamber (14) to prevent a backflow of fluid, in particular a backflow of lubricant and / or fluid to be conveyed, from the lubricant chamber (14) to the at least one conveying chamber (11), wherein the rotary vane pump (1) is designed and configured such that the discharge channel (13) is arranged to open into the lubricant chamber (14), It is characterized in that at least one ventilation channel (26) which is fluidly connected to the at least one transport chamber (11) via a transport chamber end (28) and is fluidly connected to a chamber outside the at least one transport chamber (11) via a ventilation end (27), and At least one compensation channel (29) is fluidically connected to the at least one delivery chamber (11) via a delivery chamber end (31) and is fluidly connected to the lubricant chamber (14) via a compensation end (30), wherein the rotary vane pump (1) is designed and arranged such that the compensation end (30) opens into the lubricant chamber (14) below the lubricant level (24) in the operating state of the rotary vane pump (1) and opens into the lubricant chamber (14) above the lubricant level (34) in the stationary state of the rotary vane pump (1).

2. The rotary vane pump (1) according to claim 1, characterized in that The delivery chamber end (28) of the ventilation channel (26) and / or the delivery chamber end (30) of the compensation channel (29) directly leads to the delivery chamber (11) of the rotary vane pump (1).

3. The rotary vane pump (1) according to claim 1 or 2, characterized in that The compensating channel (29) is arranged such that, in the operating state of the rotary vane pump, the compensating channel opens into the lubricant chamber (14) completely below the lubricant level (24) of the lubricant chamber (14), and preferably, in the stationary state of the rotary vane pump (1), the compensating channel opens into the lubricant chamber (14) at least partially above the lubricant level (34), preferably at least substantially completely above the lubricant level (34).

4. The rotary vane pump (1) according to claim 1, characterized in that The ventilation end (27) of the ventilation channel (26) leads to the lubricant chamber (14).

5. The rotary vane pump (1) according to claim 1, characterized in that The discharge channel (13) is arranged such that, in an operating state of the rotary vane pump (1), the discharge channel opens into the lubricant chamber (14) at least partially below the lubricant level (24) of the lubricant chamber (14), preferably at least substantially completely below the lubricant level (24) of the lubricant chamber (14).

6. The rotary vane pump (1) according to claim 1, characterized in that The lubricant chamber (14) has a lubricant groove (17) adjacent to the discharge channel (13), and a lubricant storage area (18), wherein the lubricant groove (17) and the lubricant storage area (18) are preferably separated from each other by a partition wall, and preferably separated from each other by an overflow partition wall (19).

7. The rotary vane pump (1) according to claim 6, characterized in that The partition wall (19) has at least one drainage opening (37) and / or at least one recess (36) in the region of an upper edge (35) of the partition wall (19).

8. Rotary vane pump (1) according to one of the preceding claims, in particular claim 6 or 7, characterized in that At least one volume reduction device, in particular a bead device (39), is arranged in the lubricant chamber (14), in particular in the lubricant groove (17), particularly preferably in the upper filling level area of ​​the lubricant chamber (14) and / or the lubricant groove (17).

9. The rotary vane pump (1) according to claim 1, characterized in that The valve device (21) is designed at least in some areas as a valve tongue device (23).

10. The rotary vane pump (1) according to claim 1, characterized in that It has multiple inlet channels (12), and / or discharge channels (13), and / or valve devices (21), and / or valve tongue devices (23), and / or ventilation channels (26), and / or compensation channels (26), and / or conveying chambers (11), and / or rotors (4), and / or rotor receiving chambers (3).

11. The rotary vane pump (1) according to claim 1, characterized in that At least one ventilation channel (26) and / or at least one compensation channel (26) comprises at least one fluid flow rate limiting device, in particular at least one throttling device (32, 33).

12. The rotary vane pump (1) according to one of the preceding claims, in particular one of claims 9 to 11, characterized in that At least one valve device (21) is designed as a completely sealed valve device, in particular such that at least one valve tongue device (23) is designed substantially without recesses.

13. The rotary vane pump (1) according to one of the preceding claims, in particular one of claims 6 to 12, characterized in that The dimensions of the rotary vane pump (1), in particular the volume of the lubricant chamber (14), particularly preferably the volume of the lubricant groove (17), are selected such that during a transition from an operating state of the rotary vane pump (1) to a stationary state, a reduction in the lubricant level (24) is achieved by an initial lubricant transfer from the lubricant chamber (14) and / or the lubricant groove (17) to the delivery chamber (11) via the compensation channel (29), whereby the maximum lubricant transfer into the delivery chamber (11) is dimensioned such that a restart of the rotary vane pump (1) is not impaired by the lubricant present in the delivery chamber (11).

14. The rotary vane pump (1) according to one of the preceding claims, in particular one of claims 6 to 13, characterized in that The rotary vane pump (1) is designed and configured such that the relative arrangement of the lubricant level (24, 34) in the lubricant chamber (14) and / or the lubricant groove (17) on the one hand and the compensating end (30) of the discharge channel (13) and / or the compensating channel (29) on the other hand is caused by a change in the lubricant level (24, 34).

15. The rotary vane pump (1) according to claim 1, characterized in that The at least one conveying chamber (11) is at least partially delimited by a wall element (7) which is able to slide and / or pivot relative to the rotor (4).

16. The rotary vane pump (1) according to one of the preceding claims, in particular one of claims 11 to 15, characterized in that The ventilation channel (26), in particular the fluid flow rate restriction device (32) of the ventilation channel (26), is dimensioned so as to achieve a noise reduction in the operating state of the rotary vane pump (1) without significantly impairing the delivery capacity of the rotary vane pump (1).

17. The rotary vane pump (1) according to one of the preceding claims, in particular one of claims 11 to 16, characterized in that The compensation channel (29), in particular the fluid flow rate restriction device (33) of the compensation channel (29), is dimensioned so that sufficient ventilation of the delivery chamber (11) is achieved during standstill of the rotary vane pump (1) without significantly impairing the operating state due to lubricant and / or fluid to be delivered flowing back through the compensation channel (29).

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