Adapter element and holding device for air deoiling element of vacuum pump

Abstract

The present invention relates to an adapter element suitable for a holding device for an air de-oiling element of a vacuum pump 1, comprising a first cylindrical portion 11a with a first diameter and a second cylindrical portion 11b with a second diameter adapted to receive the air de-oiling element, the first diameter being equal to or smaller than the second diameter, the second cylindrical portion 11b having an outer peripheral recess forming at least three fixing fingers 11e arranged parallel to the longitudinal axis of the adapter element and distributed evenly or unevenly around the circumference of the second cylindrical portion 11b, at least two fixing fingers 11f being mounted so as to be elastically displaceable in the radial direction. The present invention also relates to a holding device for an air de-oiling element of a vacuum pump, in particular an oil vacuum pump.

Description

[Technical field]

[0001] The present invention relates to an adapter element suitable for a holding device for an air de-oiling element of a vacuum pump, in particular an oil sealed vacuum pump (hereinafter referred to as oil vacuum pump). The present invention also relates to a holding device for an air de-oiling element of a vacuum pump. The present invention particularly relates to such an adapter element and such a holding device which allows quick and easy assembly and replacement of the air de-oiling element, in particular in a limited space. [Background technology]

[0002] In vacuum pumps, especially oil vacuum pumps such as rotary vane pumps, the fluid conveyed by the pump, consisting of a mixture of lubricating oil and gas, must be filtered before it leaves the pump. In the following, for ease of understanding, the term air is used instead of fluid. By means of a suitable air de-oiling element, the lubricating oil is returned to the lubrication system and the remaining purified air is exhausted. The air de-oiling element is held in the pump with an adapter element and a holder designed for this purpose, but it loses its filtering ability over time and must therefore be replaced periodically.

[0003] With known pumps and holding devices, replacing the air de-oiling element is laborious. In particular, it is often necessary to remove several parts connected to the air de-oiling element. These parts are required again for the assembly and installation of the new air de-oiling element. On the one hand, this is laborious and, on the other hand, often involves contamination, since the parts are covered with lubricating oil. In addition to this, the known adapter elements, i.e. the elements of the holding device which connect the air de-oiling element with the holding device, are too rigid and not easy to assemble.

[0004] EP 1 339 636 A1 proposes a holding device for an air deoiling element, which partially solves the above-mentioned problems. This device somewhat facilitates the installation of the air deoiling element compared to other known devices, and in particular prevents contamination, but even with this device a convenient installation is not always possible. The assembly of the air deoiling element with this device and other known devices is very difficult, especially in very limited spaces, where one-handed assembly is often required. When the installation space of the vacuum pump is limited, especially when there are restrictions on the direction in which the air deoiling element can be pulled out of the pump during replacement, it is difficult or very time-consuming to carry out the operations required for replacement and to check the correct position of the parts after re-installation is completed. Furthermore, EP 1 339 636 A1 discloses an adapter element which cooperates tightly with the air deoiling element, which further complicates the assembly.

[0005] Starting from the state of the art, the present invention aims to eliminate the aforementioned disadvantages of known devices and to propose an adapter element and a holding device for an air deoiling element of a vacuum pump, in particular an oil vacuum pump, which allows easy assembly and replacement of the air deoiling element. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2018 / 197614 Summary of the Invention

[0007] According to the invention, these objects are achieved, inter alia, by means of the elements of the two independent claims. Further preferred embodiments emerge from the dependent claims and the description.

[0008] In particular, according to a first aspect of the invention, the object is achieved by an adapter element suitable for a holding device for an air de-oiling element of a vacuum pump, the adapter element comprising a first cylindrical portion having a first diameter and a second cylindrical portion having a second diameter and adapted to receive the air de-oiling element, the first diameter being equal to or smaller than the second diameter, the second cylindrical portion having peripheral recesses forming at least three fixing fingers arranged parallel to a longitudinal axis of the adapter element and evenly or unevenly distributed over the circumference of the second cylindrical portion, at least two fixing fingers being mounted so as to be elastically radially displaceable.

[0009] The adapter element according to the invention ensures that the mounting of the holding device and the air de-oiling element can be carried out very easily. In particular, the presence of at least two elastically radially displaceable fixing fingers makes assembly and removal particularly easy and reliable. In addition to this, the adapter element can be made space-saving. The peripheral recess allows optimal circulation of the air discharged from the air de-oiling element. This ensures that excessive pressure does not build up between the air de-oiling element and the adapter element, which would impair the proper functioning of the pump.

[0010] In a first preferred embodiment of the first aspect of the invention, the diameter of the first cylindrical portion is smaller than the diameter of the second cylindrical portion and the adapter element has a conical portion between the first and second cylindrical portions, which has the advantage that the cross-sectional area of ​​the adapter involved in the flow is reduced and the exhausted air is directed to the outlet hole without additional flow losses.

[0011] In a second preferred embodiment of the first aspect of the invention, the cone of the adapter element has at least one, advantageously at least three, preferably at least five circumferential recesses. The circulation of the air leaving the air de-oiling element is further improved. Especially in the case of larger dimensions, the number of recesses should be increased to six or more for reasons of strength or stability of the adapter element.

[0012] According to a second aspect, the object of the invention is also achieved by a holding device for an air de-oiling element of a vacuum pump, in particular an oil vacuum pump, which holding device comprises: an adapter element for receiving the air deoiling element; an exhaust cover attachable to the housing of the vacuum pump to seal the exhaust port; a spiral spring disposed between the adapter element and the exhaust cover; Including, The holding device comprises a limiting means for limiting the distance between the adapter element and the exhaust cover.

[0013] Such a construction of the holding device according to the invention makes the assembly of the air de-oiling element and the holding device to the housing of the vacuum pump particularly easy. The restricting means ensure that the exhaust cover and the adapter element form a unit, so that the two elements cannot be separated from each other during assembly. Such a device is particularly advantageous in situations where the space for installation is very small, for example when the pump is mounted on a pumping unit. In such cases, one-handed assembly is particularly important. In addition to this, the spiral spring allows an optimal pressure to be applied to the air de-oiling element, so that this element is properly held and supported in the housing. The spring-type mounting of the air de-oiling element is important in order to be able to damp the vibrations of the pump and to compensate for the dimensional variations inherent to the parts related to production.

[0014] In a first preferred embodiment of the second aspect of the invention, the adapter element is an adapter element according to the first aspect of the invention, so that the orientation of the holder relative to the pump housing and the air de-oiling element is not critical for assembly, further simplifying assembly.

[0015] In a second preferred embodiment of the second aspect of the present invention, the adapter element, exhaust cover, and spiral spring are coaxially arranged, so that the orientation of the retainer relative to the pump housing and air de-oiling element is not critical to assembly, further simplifying the assembly.

[0016] In another preferred embodiment of the second aspect of the invention, the adapter element is freely rotatable relative to the exhaust cover, allowing the orientation of the adapter element to correspond to the exact shape of the air de-oiling element, which may be important where the air de-oiling element is not symmetrical or where there are provisions to prevent incorrect installation.

[0017] In a further preferred embodiment of the second aspect of the invention, the regulating means is in the form of a screw, the screw head of which is arranged on the outside air side of the exhaust cover and the cylindrical body opposite the screw head is provided with a locking means, preferably a removable locking means. A screw is a particularly simple embodiment of the regulating means. Furthermore, a removable locking means is particularly advantageous since the holding device can be designed as a kit. Thus, the adapter element or the spiral spring can be replaced as required. The adapter element can also be selected depending on the exact design of the air de-oiling element. The spiral spring can be replaced, for example, if the spring function no longer works as expected.

[0018] In a further preferred embodiment of the second aspect of the invention, the distance between the locking means and the exhaust cover is adjustable, which allows the retention device to be adapted to the shape of the pump housing and also allows the preload of the spiral spring to be adjusted. Adjustment of the distance between the locking means and the exhaust cover can be achieved by suitable components, for example lock nuts.

[0019] In another preferred embodiment of the second aspect of the invention, the locking means is in the form of an O-ring. O-rings have the advantage that they are cheap and easy to install and reposition. In addition to this, O-rings also have a degree of resiliency which may be advantageous over a relaxed spiral spring.

[0020] In yet another preferred embodiment of the second aspect of the invention, the holding device comprises a rubber-elastic plate, preferably made of elastomer, between the screw head and the exhaust cover, and an exhaust cover spring, advantageously in the form of a spider spring, between the screw head and the rubber-elastic plate, which allows the rubber-elastic plate to be pressed against the exhaust cover and close the exhaust holes of the exhaust cover. The spider spring has the advantage that the contact pressure of the spring is evenly distributed to a number of points on an annular line on the rubber-elastic plate. The rubber-elastic plate has the advantage that the air flowing out of the exhaust cover opens the plate to open the exhaust holes and, under the action of the spring force of the exhaust cover spring, the plate returns to its original position and closes the outlet holes again. This makes relative movement of the parts to each other unnecessary and eliminates mechanical wear of the parts.

[0021] In another preferred embodiment of the second aspect of the invention, the exhaust cover has a groove on its vacuum side for receiving an O-ring, the groove being formed in such a way that an O-ring inserted in the groove cannot be removed from the exhaust cover. This makes assembly particularly convenient. It is particularly advantageous when mounting a retaining device for an air de-oiling element, especially in a confined space, if it is ensured that the O-ring cannot be removed from the exhaust cover by movements or forces that normally occur during mounting or assembly.

[0022] In yet another preferred embodiment of the second aspect of the invention, the groove is chicane or baffled in at least two places. The chicane or baffled groove ensures that the O-ring will not become dislodged from the groove due to normal movements and forces encountered during assembly, without the shape of the groove affecting the sealing ability of the O-ring.

[0023] Further details of the invention will become apparent from the following description of preferred embodiments thereof, as illustrated in the accompanying drawings, in which: Further advantages of the invention can be seen from the specification, as well as suggestions and suggestions as to how the subject matter of the invention can be modified or further developed within the scope of the claims. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a cross-sectional view of a vacuum pump, an adapter element, and a retention device for an air de-oiling element, according to a preferred embodiment of the retention device and adapter element of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view of an air deoiling element, an adapter element, and a retention device according to a preferred embodiment of the present invention. [Diagram 3] FIG. 3 is a perspective cross-sectional view of an air deoiling element, an adapter element, and a retention device according to a preferred embodiment of the present invention. [Figure 4] FIG. 4 shows an exhaust cover of a holding device according to a preferred embodiment of the present invention. [Figure 4a] FIG. 4a is a detailed view of the exhaust cover of a holding device according to a preferred embodiment of the present invention. [Diagram 5] FIG. 5 is a perspective view of an adapter element and a retaining device according to a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] 1 is a cross-sectional view of a vacuum pump 1 including an air de-oiling element 2 and a holding device 10 according to a preferred embodiment of the present invention. The holding device 10 is designed to hold the air de-oiling element firmly and at the same time allow the air de-oiling element to be replaced.

[0026] The holding device 10 in this embodiment comprises an adapter element 11 according to the invention, which receives the air deoiling element 2. It should be noted, however, that the holding device can also comprise an adapter element known from the state of the art instead of the adapter element according to the invention, the details of which are explained below.

[0027] The holding device 10 further comprises an exhaust cover 12 sealing the exhaust hole 4 of the housing 3 of the pump 1, and a spiral spring 13 arranged between the adapter element 11 and the exhaust cover 12. Furthermore, in order to regulate the maximum distance between the adapter element 11 and the exhaust cover 12, a regulating means 14, here in the form of a screw, is provided. For this purpose, the screw 14 has in its cylindrical body 14a a locking means 15, here in the form of an O-ring. In the embodiment shown, the O-ring is arranged in a groove designed for it in the cylindrical body 14a of the screw 14. The advantage of the O-ring is that it is very easily separable from the screw 14, facilitating dismantling of the holding device 10. It should be noted that the maximum distance between the adapter element 11 and the exhaust cover 12 is preferably adjusted by a suitable part (not shown), such as a locking nut.

[0028] The adapter element 11 is preferably freely rotatable about the cylindrical body 14a of the screw 14. This allows the rotational position of the adapter element 11 relative to the air de-oiling element 2 to be adjusted. This is particularly advantageous if the adapter element 11 must be in a specific rotational position relative to the air de-oiling element 2 when the holding device 10 is mounted on the pump 1.

[0029] By means of the spiral spring 13 and the exhaust cover 12 the holding device 10 is able to press the air de-oiling element 2 with the required contact pressure so that the air de-oiling element 2 is securely attached to the housing 3 of the pump 1 .

[0030] 3, the exhaust cover 12 has a groove 12c for receiving an O-ring 16. Additionally, a retaining screw 17 is provided for securing the retaining device 10 to the housing 3 of the pump 1.

[0031] Figure 4 shows the vacuum side of the exhaust cover 12 in more detail. The grooves 12c for receiving the O-rings 16 are advantageously chicane- or baffle-like in at least two places, here four (see also Figure 4a). These chicane- or baffle-like portions 12d ensure that the O-ring 16 is held in the grooves 12c and cannot be removed from the exhaust cover 12. By holding the O-ring 16 in place, the risk of the O-ring 16 falling out is greatly reduced, so that the retention device 10 can be easily attached to the housing 3.

[0032] As shown in Fig. 5, the retaining device 10 has an elastomeric plate 18 and a spider spring 19 between the screw head 14b of the screw 14 and the exhaust cover 12. The spider spring 19 has the advantage that the spring pressure is uniformly distributed over many points on the annular line on the rubber-elastic plate 18. The elastomeric plate 18 has the advantage that the air flowing out from the exhaust cover can open the plate and open the exhaust hole, and under the action of the spring force of the spider spring 19, the plate can return to its original position and close the outlet hole again. This makes the relative movement of the parts to each other unnecessary and eliminates mechanical wear of the parts.

[0033] In the preferred embodiment shown in Figures 1 to 5, the adapter element 11 comprises a first cylindrical part 11a, a second cylindrical part 11b and a conical part 11c between the two cylindrical parts. The second cylindrical part 11b has recesses forming fixed fingers 11e. The fixed fingers 11e allow the reception of the air de-oiling element 2, the recesses allowing a better circulation of the air discharged from the filter. At least two fixed fingers 11f, four in this embodiment, are mounted elastically so as to be radially displaceable.

[0034] These fixing fingers 11f are advantageously inclined with respect to the longitudinal axis of the adapter element 11 in the absence of the air de-oiling element 2. When the air de-oiling element 2 is inserted into the adapter element 11, the fixing fingers 11f move radially outwards. This allows the adapter element to easily receive the air de-oiling element while at the same time ensuring optimal retention. Furthermore, the resiliently mounted fixing fingers 11f damp vibrations occurring during operation of the pump. As can be seen, the fixing fingers are chamfered in order to allow an easier insertion of the air de-oiling element 2 into the adapter element 11.

[0035] As can be seen from figure 5, the conical part 11c also has a recess 20 in order to allow a better circulation of the air discharged from the air de-oiling element 2. Furthermore, the first cylindrical part 11a of the adapter 11 advantageously has a recess 11d for receiving the spiral spring 13, so that the latter is optimally guided and cannot deform radially. Similarly, the exhaust cover 12 preferably has a recess 12b for receiving the spiral spring 13.

[0036] It should be noted that both the adapter element 11 and the holding device 10 are inventive and advantageous on their own, although in the figures they are always shown in combination. In other words, the adapter element 11 can also be used in combination with a holding device known from the state of the art. The same applies to the holding device 10, which can also be equipped, without further ado, with an adapter element known from the state of the art. The holding device 10 and the adapter element 11 are advantageous on their own, but together they also have a synergistic effect. Indeed, the combination of the adapter element 11 and the holding device 10 according to the invention allows in particular an easy assembly.

[0037] In conclusion, it is pointed out once again that the embodiments described herein as examples only represent possibilities for implementing the ideas of the invention and should not be considered as limiting them in any way.Those skilled in the art will understand that other implementations of the invention and additional elements are possible without losing sight of the essential features of the invention.

Claims

1. An adapter element (11) suitable for a holding device for an air deoiling element of a vacuum pump (1), comprising: The adapter element (11) comprises: a first cylindrical portion (11a) having a first diameter and a second cylindrical portion (11b) having a second diameter and adapted to receive an air deoiling element; the first diameter is less than or equal to the second diameter; the second cylindrical portion (11b) has peripheral recesses forming at least three fixing fingers (11e) arranged parallel to the longitudinal axis of the adapter element and evenly or unevenly distributed over the circumference of the second cylindrical portion (11b); An adapter element, characterized in that at least two fixing fingers (11f) are mounted so as to be elastically radially displaceable.

2. 2. The adapter element according to claim 1, wherein the diameter of the first cylindrical portion (11a) is smaller than the diameter of the second cylindrical portion (11b), and the adapter element (11) has a conical portion (11c) between the first cylindrical portion (11a) and the second cylindrical portion (11b).

3. 3. An adapter element according to claim 2, wherein the conical portion (11c) of the adapter element (11) has at least one peripheral recess.

4. 3. An adapter element according to claim 2, wherein the conical portion (11c) of the adapter element (11) has at least three peripheral recesses.

5. 3. An adapter element according to claim 2, wherein the conical portion (11c) of the adapter element (11) has at least five peripheral recesses.

6. A holding device (10) for an air de-oiling element (2) of a vacuum pump (1), in particular an oil vacuum pump, comprising: The holding device (10) comprises: an adapter element (11) for receiving the air deoiling element (2); an exhaust cover (12) attachable to the housing of the vacuum pump to seal the exhaust hole (4); a spiral spring (13) disposed between the adapter element (11) and the exhaust cover (12); Including, The adapter element (11) is an adapter element according to any one of claims 1 to 5, The holding device (10) is characterized in that it comprises a regulating means (14) for regulating the distance between the adapter element (11) and the exhaust cover (12).

7. 7. The retaining device according to claim 6, wherein the adapter element (11), the exhaust cover (12) and the spiral spring (13) are arranged coaxially.

8. 8. A holding device according to claim 6 or 7, wherein the adapter element (11) is freely rotatable relative to the exhaust cover (12).

9. The retaining device according to any one of claims 6 to 8, wherein the regulating means (14) is in the form of a screw, the screw head (14b) is arranged on the outside air side of the exhaust cover (12), and a locking means (15) is provided on a cylindrical body (14a) on the opposite side of the screw head (14b).

10. A retaining device as described in claim 9, wherein the locking means (15) is a removable locking means.

11. 11. A holding device according to claim 9 or 10, wherein the distance between the locking means (15) and the exhaust cover (12) is adjustable.

12. A retaining device according to any one of claims 9 to 11, wherein the locking means is in the form of an O-ring.

13. A retaining device as claimed in any one of claims 9 to 12, further comprising a rubber elastic plate (18) between the screw head (14b) and the exhaust cover (12), and an exhaust cover spring (19) between the screw head (14b) and the rubber elastic plate (18).

14. A retaining device as described in Claim 13, wherein the rubber elastic plate (18) is a rubber elastic plate made of an elastomer.

15. A retaining device as described in claim 13 or 14, wherein the exhaust cover spring (19) is in the form of a spider spring.

16. The retaining device according to any one of claims 9 to 15, wherein the exhaust cover (12) has a groove (12c) on its vacuum side for receiving an O-ring (16), and the groove is formed so that the O-ring (16) inserted into the groove (12c) does not come off the exhaust cover (12).

17. 17. A retaining device according to claim 16, wherein the groove (12c) is chicane- or baffle-shaped in at least two places (12d).

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