SEAL BUSHING AND HIGH-PRESSURE CLEANING DEVICE
Patent Information
- Authority / Receiving Office
- DK · DK
- Patent Type
- Patents
- Current Assignee / Owner
- PAUL HAMMELMANN MASCHINENFABRIK GMBH
- Filing Date
- 2022-04-05
- Publication Date
- 2026-07-20
Abstract
Description
[0001] The present invention relates to a sealing bush, in particular for a high-pressure cleaning device according to the preamble of claim 1. The invention further relates to a high-pressure cleaning device according to the preamble of claim 8.
[0002] Sealing bushings of this type are used in particular in high-pressure cleaning devices, as known, for example, from the subsequently published DE 10 2019 134 040 A1.
[0003] The sealing bush serves to seal a hollow shaft rotating relative to the sealing bush, forming a gap seal between an inner surface of the sealing bush and the outer surface of the hollow shaft.
[0004] The high-pressure cleaning device in which such sealing bushings are used typically consists of a hollow input shaft and several hollow output shafts fluidly connected to the hollow input shaft. A hollow output shaft housing, which accommodates the hollow output shafts, rotates with the hollow input shaft housed in a hollow input shaft housing.
[0005] The high-pressure cleaning device known from the publication mentioned at the beginning has proven itself to be effective.
[0006] It has been found to be problematic that the rotation of the hollow output shaft housing causes centrifugal forces to act on the sealing bushings that seal the hollow output shafts against the hollow output shaft housing. As a result of these centrifugal forces, the sealing bushing, which is usually mounted floating in the hollow shaft housing, is not pressed centrally in the designated receptacle but into an eccentric position due to the centrifugal force. This leads to increased leakage due to the resulting eccentric gap and possibly to premature wear of the sealing bushings due to friction between the sealing bushings and the hollow shaft housing.
[0007] The object of the present invention is to further develop a sealing bushing in such a way that the sealing bushing remains as centrally as possible in the receptacle in the hollow shaft housing even when subjected to centrifugal forces.
[0008] This object is achieved by a sealing bush, in particular for a high-pressure cleaning device, having the features of claim 1 and by a high-pressure cleaning device having the features of claim 8.
[0009] The sealing bushing according to the invention has a cylinder jacket-shaped base body with a plurality of window openings arranged side by side in the base body perpendicular to a rotation axis, as well as circumferential sealing ring grooves formed spaced apart from one another in the direction of the rotation axis on both sides of the window openings in an outer jacket surface of the base body.
[0010] In this case, a distance between the sealing ring grooves spaced apart from one another in a first jacket region of the base body is greater than a distance between the sealing ring grooves spaced apart from one another in a second jacket region of the base body opposite the first jacket region.
[0011] Due to the varying distance between the sealing ring grooves over the outer surface of the sealing bushing, different sized contact surfaces arise in the area between the sealing ring grooves, which, when the sealing bushing is installed in the appropriate position and pressurised, results in a force which counteracts the centrifugal force when the sealing bushing rotates about a rotation axis located outside the sealing bushing.
[0012] This results in the sealing bush remaining centric or almost centric in the recess provided for it in the hollow shaft housing.
[0013] Advantageous embodiments of the invention are the subject of the subclaims.
[0014] According to an advantageous embodiment of the sealing bushing according to the invention, the sealing ring grooves are aligned obliquely to a plane perpendicular to the axis of rotation of the base body.
[0015] The oblique alignment of the sealing ring grooves across the outer surface of the sealing bushing creates a surface between the sealing ring grooves that, when developed, corresponds to two trapezoids with their bases adjacent to each other. To achieve the desired effect (compensation of centrifugal force), the longer base sides of the trapezoids are positioned radially outward relative to the rotational axis located outside the sealing bushing, while the shorter base sides of the trapezoids are positioned radially inward relative to the rotational axis located outside the sealing bushing.
[0016] According to an advantageous embodiment of the sealing bushing according to the invention, the sealing ring grooves are aligned such that the larger distance between the spaced-apart sealing ring grooves continuously decreases towards the smaller distance.
[0017] In an advantageous further development, the outer surface of the base body is designed as a pocket-like first depression in an area surrounding the window openings in a ring shape.
[0018] In a further embodiment, an inner surface of the base body is designed as a pocket-like second depression in an area surrounding the window openings in a ring shape.
[0019] According to a further advantageous embodiment, the base body of the sealing bush is made of a bearing metal, preferably bronze.
[0020] The high-pressure cleaning device according to the invention has an input hollow shaft housing, an input hollow shaft mounted in the input hollow shaft housing so as to be rotatable relative thereto about a rotation axis, which can be connected to a hydraulic pressure source.
[0021] The high-pressure cleaning device further comprises an output hollow shaft housing which is mounted so as to be rotatable about the rotation axis relative to the input hollow shaft housing together with the input hollow shaft.
[0022] At least one hollow output shaft mounted so as to be rotatable about a rotation axis is arranged in the hollow output shaft housing.
[0023] A fluid channel of the input hollow shaft is fluidically coupled to a fluid channel of the output hollow shaft via a connecting channel.
[0024] In the output hollow shaft housing, a section of the output hollow shaft is encompassed by a sealing bush, which is arranged in a fixed position and rotationally fixed manner to the output hollow shaft housing and forms a gap seal with the output hollow shaft.
[0025] Spaced-apart circumferential sealing ring grooves are formed on an outer surface of the sealing bushing, in which sealing rings are accommodated to form static seals to the output hollow shaft housing.
[0026] According to the invention, the sealing bushing is designed as described above, wherein the sealing ring grooves are aligned obliquely to a rotation plane of the output hollow shaft housing.
[0027] A distance between the spaced-apart sealing ring grooves is greater in a shell region of the base body of the sealing bushing that is radially remote from the rotational axis of the output hollow shaft housing than a distance between the spaced-apart sealing ring grooves in a shell region of the base body of the sealing bushing that is radially close to the rotational axis of the output hollow shaft housing.
[0028] In an advantageous embodiment of the high-pressure cleaning device, the inner diameter of the sealing bushings in the area of the gap seal is the same or almost the same on both sides of the window openings.
[0029] In a further preferred embodiment, the input hollow shaft is coupled to the output hollow shafts via a mechanical gear.
[0030] Preferred embodiments are explained in more detail below with reference to the accompanying drawings. They show: Figure 1 shows a schematic sectional view through an embodiment variant of a sealing bush according to the invention, Figures 2a, b, c show different schematic views of the Figure 1 shown sealing bushing Figure 3 a schematic isometric representation of an embodiment variant of a high-pressure cleaning device according to the invention, Figure 4 a cross-sectional representation of a partial area of the in Figure 3shown high-pressure cleaning device and Figure 5 is an enlarged detail of an area of the high-pressure cleaning device showing the arrangement of one of the sealing bushings.
[0031] In the following description of the figures, terms such as top, bottom, left, right, front, rear, etc., refer exclusively to the exemplary representation and position of the sealing bushing, base body, seal ring grooves, high-pressure cleaning device, hollow input shaft, hollow output shaft, and the like chosen in the respective figures. These terms are not to be understood as limiting; i.e., these references may change due to different operating positions or the mirror-symmetrical design, etc.
[0032] In the Figures 1 and 2a to 2cA variant of a sealing bushing according to the invention is designated by the reference numeral 5. The sealing bushing 5 is particularly suitable for installation in a high-pressure cleaning device, as described in the Figures 3-5 is shown.
[0033] The sealing bushing 5 has a cylindrical shell-shaped base body 51. In the direction of a rotational axis R of the base body 51, several adjacent window openings 52 are provided, which, when used in the high-pressure cleaning device 1 according to Figures 3 to 5 serve to allow the flow of a high-pressure liquid, such as water.
[0034] High pressure is understood here to mean pressures from 100 bar up to about 4000 bar, particularly preferably from 150 bar to 2000 bar, which are used in such high-pressure cleaning devices 1.
[0035] In the direction of the rotation axis R on both sides of the window openings 52, as shown in the Figures 1 , 2a, 2b and 2c As shown, circumferential sealing ring grooves 55 are formed in a shell outer surface 53 of the base body 51 at a distance from one another.
[0036] The sealing ring grooves 55 are in Figure 1 shown cross-section preferably rectangular in shape and serve to accommodate a sealing ring 9, as for example in the Figures 4 and 5 can be seen. Depending on the cross-section of the sealing ring 9 to be used, other cross-sectional designs for the sealing ring grooves 55 are also conceivable.
[0037] As in the Figures 1 , 2a, 2b and 2c As shown, the sealing ring grooves 55 are aligned obliquely to an imaginary plane whose surface normal is formed by the rotation axis R of the base body 51.
[0038] As in the Figures 1 and 2bis shown, a distance d 1 of the spaced-apart sealing ring grooves 55 in a first jacket region of the base body 51 is greater than a distance d 2 of the spaced-apart sealing ring grooves 55 in a second jacket region of the base body 51 opposite the first jacket region, ie offset by 180° in the circumferential direction of the sealing ring grooves 55.
[0039] In the version shown here, the Figure 2b on the left side of the lateral surface, the maximum distance d 1 to the minimum distance d 2 visible on the right side of the lateral surface decreases continuously, which has the advantage that a conventional sealing ring 9 can be inserted into the sealing ring grooves 55.
[0040] In principle, a stepped formation of the circumferential sealing ring grooves 55 would also be conceivable.
[0041] Important for the intended use is the installation direction of the sealing bushing 5 in the high-pressure cleaning device, which is explained in more detail below.
[0042] Like the Figures 1 and 2a to 2c As can be seen further, the outer surface 53 of the base body 51 is designed as a pocket-like first circumferential depression 56 in an area surrounding the window openings 52 in a ring shape.
[0043] This first recess 56 serves, when installed in the high-pressure cleaning device 1, to form a fluid chamber from which the high-pressure fluid passes along the outer casing 53 of the base body 51 of the sealing bushing 5 into the area of the sealing rings 9 inserted into the sealing ring grooves 55.
[0044] Furthermore, an inner surface 54 of the base body 51 is formed as a pocket-like circumferential second recess 57 in an area surrounding the window openings 52 in a ring shape.
[0045] The second recess 57 also serves, when installed in the high-pressure cleaning device, to form a further fluid chamber, from which the high-pressure fluid forms a gap seal 7 along the inner surface 54 of the base body 51 of the sealing bush 5 with an outer surface of an output hollow shaft 6 received by the sealing bush 5, as shown in Figure 4 and Figure 5 is shown.
[0046] A bearing metal, preferably bronze, is particularly suitable for manufacturing the sealing bushing 5. It is also conceivable that the sealing bushing 5 could be manufactured from a different bearing material.
[0047] As mentioned above, the sealing bushing 5 is particularly suitable for use in a high-pressure cleaning device 1, as described below with reference to the Figures 3 to 5 is explained in more detail.
[0048] The high-pressure cleaning device 1 has an input hollow shaft housing 2 and an input hollow shaft 3 which is mounted in the input hollow shaft housing 2 so as to be rotatable relative thereto about a rotation axis R 3, 4 and which can be connected to a hydraulic pressure source.
[0049] To connect the hydraulic pressure source, a Figure 3 shown pressure connection 25.
[0050] The input hollow shaft housing 2 can be fixed in place to a holder (not shown here) via a mounting flange 21 formed thereon.
[0051] How to continue in Figure 3As can be seen, the high-pressure cleaning device 1 further comprises an output hollow shaft housing 4 which is mounted so as to be rotatable relative to the input hollow shaft housing 2 together with the input hollow shaft 3 about the rotation axis R 3, 4.
[0052] The hollow output shaft housing 4 is shaped in such a way that two hollow output shafts 6 can be mounted in it. It is also conceivable to design an output hollow shaft housing 4 in which only one or more than two, for example three or four hollow output shafts 6 can be mounted. In the latter case, the hollow output shaft housing 4 is preferably star-shaped in plan view instead of bar-shaped as in the Figure 3 shown design variant.
[0053] The output hollow shafts 6 are arranged at a distance from one another in the output hollow shaft housing 4 and are rotatably mounted about rotation axes R 6 in the output hollow shaft housing 4.
[0054] The rotation axes R 6 are arranged parallel and offset to the rotation axis R 3, 4 of the input hollow shaft 3. It is also conceivable to arrange the rotation axis(es) R 6 at an angle, preferably at an acute angle, to the rotation axis R 3, 4 of the input hollow shaft 3.
[0055] As in Figure 4 As shown, a fluid channel 31 of the input hollow shaft 3 is fluidly coupled via respective connecting channels 42 to respective fluid channels 61 of the output hollow shafts 6. For this purpose, the input hollow shaft 3 projects into a through-bore provided for this purpose in the output hollow shaft housing 4.
[0056] In the region of a lower end of the fluid channel 31, it splits into two outlets 33, which open into the two connecting channels 42 for forwarding the high-pressure fluid into the fluid channels 61 of the output hollow shafts 6.
[0057] Static seals 34, for example in the form of sealing rings, are placed around the connection points of the output hollow shaft housing 4 to the outputs 33 of the input hollow shaft 3, as shown in Figure 4 is shown.
[0058] How to continue in the Figures 4 and 5 As shown, the sealing bushings 5 are arranged fixed in position and rotation relative to the output hollow shaft housing 4.
[0059] Each of the sealing bushings 5 encompasses a section of the respective hollow output shaft 6, forming a gap seal 10. Here, on the outer surface 53 of each of the sealing bushings 5, as already explained above, spaced-apart circumferential sealing ring grooves 55 are formed, in which sealing rings 9 are received to form static seals to the hollow output shaft housing 4.
[0060] The sealing ring grooves 55 are aligned obliquely to a rotation plane of the output hollow shaft housing 4 with reference to the components of the high-pressure cleaning device 1.
[0061] The sealing bushings 5 are installed in such an orientation that the distance d 1 of the spaced-apart sealing ring grooves 55 in a jacket region of the base body 51 of the sealing bushings 5 radially removed from the rotational axis R 3, 4 of the output hollow shaft housing 4 is greater than the distance d 2 of the spaced-apart sealing ring grooves 55 in a jacket region of the base body 51 of the sealing bushings 5 radially close to the rotational axis R 3, 4 of the output hollow shaft housing 4.
[0062] As explained at the beginning, this makes it possible to prevent centrifugal force-induced pressure on the sealing bushings 5 in the direction of the output hollow shaft 6 when the output hollow shaft housing 4 rotates with the input hollow shaft 3.
[0063] This is achieved by the fact that the high-pressure fluid in the gap between the outer casing 53 of the sealing bush 5 and the inside of the recesses in the hollow output shaft housing 4 rests on a larger surface of the sealing bush 5 than on the side of the outer casing 53 of the sealing bush 5 which is radially closer to the axis of rotation R 3, 4 of the hollow output shaft housing 4.
[0064] The spreading of the high-pressure fluid in a direction axial to the rotational axis R 3, 4 of the hollow output shaft housing 4 is more narrowly limited by the sealing rings 9 being closer together than on the opposite side of the outer shell 53 of the sealing bushings 5, where the sealing rings 9 are further apart from each other.
[0065] The inner diameter of the sealing bushings 5 is preferably the same or almost the same in the area of the gap seal 12 on both sides of the window openings 52.
[0066] How to continue in Figure 4As shown, the input hollow shaft 3 is coupled to the output hollow shaft 6 via a mechanical gear 8.
[0067] The mechanical transmission 8 has a first gear wheel 81 which is mounted on the output hollow shaft 6 in a rotationally fixed manner, and a second gear wheel 82 which meshes with the first gear wheel 81 and further meshes with a gear wheel 24 which is fixed in a stationary manner on the input hollow shaft housing 2.
[0068] In order to be able to drain leakage fluid from the gap seals 10, as shown in the Figures 4 and 5 shown, a leakage channel 44 is provided in an area above and below the sealing bush 5 in the output hollow shaft housing 4.
[0069] The gear wheels 81, 82 are preferably covered by a cover 45 of the output hollow shaft housing 4.
[0070] Nozzles 64 arranged at the outlets 63 of the hollow output shafts 6 are also arranged protruding from a further cover 46 of the hollow output shaft housing 4. List of reference symbols
[0071] 1High-pressure cleaning device 2Input hollow shaft housing 21Mounting flange 22First housing 23Second housing 24Gear wheel 25Pressure connection 3Input hollow shaft 31Fluid channel 32Hollow shaft body 33Output 34Seal 4Output hollow shaft housing 41Base body 42Connecting channel 43Recess 44Leakage channel 45Cover 46Cover 5Sealing bushing 51Base body 52Window opening 53Outer casing surface 54Inner casing surface 55Seal ring groove 56Recess 57Recess 6Output hollow shaft 61Channel 62Input channel 63Output 64Nozzle 65Recess 7Gap seal 8Gearbox 81First gear wheel 82Second gear wheel 9Sealing ring d 1 distance d 2 distance ti depth ta depth R 3, 4 rotation axis R 6 rotation axis R rotation axis
Claims
1. Sealing bushing (5), in particular for a high-pressure cleaning device, comprising: - a cylindrical base body (51) with several window openings (52) arranged side by side in the base body (51) perpendicular to an axis of rotation (S), - circumferential sealing ring grooves (55) formed at intervals from each other on both sides of the window openings (52) in an outer surface (53) of the base body (51) in the direction of the axis of rotation (S), characterized by the fact that - a distance (d1) between the spaced sealing ring grooves (55) in a first shell area of the base body (51) is greater than a distance (d2) between the spaced sealing ring grooves (55) in a second shell area of the base body (51) opposite the first shell area.
2. Sealing bushing (5) according to claim 1, characterized by the fact that the sealing ring grooves (55) are oriented obliquely to a plane perpendicular to the axis of rotation (S) of the base body (51).
3. Sealing bushing (5) according to claim 1 or 2, characterized by the fact that the sealing ring grooves (55) are aligned such that the larger distance (d1) between the spaced sealing ring grooves (55) decreases continuously towards the smaller distance (d2).
4. Sealing bushing (5) according to one of the preceding claims, characterized by the fact that the outer surface (53) of the base body (51) is formed as a pocket-like first depression (56) in an area surrounding the window openings (52) in a ring-like manner.
5. Sealing bushing (5) according to one of the preceding claims, characterized by the fact that an inner surface (54) of the base body (51) is formed as a pocket-like second depression (57) in an area surrounding the window openings (52) in a ring-like manner.
6. Sealing bushing (5) according to one of the preceding claims, characterized by the fact that the base body (51) is made of a bearing metal, preferably bronze.
7. High-pressure cleaning device (1), comprising - an inlet hollow shaft housing (2), - a rotating axis (R) in the inlet hollow shaft housing (2) relative to it. 3, 4 ) rotatably mounted input hollow shaft (3) which can be connected to a hydraulic pressure source, - a relative to the input hollow shaft housing (2) together with the input hollow shaft (3) about the axis of rotation (R 3, 4) rotatably mounted output hollow shaft housing (4), - at least one output hollow shaft (6) arranged in the output hollow shaft housing (4) and rotatably mounted about an axis of rotation (R6), - wherein a fluid channel (31) of the input hollow shaft (3) is fluidically coupled to a fluid channel (61) of the output hollow shaft (6) via a connecting channel (42), - wherein a sealing bushing (5) encompassing a section of the output hollow shaft (6) forming a gap seal (10) is arranged in the output hollow shaft housing (4) in a positionally and rotationally fixed manner to the output hollow shaft housing (4), - wherein spaced-apart circumferential sealing ring grooves (55) are formed on an outer surface (53) of the outer shell of the sealing bushing (5), in which sealing rings (9) are received to form static seals to the output hollow shaft housing (4), characterized by the fact that- the sealing bushing (5) is designed according to one of claims 1 to 5, - wherein a distance (d1) between the spaced-apart sealing ring grooves (55) in a shell area of the base body (51) of the sealing bushing (5) located radially away from the axis of rotation of the output hollow shaft housing (4) is greater than a distance (d2) between the spaced-apart sealing ring grooves (55) in a shell area of the base body (51) of the sealing bushing (5) located radially away from the axis of rotation (R4) of the output hollow shaft housing (4).
8. High-pressure cleaning device (1) according to claim 7, characterized by the fact that an inner diameter of the sealing bushing (5) in the area of the gap seal (12) on both sides of the window openings (52) is the same or nearly the same.
9. High-pressure cleaning device (1) according to claim 7 or 8, characterized by the fact that the input hollow shaft (3) is coupled to the output hollow shaft (6) via a mechanical transmission (8).