PISTON DEVICE

Description

[0001] The present invention relates to a piston device.

[0002] A piston device can in particular be a component of a transmission arrangement, for example an automatic transmission or dual-clutch transmission for motor vehicles.

[0003] A sealing element for a piston device is known, for example, from DE 10 2009 025 720 A1.

[0004] Piston devices and / or sealing elements are known, for example, from US 5 492 053 A, US 5 865 442 A, US 2 467 210 A, US 3 166 360 A, FR 1 168 857 A, DE 10 2014 002727 A1, WO 2015 / 022144 A1, DE 10 2011 084422 A1, EP 2 827 026 A2 and FR 2 775 045 A1.

[0005] The present invention is based on the object of providing a piston device comprising a sealing element which can be produced easily and inexpensively and enables efficient sealing.

[0006] This object is achieved according to the invention by the piston device according to claim 1.

[0007] Because the sealing element is annular and comprises a base body embedded in an elastomer body, an efficiently sealing sealing element can be produced. In particular, such a sealing element can be produced independently of a piston of the piston device according to the invention and can be mounted on the same.

[0008] In one embodiment of the invention, it can be provided that the base body has an L-shaped cross-section.

[0009] In this description and the appended claims, a cross-section is understood to mean, in particular, a section taken in a plane extending perpendicular to the circumferential direction of the sealing element. This plane is, in particular, a plane in which an axis of symmetry of the sealing element extends.

[0010] The plane is spanned in particular by a radial direction and an axial direction, in particular relative to an axis of rotation or axis of symmetry of the sealing element.

[0011] Furthermore, it can be provided that the base body has a Z-shaped cross-section.

[0012] A Z-shaped cross-section is to be understood in particular as meaning that the base body comprises two coaxially arranged hollow cylindrical sections with different radii or diameters, wherein the two hollow cylindrical sections are connected to one another by means of a hollow truncated cone or annular disc-shaped section.

[0013] The hollow cylindrical sections can be arranged overlapping in sections or offset or spaced apart from one another in the axial direction.

[0014] It may be advantageous if the base body and the elastomer body together have a C-shaped, V-shaped or U-shaped cross-section.

[0015] In particular, the base body and the elastomer body together have two legs connected to one another, wherein one of the legs comprises a hollow cylindrical section and wherein another leg comprises the sealing lip.

[0016] It can be provided that the base body comprises a metallic material or is formed from a metallic material. In particular, the base body is formed from a steel material. For example, the base body is formed from spring steel.

[0017] The base body is preferably a sheet metal bent product and / or a sheet metal stamping product.

[0018] The elastomer body is molded onto the base body. For example, the elastomer body can be molded onto the base body in an injection molding process.

[0019] In one embodiment of the invention, it can be provided that the elastomer body comprises a sealing ring which is located inside with respect to a radial direction and a sealing ring which is located outside with respect to the radial direction, wherein the inner sealing ring surrounds or comprises a hollow cylindrical section of the base body and / or wherein the outer sealing ring is formed by the sealing lip.

[0020] The two sealing rings are in particular the two legs which, in cross-section, lead to the C-shape, V-shape or U-shape of the base body and the elastomer body.

[0021] The outer sealing ring, which is formed by the sealing lip, is preferably formed exclusively by the elastomer body.

[0022] In particular, the base body does not protrude into the area of ​​the sealing lip.

[0023] The inner sealing ring is preferably a shell of a truncated cone.

[0024] The outer sealing ring is preferably a conical shell.

[0025] It may be advantageous if the inner sealing ring and the outer sealing ring, as well as a connecting section for connecting the two sealing rings, are formed in one or two pieces. In particular, the inner sealing ring and the outer sealing ring, as well as the connecting section, are formed exclusively by the elastomer body and the base body.

[0026] In one embodiment of the invention, it can be provided that a material thickness of the elastomer body, starting from the inside of the hollow cylindrical section of the base body, directed radially inwards is at least approximately 0.3 mm, in particular at least approximately 0.5 mm, and / or at most approximately 2 mm, in particular at most approximately 1 mm, for example approximately 0.6 mm.

[0027] In a further embodiment, it can be provided that the material thickness of the elastomer body, starting from the inside of the hollow cylindrical section of the base body, directed radially inwards is at least approximately 0.3 mm, in particular at least approximately 0.5 mm, and / or at most approximately 3 mm, in particular at most approximately 2 mm, for example approximately 1.5 mm.

[0028] It may be advantageous if a material thickness of the elastomer body, starting from the base body in the axial direction outwards, is on one side or on both sides at least approximately 0.3 mm, in particular at least approximately 0.5 mm, and / or at most approximately 3 mm, in particular at most approximately 2 mm, for example approximately 1 mm or 1.5 mm.

[0029] A minimum distance taken along the axial direction between an axially deepest point of a depression of the elastomer body surrounded by the sealing lip on the one hand and a section of the base body arranged radially at the same height as the deepest point of the depression on the other hand is preferably at least approximately 1 mm, in particular at least approximately 2 mm, and / or at most approximately 7 mm, in particular at most approximately 5 mm, for example approximately 3 mm or 2.7 mm.

[0030] It may be advantageous if a radially outer end of the sealing lip is arranged axially between two opposing ends of the hollow cylindrical section of the base body. The forces exerted by the sealing lip and the hollow cylindrical section then preferably do not lead to twisting of the sealing element. Rather, the sealing element is thus designed to be particularly stable.

[0031] In one embodiment of the invention, it can be provided that the base body extends radially outwards at least to a height of a deepest point in the axial direction of a recess of the elastomer body surrounded by the sealing lip.

[0032] Alternatively or additionally, it can be provided that the base body extends radially outwards at most to a height of a radially outer edge of a surface, curved in a cross-section, of a recess of the elastomer body surrounded by the sealing lip.

[0033] The term "surrounding the recess" is understood in particular to mean that the sealing lip adjoins the recess in a radial outward direction.

[0034] It may be advantageous if at least one section of the elastomer body, which adjoins the inner side of the hollow cylindrical section in the radial direction inwards, has an uneven and / or structured surface structure, for example a wave structure, facing away from the hollow cylindrical section.

[0035] The sealing element is particularly suitable for use in the piston device according to the invention.

[0036] The present invention relates to the piston device.

[0037] The piston device is particularly suitable for use in a transmission arrangement, for example an automatic transmission or dual-clutch transmission of a motor vehicle.

[0038] Preferably, the piston device is a pressure piston device of a gear arrangement.

[0039] The piston device includes the sealing element.

[0040] The sealing element can be or is applied to a radially outer mounting surface of a piston of the piston device.

[0041] The sealing element can preferably be fixed to the piston by means of a press fit.

[0042] It can be advantageous if the base body is subjected to tensile stress along a circumferential direction when the sealing element is mounted on the piston.

[0043] In particular, the part of the elastomer body arranged on the inside of the hollow cylindrical section is pressed against the piston.

[0044] Due to the use of the base body, a constant contact pressure is preferably achieved over a long period of time, which ultimately enables a high level of tightness of the sealing element.

[0045] Alternatively or additionally, it can be provided that the sealing element is or is fixed to the piston, in particular the mounting surface of the piston, by means of a material connection.

[0046] For example, it can be provided that the sealing element can be or is fixed to the mounting surface of the piston in a reliable and efficient sealing manner by means of an adhesive and / or an adhesion promoter.

[0047] Preferably, the sealing element on the piston provides a seal both in the radial direction and in the axial direction.

[0048] In particular, the seal is achieved by the elastomer body being in contact with the piston in the radial and axial directions.

[0049] It may be advantageous if a radially inner side of the elastomer body, outside a region radially adjacent to the hollow cylindrical section, is provided with an uneven and / or structured surface structure, for example, a wave structure. This can, in particular, form a micro-dimple structure, which serves to optimize sealing and / or absorb leakage fluid.

[0050] With the exception of holding areas for receiving the base body in an injection molding tool, the base body is preferably completely surrounded by the elastomer body.

[0051] It can be advantageous if the base body is completely surrounded by the elastomer body and is therefore not directly accessible from the outside.

[0052] The transmission arrangement can be, for example, an automatic transmission or a dual-clutch transmission.

[0053] Further preferred features and / or advantages of the invention are the subject of the following description and the drawings of exemplary embodiments.

[0054] The drawings show: Fig. 1 is a schematic plan view of a sealing element for a piston device of a transmission arrangement according to the invention; Fig. 2 is a partial section through a piston of the piston device according to the invention for receiving the sealing element of Fig. 1 ; Fig. 3 a schematic cross section through the sealing element from Fig. 1 along line 3-3 in Fig. 1 in the compressed state of the same; Fig. 4 one of the Fig. 1 corresponding schematic representation of a second embodiment of a sealing element; Fig. 5 one of the Fig. 2 corresponding schematic representation of a further embodiment of a piston of a piston device according to the invention; and Fig. 6 a schematic cross section through the sealing element from Fig. 5 along line 6-6 in Fig. 4 .

[0055] Identical or functionally equivalent elements are provided with the same reference numerals in all figures.

[0056] One in the Fig. 1 to 3 The first embodiment of a sealing element designated as a whole by 100 shown serves to seal between two spaces 102 and is used in particular as a component of a piston device 104 according to the invention.

[0057] The piston device 104 according to the invention is, for example, a component of a transmission arrangement 106, for example an automatic transmission or dual-clutch transmission.

[0058] The piston device 104 according to the invention comprises in particular a piston 108 on which the sealing element 100 can be or is fixed for sealing.

[0059] The piston 108 is in particular rotationally symmetrical about a rotation axis (not shown) which defines an axial direction 110.

[0060] The sealing element 100 can be fixed to the piston 108, in particular on an outer side 112 facing away from the axis of rotation.

[0061] The piston 108 comprises a mounting surface 114 for arranging and / or fixing the sealing element 100.

[0062] The piston 108 further includes one or more offset portions 116 which are offset outwardly from the mounting surface 114 in a radial direction 128.

[0063] Due to this one or more offset regions 116, a contact surface 118 of the piston 108 is formed adjacent to the mounting surface 114, preferably arranged in a plane perpendicular to the axial direction 110.

[0064] The sealing element 100 can be applied to this contact surface 118, preferably in the axial direction 110.

[0065] The sealing element 100 can, for example, be fixed directly to the piston 108 by being manufactured on the piston 108, for example by being injection-molded onto the piston 108.

[0066] Preferably, however, the sealing element 100 is a different element from the piston 108 and is manufactured separately.

[0067] The sealing element 100 comprises a base body 120, which is, for example, a bent sheet metal product 122 and / or a stamped sheet metal product 124.

[0068] The base body 120 comprises one or more hollow cylindrical sections 126.

[0069] In the Fig. 1 to 3In the first embodiment of the sealing element 100 shown, the base body 120 comprises two essentially hollow cylindrical sections 126, which are arranged offset from one another in the axial direction 110 and in the radial direction 128.

[0070] The two hollow cylindrical sections 126 are connected to each other by means of a hollow truncated cone-shaped section 130.

[0071] By means of the hollow truncated cone-shaped section 130 and the adjacent hollow cylindrical sections 126, in particular a Z-shape of the base body 120 is formed.

[0072] The base body 120 is formed in particular from a metallic material, for example spring steel.

[0073] The sealing element 100 further comprises an elastomer body 132, which is formed in particular from an elastomeric plastic material.

[0074] The base body 120 is preferably embedded in the elastomer body 132.

[0075] In particular, it can be provided that the base body 120 is substantially completely surrounded by the elastomer body 132. Only the Fig. 3 The recesses shown, which may be necessary for the production of the sealing element 100, allow direct access to the base body 120.

[0076] The entire sealing element 100 is preferably designed to be substantially rotationally symmetrical about a rotation axis (not shown).

[0077] The axis of rotation of the sealing element 100 is preferably the same axis of rotation as that of the piston 108.

[0078] The elastomer body 132 together with the base body 120 forms an internal sealing ring 134.

[0079] With this internal sealing ring 134, in the assembled state of the sealing element 100, a seal in the radial direction 128 inwards is achieved.

[0080] For the sealing on the piston 108 directed inwards in the radial direction 128, the hollow cylindrical section 126 of the base body 120, which is arranged radially further inwards, serves in particular together with a part of the elastomer body 132 covering the hollow cylindrical section 126 on its inner side 136.

[0081] The elastomer body 132 thus forms an elastomer coating on the inner side 136 of the hollow cylindrical section 126, which acts as a seal.

[0082] The base body 120, in particular the radially inner hollow cylindrical section 126 of the base body 120, as well as the section of the elastomer body 132 arranged on the inner side 136 of the base body 120, in particular the radially inner hollow cylindrical section 126 of the base body 120, are dimensioned such that the entire sealing element 100 can be fixed by means of a press fit on the mounting surface 114 of the piston 108.

[0083] For an optimized sealing effect, it can be provided that a radially inner surface of the elastomer body 132 facing away from the base body 120 is provided at least in sections with a structure, for example a wave structure.

[0084] In the area of ​​the radially inner hollow cylindrical section 126, this structure serves, in particular, to optimize the sealing effect through targeted compression of the structure. In the remaining part of the elastomer body 132, the structure can serve, in particular, as a micro-dimple structure to optimize adhesion and / or absorb leakage fluid.

[0085] The sealing element 100 further comprises an external sealing ring 138.

[0086] By means of this external sealing ring 138, a seal in the radial direction 128 to the outside can be realized.

[0087] The outer sealing ring 138 is formed in particular by a sealing lip 140 of the sealing element 100.

[0088] This sealing lip 140 protrudes in particular obliquely to the radial direction 128 and obliquely to the axial direction 110 from the base body 120.

[0089] The sealing lip 140 is in particular formed exclusively by the elastomer body 132 and thus exclusively by an elastomer material.

[0090] In particular, due to the shape of the sealing lip 140 and its arrangement relative to the remaining part of the elastomer body 132, a recess 142 results in the elastomer body 132.

[0091] This recess 142 has, in particular, a partially curved surface 144.

[0092] The region of the elastomer body 132 which has the curved surface 144 is in particular the region of the elastomer body 132 which is compressed inwardly in the radial direction 128 when the sealing lip 140 is deflected.

[0093] The base body 120 is preferably provided to stabilize the elastomer body 132.

[0094] In particular, the base body 120 preferably extends outwards in the radial direction 128 to such an extent that the outermost end of the base body 120 in the radial direction 128 is arranged at least at the level of a deepest point 146 of the recess 142 with respect to the axial direction 110.

[0095] Since an excessively wide extension of the base body 120 in the radial direction 128 outwards can result in an excessively rigid design of the outer sealing ring 138, the base body 120 ends with its outermost end in the radial direction 128 preferably in the radial direction 128 in front of an outer end or edge of the curved surface 144 of the recess 142 in the radial direction 128.

[0096] A distance taken in the axial direction 110 between the deepest point 146 of the recess 142 and a section of the base body 120 that exactly follows the deepest point 146 in the axial direction 110 is preferably between approximately 2 mm and approximately 5 mm, in particular approximately 3 mm.

[0097] The material thickness of the elastomer body 132 on the inner side 136 of the radially inner hollow cylindrical section 126 is preferably between approximately 0.3 mm and approximately 2 mm, for example approximately 0.6 mm.

[0098] In particular, in the direction of the contact surface 118 of the piston 108, the elastomer body 132 extends in the axial direction 110 beyond the base body 120 by preferably at least approximately 0.3 mm, for example 1 mm. A maximum material thickness in the axial direction 110, starting from the base body 120, is preferably at most approximately 3 mm.

[0099] For mounting the sealing element 100 on the mounting surface 114, for example, an adhesion promoter material can be arranged on the mounting surface 114 and / or on the sealing element 100.

[0100] Alternatively and / or in addition to an adhesion promoter material, an adhesive may be provided.

[0101] Preferably, however, a stable connection is achieved between the sealing element 100 and the piston 108, particularly due to the press fit.

[0102] One in the Fig. 4 to 6 The second embodiment of a sealing element 100 and a piston 108 shown in FIG. 1 differs from that shown in FIGS. Fig. 1 to 3 illustrated first embodiment essentially in that the base body 120 comprises only a hollow cylindrical section 126, to which a radially outwardly projecting annular disc-shaped section 148 is connected.

[0103] The base body 120 is thus in the Fig. 4 to 6shown second embodiment is substantially L-shaped.

[0104] The piston 108 preferably also has a slightly different geometry.

[0105] A material thickness in the radial direction 128 on the inner side 136 of the hollow cylindrical section 126 is preferably approximately 1.5 mm.

[0106] A distance taken in the axial direction 110 between the deepest point 146 of the recess 142 and the annular disk-shaped section 148 is preferably between approximately 2 mm and approximately 5 mm, in particular approximately 2.7 mm.

[0107] A material thickness of the elastomer body 132 in the axial direction 110 on the side of the annular disk-shaped section 148 facing away from the hollow cylindrical section 126 is preferably between approximately 0.3 mm and approximately 3 mm, in particular approximately 1.5 mm.

[0108] Furthermore, the Fig. 4 to 6The second embodiment of a sealing element 100 and / or a piston 108 shown in FIG. 1 is similar in structure and function to that shown in FIGS. Fig. 1 to 3 illustrated first embodiment, so that reference is made to the above description thereof in this respect.

Claims

1. Piston device (104), in particular for use in a transmission arrangement (106), the piston device (104) comprising a sealing element (100) for providing a seal between two spaces (102), wherein the sealing element (100) can be or is placed on a radially outer mounting surface (114) of a piston (108) of the piston device (104), the sealing element (100) being annular and comprising a main body (120), the main body (120) comprising a hollow-cylindrical portion (126) which extends parallel to an axial direction (110) of the sealing element (100), wherein the hollow-cylindrical portion (126) has an internal inner side (136) with respect to a radial direction (128) and is partially or completely covered by an elastomer body (132), the elastomer body (132) comprising a sealing lip (140) which projects outwards in the radial direction (128) or obliquely thereto away from the main body (120), the elastomer body (132) being moulded on the main body (120), in particular in an injection moulding process and / or compression moulding process, characterized in that the main body (120) is partially embedded in the elastomer body (132) and, except for retaining regions for holding the main body (120) in an injection moulding tool, is completely surrounded by the elastomer body (132), or in that the main body (120) is completely embedded in and completely surrounded by the elastomer body (132) and therefore cannot be accessed directly from the outside.

2. Piston device (104) according to Claim 1, characterized in that the main body (120) has an L-shaped cross section or a Z-shaped cross section.

3. Piston device (104) according to either of Claims 1 and 2, characterized in that the main body (120) and the elastomer body (132) together have a C-shaped or V-shaped or U-shaped cross section.

4. Piston device (104) according to one of Claims 1 to 3, characterized in that the main body (120) comprises a metal material or is made of a metal material.

5. Piston device (104) according to one of Claims 1 to 4, characterized in that the main body (120) is a bent sheet metal product (122) and / or a stamped sheet metal product (124).

6. Piston device (104) according to one of Claims 1 to 5, characterized in that the elastomer body (132) is moulded on the main body (120) in an injection moulding process and / or compression moulding process.

7. Piston device (104) according to one of Claims 1 to 6, characterized in that the elastomer body (132) comprises an internal sealing ring (134) with respect to a radial direction (128) and an external sealing ring (138) with respect to the radial direction (128), the internal sealing ring (134) surrounding a hollow-cylindrical portion (126) of the main body (120) and / or the external sealing ring (138) being formed by the sealing lip (140).

8. Piston device (104) according to Claim 7, characterized in that the internal sealing ring (134) and the external sealing ring (138) and a connecting portion for connecting the two sealing rings (134, 138) are formed in one piece or two pieces with one another.

9. Piston device (104) according to one of Claims 1 to 8, characterized in that a) a material thickness of the elastomer body (132), directed radially inwards from the inner side (136) of the hollow-cylindrical portion (126) of the main body (120), is at least approximately 0.3 mm, in particular at least approximately 0.5 mm, and / or at most approximately 2 mm, in particular at most approximately 1 mm, for example approximately 0.6 mm; and / or b) a material thickness of the elastomer body (132), outwards from the main body (120) in an axial direction (110) on one side or on two sides, is at least approximately 0.3 mm, in particular at least approximately 0.5 mm, and / or at most approximately 3 mm, in particular at most approximately 2 mm, for example approximately 1 mm.

10. Piston device (104) according to one of Claims 1 to 9, characterized in that a minimum spacing along the axial direction (110) between an axially (110) deepest point (146) of a depression (142), surrounded by the sealing lip (140), of the elastomer body (132) on the one hand and a portion, arranged radially (128) at the same height as the deepest point (146) of the depression (142), of the main body (120) on the other hand is at least approximately 1 mm, in particular at least approximately 2 mm, and / or at most approximately 7 mm, in particular at most approximately 5 mm, for example approximately 3 mm.

11. Piston device (104) according to one of Claims 1 to 10, characterized in that a radially (128) outer end of the sealing lip (140) is located axially (110) between two mutually opposite ends of the hollow-cylindrical portion (126) of the main body (120).

12. Piston device (104) according to one of Claims 1 to 11, characterized in that the main body (120) extends radially (128) outwards (i) at least as far as a height of an axially (110) deepest point (146) of a depression (142), surrounded by the sealing lip (140), of the elastomer body (132) and / or (ii) at most as far as a height of a radially (128) outer edge of a cross-sectionally curved surface (144) of a depression (142), surrounded by the sealing lip (140), of the elastomer body (132).

13. Piston device (104) according to one of Claims 1 to 12, characterized in that at least one portion of the elastomer body (132) that radially (128) inwardly adjoins the radially (128) internal inner side (136) of the hollow-cylindrical portion (126) has an uneven and / or structured surface structure, for example a corrugated structure, facing away from the hollow-cylindrical portion (126).

14. Piston device (104) according to one of Claims 1 to 13, characterized in that, when the sealing element (100) has been mounted on the piston (108), the main body (120) is subjected to tensile loading along a circumferential direction.

15. Piston device (104) according to one of Claims 1 to 14, wherein the sealing element (100) is fixed on the piston (108) by means of a press fit.