Swivel actuator for providing a swivel movement

Abstract

The invention relates to a pivoting actuator (1) for providing a pivoting movement, with an actuator housing (2) in which a working recess (14) is formed, in which a working piston (41; 101; 111; 121; 131; 141; 151; 161; 171) is linearly movable along a movement axis (7) and a threaded spindle (31), which passes through the working piston (41; 101; 111; 121; 131; 141; 151; 161; 171), is rotatably mounted about the movement axis (7), wherein a first sealing system (51) is associated with the working piston (41; 101; 111; 121; 131; 141; 151; 161; 171), which has a first, annularly shaped, The spindle seal (71; 102; 112; 122; 132; 142; 152; 162; 172) comprises a spindle seal (71; 102; 112; 122; 132; 142; 152; 162; 172) which abuts a first axial surface (43) of the working piston (41; 101; 111; 121; 131; 141; 151; 161; 171) in a sealing manner, wherein the first spindle seal (71; 102; 112; 122; 132; 142; 152; 162;172) has a first internal thread section (77) adapted to the external thread section (35) of the threaded spindle (31) and seals against the threaded spindle (31).;

Description

[0001] The invention relates to a swivel actuator for providing a swivel movement.

[0002] DE 10 2008 034 994 B3 discloses a rotary drive for pivoting door leaves. It comprises a spindle, which is rotatably and concentrically mounted in a cylinder and has a thread-like helix on its circumference, and an axially displaceable piston, which is non-rotatably guided in the pneumatic cylinder and surrounds the spindle with a profile corresponding to the helix. A base plate designed as a piston is provided at the bottom of the cylinder. This base plate is axially displaceable within the cylinder and in which the spindle is rotatably mounted and secured against ascending.

[0003] The object of the invention is to provide a swivel actuator that can be easily adapted to different requirement profiles.

[0004] This object is achieved for a swivel actuator of the type mentioned at the outset in that the swivel actuator comprises an actuator housing in which a working recess is formed, and a working piston which is accommodated in the working recess in a linearly movable manner along a movement axis, and a threaded spindle which is mounted on the actuator housing in a rotatable manner about the movement axis and passes through the working piston, wherein an external thread section of the threaded spindle engages in an internal thread section of the working piston in order to convert a linear movement of the working piston into a swivel movement of the threaded spindle about the movement axis, wherein the working piston is assigned a first sealing system which comprises a first, annularly designed spindle seal which bears sealingly against a first axial surface of the working piston which is arranged adjacent to the internal thread section,wherein the first spindle seal has a first internal thread section adapted to the external thread section of the threaded spindle and sealingly abuts the threaded spindle.

[0005] The actuator housing is preferably formed from a tubular base body extending along the movement axis with a constant profile, which can in particular be an aluminum extrusion, as well as end covers attached to the inside of the base body. The inner surfaces of the base body and the end cover define a cavity referred to as the working recess. The profile of the base body in a cross-sectional plane oriented transversely to the movement axis can be circular, but is preferably designed in a non-circular manner, as this can ensure that the working piston is secured against rotation about the movement axis. For example, the profile of the base body is oval, square, or rectangular. If the profile of the base body is circular, additional measures must be taken to prevent the working piston from rotating.This can be achieved, for example, by one or more support rods running parallel to the movement axis, which extend in the working recess between the oppositely arranged end covers and penetrate the working piston. The working recess is divided by the working piston, which can be displaced linearly along the movement axis, into a first working chamber of variable size and a second working chamber of variable size. For example, a first working connection is assigned to the first working chamber, through which compressed air can be supplied to the first working chamber and compressed air can be discharged from the first working chamber. As a result, a variable pressure force, particularly directed in the direction of the second working chamber, acts on the working piston, which can cause a linear displacement of the working piston.To convert the linear movement of the working piston into a pivoting or rotational movement of the threaded spindle, the working piston is provided with an internal thread section that engages with an external thread section of the threaded spindle. In addition to a material selection for the threaded spindle and the internal thread section of the working piston, a number of threads and a thread pitch of this threaded connection are also designed such that no self-locking occurs. To ensure advantageous use of the compressed air supplied to the first working chamber, a first sealing system is assigned to the working piston, which includes a first spindle seal that ensures sealing in the area of ​​the threaded connection.For this purpose, the first spindle seal is annular and rests with a first end face, which is preferably oriented transversely to the axis of movement, in a sealing manner against a first axial surface of the working piston. Furthermore, the spindle seal is provided with an internal thread section that ensures a sealing connection with the threaded spindle. Preferably, a geometry of the internal thread section of the spindle seal is identical to a geometry of the external thread section of the threaded spindle. It is particularly preferably provided that the first spindle seal is made of a plastic material with advantageous sliding properties compared to the threaded spindle - typically made of metal, in particular using a thread rolling process. For this purpose, materials such as silicone or acrylonitrile butadiene rubber (NBR - nitrile butadiene rubber) are used in particular for the first spindle seal.

[0006] Advantageous further developments of the invention are the subject of the subclaims.

[0007] It is expedient if the first sealing system comprises a first pressure body and if the first spindle seal is accommodated between the first axial surface and the first pressure body arranged at an adjustable distance from the first axial surface. The task of the first pressure body is to enable the application of compressive forces acting parallel to the axis of movement to the first spindle seal, wherein these compressive forces lead to a deformation of the first spindle seal in the radial direction due to the elastically deformable, in particular rubber-elastic, material of the first spindle seal. Depending on the mounting of the first spindle seal on the working piston, the compressive forces lead either to an exclusively radially inward deformation of the first spindle seal or to a radially inward and radially outward deformation of the first spindle seal.This improves the geometric fit between the internal thread section of the first spindle seal and the external thread section of the threaded spindle, thus resulting in an improved sealing effect between the first working chamber and the second working chamber. For example, the first pressure element is secured to the working piston with several screws, each aligned parallel to the movement axis, and a change in the distance between the pressure element and the working piston can be achieved by moving the respective screws.

[0008] It is preferably provided that the first pressure body comprises a pressure plate which bears in a sealing manner against an upper side of the first spindle seal facing away from the working piston, and that the first pressure body has a circumferential annular collar which extends axially along the movement axis from the pressure plate in the direction of the working piston and is guided in a linearly movable manner along the movement axis in an annular guide recess in the working piston, and that the first pressure body, with the first spindle seal and the working piston, delimits a sealing chamber of variable size. In this case, the pressure body is essentially cup-shaped and has a recess in the region of the cup base, also referred to as the pressure plate, through which the threaded spindle is guided. The pressure plate rests in a sealing manner on an upper side of the first spindle seal with an inner surface facing the spindle seal.An annular collar of the first pressure body, which can also be referred to as the cup wall and which is preferably integrally connected to the pressure plate, extends axially along the movement axis and engages in an annular guide recess in the working piston. A circumferential seal is incorporated in the guide recess, which, together with the annular collar of the pressure body, ensures a linearly movable, sealing guide of the pressure body relative to the working piston. Thus, the pressure body, together with the first spindle seal and the working piston, define a variable-size sealing chamber in which a predeterminable pneumatic pressure prevails, which, for example, corresponds at least approximately to ambient pressure.When the first working chamber is pressurized with a working pressure, typically in the range of 1 to 6 bar, a compressive force is exerted on the pressure body, leading to a deformation of the first spindle seal, provided the pneumatic pressure in the sealing chamber is lower than the working pressure. This increases the sealing effect between the first spindle seal and the threaded spindle. When the working pressure in the first working chamber is reduced, the deformation of the first spindle seal is also reduced, allowing a smooth screwing movement for the threaded spindle. This design therefore represents a sealing effect that is dynamically adapted to the working pressure.

[0009] In a further development of the invention, it is provided that the first spindle seal is received in a first ring which projects from the first axial surface along the axis of movement, is formed in particular integrally with the working piston and is elastic in the radial direction, and that a first adjustment device is assigned to the first ring, which is designed to adjust an inner diameter of the first ring. In this embodiment, a pre-adjustment of the sealing effect between the first spindle seal and the threaded spindle is carried out. For this purpose, a first ring is attached to the working piston, the inner diameter of which ring corresponds at least substantially to an outer diameter of the first spindle seal. Furthermore, an adjustment device is provided with the aid of which the inner diameter of the first ring can be adjusted in order to enable a deformation of the first spindle seal in the radially inward direction.This allows adjustment of the sealing effect between the first spindle seal and the threaded spindle. Preferably, the first ring is attached to the working piston, for example, fixed, in particular formed integrally with the working piston.

[0010] In a further embodiment of the invention, it is provided that an outer peripheral surface of the first ring is conical and that the first adjustment device has an inner surface corresponding to the outer peripheral surface of the first ring and forms a threaded arrangement with the working piston, wherein a thread axis of the threaded arrangement is aligned parallel to the axis of movement. This enables forces acting radially inward on the first spindle seal to be introduced by means of a cone arrangement in order to adjust the sealing effect against the threaded spindle. The first cone is formed by the inner surface, the second cone is formed by the outer peripheral surface of the ring. When the first adjustment device is used as intended, both the first cone and the second cone are aligned with the first and second cone axes, respectively, parallel to the axis of movement.When the first adjustment device performs a screwing movement, the first adjustment device approaches the first ring, resulting in a radially inward force being applied to the first ring and the first spindle seal housed therein via the cone arrangement. This creates a sealing effect in both the axial and radial directions.

[0011] It is advantageous if the first spindle seal is accommodated in a cylindrical, in particular circular-cylindrical, recess of the working piston, wherein an inner surface of the recess facing the first spindle seal and an outer circumferential surface of the first spindle seal delimit a working gap of variable size, or wherein the first spindle seal in a radially outer region bears sealingly against an inner surface of the recess facing the first spindle seal and is arranged in a radially inner region at a distance from the first axial surface of the working piston in order to form a buffer space of variable size with the working piston.The working gap between the recess in the working piston and the first spindle seal serves to enable the outer peripheral surface of the first spindle seal to be subjected to the working pressure prevailing in the first working chamber, in order to thereby introduce force in a radially inward direction onto the first spindle seal and thus achieve an improved sealing effect against the threaded spindle. Purely as an example, the working gap is circular in shape so that a homogeneous pressure application for the outer peripheral surface of the first spindle is ensured. In an alternative embodiment, the first spindle seal rests against the first axial surface of the working piston in a radially outer region, while a radially inner region of the first spindle seal is arranged at a distance from the first axial surface of the working piston.The cavity enclosed by the first spindle seal and the working piston is referred to as the buffer chamber and is sealed off from the first working chamber. When pressure is applied to the first working chamber, compressive forces act in the axial direction on the first spindle seal, which can lead to elastic deformation of the radially inner region of the first spindle seal. This increases the contact surface and / or the contact pressure between the first spindle seal and the threaded spindle, thus improving the sealing effect between the first spindle seal and the threaded spindle.

[0012] It is expedient if the first spindle seal is accommodated in a cylindrical, in particular circular-cylindrical, recess of the working piston, and if a clamping ring with a variable diameter is arranged between an inner surface of the recess facing the first spindle seal and an outer circumferential surface of the first spindle seal, which clamping ring is designed to adjust the diameter of the first spindle seal. For example, the clamping ring is designed in the manner of an adjustable pipe clamp or hose clamp and can be adjusted to a predetermined diameter during assembly of the swivel actuator, achieving a favorable compromise between the sealing effect of the first spindle seal against the threaded spindle and a friction effect between the first spindle seal and the threaded spindle.

[0013] In an advantageous development of the invention, it is provided that the first spindle seal is received in a circumferential annular groove of the working piston, and that a groove wall of the annular groove facing the first spindle seal and an outer circumferential surface of the first spindle seal delimit a variable-sized working gap. The working gap is preferably filled with a pressurized fluid in order to provide a radially inward-acting compressive force on the first spindle seal. The working gap is optionally pressurized with a static pressure or with a variable pressure, in particular one that can be adjusted or regulated from the outside. Both gaseous and liquid fluids can be used to pressurize the working gap. It is preferably provided that the variable-sized working gap is fluidically coupled to the first working chamber via a connecting bore, preferably formed in the working piston.Thus, when the first working chamber is pressurized, the annular groove is also pressurized, which can cause a deformation of the first spindle seal in the radial inward direction, with which a sealing effect of the first spindle seal against the threaded spindle can be increased.

[0014] In a further embodiment of the invention, a cavity is formed in the first spindle seal, which cavity can be supplied with a pressurized fluid via a supply opening. For example, the supply opening is provided in a fluidly communicating manner with a first working chamber, which is delimited by the actuator housing and the working piston and via which the cavity is also pressurized when the working chamber is pressurized. In this embodiment, the first spindle seal is pressurized with the working pressure from the first working chamber and is inflated like a hose, whereby the sealing effect of the first spindle seal against the threaded spindle can be increased. Alternatively, it can be provided that the cavity can be filled with a pressurized fluid independently of the pressurization of the working chamber.The cavity can be pressurized either with a static pressure or with a variable pressure, particularly one that can be adjusted or regulated externally. Both gaseous and liquid fluids can be used to pressurize the cavity.

[0015] Preferably, a second sealing system is assigned to the working piston, which is designed in the same way as the first sealing system and is arranged on the working piston in a mirror image of the first sealing system. Preferably, the second sealing system has the same features and properties as the first sealing system and is aligned in a mirror image with respect to a mirror plane on the working piston oriented transversely to the movement axis. Such a second sealing system is of particular interest when the swivel actuator is to be used for active swivel movements in two mutually opposite swivel directions and, for this purpose, pressurization of a second working chamber of variable size, delimited by the actuator housing and the working piston, is also provided.

[0016] Advantageous embodiments of the invention are illustrated in the drawing. Fig. 1 a perspective overview of a swivel actuator comprising a circular cylindrical actuator housing in which a valve unit is arranged on a first end face and an output gear is arranged on a second end face, Fig. 2 a planar sectional view of the swivel actuator according to the Fig. 2, Fig. 3 to 11 show several embodiments of working pistons equipped with different sealing systems.

[0017] The one in the Fig. The swivel actuator 1 shown in Figure 1 is designed to provide a swivel movement and comprises a purely exemplary circular-cylindrical actuator housing, wherein a valve unit 5 is arranged on a first end face 3 of the actuator housing 2 and an output gear 6 is arranged on a second end face 4 of the actuator housing 2. For example, the swivel actuator 1 can be attached to the actuator housing 2 on a machine (not shown) in order to perform a swivel movement of the output gear 6 about a swivel axis 7 upon provision of compressed air and electrical control signals which are made available to the valve unit 5, and thus to bring about a movement of a machine component (likewise not shown).

[0018] The valve unit 5 comprises several electromechanically operating valves (not shown in detail and purely exemplary), in particular solenoid valves, which enable compressed air to be supplied to the swivel actuator 1 and compressed air to be discharged from the swivel actuator 1 depending on electrical control signals. These control signals can be provided to the swivel actuator 1, for example, by a higher-level control system (not shown in detail).

[0019] As the representation of the Fig. 2, the actuator housing 2 is formed, for example, from a cup-shaped housing part 11 and a cover plate 12, wherein the cover plate 12 closes a housing opening 13. Thus, the actuator housing 2 defines a purely exemplary circular-cylindrical working recess 14, which extends along the pivot axis 7, also referred to as the movement axis 7, with a constant profile.

[0020] In the working recess 14, several guide rods 15 are arranged which are aligned parallel to the movement axis 7 and which are aligned, for example, in a 120-degree pitch with respect to the movement axis 7, so that in the representation of the Fig. 2, only two of these guide rods 15 are visible. The function of the guide rods 15 is to prevent rotation of the working piston 41, which is described in more detail below.

[0021] Coaxial with the pivot axis 7, a threaded spindle 31 is received in the working recess 14, the first, circular-cylindrical end section 32 of which penetrates a base region 16 of the housing part 11. The first end section 32 is rotatably mounted in a ball bearing 17 on the base region 16 and is rotatably sealed by a sealing ring 18, which is received in an annular groove 19 in the base region 16. A second end section 33 of the threaded spindle 31, which is also circular-cylindrical, penetrates the end cover 12 and is rotatably sealed relative to the end cover 12 by a sealing ring 20, which is received in an annular groove 21 of the end cover 12. The second end section 33 has a driver section 34 which is connected in a rotationally fixed manner to the output gear 6, so that a pivoting movement of the threaded spindle 31 leads to a pivoting movement of the output gear 6.Purely as an example, the output gear 6 is mounted in a double ball bearing 8 so that it can rotate relative to the end cover 12.

[0022] The threaded spindle 31 is provided between the first end section 32 and the second end section 33 with a multi-start external thread 35, into which an internal thread section 42 of the working piston 41 engages. This creates a forced movement coupling between the threaded spindle 31 and the working piston 41, so that a movement of the working piston 41, which is guided on the guide rods 15 and on an inner wall 22 of the working recess 14 for linear movement along the movement axis 7, is inevitably accompanied by a rotational movement of the threaded spindle 31 about the movement axis 7.

[0023] The working piston 41 is provided on an outer peripheral surface with a circumferential annular groove 45 which is open outwards in the radial direction and in which a sealing ring 46 is received.

[0024] The sealing ring 46 creates a sealing effect between the working piston 41 and the inner wall 22. The task of the working piston 41 is to ensure the most complete fluidic separation possible between a first working chamber 47 and a second working chamber 48. For this purpose, a first sealing system 51 and a second sealing system 52, arranged in a mirror image and designed identically to the first sealing system 51, are assigned to the working piston 41. Furthermore, each of the guide rods 15 is assigned a guide rod seal 23, designed purely as an O-ring made of a rubber-elastic material, and a sleeve-shaped holder 24, designed to secure the guide rod seal 23 in a sealing recess 63 provided for this purpose and designed as a stepped bore. This also ensures a seal between the first working chamber 47 and the second working chamber 48 in the area of ​​the respective guide rods 15.

[0025] For the intended use of the swivel actuator 1, a pressure difference is created between the two working chambers 47, 48 by targeted venting and venting of the first working chamber 47 and the second working chamber 48. If this pressure difference is sufficiently large, a linear movement of the working piston 41 and a resulting pivoting movement of the threaded spindle 31 with the output gear 6 attached to it occurs. The pitch of the threaded spindle 31 and the internal thread section 42 of the working piston 41 is selected such that no self-locking occurs. The venting and venting of the two working chambers 47, 48 is carried out by means of the valve unit 5 and with working connections that are individually assigned to the working chambers 47, 48. Fig. 1 shows the working connection 62, which is inserted in a manner not shown in detail into the Fig. 2 shown working space 48.

[0026] For the following descriptions of the sealing systems according to the Fig. 2 to 11, reference is made only to the first sealing system (e.g. 51), since the second sealing system (e.g. 52), if present, is preferably designed identically.

[0027] In the embodiment according to the Fig. 2, the internal threaded portion 42 is realized in a threaded insert 53, which is secured in a receiving recess 55 of the working piston 41 by means of a screw connection 54. For sealing between an inner surface 56 of the receiving recess 55 and the threaded insert 53, the threaded insert 53 is provided on an outer peripheral surface 57 with a circumferential groove 58 in which a sealing ring 59 is received.

[0028] According to the presentation of the Fig. 2, a first, ring-shaped first spindle seal 71 is arranged below the threaded insert 53 in the receiving recess 55 of the working piston 41. The first spindle seal 71 bears axially and seals axially against a lower pressure body 74. Furthermore, the first spindle seal 71 bears radially against the receiving recess 55 and seals radially inward against the threaded spindle 31. The threaded insert 53 seals radially with the receiving recess 55 via the sealing ring 59. In order to enable an adjustable sealing effect for the first spindle seal 71, the lower pressure body 74, which is purely exemplary and plate-shaped, is assigned to the working piston 41. The lower pressure body 74 is positioned at an adjustable distance 76 from the working piston 41 via a plurality of screw connections 75, preferably arranged at the same angular pitch around the movement axis 7.Depending on the set distance 76, an elastic deformation of the first spindle seal 71 in the axial direction results, which leads to an evasive movement of the first spindle seal 71 in the radial direction, whereby a radially acting contact pressure can be set against the inner surface 56 of the receiving recess 55 and against the threaded spindle 31.

[0029] The second spindle seal 72 is received in the recess 60 in the threaded insert 53 and, in the same way as the first spindle seal 71, can be compressed by the associated upper pressure body 78 using the screw connections 79, thus adjusting its sealing effect. The second spindle seal 72 seals radially inward against the threaded spindle 31 and radially outward with its outer circumferential surface 73 against the recess 60 in the threaded insert 53. Furthermore, it bears downwardly against a second axial surface 44 of the threaded insert 53, forming a seal in the axial direction, and upwardly against the upper pressure body 78.

[0030] For the working pistons according to the Fig. 3 to 11, the working piston is shown only schematically as a circular cylindrical component for reasons of clarity. Furthermore, Fig. 3 to 11 only describe one sealing system each, since in most cases a mirror-symmetrical arrangement of two identical sealing systems is provided.

[0031] In the working piston 101 according to the Fig. 3 is similar to the working piston 41 according to the Fig. 2, a first spindle seal 102 is accommodated in a circular cylindrical recess 103. The sealing effect of the first spindle seal 102 can be adjusted by adjusting a distance 106 between the working piston 101 and a plate-shaped pressure body 106 using screw connections 105.

[0032] In the working piston 111 according to the Fig. 4, a first spindle seal 112 is accommodated in a circular cylindrical recess 113. The sealing effect of the first spindle seal 112 is influenced by a cup-shaped pressure body 114, which engages with a cup rim 118 in an annular groove 115 formed in the working piston 111. The pressure body 114 lies sealingly against an upper side 116 of the first spindle seal 112 and is sealed off from the working piston 111 by a sealing ring 117. A sealing chamber 119 delimited by the working piston 111, the first spindle seal 112 and the pressure body 114 is thus separated from the first working chamber 47, as shown in the Fig. 2. The pressure in the sealing chamber 119 is preferably lower than in the first working chamber 47, resulting in a reduction in volume for the sealing chamber 119 and a compression of the first spindle seal 112. Thus, the pressure body 114 enables pressure adjustment for the first spindle seal depending on the pressure conditions between the first working chamber 47 and the sealing chamber 119.

[0033] In the working piston 121 according to the Fig. 5, a first spindle seal 122 is accommodated in a circular cylindrical groove recess 123. The groove recess 123 is in fluid communication with the first working chamber 47 via a connecting channel (not shown) and is therefore always subjected to the same pressure that prevails in the working chamber 47. Alternatively, a pressure supply for the groove recess 123 that is independent of the pressure in the working chamber 47 can be provided. By pressurizing the groove recess 123, a radially inwardly directed pressure force is introduced onto the first spindle seal 122, which is thereby connected to the Fig. 2, the contact pressure being dependent on the pressure in the groove recess 123.

[0034] In the working piston 131 according to the Fig. 6, a first spindle seal 132 is accommodated in a circular cylindrical groove recess 133. The first spindle seal 132 is provided with a circular circumferential bore 134, which is designed as a cavity within the first spindle seal 132. Via a connecting channel (not shown), the bore 134 is in fluid communication with the first working chamber 47. Thus, the same pressure always prevails in the bore 134 as in the working chamber 47, and the first spindle seal 132 expands depending on this pressure, which in turn is connected to the Fig. 2, the contact pressure being dependent on the pressure in the bore 134. Alternatively, a pressure supply for the bore 134 that is independent of the pressure in the working chamber 47 can also be provided.

[0035] In the working piston 141 according to the illustrations of Fig. 7 and Fig. 8, the first spindle seal 142 is received in a groove recess 143 in the working piston 141, wherein this groove recess 143 has a wedge-shaped opening 144 extending radially outwards. This opening 144 allows a pipe clamp 145 to be placed around the first spindle seal 142, wherein this pipe clamp 145 has an adjustable diameter in order to thereby adjust the radial preload of the first spindle seal 142. For example, the pipe clamp 145 is provided with a hexagon 146, which enables torque to be introduced onto a threaded section (not shown), which in turn enables the desired diameter adjustment for the pipe clamp 145.

[0036] In the working piston 151 according to the Fig. 9, the first spindle seal 152 is housed in an elastically deformable ring formed from a plurality of tongue-shaped ring segments 153, arranged, in particular, at equal angular pitch around the movement axis 7 and separated from one another by narrow slots. The ring segments 153 define a conical-segment-shaped envelope geometry (not shown), which is adapted to an inner surface 155 of the pressure body 154, also shaped like a conical segment. Furthermore, the pressure body 154 is provided with an external thread 157, which is designed to engage an internal thread 158 of the working piston 151.Accordingly, a screwing movement of the pressure body 154 relative to the working piston 151 can cause a change in a distance 156 between the pressure body 154 and the ring segments 153 and thus a change in the pressure forces acting from the pressure body 154 via the ring segments 153 on the first spindle seal and thus an adjustment of the axial and radial sealing effect by the first spindle seal 152. Deviating from the representation of the . Fig. 9, a mirror-symmetrical arrangement of two pressure bodies and associated spindle seals can also be provided.

[0037] In the working piston 161 according to the Fig. 10, the first spindle seal 162 is received in a circular recess 163 of the working piston 161. The first spindle seal 162 sealingly abuts an axial surface 164 of the recess 162 facing the first spindle seal 162 in a radially outer region and is arranged at a distance from the first axial surface of the working piston in a radially inner region in order to form a variable-size buffer chamber 165 with the working piston 161. The geometry and material selection of the first spindle seal 162 are designed such that, during intended use, it can deform elastically, provided there is a pressure difference between the first working chamber and the buffer chamber 165, whereby a dynamic adaptation of the first spindle seal 162 to different operating situations can be achieved.

[0038] In the working piston 171 according to the Fig.11, the first spindle seal 172 is received in a circular recess 173 of the working piston 171. An outer diameter of the first spindle seal 172 is selected to be larger than an inner diameter of the recess 173, so that the first spindle seal 172 is received in the recess 173 with an internal preload. This preload causes radially inwardly directed compressive forces to be introduced onto the first spindle seal 172, so that it is pressed sealingly against the threaded spindle 31.

[0039] Additionally or alternatively, it can also be provided that the internal thread section 174 of the first spindle seal 172 is designed with an undersize relative to the external thread 35 of the threaded spindle 31, so that a tight sealing connection between the first spindle seal 172 and the external thread 35 is ensured regardless of an interaction between the external diameter of the first spindle seal 172 and the internal diameter of the recess 173. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2008 034 994 B3

[0002]

Claims

[1] Swivel actuator (1) for providing a swivel movement, with an actuator housing (2) in which a working recess (14) is formed, with a working piston (41; 101; 111; 121; 131; 141; 151; 161; 171) which is received in the working recess (14) in a linearly movable manner along a movement axis (7), and with a threaded spindle (31) which is mounted on the actuator housing (2) in a rotatable manner about the movement axis (7) and which passes through the working piston (41; 101; 111; 121; 131; 141; 151; 161; 171), wherein an external thread section (35) of the threaded spindle (31) engages in an internal thread section (42) of the working piston (41; 101; 111; 121; 131; 141; 151; 161; 171) engages in order to convert a linear movement of the working piston (41; 101; 111; 121; 131; 141; 151; 161; 171) into a pivoting movement of the threaded spindle (31) about the movement axis (7), wherein the working piston (41; 101; 111; 121; 131; 141; 151; 161;171) is assigned a first sealing system (51), which comprises a first, annular spindle seal (71; 102; 112; 122; 132; 142; 152; 162; 172) which sealingly bears against a first axial surface (43) of the working piston (41; 101; 111; 121; 131; 141; 151; 161; 171), which is arranged adjacent to the internal thread section (42), wherein the first spindle seal (71; 102; 112; 122; 132; 142; 152; 162; 172) has a first internal thread section (77) adapted to the external thread section (35) of the threaded spindle (31) and sealingly bears against the threaded spindle (31) is present.; [2] Swivel actuator (1) according to claim 1, characterized bythat the first sealing system (51) comprises a first pressure body (74; 104; 114; 154) and that the first spindle seal (71; 102; 112; 122; 132; 142; 152; 162; 172) is received between the first axial surface (43) and the first pressure body (74; 104; 114; 154) arranged at an adjustable distance (76; 106; 156) from the first axial surface. [3] Swivel actuator (1) according to claim 2, characterized bythat the first pressure body (74; 104; 114; 154) comprises a pressure plate which bears sealingly against an upper side (116) of the first spindle seal (71; 102; 112; 122; 132; 142; 152; 162; 172) facing away from the working piston (41; 101; 111; 121; 131; 141; 151; 161; 171), and that the first pressure body (74; 104; 114; 154) has a circumferential annular collar which extends axially along the movement axis (7) starting from the pressure plate in the direction of the working piston (41; 101; 111; 121; 131; 141; 151; 161; 171) and is guided in a linearly movable, sealing manner along the movement axis (7) in an annular guide recess (115) in the working piston (41; 101; 111; 121; 131; 141; 151; 161; 171), and in that the first pressure body (74; 104; 114; 154) with the first spindle seal (71; 102; 112; 122; 132; 142; 152; 162; 172) and the working piston (41; 101; 111; 121; 131; 141; 151; 161; 171) delimits a variable-size sealing chamber (119). [4] Swivel actuator (1) according to claim 1, characterized by that the first spindle seal (71; 102; 112; 122; 132; 142; 152; 162; 172) is received in a first ring (153) which projects from the first axial surface (43) along the movement axis (7), is formed in particular in one piece with the working piston (41; 101; 111; 121; 131; 141; 151; 161; 171) and is elastic in the radial direction, and that the first ring (153) is assigned a first adjusting device (154) which is designed to adjust an inner diameter of the first ring (153). [5] Swivel actuator (1) according to claim 4, characterized bythat an outer peripheral surface of the first ring (153) is conical and that the first adjusting device (154) has an inner surface (155) corresponding to the outer peripheral surface of the first ring (153) and forms a thread arrangement (157, 158) with the working piston (41; 101; 111; 121; 131; 141; 151; 161; 171), wherein a thread axis of the thread arrangement (157, 158) is aligned parallel to the movement axis (7). [6] Swivel actuator (1) according to claim 1, characterized bythat the first spindle seal (71; 102; 112; 122; 132; 142; 152; 162; 172) is accommodated in a cylindrical, in particular circular-cylindrical, recess of the working piston (41; 101; 111; 121; 131; 141; 151; 161; 171), wherein an inner surface of the recess facing the first spindle seal (71; 102; 112; 122; 132; 142; 152; 162; 172) and an outer circumferential surface of the first spindle seal (71; 102; 112; 122; 132; 142; 152; 162; 172) delimit a variable-size working gap, or wherein the first Spindle seal (71; 102; 112; 122; 132; 142; 152; 162; 172) in a radially outer region sealingly bears against the first axial surface of the recess facing the first spindle seal (71; 102; 112; 122; 132; 142; 152; 162; 172) and is arranged in a radially inner region spaced from the first axial surface of the working piston (41; 101; 111; 121; 131; 141; 151; 161; 171) in order to form a variable-size buffer space with the working piston (41; 101; 111; 121;131; 141; 151; 161; 171). [7] Swivel actuator (1) according to claim 1, characterized by that the first spindle seal (71; 102; 112; 122; 132; 142; 152; 162; 172) is accommodated in a cylindrical, in particular circular-cylindrical, recess of the working piston (41; 101; 111; 121; 131; 141; 151; 161; 171) and that between an inner surface of the recess facing the first spindle seal (71; 102; 112; 122; 132; 142; 152; 162; 172) and an outer circumferential surface of the first spindle seal (71; 102; 112; 122; 132; 142; 152; 162; 172) a clamping ring (145) with a variable diameter which is designed for a diameter adjustment for the first spindle seal (71; 102; 112; 122; 132; 142; 152; 162; 172). [8] Swivel actuator (1) according to claim 1, characterized bythat the first spindle seal (71; 102; 112; 122; 132; 142; 152; 162; 172) is received in a circumferential annular groove (123; 133) of the working piston (41; 101; 111; 121; 131; 141; 151; 161; 171) and that a groove wall of the annular groove (123; 133) facing the first spindle seal (71; 102; 112; 122; 132; 142; 152; 162; 172) and an outer circumferential surface of the first spindle seal (71; 102; 112; 122; 132; 142; 152; 162; 172) form a limit the working gap of variable size. [9] Swivel actuator (1) according to claim 1, characterized by that a cavity (134) is formed in the first spindle seal (71; 102; 112; 122; 132; 142; 152; 162; 172), which cavity can be supplied with a pressurized fluid via a supply opening. [10] Swivel actuator (1) according to one of the preceding claims, characterized bythat the working piston (41; 101; 111; 121; 131; 141; 151; 161; 171) is assigned a second sealing system which is designed in the same way as the first sealing system and which is arranged on the working piston (41; 101; 111; 121; 131; 141; 151; 161; 171) in a mirror image of the first sealing system.

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