A valve, which has at least one seal ring arranged in a recess of a valve housing, which seal ring has a seal housing having a U-shaped cross-section, in which seal housing an annular sealing element is arranged. The seal housing has a multi-part design and contains at least one separate housing leg, which is fixed to an annular bottom section of the seal housing in a joining region. The sealing element has a static sealing section, which engages in a sealing groove formed in the bottom section and is suitable for interacting with the two groove flanks of the sealing groove in a sealing manner.
1. A valve comprising a valve housing and a piston valve spool arranged in a recess of the valve housing in an axially displaceable manner for performing linear switching movements between various working positions, the recess having a central longitudinal axis, and further comprising at least one seal ring which coaxially encloses the valve spool in the recess and which has a multi-part annular seal housing located stationary relative to the valve housing and having a U-shaped cross-section with two opposite housing legs connected to each other by a radially outward annular base section, wherein each of the two housing legs is designed as a body which is separate from the base section and secured to the base section in a respective joining region, the seal housing bounding a reception chamber which has a housing opening defining a radially inward facing slot laterally flanked by the two housing legs and in which an annular sealing element designed for acting together with an inner surface of the seal housing to form a static seal and for acting together with an outer circumferential surface of the valve spool to form a dynamic seal is coaxially arranged, the sealing element having, for dynamic sealing, a dynamic sealing section located in a region of housing opening and coaxially enclosing the valve spool with sealing contact in at least one of the working positions, wherein a sealing groove is formed in a radially inward-oriented inner circumferential surface of the base section in an interior of the reception chamber of the seal housing between said joining regions, said sealing groove being radially open towards the inside and being designed as an annular groove having two axially opposite groove sides, wherein the sealing element dips into the sealing groove with a radially outward static sealing section which is designed for acting together axially with the two groove sides of the sealing groove arranged opposite one another in the base section for providing a static seal.
2. The valve according to claim 1 , wherein the static sealing section of the annular sealing element has axially opposite side surfaces and at least one raised sealing region provided on each side surface, said sealing region comprising a sealing edge or a sealing bead and which can bear against the adjacent groove side of the sealing groove to form a static seal.
3. The valve according to claim 1 , wherein each of said joining region is permeable to fluids.
4. The valve according to claim 1 , wherein each of said joining region comprises an annular joining groove formed in an axial outer surface of the annular base section, each housing leg being installed in a respective one of the two annular joining grooves.
5. The valve according to claim 1 , wherein the static sealing section has a smaller width than the sealing groove, the annular sealing element being axially movable in the seal housing, so that in operation the annular sealing element can be axially pressed by axially applied fluid pressure against a groove side of the sealing groove while forming a seal.
6. The valve according to claim 1 , wherein the sealing element is provided with at least one axially protruding securing projection, which engages with an axial securing recess formed laterally on the inner surface of the seal housing, so that the sealing element is secured against radial extraction from the reception chamber of the seal housing.
7. The valve according to claim 6 , wherein the sealing element is provided with two axially opposite side surfaces with a securing projection provided on each side surface, which engages with one of two opposite axial securing recesses on the inner surface of the seal housing.
8. The valve according to claim 6 , wherein the at least one securing projection and the at least one securing recess are designed to be annular.
9. The valve according to claim 6 , wherein the at least one securing projection is represented by the static sealing section, at least a section of the at least one securing recess being represented by the sealing groove.
10. The valve according to claim 6 , wherein the at least one securing projection is located at a radial distance from the static sealing section and closer to the housing opening of the seal housing.
11. The valve according to claim 1 , wherein several seal rings enclosing the valve spool are arranged at an axial distance from one another in the recess of the valve housing.
12. The valve according to claim 1 , wherein at least the dynamic sealing section of the sealing element is capable of floating movement relative to the seal housing in a radial plane perpendicular to the central longitudinal axis of the recess.
13. The valve according to claim 1 , wherein a free annular gap is formed between a radially outward-oriented outer circumferential surface of the sealing element and the radially inward-oriented inner circumferential surface of the seal housing.
14. The valve according to claim 1 , wherein one of the two housing legs of the seal housing is designed as a guide leg, which has at least one radially inward-oriented guide surface, which, by direct contact with the outer circumferential surface of the valve spool and independent of the sealing element provides a transverse support and a linear guidance of the valve spool.
15. The valve according to claim 4 , wherein the annular housing leg is located in the annular joining groove by plastically deformed retaining sections of the base section.
16. The valve according to claim 12 , wherein the entire sealing element is capable of floating movement relative to the seal housing in a radial plane perpendicular to the longitudinal axis of the seal ring.
17. A valve comprising a valve housing and a piston valve spool arranged in a recess of the valve housing in an axially displaceable manner for performing linear switching movements between various working positions, the recess having a central longitudinal axis, and further comprising at least one seal ring, which coaxially encloses the valve spool in the recess, the seal ring comprising:
an annular seal housing located stationary relative to the valve housing and having a U-shaped cross-section bounding a reception chamber, the reception chamber defining a radially inward facing housing opening; and
an annular sealing element received within said housing opening coaxially with said annular seal housing, said annular sealing element acting together with an outer circumferential surface of the valve spool to form a dynamic seal, the sealing element having, for dynamic sealing, a dynamic sealing section located in a region of the housing opening and coaxially enclosing the valve spool with sealing contact in at least one of the working positions of the valve spool,
wherein the annular seal housing comprises two opposite housing legs connected to a radially outward annular base section, the housing legs and the base section being separate parts flanking the reception chamber, and
wherein the base section comprises two joining regions and a sealing groove formed in a radially inward-oriented inner circumferential surface of the base section between the two joining regions, each joining region receiving a respective housing leg, and the sealing groove having opposite groove sides engaged by a static sealing section of the sealing element to form a static seal.