VALVE UNIT FOR A PISTON COMPRESSOR AND PISTON COMPRESSOR

Abstract

A valve unit for a piston compressor includes a housing, in which at least one inlet valve and at least one outlet valve are arranged. The housing includes a first cylinder-head-side surface and a second, cylinder-side surface which is away from the first cylinder-head-side surface. The surfaces extending transversely to a longitudinal axis of the valve unit. A peripheral wall of the housing of the valve unit, and which surrounds the longitudinal axis of the valve unit, includes at least one contact section. The at least one contact section is provided for contact on a contact surface on the cylinder or on the cylinder head and extends obliquely to the longitudinal axis.

Claims

1. A valve unit for a piston compressor with a cylinder an with a cylinder head, the valve unit comprising a housing, in which at least one inlet valve and at least one outlet valve are arranged, the housing comprising: a first, cylinder-head-side surface; a second, cylinder-side surface which faces away from the first, cylinder-head-side surface, the first, cylinder-head-side surface and the second, cylinder-side surface extending transversely to a longitudinal axis of the valve unit; and a peripheral wall which surrounds the longitudinal axis of the valve unit, the peripheral wall comprising cylinder or cylinder head contact section for contact on the cylinder or the cylinder head, the cylinder or cylinder head contact section extending obliquely to the longitudinal axis.

2. A valve unit according to claim 1, wherein the housing comprises a round outer contour, wherein the longitudinal axis defines a middle axis of this outer contour.

3. A valve unit according to claim 1, wherein the cylinder or cylinder head contact section extends over one or more peripheral sections of the peripheral wall.

4. A valve unit according to claim 1, wherein the cylinder or cylinder head contact section extends over a complete periphery of the peripheral wall.

5. A valve unit according to claim 1, wherein an angle, at which the cylinder or cylinder head contact section extends obliquely to the longitudinal axis, is constant over a peripheral extension of the cylinder or cylinder head contact section.

6. A valve unit according to claim 1, wherein the cylinder or cylinder head contact section is situated on an outer peripheral wall or an inner peripheral wall of the housing.

7. A valve unit according to claim 1, wherein the cylinder or cylinder head contact section is formed by a conical surface or a spherical surface or by both a conical surface or a spherical surface.

8. A valve unit according to claim 1, wherein an angle at which the cylinder or cylinder head contact section extends obliquely to the longitudinal axis is selected such that no self-locking occurs given a contact on a contact surface extending in a parallel manner.

9. A valve unit according to claim 1, wherein: the housing, radially outwardly of the longitudinal axis, comprises a projection projecting in a direction of the longitudinal axis; the cylinder or cylinder head contact section is situated on a side of the projection which faces the longitudinal axis; and the projection is preferably configured as an annular collar, on whose inner periphery the cylinder or cylinder head contact section is situated.

10. A piston compressor comprising: at least one cylinder and cylinder head connected to the cylinder; and a valve unit comprising a housing, in which at least one inlet valve and at least one outlet valve are arranged, the housing comprising: a first, cylinder-head-side surface; a second, cylinder-side surface which faces away from the first, cylinder-head-side surface, the first, cylinder-head-side surface and the second, cylinder-side surface extending transversely to a longitudinal axis of the valve unit; and a peripheral wall which surrounds the longitudinal axis of the valve unit, the peripheral wall comprising cylinder or cylinder head contact section for contact on the cylinder or the cylinder head, the cylinder or cylinder head contact section extending obliquely to the longitudinal axis.

11. A piston compressor according to claim 10, wherein a valve unit contact surface with a contour corresponding to a contour of the cylinder or cylinder head contact section of the valve unit and which is in contact with the cylinder and/or cylinder head contact section of the valve unit is formed on the cylinder or on the cylinder head.

12. A piston compressor according to claim 11, wherein the cylinder and/or the cylinder head comprises a recess into which the housing of the valve unit engages, wherein a peripheral wall of the recess forms the valve unit contact surface, with which the cylinder or cylinder head contact section of the valve unit is in contact.

13. A piston compressor according to claim 12, wherein the recess is formed on a side of the cylinder head which faces the cylinder and/or on the side of the cylinder which faces the cylinder head, wherein the recess is a radial widening of an interior of the cylinder.

14. A piston compressor according to claim 13, wherein the recess comprises a shoulder which is directed radially inwards transversely to the longitudinal axis and on which the housing of the valve unit bears.

15. A piston compressor according to claim 11, wherein the valve unit contact surface for the contact section of the housing of the valve unit is formed on both the cylinder and on the cylinder head, wherein the contact surface which is formed on the cylinder head is aligned obliquely to the longitudinal axis and tapers obliquely in a direction away from the cylinder, wherein the contact surface formed on the cylinder, in at least in a peripheral section, is aligned obliquely to the longitudinal axis and tapers obliquely in a direction away from the cylinder head.

16. A piston compressor according to claim 13, wherein the recess is formed on an end of the cylinder, which end faces the cylinder head, at an outer periphery of the cylinder.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The invention is hereinafter explained in more detail by way of embodiment examples represented in the drawings. In the drawings:

[0020] FIG. 1 is a perspective exploded representation of a part of the piston compressor;

[0021] FIG. 2 is the representation according to FIG. 1, in a sectioned view,

[0022] FIG. 3 is a sectioned view, the part of a piston compressor which is represented in FIGS. 1 and 2, in the assembled condition;

[0023] FIG. 4 is a sectioned view, a part of a piston compressor according to a second embodiment;

[0024] FIG. 5 is a sectioned view, a part of a piston compressor according to a third embodiment;

[0025] FIG. 6 is a sectioned view, a part of a piston compressor according to a fourth embodiment;

[0026] FIG. 7 is a sectioned view, a part of a piston compressor according to a fifth embodiment; and

[0027] FIG. 8 is a sectioned view, a valve unit of a piston compressor which belongs to the state of the art.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Referring to the drawings a piston compressor is represented in parts in FIG. 1-3. This piston compressor comprises a cylinder 18, in whose interior 20 a piston is guided in a linearly movable manner. The representation of the piston and its drive has been omitted in the drawings for reasons of a better overview, since the piston and its drive are not essential to the invention and the piston as well as piston drives of piston compressors has been known for some time now from the state of the art. The cylinder 18 is closed at one end by a cylinder head 22. Here, in this example, the cylinder head 22, lying on a side 24 of the cylinder 18, is screwed to the cylinder 18 via four threaded pins 26. The cylinder head 22 however could also be connected to the cylinder 18 in another manner, for example via more or less than four threaded pins 26.

[0029] A valve unit 28 is arranged in the piston compressor, between the cylinder 18 and the cylinder head 22. A housing 30 of this valve unit 28 is designed in a stepped manner. The housing 30 is thereby designed in a two-part manner, from a first housing part 32 and a second housing part 34, wherein a first housing part 32 is radially widened or extended compared to a second housing part 34 which connects onto the first housing part 32 in a direction of a longitudinal axis A of the valve unit 28, and thus has a larger cross section than the second housing part 34. As a whole, the valve unit 28 with regard to is basic construction can correspond to the construction according to FIG. 8, wherein the housing part 32 corresponds to the housing part 2 in FIG. 8, and the housing part 34 corresponds to the housing part 4 in FIG. 8. Both housing parts 32 and 34 have a circular outer contour. The housing parts 32 and 34 are suitable for being connected to one another, but can also be designed in a single-part manner. At least one inlet valve and one outlet valve are arranged in the housing 30 of the valve unit 28, in a cross-sectional region of the housing 30 which is delimited by the cross-sectional contour of the housing part 34. The at least one inlet valve and the at least one outlet valve have been omitted in the drawings in each case for reasons of a better overview, but can for example also be designed in the same manner as the valve unit which is represented in FIG. 8 and which belongs to the state of the art. With all valve units 28 which are represented in the drawings, the at least one inlet valve 12 forms a closable flow path through the valve unit 28, running from a surface 36 of the housing 30 to a surface 38, and the at least one outlet valve 14 forms a closable flow path through the valve unit 28, running from the surface 38 of the housing 30 to the surface 36.

[0030] With its arrangement between the cylinder 18 and the cylinder head 22 of the piston compressor represented in FIG. 1-3, the valve unit 28 engages into a recess 40 of the cylinder head 22 which is formed on a side 42 of the cylinder head 22 which faces the cylinder 18 and is arranged there in a manner such that the longitudinal axis A of the valve unit 28 engaging into the recess 40 corresponds to a longitudinal axis B of the piston compressor or the cylinder head 22. The recess 40 is radially widened compared to the interior 20 of the cylinder 8, i.e. the recess 40 has a larger diameter compared to the interior 20.

[0031] In the cylinder head 22, the housing 30 of the valve unit 28 is supported in a gastight manner on a flow channel 48 which is formed there, via a sealing ring 44 which engages into a recess 46 formed on the surface 36 of the housing part 34. The flow channel 48 which in the cylinder head 22 is arranged coaxially to the longitudinal axis B of the piston compressor, which is to say coaxially to the longitudinal axis A of the valve unit 28, projects on the outer side of the cylinder head 22 which is away from the cylinder 18, and there this flow channel forms a gas inlet of the piston compressor. Gas which is to be compressed in the piston compressor can flow from this gas inlet into the interior 20 of the cylinder 18 via the at least one gas inlet valve 12 arranged on the valve unit 28.

[0032] The at least one gas outlet valve 14 of the valve unit 28 is arranged on the valve unit 28, radially to the outside on the recess 46 formed on the housing 30 of the valve unit 28 and is flow-connected to an annular space 50 which is formed in the cylinder head 22 and which surrounds the flow channel 48 at the outer periphery. The annular space 50 is flow-connected to a gas outlet 52 of the piston compressor which is formed on the cylinder head 22, so that compressed gas in the interior 20 of the cylinder 18 can get to the gas outlet 52 via the at least one outlet valve of the valve unit 28 and via the annular space 50.

[0033] An outer peripheral wall 54 of the housing part 32 contacts a peripheral wall 56 of the recess 40, with the engagement of the housing 30 of the valve unit 28 into the recess 40 formed on the cylinder head 22. Accordingly, the outer peripheral wall 54 forms a contact section of the valve unit 28 which comes into bearing contact on a contact surface (valve unit contact surface) formed by the peripheral wall 56 of the recess 40.

[0034] The outer peripheral wall 54 of the housing part 32, over its entire peripherally about the longitudinal axis A, extends at a constant angle obliquely to the longitudinal axis A of the valve unit 28 in a direction away from the cylinder 18. The housing part 32 of the valve unit 28 thus has a conical shape or the shape of a truncated cone, wherein the cross section of the housing part 32 reduces in the direction of the cylinder head 22. The peripheral wall 56 over its entire periphery is also aligned obliquely to the longitudinal axis A of the valve unit 28 at the same constant angle as the outer peripheral wall 54, indeed in a manner corresponding to this outer peripheral wall 54, wherein the peripheral wall 56 tapers obliquely to the longitudinal axis A of the valve unit 28 in a direction away from the cylinder 18. The peripheral wall 56 also has a conical shape. With the engagement of the housing 30 of the valve unit 28 into the recess 40 of the cylinder head 22, the outer peripheral wall 54 of the shoulder 32 of the housing 30 thus bears on the peripheral wall 56 of the recess 40 over the complete surface. The magnitude of the angle, at which the outer peripheral wall 54 of the housing part 32 of the valve unit 28 as well as the peripheral wall 56 of the recess 40 of the cylinder head 22 is aligned obliquely to the longitudinal axis A of the valve unit 28, is preferably such that essentially no self-locking or jamming can occur between the housing 30 engaging into the recess 40 and the recess 40.

[0035] It is to be understood that the outer peripheral wall of the second housing part 34, alternatively or additionally could also be aligned conically or obliquely to the longitudinal axis A of the valve unit 28, in a manner corresponding to the outer peripheral wall 54. A contact surface (valve unit contact surface) for the outer peripheral wall of the housing part 34 could then be formed in the cylinder head, similarly to the design of the peripheral wall 56.

[0036] With this engagement of the housing part 32 into the recess 40 of the cylinder head 22, the housing 30 moreover bears on an annular shoulder 60 via a surface 58 of the housing part 32 which is away from the surface 38. The shoulder 60, at that end of the peripheral wall 56 of the recess 40 which is away from the cylinder 18 extends transversely to the longitudinal axis A of the valve unit 28 in the direction of the longitudinal axis A and narrows the cross section of the recess 40 to the cross section of the housing part 34. On assembly of the cylinder head 22 on the cylinder 18, the cylinder head 22, with the valve unit 28 whose surface 38 is flush with the side 40 of the cylinder head 22 is placed onto the side 24 of the cylinder 18 and is screwed to the cylinder 18, wherein an annular flat seal 62 is previously arranged on the side 24 of the cylinder 18, said seal sealing the cylinder 18 with respect to the valve unit 28 and to the cylinder head 22 as well as the surroundings or atmosphere, in a gas-tight manner.

[0037] FIG. 4 shows a piston compressor which merely differs from the piston compressor represented in FIG. 1-3 with regard to the design of the cylinder head, wherein the cylinder 18 and the valve unit 28 of the piston compressor represented in FIG. 4 is identical to the cylinder 18 and the valve unit 28 of the piston compressor represented in FIG. 1-3. The cylinder head 22′ of the piston compressor 22 represented in FIG. 4 largely corresponds to the cylinder head 22 of the piston compressor represented in FIGS. 1-3, wherein the single difference between the cylinder head 22′ and the cylinder head 22 lies in the fact that with the cylinder head 22′, the shoulder 60 provided in the case of the cylinder head 22 has been omitted and a peripheral wall 56′ of the recess 40′ of the cylinder head 22′ extends obliquely in the direction of the longitudinal axis A of the valve unit 28 in a direction away from the cylinder 18, wherein the peripheral wall 56′ ends directly at the annular space 50 of the cylinder head 22′. The valve unit 28 in the region of its outer periphery therefore only bears on the cylinder head 22′ via the peripheral wall 54.

[0038] The piston compressor which is represented in FIG. 5 comprises a cylinder head 22′ which is identical to the cylinder head 22′ of the piston compressor represented in FIG. 4. A cylinder 18′ of the piston compressor represented in FIG. 5 largely corresponds to the cylinder head 18 of the piston compressor represented in FIG. 1-3. The cylinder 18′ however differs from cylinder 18 to the extent that a recess 64 forming a radial widening of the interior 20 of the cylinder 18′ is formed on its side 24 facing the cylinder head 22′. A peripheral wall 66 which radially delimits the recess 64 is configured in a manner such that in a direction away from the cylinder head 22′, its tapers obliquely to the longitudinal axis A of a valve unit 28′ provided in the piston compressor. The peripheral wall 66 thus likewise has a conical shape. Hereby, an end of the peripheral wall 66 which faces the cylinder head 22′ is flush with the end of the peripheral wall 56 of the recess 40′formed on the cylinder head 22′, said end facing the cylinder 18′. The valve unit 28′ differs from the valve unit 28 which is represented in FIGS. 1-4, only with regard to the design of the housing part 32′. The housing part 32′ comprises an outer peripheral wall 54′ which, from a plane 68 situated essentially centrally between a surface 38′ and a surface 58′ of the housing part 32′, in a region facing the cylinder head 22′ tapers to the longitudinal axis A of the valve unit 28 in a direction way from the cylinder 18′ and in a region facing the cylinder 18′ tapers to the longitudinal axis A of the valve unit 28′ in a direction away from the cylinder head 22′. The outer peripheral wall 54′ thus has the shape of a double cone which departing from the middle tapers to both axial ends. The angle, at which the outer peripheral wall 58′, in its region facing the cylinder head 22′ tapers to the longitudinal axis A, corresponds to the angle, at which the peripheral wall 56 of the recess 40′ formed on the cylinder head 22′ tapers to the longitudinal axis of the valve unit 28′, whereas the angle, at which the outer peripheral wall 58′ in its region facing the cylinder 18′ tapers to the longitudinal axis A corresponds to the angle, at which the peripheral wall 66 of the recess 64 formed on the cylinder 18′ tapers to the longitudinal axis A. The housing part 32′, with the region facing the cylinder 18′ engages into the recess 64 formed on the cylinder 18′, wherein the region of the housing part 32′ which faces the cylinder head 22′ is received by the recess 40′ which is formed on the cylinder head 22′. In this position, the valve unit 28′ is fixed in the piston compressor, between the cylinder 18′ and the cylinder head 22′.

[0039] The piston compressor which is represented in FIG. 6 has the same cylinder 18′ as the piston compressor represented in FIG. 5. A cylindrical recess 40″ running out into the annular space 50 is formed on a cylinder head 22″ of the piston compressor in a manner departing from the side facing the cylinder 18′. The diameter of the recess 40″ is smaller than the largest diameter of the recess 64 formed on the cylinder 18′. A valve unit 28″ with its housing part 32″ engages into the recess 64. An outer peripheral wall 54″ of the housing part 32″ over its entire periphery tapers obliquely to the longitudinal axis A of the valve unit 28′ in a direction away from the cylinder head 22″ in a manner corresponding to the peripheral wall 66 of the recess 64 of the cylinder 18′. The housing part 32″ in the direction of the longitudinal axis A is dimensioned such that a surface 58″ of the housing part 32″ is flush with the side 24 which is to say the axial end-face 24 of the cylinder 18′. A part of the wall of the cylinder head 22″, said wall radially surroundings the recess 40″ of the cylinder head 22″, lies on the surface 58″ of the housing part 32″, so that the valve unit 28″ is fixed between the cylinder 18′ and the cylinder head 22″.

[0040] The piston compressor which is represented in FIG. 7 comprises a cylinder 18″ which only differs from the cylinder 18 of the piston compressor represented in FIGS. 1-3 in that a recess 72 extending over the entire outer periphery 70 is formed on the outer periphery 70 of the cylinder 18″ in a manner adjacent the side 24 of the cylinder 18″. An outer peripheral wall 74 of the recess 72 tapers obliquely to a longitudinal axis A of a valve unit 28″' of the piston compressor, in the direction of the cylinder head 22″, i.e. has a conical shape. The cylinder head 22″ is identical to the cylinder head 22″ of the piston compressor represented in FIG. 6. The valve unit 28″ is characterized in that a housing part 32″' of the valve unit 28″' has a diameter which corresponds to the outer diameter of the cylinder 18″, in the region which is adjacent the recess 72, wherein a projection 76 in the form of an annular collar engaging into the recess 72 formed on the cylinder 18″ is formed on a surface 38″ facing the cylinder 18″, in a manner projecting in the direction of the longitudinal axis A. Here, an inner peripheral wall 78 of the projection 76 which has an inclination corresponding to the inclination of the peripheral wall 74 of the recess 72 and tapers obliquely in the direction of the cylinder head 22″ comes into contact with the peripheral wall 74 of the recess 72 of the cylinder 18″.