Expansion valve

Abstract

The invention relates to an expansion valve (10), comprising: a pressure vessel (12); a linear actuator (14) arranged at least partially in the pressure vessel (12); the invention relates to a linear actuator (14) for a pressure vessel (12), comprising a linear actuator (14), a valve piston (16), the linear actuator (14) being arranged to cause a linear movement of the valve piston (16), and further comprising a valve block (18), in which a valve seat (20) corresponding to the valve piston (16) is arranged, on which the pressure vessel (12) is fixed in a fluid-tight manner. According to the invention, the expansion valve (10) has an insert element (22) which is arranged in a bottom region (24) of the pressure vessel (12) and which is designed to guide the valve piston (16) during a linear movement.

Description

TECHNICAL FIELD

[0001] The invention relates to an expansion valve. BACKGROUND

[0002] DE 10 2019 111 208 A1 has disclosed an expansion valve having a pressure vessel for partially accommodating a linear actuator. The linear actuator serves to cause a linear movement of a valve piston of the expansion valve. The expansion valve also has a valve block in which a valve seat corresponding to the valve piston is arranged, and the pressure vessel is fixed to the valve block in a fluid-tight manner. In order to guide the valve piston during the linear movement, the expansion valve has an adapter made of metal, which is connected to the pressure vessel by a welded connection. SUMMARY

[0003] It is an object of the present invention to provide an expansion valve which is compact in design and / or cost-effective. The object is achieved by the following technical solution.

[0004] The invention relates to an expansion valve having a pressure vessel, a linear actuator arranged at least partially in the pressure vessel, a valve piston, wherein the linear actuator is designed to cause a linear movement of the valve piston, and the expansion valve also has a valve block in which a valve seat corresponding to the valve piston is arranged, the pressure vessel being fixed to the valve block in a fluid-tight manner.

[0005] The expansion valve has an insertion element arranged in a bottom region of the pressure vessel, which is designed to guide the valve piston during the linear movement.

[0006] The expansion valve is in particular used for controlling and / or regulating a fluid flow in a fluid passage. "Provided" is in particular to be understood as specially programmed, designed and / or configured. The fact that an object is intended for a specific function is in particular to be understood as the object implementing and / or executing this specific function in at least one application and / or operating state. The expansion valve can in particular be used to influence a fluid flow, in particular a coolant flow, in a motor vehicle. In particular, the expansion valve can be used to control and / or regulate a refrigerant flow in an air conditioning circuit of an air conditioning system, in particular a motor vehicle air conditioning system.

[0007] The expansion valve is designed as a needle valve in particular. A "needle valve" is to be understood in particular as a valve having a valve piston, in particular a needle-shaped valve piston, which can be moved linearly in order to enlarge and / or reduce the size of the passage opening of the fluid passage. A linear actuator is arranged within the needle valve, in particular for causing a linear movement of the valve piston of the needle valve. The shaft of the linear actuator is in particular connected, directly or indirectly, to the valve piston. The shaft of the linear actuator is in particular used to drive or move the valve piston of the expansion valve. In this context, "fluid flow" is to be understood in particular as a liquid flow, a gas flow and / or combinations thereof. The fluid passage of the expansion valve is provided for guiding a fluid flow which is to be regulated and / or controlled by means of the valve block of the expansion valve. In particular, the fluid passage extends entirely within the valve block of the expansion valve. In particular, the fluid passage has at least one fluid inlet for introducing a fluid flow into the valve block and at least one fluid outlet for discharging a fluid flow from the valve block. The valve block is preferably designed as a one-piece metal element, in particular with a fluid passage introduced therein by means of mechanical processing and / or a connection geometry for connecting the linear actuator to the valve block.

[0008] A valve seat corresponding to the valve piston of the expansion valve is provided within the valve block. The valve seat can in particular be incorporated directly into the material of the valve block. Preferably, however, the valve seat is arranged in a separate component, in particular a cage element, which is inserted into a corresponding receptacle of the valve block. When the expansion valve is open, the fluid flow passes through the valve seat located inside the valve block. By means of the movement of the valve piston of the expansion valve relative to the valve seat of the expansion valve, the fluid passage within the valve block can be closed or opened, or the passage cross section of the fluid passage within the valve block can be enlarged or reduced.

[0009] The linear actuator in particular comprises an electric motor having a stator and a rotor, and a shaft connected to the rotor of the electric motor in a non-rotatable manner. The expansion valve, in addition to the linear actuator, has a fluid-tight pressure vessel in which the shaft of the linear actuator and the rotor of the electric motor of the linear actuator are arranged. The rotor of the electric motor is in particular arranged on the shaft in a non-rotatable manner. The stator of the electric motor of the linear actuator is in particular arranged on the outside of the pressure vessel and completely surrounds the rotor of the electric motor and the pressure vessel in a circumferential direction. The rotor of the electric motor, the pressure vessel and the stator of the electric motor are arranged at least substantially coaxially with respect to one another. The pressure vessel outer wall is located in a working air gap between the rotor and the stator of the electric motor. A control unit of the linear actuator and / or of the needle valve is arranged on the outside of the pressure vessel. In particular, the expansion valve has a housing in which the linear actuator, the pressure vessel and the control unit are arranged.

[0010] The shaft of the linear actuator is rotatably supported at a first end of the shaft, in particular facing the valve piston of the needle valve, by means of ball bearings. In order to support a second end of the shaft, which is axially opposite the first end of the shaft, the linear actuator comprises a plain bearing unit. The plain bearing unit has a bearing body in which the second end of the shaft is slidably supported. The bearing body is formed at least substantially from plastic and / or fiber-reinforced plastic. The bearing body has a bearing recess for receiving the second end of the shaft. The inner geometry of the bearing recess of the bearing body corresponds in particular at least substantially to the outer geometry of the second end of the shaft. Alternatively, the bearing recess can have three inner surfaces which are arranged at an angle of at least approximately 60° to one another and which bear tangentially on the second end of the shaft. The second end of the shaft is guided in particular in a clearance fit in the bearing recess of the bearing body. Alternatively or additionally, the plain bearing unit can comprise a plurality of resilient arms which are arranged uniformly on and bear on the outer circumference of the second end of the shaft.

[0011] The expansion valve has an insertion element for guiding the valve piston when the valve piston is moved linearly by the linear drive. The insertion element is at least partially inserted into a bottom region of the pressure vessel. The bottom region of the pressure vessel has an opening which, in the assembled state of the pressure vessel, points in the direction of the valve block and in which the insertion element is arranged. In particular, the insertion element is at least partially inserted axially into the opening of the bottom region of the pressure vessel, which opening, when the pressure vessel is in the assembled state, points in the direction of the valve block. The insertion element inserted into the bottom region of the pressure vessel is in particular fixed inside the pressure vessel in a form-locking and / or material-locking manner, but preferably at least in a force-locking manner. The insertion element is preferably designed as a plastic insertion element, in particular a plastic injection-molded component. In particular, the insertion element is made of a thermoplastic, for example polyphenylene sulfide (PPS). During production of the insertion element, additives known to the person skilled in the art can be added to the thermoplastic in order to adapt the material properties, for example with regard to mechanical and / or thermal strength and / or with regard to sliding properties, to the respective application. Alternatively, however, it is also conceivable that the insertion element is designed as a metal insertion element, in particular a metal insertion element made of aluminum or steel.

[0012] By such a configuration, a compact and / or advantageously designed universal expansion valve can be provided. In particular, the insertion element can be produced cost-effectively, in particular as an injection-molded part, so that the use of cost-intensive and processing-intensive elements, in particular metals, for guiding the valve piston can be dispensed with.

[0013] In addition, the insert element has a plurality of compressed ribs which are designed for force-locked fixing of the insert element in the bottom region of the pressure vessel. This enables the insert element to be advantageously reliably and / or simply fixed in the pressure vessel. In particular, the compressed ribs are radially outwardly projecting elements on the outer surface of the insert element. The compressed ribs are formed in particular on the outer surface of the insert element. In particular, the compressed ribs are formed on the outer surface of the insert element during production of the insert element by means of an injection-molding method. Preferably, the insert element has four compressed ribs which are uniformly distributed in the circumferential direction on the outer surface of the insert element. The compressed ribs have an at least approximately triangular or circular-arc cross section when viewed in the axial direction. The compressed ribs are designed in such a way that, when the insert element is inserted into the pressure vessel, the radial end portions of the compressed ribs are deformed, thereby achieving an advantageous close fit of the insert element in the pressure vessel.

[0014] The insert element has a guide region with a guide geometry in which the valve piston is guided in a torsion-resistant manner during the linear movement. This allows the rotational movement of the shaft of the linear actuator to be easily and / or reliably converted into a linear movement of the valve piston. In particular, the valve piston has at least locally an outer geometry which corresponds to the guide geometry of the guide region of the insert element. The guide region which guides the valve piston extends in the axial direction within the insert element. Preferably, the valve piston has a polygonal cross section at least in partial regions, and the guide region of the insert element has an inner geometry which corresponds to the polygonal cross section of the valve piston. In particular, the cross section of the valve piston can form at least partially a polygonal shape with three or more corners, for example a polygon with four, six or eight corners, when viewed in a cross section perpendicular to the axial extension of the valve piston. Preferably, the polygon has at least three rounded corners, each of which is connected by a convex or concave side face. In particular, the polygon has a basic shape which corresponds to a regular polygon. The polygonal shape is formed in particular from an original basic shape by rounding off the side edges for the corner angles and / or forming convex or concave side faces. The polygonal shape can in particular have a basic shape which corresponds to a square. Alternatively, the polygonal shape can in particular have a basic shape which corresponds to an equilateral triangle. In particular, the polygonal shape can at least substantially correspond to the P3G profile described in DIN 32711 or to the H3 profile. However, alternatively, other geometries which are suitable for the person skilled in the art can also be used to achieve the rotation protection of the valve piston.

[0015] Further, the pressure vessel has a radially inwardly directed step as an axial stop for the insert element, and the insert element has a radially outwardly directed step corresponding to the step of the pressure vessel. In this way, an axial stop can be formed in an advantageous simple manner, which advantageously reliably limits the axial insertion depth of the plastic insert element into the pressure vessel. The step of the pressure vessel extends in particular over the entire inner circumference of the pressure vessel. The step of the pressure vessel is in particular designed in such a way that the inner diameter and in particular the outer diameter of the pressure vessel is enlarged. In particular, the inner diameter of the pressure vessel in the region of the bottom is larger than the inner diameter in the region of the top. In particular, in the assembled state, the step of the insert element corresponding to the step of the pressure vessel rests against the step of the pressure vessel.

[0016] In the present application, the linear actuator comprises a shaft which is rotatably supported at least by a ball bearing, wherein a ball bearing seat for receiving the ball bearing is arranged in the insertion element. This enables an advantageous simple and / or secure arrangement of the ball bearing. The ball bearing seat has a receptacle with a circular cross section for receiving the ball bearing and centering it radially. The ball bearing is axially inserted into the receptacle of the ball bearing seat. The insertion element has a plurality of catches which are designed for axially fixing the ball bearing arranged in the ball bearing seat of the insertion element. In particular, the insertion element can have four catches which are arranged uniformly distributed along the circumferential direction of the receptacle of the ball bearing seat. The free end of each catch has a radially inwardly pointing catch lug which, in the assembled state, projects beyond the outer ring of the ball bearing arranged in the ball bearing seat. The catches have a spring elasticity. When the ball bearing is inserted into the receptacle of the ball bearing seat, the catches are pressed radially outwardly in order to be able to introduce the ball bearing axially through the catches into the receptacle of the ball bearing seat. In order to prevent the catches from opening radially when the insertion element is installed in the pressure vessel, the catches are arranged (abut) on the inner wall of the pressure vessel when the insertion element is installed. Thereby, the catches can be reliably prevented from spreading apart. Furthermore, the catches can be designed to be pressed radially inwardly by the pressure vessel. In order to further improve the effect of the catches, the catches can have a radially outwardly projecting protrusion at their free end which is of the same height as the catch lug. The radially outwardly projecting protrusion on the catch is designed to abut on the inner wall of the pressure vessel when the insertion element is in the assembled state. Thereby, the radial opening of the catches is reliably prevented and the ball bearing is advantageously fixed axially. The insertion element also preferably has at least one elastic element which is designed to compensate for the axial play of the ball bearing arranged in the ball bearing seat of the insertion element. The elastic element is in particular arranged on the bottom of the receptacle of the ball bearing seat. In particular, the elastic element can be molded as a plastic elastic element on the bottom of the ball bearing seat during production of the insertion element by means of the injection molding method. Alternatively, the elastic element can also be a separate elastic element, for example a wave spring washer, which is inserted into the receptacle of the ball bearing seat before the ball bearing is inserted.

[0017] The insertion element can also have a plurality of shaped elements which are designed to cooperate with corresponding shaped elements in the valve block in order to prevent the insertion element from being twisted. This advantageously prevents the insertion element from being twisted about the rotational axis of the linear drive. The insertion element preferably has at least two shaped elements in order to achieve the anti-twist protection. The shaped elements of the plastic element can in particular be designed as outwardly pointing shaped elements which are intended to engage with corresponding shaped elements in the valve block. In particular, the shaped elements of the insertion element can be designed as radially outwardly pointing ribs and / or axially downwardly pointing pins which are designed to engage in corresponding recesses in the valve block. Alternatively, the shaped elements of the insertion element can be designed as radial and / or axial recesses, while the corresponding shaped elements in the valve block are designed to engage into the shaped elements of the insertion element. The form-locking elements which are arranged in the valve block and correspond to the shaped elements of the insertion element can in particular be formed in and / or on the material of the valve block. Alternatively, the form-locking elements which correspond to the shaped elements of the insertion element and are arranged in the valve block can in particular be formed in and / or on an element which is arranged in a non-rotating manner in the valve block, in particular a cage element.

[0018] The insertion element can also have at least one compensation element which is designed to compensate for an axial play of the insertion element in the valve block. The compensation element is in particular arranged on the lower end face of the insertion element. In particular, the compensation element can be molded as a plastic spring element on the lower end face of the insertion element during production of the insertion element by means of the injection molding method. Alternatively, the compensation element can also be a separate compensation element, for example a wave spring washer, which is arranged between the lower end face of the insertion element and the valve block, in particular a step in the valve block.

[0019] It is further proposed that the valve block has a circular receiving region for receiving a bottom region of the pressure vessel. In order to secure the bottom region of the pressure vessel in the circular receiving region of the valve block, the expansion valve has a locking bushing element which can be screwed into the circular receiving region of the valve block. The locking bushing element is designed in particular as a union nut. In order to transmit a tightening torque from an assembly tool to the locking bushing element, the locking bushing element has a drive geometry on the outer circumference. The drive geometry has, when viewed in a cross section perpendicular to the axial direction of the adapter, a plurality of convex and / or concave cam elements for interacting with the assembly tool. The cross section extends in particular through the drive geometry. The drive geometry can have, when viewed in a cross section extending perpendicular to the axial extension of the locking bushing element, in particular a polygonal shape with at least three corners, which form the cam elements of the drive geometry. In particular, the drive geometry can have, when viewed in a cross section perpendicular to the axial direction of the adapter, a polygonal shape with more than three corners, for example with four, six or eight corners. Preferably, the polygon has at least three rounded corners, which form the cam elements of the drive geometry, and each cam element is connected by a convex or concave side. In particular, the polygon has a basic shape which corresponds to a regular polygon. The polygonal shape is formed in particular from the original basic shape by rounding the side edges for the corner angles and / or forming convex or concave sides. Alternatively, the drive geometry can have, when viewed in a cross section extending perpendicular to the axial direction of the locking bushing element, in particular a plurality of circumferentially arranged circular-arc-segment-like grooves, which form the cam elements of the drive geometry. Preferably, the grooves have a semicircular cross section. The drive geometry can preferably have a circular basic shape, wherein the grooves are arranged distributed on the outer circumference of the basic shape. The bottom region of the pressure vessel has a flange, which is clamped between the bottom of the circular receiving region and the locking bushing element in the assembled state of the locking bushing element. The flange is located at the open end of the bottom region. The flange extends radially outward from the pressure vessel wall of the bottom region. In particular, the flange forms an angle of at least approximately 90° with the wall of the pressure vessel. In particular, the outer diameter of the flange of the pressure vessel corresponds at least essentially to the inner diameter of the circular receiving region of the valve block. The lower side of the flange rests directly or indirectly on the bottom of the circular receiving region of the valve block when the pressure vessel is mounted on the valve block. The upper side of the flange rests on the end side of the locking bushing element facing in the direction of the bottom of the circular receiving region of the valve block when the pressure vessel is mounted on the valve block. In the assembly process, the bottom region of the pressure vessel and the locking bushing element are introduced into the circular receiving region of the valve block. When the locking bushing element is introduced, in particular screwed, into the circular receiving region of the valve block, the flange of the bottom region is clamped in particular without play between the bottom of the circular receiving region of the valve block and the end side of the locking bushing element facing in the direction of the bottom of the circular receiving region of the valve block.Furthermore, the pressure vessel can have a radially outwardly directed step, and the locking bushing element can have a radially inwardly directed step corresponding to the step of the pressure vessel. Thereby, the pressure vessel can be advantageously fixed to the valve block even in the event of a failure of the pressure vessel. The step of the pressure vessel extends in particular over the entire circumference of the pressure vessel. The step of the pressure vessel can in particular be designed by widening the outer diameter of the pressure vessel. In particular, the step of the adapter corresponding to the step of the pressure vessel abuts in the mounted state on the step of the pressure vessel along the entire circumference of the pressure vessel. Thereby, the pressure vessel can be fastened to the valve block in a simple, safe and / or reliable manner.

[0020] A sealing element can furthermore be arranged between the bottom of the circular receiving region and the flange of the bottom region of the pressure vessel. The sealing element is in particular designed as a flat seal or a bead seal. In particular, the sealing element is ring-shaped. The sealing element is preferably designed as a metallic flat seal, for example a copper flat seal, or a metallic bead seal. When the locking bushing element is introduced, in particular screwed, into the circular receiving region of the valve block, the sealing element is pressed between the flange of the bottom region of the pressure vessel and the bottom of the circular receiving region of the valve block. Thereby, a liquid or gas-tight sealing can be achieved which is advantageously reliable and / or pressure-resistant.

[0021] The expansion valve according to the application is not to be limited to the above-mentioned applications and embodiments here. In particular, the expansion valve according to the application can have a different number of individual elements, components and units than described herein in order to achieve the functions described herein. BRIEF DESCRIPTION OF DRAWINGS

[0022] Further advantages will be shown in the following description of the drawings. The drawings show embodiments of the application. The drawings, the description and the claims contain combinations of numerous features. The person skilled in the art will also expediently consider the individual features separately and combine them into further meaningful combinations. In the drawings: Figure 1 A sectional view of an expansion valve according to the application is shown; Figure 2 An exploded view of an expansion valve is shown Figure 1 in the middle; Figure 3 A perspective view of an insertion element of an expansion valve is shown; Figure 4 Another perspective view of an insertion element of an expansion valve is shown; Figure 5 A sectional view of an expansion valve insertion is shown. DETAILED DESCRIPTION

[0023] Figure 1A sectional view of an expansion valve 10 according to the present application is shown. The expansion valve 10 is designed for controlling a fluid flow in a fluid passage 64. The expansion valve 10 comprises a valve piston 16 for opening or closing the fluid passage 64. The fluid passage 64 extends completely within a valve block 18. The fluid passage 64 has a fluid inlet 68 and a fluid outlet 70. The fluid passage 64 is flowable in both directions, which is the reason why the fluid inlet 68 and the fluid outlet 70 are also interchangeable. The expansion valve 10 has a linear actuator 14 for driving the valve piston 16. The linear actuator 14 comprises a shaft 38 and an electric motor 72 for driving the shaft 38 in rotation. The valve piston 16 is moved linearly by means of the shaft 38 in order to reduce the cross-sectional area of the fluid passage 64 or to close the fluid passage 64 completely. The valve block 18 is provided with a valve seat 20 corresponding to the valve piston 16. The valve piston 16 is moved linearly by means of the shaft 38 into the valve seat 20 in order to reduce the cross-sectional area of the fluid passage 64 and / or to close the fluid passage 64 completely. In Figure 1 the valve piston 16 is in the open position.

[0024] The electric motor 72 comprises a stator 74 and a rotor 76. The electric motor 72 is designed as an inner rotor motor. In order to drive the shaft 38 in rotation, a voltage is applied to the stator winding 78 of the electric motor 72, whereby the rotor 76 arranged in the stator 74 is set into rotational motion. The rotor 76 rotates the shaft 38, which is connected to the rotor 76 in a non-rotational manner. The rotational motion of the shaft 38 is converted into a linear motion of the valve piston 16 by means of a thread 80. Furthermore, the expansion valve 10 comprises a printed circuit board 84, on which an electronic circuit for controlling the electric motor 72 is arranged. The printed circuit board 84 and the stator 74 are arranged together in a housing 82. The electric motor 72 can move the shaft 38 of the linear actuator 14 within the pressure vessel 12 of the expansion valve 10. The housing 82 is sealed directly on the pressure vessel 12 of the expansion valve 10 by means of an O-ring 122.

[0025] The linear actuator 14 further comprises a ball bearing 40 for rotatably supporting a first end portion 86 of the shaft 38, wherein the first end portion 86 of the shaft 38 faces the valve piston 16 of the expansion valve 10. In order to support a second end portion 88 of the shaft 38, which is axially opposite to the first end portion 86 of the shaft 38, the linear actuator 14 has a plain bearing 90. The plain bearing 90 is inserted into the pressure vessel 12 of the expansion valve 10. The pressure vessel 12 has a dome-shaped section 92. The plain bearing 90 is accommodated in the dome-shaped section 92 of the pressure vessel 12.

[0026] Figure 2 An exploded view of the expansion valve 10 shown in Figure 1 is shown. For the sake of clarity, the stator 74, the printed circuit board 84 and the housing 82 are not shown in the exploded view.

[0027] The expansion valve 10 further comprises an insertion element 22. Figures 3 to 5The insertion element 22 is shown in different views. The insertion element 22 is arranged in a bottom region 24 of the pressure vessel 12. The insertion element 22 has a plurality of pressure ribs 26. The pressure ribs 26 are designed for fixing the insertion element 22 in a force-locked manner in the bottom region 24 of the pressure vessel 12. Preferably, the insertion element 22 has four pressure ribs 26 as shown, which are uniformly distributed in a circumferential direction on an outer surface of the insertion element 22. The pressure ribs 26 are elements projecting radially outward on the outer surface of the insertion element 22.

[0028] The insertion element 22 is designed for guiding the valve piston 16 during linear movement. In order to guide the valve piston 16 during linear movement, the insertion element 22 comprises a guide region 28 having a guide geometry 30 in which the valve piston 16 is guided in a non-rotational (torsion-proof) manner during linear movement. The rotational movement of the shaft 38 is converted into linear movement of the valve piston 16 by means of the anti-rotation device of the valve piston 16. The valve piston 16 has an outer geometry 32 at least in partial regions, which corresponds to the guide geometry 30 of the guide region 28 of the insertion element 22. In addition to the cylindrical section 100, the valve piston 16 comprises a collar 102 having a polygonal cross section. The collar 102 of the valve piston 16 has a polygonal shape with a basic shape corresponding to a regular polygon as seen in a cross section perpendicular to the axial direction of the valve piston 16. In particular, the polygon can have a basic shape as shown, which corresponds to a square. The corners of the polygon are rounded. The guide region 28 of the insertion element 22 in which the valve piston 16 is guided has a guide geometry 30 corresponding to the polygonal cross section of the valve piston 16. Due to the interaction of the polygonal cross section of the collar 102 of the valve piston 16 and the corresponding guide geometry 30 of the guide region 28, the valve piston 16 is fixed against twisting during linear movement between the open position and the closed position.

[0029] In order to limit the depth of insertion of the insertion element 22 into the pressure vessel 12, the pressure vessel 12 has a radially inward step 34 as an axial stop for the insertion element 22. The insertion element 22 has a radially outwardly directed step 36, which corresponds to the step 34 of the pressure vessel 12. The step 34 of the pressure vessel 12 extends over the entire inner circumference of the pressure vessel 12. The step 34 of the pressure vessel 12 is formed by widening the inner diameter of the pressure vessel 12, so that the pressure vessel 12 has a larger inner diameter in the bottom region 24 than in the top region 104. In the assembled state, the step 36 of the insertion element 22, which corresponds to the step 34 of the pressure vessel 12, rests against the step 34 of the pressure vessel 12.

[0030] Furthermore, a ball bearing seat 42 for receiving a ball bearing 40 is arranged in the insertion element 22, which rotatably supports a first end portion 86 of a shaft 38 of the linear actuator 14. The ball bearing seat 42 comprises a receptacle 106 having a circular cross section, which is designed for accommodating the ball bearing and for radially centering it. In order to axially fix the ball bearing 40 in the receptacle 106 of the ball bearing seat 42, the insertion element 22 has a plurality of catches 44. In particular, the insertion element 22 can have four catches 44 as shown, which are arranged uniformly distributed in the circumferential direction of the receptacle 106 of the ball bearing seat 42. The catches 44 have a radially inwardly directed catch lug 108 at their free end portion, which projects in the assembled state with respect to the outer ring of the ball bearing 40 arranged in the ball bearing seat 42. The catches 44 have a spring elasticity. In order to reliably prevent the catches 44 from opening radially in the state in which the insertion element 22 is assembled in the pressure vessel 12, the catches 44 have a radially outwardly directed protrusion 110 at their free end portion and at the height of the catch lug 108. The radially outwardly directed protrusion 110 on the catches 44 is designed to rest against the inner wall of the pressure vessel 12 in the assembled state of the insertion element 22.

[0031] Furthermore, the insertion element 22 has at least one elastic element 46, which is designed for compensating an axial play of the ball bearing 40 arranged in the ball bearing seat 42 of the insertion element 22. Preferably, the insertion element 22 has a plurality of elastic elements 46, for example four elastic elements 46. The elastic elements 46 are arranged on the bottom 112 of the receptacle 106 of the ball bearing seat 42. Preferably, the elastic elements 46 are molded as plastic elastic elements on the bottom 112 of the receptacle 106 of the ball bearing seat 42 during production of the insertion element 22 by means of an injection molding method.

[0032] In order to prevent a torsion of the insertion element 22 about the rotational axis 94 of the shaft 38 within the valve block 18, the insertion element 22 has a plurality of shaped elements 48. The shaped elements 48 interact with corresponding shaped elements 50 within the valve block 18, thereby reliably preventing a torsion of the insertion element 22. The shaped elements 48 of the plastic element 22 are designed as outwardly directed shaped elements 48, which are used for engaging with corresponding shaped elements 50 within the valve block 18. Preferably, the shaped elements 48 of the insertion element 22 are designed as radially outwardly directed ribs 116, which are designed for engaging into corresponding recesses 114 within the valve block 18.

[0033] Furthermore, the insert element 22 has at least one compensation element 52, which is designed to compensate for an axial clearance of the insert element 22 in the valve block 18. In the shown embodiment, the insert element 22 has four compensation elements 52, which are arranged on the lower end face 118 of the insert element 22. The compensation elements 52 are designed as conical stegs in such a way that they are arranged on a step 120 in the valve block 18 during assembly and, if necessary, are plastically deformed in order to compensate for an axial clearance of the insert element 22 in the valve block 18. Preferably, the compensation elements 52 are formed on the lower end face 118 of the insert element 22 during production of the insert element 22 by means of an injection molding method.

[0034] In order to fluid-tightly fix the pressure vessel 12 on the valve block 18, the valve block 18 has a circular receiving area 54. The circular receiving area 54 serves to receive the bottom region 24 of the pressure vessel 12. When the pressure vessel 12 is mounted on the valve block 18 together with the portion of the linear actuator 14 arranged in the pressure vessel 12, the pressure vessel 12 is arranged on the valve block 18 in such a way that the bottom region 24 of the pressure vessel 12 is arranged in the circular receiving area 54 in the valve block 18. The bottom region 24 of the pressure vessel 12 is mechanically fixed in the circular receiving area 54 of the valve block 18. The bottom region 24 of the pressure vessel 12 is fixed in the circular receiving area 24 by means of a locking bush element 56. The locking bush element 56 is in particular hollow-cylindrical. In the assembled state, the locking bush element 56 is guided on the pressure vessel 12 and completely surrounds the bottom region 24 of the pressure vessel 12 in the circumferential direction. Preferably, the locking bush element 56 can be screwed into the circular receiving area 54. To this end, the locking bush element 56 has an outer thread 96, which can be screwed into a corresponding inner thread 98 of the circular receiving area 54.

[0035] In order to ensure that the pressure vessel 12 and the portion of the linear actuator 14 located therein are firmly fastened on the valve block 18, the bottom region 24 of the pressure vessel 12 has a flange 58. The flange 58 is arranged at the open end of the bottom region 24 of the pressure vessel 12 and extends radially outward from the wall of the pressure vessel 12. The flange 58 extends in the circumferential direction over the entire circumference of the bottom region 24 of the pressure vessel 12. When the locking bush element 56 is screwed in, the flange 58 is clamped between the bottom 60 of the circular receiving area 54 and the locking bush element 56. Thus, when the locking bush element 56 is screwed in, the pressure vessel 12 is firmly mechanically fixed on the valve block 18.

[0036] A sealing element 62 is arranged between the bottom 60 of the circular receiving area 54 and the flange 58 of the bottom area 24 of the pressure capsule 12. The sealing element 62 is designed as a ring-shaped flat sealing. The sealing element 62 is preferably designed as a metallic flat sealing, for example a copper flat sealing, or as a crimped sealing. When the locking bush element 56 is screwed into the circular receiving area 54 of the valve block 18, the sealing element 62 is pressed between the flange 58 of the bottom area 24 of the pressure capsule 12 and the bottom 60 of the circular receiving area 54 of the valve block 18. The sealing element 62 ensures a pressure-tight and / or liquid-tight or gas-tight sealing between the pressure capsule 12 and the valve block 18. List of reference signs 10 expansion valve 72 electric motor 12 pressure capsule 74 stator 14 linear actuator 76 rotor 16 valve piston 78 stator winding 18 valve block 80 thread 20 valve seat 82 housing 22 insertion element 84 printed circuit board 24 bottom area 86 first end portion 26 pressure rib 88 second end portion 28 guide area 90 plain bearing 30 guide geometry 92 dome-shaped section 32 outer geometry 94 axis of rotation 34 step 96 external thread 36 step 98 internal thread 38 shaft 100 cylindrical section 40 ball bearing 102 collar 42 ball bearing seat 104 top area 44 latching hook 106 receptacle 46 resilient element 108 clamping lug 48 shaped element 110 protrusion 50 shaped element 112 bottom 52 compensation element 114 recess 54 receiving area 116 rib 56 locking bush element 118 lower end face 58 flange 120 step 60 bottom 122 o-ring 62 sealing element 64 fluid passageway 68 fluid inlet 70 fluid outlet

Claims

1. An expansion valve comprising: a pressure vessel (12); a linear actuator (14) at least partially disposed in the pressure vessel (12); a valve piston (16); and a valve block (18), wherein, The linear actuator (14) is configured to cause linear movement of the valve piston (16), a valve seat (20) corresponding to the valve piston (16) is arranged in the valve block (18), and the pressure vessel (12) is fixed to the valve block (18) in a fluid-tight manner. The expansion valve is characterized by having an insertion element (22) arranged in the bottom region (24) of the pressure vessel (12) and designed to guide the valve piston (16) during linear movement.

2. The expansion valve according to claim 1, characterized in that, The insertion element (22) is designed as a plastic insertion element.

3. The expansion valve according to claim 1 or 2, characterized in that, The insertion element (22) has a plurality of pressure ribs (26) designed to secure the insertion element (22) in the bottom region (24) of the pressure vessel (12) by force locking.

4. The expansion valve according to any one of the preceding claims, characterized in that, The insertion element (22) includes a guide region (28) with a guide geometry (30), within which the valve piston (16) is guided in a torsion-resistant manner during linear motion.

5. The expansion valve according to claim 4, characterized in that, The valve piston (16) has at least a partial external geometry (32) corresponding to the guide geometry (30) of the guide region (28) of the insertion element (22).

6. The expansion valve according to any one of the preceding claims, characterized in that, The pressure vessel (12) has a radially inward step (34) as an axial stop for the insertion element (22), and the insertion element (22) has a radially outward step (36) corresponding to the step (34) of the pressure vessel (12).

7. The expansion valve according to any one of the preceding claims, characterized in that, The linear actuator (14) includes a shaft (38) rotatably supported at least by a ball bearing (40), wherein a ball bearing housing (42) for receiving the ball bearing (40) is arranged in the insertion element (22).

8. The expansion valve according to claim 7, characterized in that, The insertion element (22) has a plurality of hooks (44) for axially securing a ball bearing (40) arranged in a ball bearing housing (42) of the insertion element (22).

9. The expansion valve according to claim 7 or 8, characterized in that, The insertion element (22) has at least one elastic element (46) for compensating for the axial clearance of the ball bearing (40) arranged in the ball bearing housing (42) of the insertion element (22).

10. The expansion valve according to any one of the preceding claims, characterized in that, The insertion element (22) has a plurality of forming elements (48) designed to engage with corresponding forming elements (50) within the valve block (18) to prevent the insertion element (22) from twisting.

11. The expansion valve according to any one of the preceding claims, characterized in that, The insertion element (22) has at least one compensation element (52) designed to compensate for the axial clearance of the insertion element (22) in the valve block (18).

12. The expansion valve according to any one of the preceding claims, characterized in that, The valve block (18) has a circular receiving area (54) for receiving the bottom area (24) of the pressure vessel (12).

13. The expansion valve according to claim 12, characterized in that, It has a locking bushing element (56) that can be screwed into the circular receiving area (54) of the valve block (18) to secure the bottom area (24) of the pressure vessel (12).

14. The expansion valve according to claims 12 and 13, characterized in that, The bottom region (24) of the pressure vessel (12) has a flange (58) which is sandwiched between the bottom (60) of the circular receiving region (54) and the locking bushing element (56) in the assembled state of the locking bushing element (56).

15. The expansion valve according to claim 14, characterized in that, A sealing element (62) is arranged between the bottom (60) of the circular receiving area (54) and the flange (58) of the bottom area (24) of the pressure vessel (12).

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