Description

The present invention pertains to a coil assembly housing for housing the actuator of a step per motor valve, comprising a snap feature for snap fitting the coil assembly housing to a valve house assembly, wherein the snap feature comprises at least one protrusion pointing radially inward of the coil assembly housing, wherein the protrusion is provided for interacting with a recess of the valve house assembly, and wherein the protrusion is held inside the re cess by a wall of a valve block, into which the valve house assembly and the snap feature are insertable. The invention also pertains to a valve house assembly, a valve block and a stepper motor valve comprising said components.

Stepper motor valves may comprise a number of subcomponents such as a valve house as sembly, a valve block and/or a coil assembly housing which are arranged to form a given stepper motor valve. Drawbacks of known solutions may comprise the need for special fixa tion means such as bolts, which fix the components of the valve with respect to each other.

In addition, the known designs of such valves may exhibit only limited freedom of choice or flexibility as to the angular position of the actuator with respect to other components of the valve. The aim of the present invention is to overcome these problems by providing improved step per motor valve components and, consequently, an improved stepper motor valve. This aim is reached by a coil assembly housing according to claims 1 to 6, a valve house assembly according to claims 7 to 9, and a valve block according to claims 10 and 11 and a stepper motor according to claims 12 and 13.

According to the invention, a coil assembly housing is provided for housing the actuator of a stepper motor valve. The coil assembly housing comprises a snap feature for snap fitting the coil assembly housing to a valve house assembly. The snap feature comprises at least one protrusion pointing radially inward of the coil assembly housing, wherein the protrusion is provided for interacting with a recess of the valve house assembly, and wherein the protru sion is held inside the recess by a wall of a valve block, into which the valve house assembly and the snap feature are insertable.

The recess may be understood to be a groove, a notch, or a shoulder and it may be ar ranged in a circumferential direction of the valve house assembly. The recess may be ar ranged in proximity to a portion of the valve house assembly which is closest to the coil as sembly housing while at the same time being inside the valve block in an assembled state of the stepper motor valve. In particular, the recess may not be regarded as a bottom edge or bottom shoulder of the valve house assembly, arranged closest to the side of the valve house assembly, which is furthest from the coil assembly housing in an assembled state of the stepper motor valve.

The valve house assembly may be a valve component, which comprises fluid conduits and/or one more movable fluid control element for controlling the fluid flow across the step per motor valve.

Directions such as the radial, circumferential and axial direction of the presently described components may be referenced to a cylindrical or partially cylindrical opening of the coil as sembly housing, into which the valve house assembly is at least partially insertable. The valve house assembly and the valve block may comprise corresponding partially or fully cy lindrical features, such that their radial, circumferential and axial directions may correspond to the radial, circumferential and axial directions of the coil assembly housing.

The present invention provides a simple possibility for fixing the actuator of a stepper motor valve to the remainder of the valve, such that unwanted relative movement of the compo nents is inhibited. The actuator, or rather, the coil assembly housing, in which the actuator is provided, is fixated axially to the valve house assembly via a snapping arrangement. The valve house assembly is then inserted into a valve block whereby a mechanical locking of the coil assembly housing may take place.

In a preferred embodiment of the invention, the coil assembly housing comprises an anti-ro tation feature for preventing rotation of the coil assembly housing with respect to the valve block, wherein the anti-rotation feature comprises an end portion or a recess pointing in an axial direction of the coil assembly housing. The end portion or recess points towards the valve block when the coil assembly housing is attached to it. This orientation of the end por tion or the recess makes it possible to interlock at least partially both, the anti-rotation feature and the snap feature with the valve block simultaneously.

In another preferred embodiment of the invention, the snap feature is the outermost portion of the coil assembly housing in an axial direction of the coil assembly housing and/or the snap feature comprises at least two arms pointing in an axial direction of the coil assembly housing. The arms of the snap feature may be identical to each other. The arms may exhibit some sort of rotational symmetry with respect to each other.

In another preferred embodiment of the invention, the arms are arranged in a circumferential direction of the coil assembly housing. The arms may be spaced evenly in the circumferential direction for providing a balanced connection between the coil assembly housing and the valve house assembly.

In another preferred embodiment of the invention, the anti-rotation feature is positioned radi ally outward of the snap feature and/or the anti-rotation feature and the snap feature are formed integrally with each other and/or other parts of the coil assembly housing. The manu facture of the coil assembly housing may be facilitated considerably by integrating its various features in one or only a few integrally formed components.

The invention is also directed at a valve house assembly for a stepper motor valve, compris ing at least one valve house assembly recess for interacting with the protrusion of a coil as sembly housing according to any of claims 1 to 6.

In a preferred embodiment of the invention, the valve house assembly recess is an annular groove along an outside cylindrical surface of the valve house assembly. The annular grove is easy to manufacture while at the same time making it possible to attach the valve house assembly to the coil assembly housing at any desired angle. In another preferred embodiment of the invention, the outside of the valve house assembly is formed at least in partial rotational symmetry. The valve house assembly may thus be formed as a turned part.

The invention is also directed at a valve block for a stepper motor valve, wherein an interior cylindrical wall is provided for interacting with the snap feature of a coil assembly housing ac cording to any of claims 1 to 6. The interior cylindrical wall may be a bore and/or may be di mensioned to accommodate the snap feature such that the snap feature and the valve house assembly can be inserted simultaneously into the valve block in a state, in which the snap feature is snapped into the recess of the valve house assembly.

In a preferred embodiment of the invention, at least one valve block structure is provided for interacting with the anti-rotation feature of the coil assembly housing according to claim 2.

The valve block structure may be shaped to accommodate the anti-rotation feature such that rotational movement of the coil assembly housing with respect to the valve block is inhibited.

The invention is also directed at a stepper motor valve comprising a coil assembly housing according to any of claims 1 to 6, a valve house assembly according to any of claims 7 to 9 and a valve block according to any of claims 10 or 11 , wherein the coil assembly housing is connected to the valve house assembly by means of the snap feature and the valve house assembly recess and wherein the snap feature is held in the valve house assembly recess by the valve block.

In a preferred embodiment of the invention, the anti-rotation feature of the coil assembly housing according to claim 2 interacts with the valve block structure of the valve block ac cording to claim 11 for locking the coil assembly housing with respect to the valve block in a rotational direction.

The presently described stepper motor valve and its components are shown in more detail in the figures and the corresponding description of the figures. The figures show:

Figure 1a: a side view of a stepper motor valve comprising a coil assembly housing and a valve block;

Figures 1b, 1c: exploded views of the stepper motor valve showing the coil assembly housing, the valve block and a valve house assembly;

Figures 2a - 2d: various views of the assembled stepper motor valve; and Figures 3a - 3e: various cross-sectional views of the assembly of the stepper motor valve. Figure 1a shows a side view of a stepper motor valve comprising a coil assembly housing 1 and a valve block 3. The coil assembly housing 1 may house an actuator 11 of the stepper motor valve and it may be attached to the valve block. The actuator 11 may be inside the coil assembly housing 1 and is shown in figure 3a. The coil assembly housing 1 may comprise some connection means for connecting the stepper motor valve to a power supply for supply ing power to the actuator 11 and/or it may comprise connection means for connecting the stepper motor valve to some control means for controlling the actuator 11.

According to figures 1b and 1c, the coil assembly housing 1 comprises a snap feature 12 for snap fitting the coil assembly housing 1 to a valve house assembly 2. The valve house as sembly 2 may contain some valve element, which is moveable by the actuator 11 for switch ing the stepper motor valve between some open and closed positions of the valve. The snap feature 12 comprises some arms 16 and at least one protrusion 14 pointing radially inward of the coil assembly housing 1.

The snap feature 12 may be the outermost portion of the coil assembly housing 1 in an axial direction of the coil assembly housing 1 , i.e. it may be the lowest portion of the coil assembly housing 1 as shown in figure 1b. The snap feature 12 may comprise at least two arms 16 pointing in an axial direction of the coil assembly housing 1. Said arms 16 may be arranged in a circumferential direction of the coil assembly housing 1. The axial, circumferential and radial directions may be defined with respect to an opening in the coil assembly housing 1 , into which the valve house assembly 2 is insertable. This opening may be at least partially of cylindrical shape such that corresponding axial, circumferential and radial directions may be attributed to it.

When the snap feature 12 comprises multiple arms 16, each arm 16 may comprise one or more of said protrusions 14. In figure 1b, two arms 16 are visible and in figure 1c, three arms 16 are visible. The embodiments of figures 1b and 1c may comprise a total of three, four or more arms 16.

The protrusion 14 is provided on the arm 16 for interacting with a recess 21 of the valve house assembly 2. The protrusion 14 and the recess 21 may be shaped such that the protru sion 14 can be inserted partially or fully into the recess 21 by pushing the valve house as sembly 2 into the opening of the coil assembly housing 1. The valve house assembly recess 21 may be an annular groove along an outside cylindrical surface of the valve house assem bly 2. The outside of the valve house assembly 2 may be formed at least in partial rotational symmetry. The opening of the coil assembly housing 1 may be arranged between the arms 16, such that the arms 16 may surround the valve house assembly 2 once the valve house assembly 2 has been inserted into the opening.

The valve house assembly 2 may comprise an upper part and a lower part. The upper part may comprise some components of the actuator 11 , such as the rotor or the stator. The lower part may comprise a valve housing with at least one fluid control edge and/or fluid con duit. The recess 21 may be positioned close to a portion of the valve house assembly 2 at which the upper and lower part of the valve house assembly 2 are joined.

In a state in which the valve house assembly 2 is inserted in the coil assembly housing 1, both, the valve house assembly 2 and the coil assembly housing 1 may be inserted at least partially into the valve block 3. Then, the protrusion 14 is held inside the recess 21 by a wall 32 of the valve block 3. The wall 32 may be a cylindrical wall 32 of a bore within the valve block 3, wherein the bore is provided for accommodating at least some parts of the valve house assembly 2 and the coil assembly housing 1.

The coil assembly housing 1 may comprise an anti-rotation feature 13 for preventing rotation of the coil assembly housing 1 with respect to the valve block 3. The anti-rotation feature 13 may interact with at least one valve block structure 31 in an assembled state of the stepper motor valve. The valve block structure 31 may be dimensioned for accommodating the anti rotation feature 13, or vice versa, and may be provided adjacent to the wall 32 of the bore in the valve block 3.

More than one valve block structure 31 may be provided in the valve block 3, wherein the plurality of valve block structures 31 may be arranged in a circumferential direction with re spect to the bore of the valve block 3. The anti-rotation feature 13 may interact with any of the valve block structures 31 such that the coil assembly housing 1 may be oriented at vari ous angles with respect to the valve block 3.

The anti-rotation feature 13 may be positioned radially outward of the snap feature 12. The anti-rotation feature 13 and the snap feature 12 may be formed integrally with each other and/or the remainder of the coil assembly housing 1 or some other portion of the coil assem bly housing 1.

Figures 2a - 2d show various views of the assembled stepper motor valve. According to fig ure 2a, the valve block structure 31 may be provided at a side of the valve block 3, at which one or more openings are provided for allowing a fluid connection between the inside and the outside of the valve block 3. Figures 2b - 2d show the end portion 15 of the anti-rotation feature 13 pointing in an axial direction of the coil assembly housing 1 and reaching into the valve block structure 31. The end portion 15 sits inside the valve block structure 31 such that relative rotation of the valve block 3 and the coil assembly housing 1 is inhibited. It is conceivable to provide an inverted, i.e. recessed anti-rotation feature 13, whereby the valve block structure 31 is made of some protrusion at the valve block 3 and is positioned at least partially in the recessed anti-rotation feature 13 of the coil assembly housing 1 for inhibiting rotational movement of the coil as sembly housing 1 and the valve block 3.

Figures 3a to 3e show that the stepper motor valve comprises a number of components, which interact with each other when assembled to form the complete stepper motor valve:

According to figures 3a and 3b, the coil assembly housing 1 accommodates the valve house assembly 2 such that the actuator 11 can adjust the position of a valve element provided at the valve house assembly 2 and the snap feature 12 may engage the recess 21 for creating a connection between the valve house assembly 2 and the coil assembly housing 1. The ac tuator 11 may comprise a rotor and a stator, wherein the rotor may be insertable into the sta tor. In the situation shown in figure 3a, the stator and rotor are shown separate from each other, whereas figures 3b and 3d show the rotor and stator in a situation in which the actua tor is readily assembled. The rotor may be insertable into the stator or vice versa.

The connection between the valve house assembly 2 and the coil assembly housing 1 is shown in more detail in figure 3c, where the protrusion 14 of the snap feature 12 is shown in engagement with the recess 21 of the valve house assembly 2. The recess 21 may be slightly larger than the protrusion 14 such that it can accommodated the protrusion 14. When the protrusion 14 is engaging the recess 21 , the arm 16 of the snap feature 12 may extend radially further outward than the valve house assembly 2. In addition, the arm 16 may be formed to be under no stress in a state in which the protrusion 14 is inserted in the recess 21.

Once the valve house assembly 2 and the coil assembly housing 1 are connected as shown in figures 3b and 3c, they may be inserted into the bore of the valve block 3. The inserted valve house assembly 2 and coil assembly housing 1 are shown in figures 3d and 3e. The bore in the valve block 3 is bound by the wall 32. The wall 32 may comprise two or more dis tinct portions of e.g. different diameters. An upper portion of the wall 32 may have a larger diameter than a lower portion of the wall 32. The upper portion may be dimensioned to ac commodate the arms 16 of the snap feature 12 and/or to press the arms 16 against the valve house assembly 2 when both, the valve house assembly 2 and the arms 16 of the snap fea ture 12 are inserted in the valve block 3 as shown in figures 3d and 3e.

Once the valve house assembly 2 and the arms 16 of the snap feature 12 are inserted to gether into the valve block 3, the wall 32 keeps the protrusions 14 of the arms 16 inside the recess 21.

A lower portion of the wall 32 may have a smaller diameter such that it may be close to or in contact with an outside wall of the valve house assembly 2. The upper portion of the wall 32 may extend at least as far as the arms 16 reach inside the valve block 3. Additional wall por tions may be provided lower down along the valve block 3 and may be of further reduced di ameters for accommodating other portions of the valve house assembly 2.

Figure 3d shows an assembled stepper motor valve comprising the coil assembly housing 1, the valve house assembly 2 and the valve block 3. These three components may all interact with each other to be fixedly positioned with respect to each other, wherein the coil assembly housing 1 is connected to the valve house assembly 2 by means of the snap feature 12 and the valve house assembly recess 21 and wherein the snap feature 12 is held in the valve house assembly recess 21 by the wall 32 of the valve block 3. Alternatively, the stepper mo tor valve may be understood to comprise only the coil assembly housing 1 and the valve house assembly 2, such that it may or may not be inserted into a valve block 3 at some later stage. All or some of the components of the stepper motor valve may be made of e.g. alu minium or some other suitable material.