Solenoid assembly

A solenoid assembly for use in connection with a housing and valve body is provided. The assembly includes a magnetic coil, a magnetic pole piece, an operating rod, a magnetic armature, and at least two bearings positioned between a portion of the magnetic pole piece and a portion of the operating rod. The operating rod is slidably disposed along the bearings. The magnetic armature is at least in part centered relative to the pole piece. Activation of the coil provides an attraction between the armature and the pole piece.

TECHNICAL FIELD

The present invention relates to magnetic solenoids, including an assembly for a magnetic solenoid configured for use in connection with a solenoid operated valve.

BACKGROUND

Magnetic solenoid valves are subject to tolerance “stack up” associated with the inclusion of multiple components. To improve quality and functionality of solenoid assemblies, including the function of an operating rod, there is commonly a desire to reduce the stack up of associated dimensional tolerances. A reduction in tolerance stack-up can, among other things, improve the alignment associated with operative components of the assembly.

SUMMARY

A solenoid assembly for use in connection with a housing and valve body is disclosed. The assembly includes a magnetic coil, a magnetic pole piece, an operating rod, and a magnetic armature. The operating rod is slidably disposed within a portion of the pole piece and is at least in part centered relative to the pole piece. Activation of the coil provides an attraction between the armature and the pole piece. An embodiment of the assembly may additionally include one or more bearings positioned between the operating rod and the pole piece.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments of the present invention, examples of which are described herein and illustrated in the accompanying drawings. While the invention will be described in conjunction with embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims.

An embodiment of a solenoid assembly10is shown inFIG. 1. In the illustrated embodiment, the solenoid assembly10is shown as part of a larger valve assembly. The illustrated solenoid assembly10includes a coil12, a pole piece14, an operating rod16, and an armature18. A centerline for the assembly is generally designated as CL. A portion of a valve body is generally designated as element20. However, one of skill in the art will recognize that the invention is not limited to a valve body20of the type shown, and other forms and configurations of valve bodies may be employed without departing from the teachings of the invention.

The coil12, pole piece14and armature18are each configured to be at least partially magnetic, and those components may be referred to as “magnetic.” In an embodiment, the operating rod16, which is sometimes referred to as a pin or operating pin, is not comprised of a magnetic material and, hence, may be referred to as a “non-magnetic” operating rod. For example, without limitation, the operating rod16may be comprised of stainless steel, aluminum, or brass. The illustrated solenoid assembly10may also be referred to as a magnetic solenoid or magnetic solenoid assembly.

At least a portion of pole piece14is positioned inside of coil12. In the illustrated embodiment, a majority of the pole piece that extend in the direction parallel to the centerline CL of the assembly is positioned inside of coil12.

In an embodiment of the invention, a pin or operating rod16is positioned within a portion of a cavity or opening (such as a bore) formed by an inner surface of pole piece14. Rod16can be configured to generally extend longitudinally about the centerline CL of the assembly10. As shown, armature18is positioned about an end of operating rod16that is more remote from an end configured to communicate with a valve body20.

In an embodiment, operating rod16is slidably disposed within a portion of pole piece14, and extends beyond coil12and pole piece14. The operating rod16can then, as generally illustrated, further extend into a receiving portion of armature18. The receiving portion of armature18may comprise a cavity or aperture formed in a portion of the armature positioned about centerline CL. Armature18, which can be centered relative to pole piece14, may also serve to keep the operating rod on a desired (e.g., “on-center” or centerline) path with respect to other components of the assembly10. In an embodiment of the invention, the activation of coil12can provide an attraction between armature18and pole piece14. For example, such an activation can attract the armature18to pole piece14. However, as generally illustrated inFIG. 1, the assembly10may be configured such that, in at least one operative state, coil12does not surround armature18.

As generally illustrated, armature18can be configured to interact directly with a portion of housing22. That is, the assembly10can be configured such that at least a portion of an associated flux travels from the pole piece14, into and through the armature18, and directly on to a portion of an associated housing22.

For some applications, such a configuration can eliminate the need for the assembly to include a flux collector—which can reduce the number of necessary components associated with the solenoid assembly. A reduction in the number of components can potentially provide advantages, including a potential reduction in the “stack up” of dimensional tolerances associated with various components of the solenoid assembly. For example, because the invention does not require a conventional flux collector, the costs for components may be reduced and the tolerance stack up of the assembly, for example in the direction perpendicular to the centerline CL, can potentially also be reduced.

Moreover, for some applications, the improved “packaging” of the inventive assembly (e.g., potential elimination of flux collector and/or reduction in tolerance stack-up) can permit an armature to be designed to be larger, which can potentially provide for more functional interaction between the armature and other components.

Another embodiment of the invention is generally illustrated inFIG. 2, where similar components discussed in connection with the embodiment shown inFIG. 1have been designated with similar reference numerals. As discussed in connection with the prior embodiment, the armature18may directly interact with a portion of housing22; however, the assembly10shown inFIG. 2includes a bearing, and for most embodiments, a plurality of bearings, e.g.,24a,24b. In the illustrated embodiment, the bearings are positioned between a portion of the pole piece14and a portion of the operating rod16. For example, without limitation, portions of the inner surface of pole piece14may be designed or configured to retain or “seat” one or more bearings for operative communication with an operating rod16. Moreover, the bearings may be pressed into the pole piece14from opposing ends. Further, as generally illustrated a spring element, e.g., spring26, may be adapted for operative connection with the operating rod16. In the embodiment illustrated inFIG. 2, spring26is positioned about the end of the operating rod about armature18.

In an embodiment of the invention, assembly10includes at least two bearings. In the illustrated embodiment, one bearing24ais positioned about a first longitudinal half of the operating rod16, which in this case is the half adjacent the armature18. A second bearing24bis positioned about a second longitudinal half of the operating rod16, which in the illustrated example is positioned closer to valve body20. The sizing, position and spacing of the associated plurality of bearings can be configured such that the operational rod16slides on the bearings24a,24b, which keep the armature18substantially centered relative to the pole piece14. In accordance with an embodiment of the invention, the magnetic pole piece14may be configured to receive the bearings24a,24b. In this embodiment, the bearings24a,24bmay be separately installed components. In accordance with another embodiment of the invention, the magnetic pole piece14may comprise and/or define the bearings24a,24b. In this embodiment, the bearing surfaces are formed as part of the magnetic pole piece14itself. Assembly10may be configured for allowing the alignment of two bearings24a,24bin a magnetic solenoid to depend on a single component (e.g., magnetic pole piece14), thereby avoiding the tolerance stack up associated with multiple components that would otherwise define and/or receive the bearings.

Yet another embodiment of the invention is generally illustrated inFIG. 3, in which similar components discussed in connection with the embodiments shown inFIGS. 1 and 2have been designated with similar reference numerals. In this embodiment, the valve body20is located on the other end of the solenoid assembly10when compared to the assemblies shown inFIGS. 1 and 2. For such an alternative configuration, the valve body20is located on the same end as armature18.

The embodiment depicted inFIG. 3is shown without the inclusion of bearings; however, one skilled in the art will understand that bearings, for example, as generally disclosed in connection with the embodiment shown inFIG. 2, may be optionally included. Further, as generally illustrated a spring element, e.g., spring26, may be adapted for operative connection with the operating rod16. In the embodiment illustrated inFIG. 3, spring26is positioned about the end of the operating rod remote from armature18.