Anti-Seize Adjustable Regulator

Abstract

A regulating valve having anti-seize characteristics provides a linear drive system intermediate a drive shaft connected to a motor and a lifter connected to the regulator spring. The linear drive system translates the rotational motion of the drive shaft into preferably, linear only motion of the lifter, thereby preventing binding internal to the valve.

Claims

1. A regulating valve comprising: a drive motor coupled to a drive screw; a linear drive system operably coupled to the drive screw; a lifter operably coupled to the linear drive system; a regulator spring applying a first force against the lifter in a first direction and against a regulator in a second direction, the first direction being opposite to the second direction; and a drive screw stop located opposite a portion of the lifter from the regulator spring, whereby the linear drive system translates rotational motion of the drive screw to linear motion in the first and second direction without rotation.

2. The regulating valve of claim 1 wherein the linear drive system comprises a worm and a gear.

3. The regulating valve of claim 2 further comprising a guide, said guide restricting one of the worm and gear to linear motion.

4. The regulating valve of claim 3 further comprising a guide pin base, with the guide extending from the guide pin base.

5. The regulating valve of claim 4 wherein the drive screw stop is a portion of the guide pin base.

6. The regulating valve of claim 3 wherein the worm has one of slots and bores which receive the guide thereby restricting travel of the worm to linear motion only.

7. The regulating valve of 2 wherein the drive screw rotates the gear and the worm is restrained to linear motion.

8. The regulating valve of claim 1 wherein the motor is a stepper motor.

9. The regulating valve of claim 1 further comprising an adjusting member at least selectively acting on the lifter.

10. The regulating valve of claim 9 wherein the adjusting member is a adjusting screw disposed about at least a portion of the lifter.

11. The regulating valve of claim 1 wherein the linear drive system is self contained.

12. The regulating valve of claim 1 wherein the linear drive system is self centering.

13. A regulating valve comprising: a drive motor coupled to a drive screw; a linear drive system operably coupled to the drive screw; a guide; a lifter operably coupled to the linear drive system; a regulator spring applying a first force against the lifter in a first direction and against a regulator in a second direction, the first direction being opposite to the second direction; and a drive screw stop located opposite a portion of the lifter from the regulator spring; whereby the linear drive system translates rotational motion of the drive screw to linear motion in the first and second direction and the guide assists in limiting rotation of the lifter.

14. A regulating valve comprising: a drive motor coupled to a drive screw; a linear drive system operably coupled to the drive screw; a lifter operably coupled to the linear drive system; a regulator spring applying a first force against the lifter in a first direction and against a regulator in a second direction, the first direction being opposite to the second direction; and a drive screw stop located opposite a portion of the lifter from the regulator spring; whereby the linear drive system translates rotational motion of the drive screw to linear motion in the first and second direction of the lifter while preventing rotation being imparted by the drive screw to the lifter.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The particular features and advantages of the inventions with other objects will become apparent from the following description taken in connection with the accompanying drawings in which:

[0013] FIG. 1 is a cutaway view of a gas valve of the present preferred embodiment of the present invention;

[0014] FIG. 2 is a top perspective view of the gear shown in the preferred embodiment of the present invention of FIG. 1;

[0015] FIG. 3 is a bottom perspective view of the guide pin assembly shown in the preferred embodiment of the present invention as shown in FIG. 1; and

[0016] FIG. 4 is a top perspective view of the worm shown in the preferred embodiment of the present invention as shown in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0017] FIG. 1 shows a preferred embodiment of a gas valve 10. Valve 10 is shown with a stepper motor 12 driving a drive screw 14. The drive screw 14 is connected through a linear drive system 100 to move a lifter 16. The lifter 16 can apply a selected amount of pressure to a spring such as coil spring 18 which provides a pressure force against a regulator 20. This can cause the regulator 20 to unseat from the seat 22 at specific pressures so as to adjust the amount of flow 10 through the inlet/outlet ports (obscured from view) in this view.

[0018] The valve 10 also has a position in which the drive screw 14 is backed sufficiently away in the direction 26 so that the regulator 20 seats against the seat 22. Normally for many applications the stepper motor 12 continues to move the drive screws 14 to a back seat or a hard stop position so that the valve 10 has a known position of the lifter 16 and the drive screw 14.

[0019] As can be seen from the various embodiments, the coil spring 18 exerts a pressure or force against the regulator 20 in the direction 28 illustrated by arrows or in the direction opposite to the direction 26. The opposite force is applied to the lifters 16.

[0020] The applicant is providing an improvement to the valve 10. The linear drive system 100 provides a concentric worm 102 and gear 104 focusing on a single shaft, the drive screw 14 preferably directly connected to the worm 102 to turn the worm 102 to then move the gear 104 linearly in the directions 26, 28 depending on the direction of operation of the stepper motor 12. Guide pins 106, 108, which may connect to a guide pin base 110 prevent the gear 104 from rotating when the worm 102 rotates thereby restricting movement of the gear 104 to linear travel only. Bores or slots 130, 132 in the gear 104 receive the guide pins 106, 108.

[0021] This construction has been discovered to have advantages over the prior art. Specifically, when the linear moving gear 104 hits the stop, which could be the guide pin base 110, or the adjustment screw where the lifter 16 makes contact, the engagement of the drive screw 14 shifts from the front face 112 of the gear 104 to the back face 114, or into the gap 116 between the gear 104 and the worm 102, thereby resulting in no engagement. Regardless, the gear 104 is not rotating while moving linerally and therefor does not result in a seizing situation often found with prior art designs.

[0022] The anti-seize nature of the valve 10 and its drive screw 14 may also be enhanced with at least some embodiments when the moving components of the drive screw 14 is being driven into the stop 120 with a clockwise motion of the stepper motor 12 but using a left hand thread 122 of the gear 104.

[0023] As the gear 104 moves linearly, the lifter 16 may move linearly. The adjusting screw 17 can be positioned relative to threads 26 at a desired location. Thus, the downward force exerted on the stop 120 is released and therefore the drive screw 14 does not become seized in operation. The linear drive system 100 is believed to be an improvement over prior art constructions which required alignment, and be free from inclusions, cavitations and, even if machined to tight tolerances, could still fail under various temperature situations, particularly elevated temperatures. The linear drive system 100 provides a self contained drive which may be manufactured from similar materials. The linear drive system 100 is also self centering, cost effective and quiet in operation. Unexpectedly, the linear drive system 100 is particularly resilient to seizing when driven into a fixed stop 120.

[0024] Numerous alterations of the structure herein disclosed will present themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to the preferred embodiment of the invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims. Having set forth the nature of the invention, what is claimed herein is: