CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the United States Provisional Application No. 62/165,275 filed May 22, 2015.

TECHNICAL FIELD

The field to which the disclosure generally relates includes pressure regulating valves.

BACKGROUND

Pressure regulators generally operate to reduce fluid pressure between an inlet and an outlet of the valve.

SUMMARY OF ILLUSTRATIVE VARIATIONS

In a number of illustrative variations, a product may maintain a regulated fluid pressure. A regulating spool may have a spool bore with a first end exposed to the regulated fluid pressure and a second end exposed to a low pressure. The spool bore may extend longitudinally through the regulating spool. The first end may have a hood extending to a terminal edge of the regulating spool. The hood may define an opening through the regulating spool in a direction transverse to the spool bore. A position spool may extend through the spool bore. The position spool may have an outer surface and may be rotatable relative to the regulating spool. The position spool may have a cross bore. The opening may expose a segment of the outer surface of the position spool. The regulating spool may be configured to translate longitudinally relative to the position spool so that the regulated fluid pressure may cause the regulating spool to translate which may establish registry between the opening and the cross bore. The actuator may be a motor with a cogging torque holding the position spool against rotation when the motor is de-energized. Other illustrative variations within the scope of the invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while disclosing variations within the scope of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Select examples of variations within the scope of the invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

Figure 1 is a diagrammatic illustration of a pressure regulated fluid system according to a number of variations.

Figure 2 is a partial schematic cross sectional illustration of a pressure regulator according to a number of variations.

Figure 3 is a schematic illustration demonstrating a cogging torque according to a number of variations.

Figure 4 is a side view of a regulating spool of the pressure regulator shown in Figure 2.

Figure 5 is a side view of a position spool of the pressure regulator shown in Figure 2.

Figure 6 is a fragmentary view of the regulating spool of Figure 3 interacting with the position spool of Figure 4 shown in a closed state.

Figure 7 is a fragmentary view of the regulating spool of Figure 3 interacting with the position spool of Figure 4 shown in an open state.

Figure 8 is a fragmentary view of the regulating spool of Figure 3 interacting with the position spool of Figure 4 shown in an open state. DETAILED DESCRIPTION OF ILLUSTRATIVE VARIATIONS

The following description of the variations is merely illustrative in nature and is in no way intended to limit the scope of the invention, its application, or uses.

In a number of illustrative variations as shown in Figure 1 , a simplified fluid system 10 may include a pressure source 12, which may be a pump, compressor, accumulator, or other pressure generator or receiver. The pressure source 12 may be connected to a load 14 through a conduit 16. The pressure source 12 may draw fluid from a reservoir 18, and excess fluid delivered to the load 14 may be routed to the reservoir 18. The pressure source 12 may serve a number of purposes in addition to supplying fluid pressure to the load 14 and therefore, its operation may not be dedicated to the load 14. Variations in the pressure source 12 and the load 14 may cause pressure fluctuations in the conduit 16, which may be monitored by a pressure sensor 20 engaged with the conduit 16. The conduit 16 may be interconnected with a pressure regulator 22 either directly, or through another conduit 24. The pressure regulator 22 may control a fluid path from the conduit 24 to the reservoir 18 through a third conduit 26.

In a number of variations a product which may be the pressure regulator 22, may include an actuator 28 to selectively vary the set pressure to be maintained in the conduit 16. An electrical control unit 30 may be interconnected with the pressure sensor 20, the actuator 28, and the pressure source 12. The electrical control unit 30 may be programmable to operate the pressure source 12 and/or the pressure regulator 22 to maintain a desired set point pressure in the conduit 16. To maintain the set point, when pressure increases in the conduit 16 and exceeds the set point, fluid may be unloaded to the reservoir 18 through the pressure regulator 22. The actuator 28 may operate to vary the pressure regulator 22 to achieve the set pressure by admitting more or less fluid to the reservoir 18, as needed.

In a number of variations, the pressure regulator 22 may be configured as shown in Figure 2. A block 32 may include a main bore 34 extending inward through a surface 36 in a longitudinal direction 37 to an end 38. The main bore 34 may be open to the reservoir 18 through the end 38 and the conduit 26. The reservoir 18 may be open to the atmosphere so that the main bore 34 at the end 38 is essentially at atmospheric pressure or the reservoir may be closed and maintained at a relatively low pressure compared to the operating pressure of the fluid system 10.

A regulating spool 40 may be disposed in the main bore 34 and may have a first land 42 and a second land 44 which fit closely within the main bore 34 and therein against the block 32. The regulating spool 40 may slide in the longitudinal direction 37 within the main bore 34 toward and away from the end 38. The land 42 may delimit a control chamber 46 within the main bore 34 that is open to the conduit 24, and the land 44 may delimit an exhaust chamber 48 within the main bore 34 adjacent the end 38, which may be open to the conduit 26. The regulating spool 40 may have a spool bore 49 that may extend in the longitudinal direction 37 completely through the regulating spool 40. The regulating spool 40 may include a longitudinal slot 50 in its outer surface that extends at least a part of the distance between the lands 42 and 44. A pin 52 may be fixed in the block 32 and may extend into the bore 34 to be disposed in the slot 50. Engagement of the pin 52 in the slot 50 may prevent rotation of the regulating spool 40 within the main bore 34 while allowing the regulating spool 40 to translate longitudinally within the main bore 34 a distance equal to the length of the slot 50.

A spring 54 may be disposed in the exhaust chamber 48 and may be compressed between the end 38 and the regulating spool 40 to bias the regulating spool 40 to compress fluid in the control chamber 46. The spring 54 may have a spring rate selected based on the operating pressures of the fluid system 10 and the diameter of the regulating spool 40.

A position spool 56 may extend into the spool bore 49 of the regulating spool 40 so that the position spool 56 in combination with the regulating spool 40 may separate the control chamber 46 from the exhaust chamber 48. The position spool 56 may include a tubular portion 58 defining an exhaust bore 60 that is open to the exhaust chamber 48 through a segment of the spool bore 49 that is also open to the exhaust chamber 48. The position spool 56 may extend into the main bore 34 through the surface 36. An annular insert 62 may be fixed in the main bore 34 adjacent surface 36 and may contain the fluid pressure in the control chamber 46. The position spool 56 may extend through the insert 62 and may be unloaded in the longitudinal direction 37 to be free of any fluid pressure driving force in the longitudinal direction 37, with the exhaust bore 60 continuously open to the reservoir 18. The position spool may also be unloaded rotationally under balanced radial fluid pressure and therefore, freely rotatable within the spool bore 49 of the regulating spool 40.

A rotary actuator 28, which may be an electric motor, may take the form of a stepping motor with a rotor 64 and a stator 65. The rotor 64 may be connected to the position spool 56 by a shaft 67 so that the actuator 28 may rotate the position spool 56 to establish a desired angular orientation thereof. Since the position spool 56 is neither longitudinally nor rotationally loaded by fluid pressure the actuator 28 may be of a low torque character and may have relatively low power requirements. The actuator 28 may exhibit a cogging torque characteristic due to the attraction/interaction of the magnetic poles of the stator 65 to the teeth of the rotor 64 when the motor is not energized. The cogging torque may latch the rotor 64 and therefore the position spool 56 in its established angular position and thereby eliminates holding power requirements when the pressure regulator 22 is regulating at a constant pressure. For example, in the illustration of Figure 3 the stator 65 may include a number of windings 89 that may be energized to establish an electromagnetic field with a North pole 61 and a South pole 63 as part of any number of alternating poles around the stator 65. The rotor 64 may be constructed with permanent magnets with alternating poles around its perimeter including a South pole 85 and a North pole 87. When the windings 89 of the stator 65 are de-energized, a residual magnetic field 91 may remain. The rotor 65 may continue to be attracted to the residual magnetic field 91 so that the pole 85 tends to be drawn to the pole 61 and the pole 87 tends to be drawn to the pole 63. This residual attraction establishes the cogging torque that must be overcome to rotate the rotor 64 relative to the stator 65 when the windings 89 are de-energized.

To regulate pressure in the fluid system 10, as pressure in the control chamber 46 increases, the regulating spool 40 is urged to slide toward the end 38 compressing the spring 54. The position spool 56 may include a cross bore 68 that opens through the tubular portion 58 into the exhaust bore 60. The cross bore 68 may be formed in the transverse direction 69 (perpendicular to the longitudinal direction). When the terminal edge 70 moves longitudinally exposing the cross bore 68, the control chamber 46 is open to the exhaust chamber 48 through the cross bore 68, the exhaust bore 60 and a segment of the spool bore 49. Pressure is thereby limited in the control chamber 46 to the set point pressure by the spring rate of the spring 54. To maintain the pressure at the set point, the cross bore 68 will seek an equilibrium position regarding its exposure outside the terminal edge 70 to allow a sufficient amount of fluid/pressure to be exhausted.

In a number of variations as illustrated in Figure 4, the regulating spool 40 may have a hood 72 formed at the terminal edge 70, that may include two halves 73 and 74 defining helical surfaces 75 and 76. The cutouts formed by the helical surfaces 75 and 76 form an opening 77 through the regulating spool 40 in the transverse direction 69 relative to the spool bore 49. The two halves 73 and 74 of the hood 72 may taper from the land 42 to the terminal edge 70 following the helical surfaces 75 and 76 so that the circumferential width of the opening 77 increases at points moving away from the land 42 and toward the terminal edge 70.

According to a number of variations the position spool 56 is illustrated in Figure 5. A head 71 may be connected to the tubular portion 58 and may have a diameter greater than the diameter of the tubular portion 58. The tubular portion 58, including its defined exhaust bore 60, is intersected by the cross bore 68 so that the area 57 outside the tubular portion 58 is open to the exhaust bore 60 through the cross bore 68. The head 71 may seal the left (as viewed in Figure 5), end of the tubular portion 58.

A number of variations as illustrated in Figure 6 show the regulating spool 40 and the position spool 56 engaged in a state where the cross bore 68 is covered by the hood 72 with the half 73 shown in the foreground. It should be appreciated that the back (as viewed in Figure 5), side of the cross bore will similarly be covered by the other half 74 of the hood 72. The opening 77 exposes a segment 83 of the outer surface of the position spool 56. The distance 79 from the terminal edge 70 to a point on the helical surface 75 that is aligned with the center of the cross bore 68 is less than the distance from the terminal edge 70 to the entire perimeter of the cross bore 68. This results in blocking the escape of pressure from the control chamber 46 through the cross bore 68.

In an operational condition where pressure builds in the control chamber 46 to a level above the set point, the regulating spool 40 may move to compress the spring 54 and slide longitudinally relative to the position spool 56, registering the cross bore 68 with the opening 77. This registry exposes the cross bore 68 so that fluid pressure may be exhausted through the position spool 56. Such a case is illustrated in Figure 7 where the distance 81 from the terminal edge 70 to a point of the helical surface 75 in line with the cross bore 68 is greater than at least part of the perimeter of the cross bore 68. The regulating spool may cycle in the longitudinal direction 37 thereby opening and closing the cross bore 68 relative to the control chamber 46 to modulate the pressure to the set point.

To change the set point of the pressure regulator 22, the position spool

56 may be rotated from the position of Figure 7 to, for example, the position of Figure 8 where the cross bore 68 is angularly aligned with a wider section of the opening 77. This corresponds with a point aligned with the cross bore 68 where the distance 59 to the land 42 is less than a similar point in Figure 7. Aligning the cross bore 68 with the wider (in the longitudinal direction), section of the opening 77 means that less compression of the spring 54 is required to allow fluid pressure to be exhausted through the position spool 56. In such a case the regulated pressure will be decreased by rotation of the position spool 56 and a new equilibrium pressure will be reached in the control chamber 46 at the set point. To increase the set point pressure, the position spool 56 may be rotated in the opposite direction, placing the cross bore 68 at a position along the helical surface 75 where the distance from the terminal edge 70 to the helical surface 75 is less. When the position spool 56 is rotated, for example by the actuator 28 of Figure 2, the position spool 56 may be latched in place and the actuator may be de-energized while the angular position of the position spool 56 will be held by the actuator's cogging torque.

Through the variants described herein, a pressure regulator 22 provides a regulated set point pressure for a fluid system that is a factor of the spring rate of the spring 54 and the angular position of the position spool 56. The angular position of the position spool 56 may be varied during operation of the fluid system to change the set point and latched by an actuator's cogging torque. The following description of variants is only illustrative of components, elements, acts, product and methods considered to be within the scope of the invention and are not in any way intended to limit such scope by what is specifically disclosed or not expressly set forth. The components, elements, acts, product and methods as described herein may be combined and rearranged other than as expressly described herein and still are considered to be within the scope of the invention.

Variation 1 may include a product for maintaining a regulated fluid pressure. A regulating spool may have a spool bore with a first end exposed to the regulated fluid pressure and a second end exposed to a low pressure. The spool bore may extend longitudinally through the regulating spool. The first end may have a hood extending to a terminal edge of the regulating spool. The hood may define an opening through the regulating spool in a direction transverse to the spool bore. A position spool may extend through the spool bore. An actuator may be engaged with the position spool. The position spool may have an outer surface and may be rotatable relative to the regulating spool. The position spool may have a cross bore. The opening may expose a segment of the outer surface of the position spool. The regulating spool may be configured to translate longitudinally relative to the position spool so that the regulated fluid pressure may cause the regulating spool to translate which may establish registry between the opening and the cross bore. The actuator may be a motor with a cogging torque holding the motor's rotor against rotation when the motor is de-energized and thereby holding the positon spool against rotation.

Variation 2 may include a product according to variation 1 wherein the regulating spool may have a slot. A pin may extend into the slot to prevent the regulating spool from rotating.

Variation 3 may include a product according to variation 1 or 2 wherein the actuator may be energized to selectively rotate the position spool to vary the regulated fluid pressure. Variation 4 may include a product according to any of variations 1 through 3 wherein the actuator may be a stepping motor with a permanent magnet rotor.

Variation 5 may include a product according to any of variations 1 through 4 wherein the hood may be shaped to expose an increasing amount of the outer surface of the position spool in a direction toward the terminal edge.

Variation 6 may include a product according to variation 5 wherein the hood may include double helical surfaces.

Variation 7 may include a product for establishing a regulated fluid pressure. A regulating spool may extend in a longitudinal direction. A position spool may extend through the regulating spool. The position spool may be rotatable relative to the regulating spool. The position spool may define a cross bore extending through the position spool. The regulating spool may be configured to translate longitudinally relative to the position spool to control the regulated fluid pressure to a set point by uncovering and covering the cross bore. An actuator may rotate the position spool to vary the set point. The actuator may establish a cogging torque when de-energized holding the position spool against rotation and thereby maintaining the set point.

Variation 8 may include a product according to variation 7 wherein regulating spool may have a slot. A pin may extend into the slot to prevent the regulating spool from rotating.

Variation 9 may include a product according to variation 7 wherein the position spool may define an exhaust bore through the position spool. The cross bore may intersect the exhaust bore. The exhaust bore may be open to the reservoir.

Variation 10 may include a product according to variation 7 wherein the actuator may be a stepping motor.

Variation 1 1 may include a product according to variation 7 wherein the regulating spool may include a hood shaped to expose a varying amount of the position spool when the position spool is rotated by the actuator.

Variation 12 may include a product according to variation 1 1 wherein the hood may include double helical surfaces. Variation 13 may include a pressure regulator with a block defining a main bore that extends in a longitudinal direction into the block to an end. A regulating spool may be positioned in the main bore and may be configured to translate longitudinally in the main bore, the regulating spool has a wall defining a spool bore extending through the regulating spool in the longitudinal direction and the regulating spool defining an opening through the wall, a spring disposed in the main bore and compressed between the end and the regulating spool, a position spool that has an exhaust bore extending in the position spool in the longitudinal direction, and a cross bore extending through the position spool in a transverse direction and intersecting the exhaust bore, the position spool disposed in the spool bore so that the cross bore variably registers with the opening. The position spool may be fixed against translation in the longitudinal direction. An actuator may be engaged with the position spool to rotate the position spool within the spool bore of the regulating spool.

Variation 14 may include a pressure regulator according to variation 13 and may include a pin engaging the regulating spool to prevent rotation of the regulating spool in the main bore.

Variation 15 may include a pressure regulator according to variation 14 wherein an exhaust chamber may be defined in the main bore adjacent the end and a control chamber may be defined in the main bore across the regulating spool from the exhaust chamber. The pressure regulator may be configured to maintain a set pressure in the control chamber by exhausting pressure from the control chamber and through the opening, the cross bore, the exhaust bore and the exhaust chamber.

The above description of select variations within the scope of the invention is merely illustrative in nature and, thus, variations or variants thereof are not to be regarded as a departure from the spirit and scope of the invention.