Valve assembly with electric actuator with counterbalance

Abstract

A valve assembly for a pump includes an electric actuator having a stator and an armature. The stator includes an annular outer stator portion and an annular inner stator portion, and an annular channel formed radially between the outer stator portion and the inner stator portion. A first radial channel extending through the annular outer stator portion between the outer surface of the outer stator portion and the annular channel, and at least one second opening in the annular outer stator portion, result in magnetic symmetry of the stator. When the electric actuator is actuated, the armature's attraction toward the stator is uniform, thus transferring fluid between the stator and armature in a uniform manner and avoiding high-speed, potentially disruptive fluid flow.

Description

Technical Field

[0001] This disclosure generally relates to the design and operation of stators in electric actuators, and more specifically to a valve assembly having an electric actuator stator shaped to restrict high-speed flow of fluid displaced by the movement of an armature in the valve assembly. Background Technology

[0002] Many different pump designs are used to transfer and pressurize fluids. In the context of fuel systems, such as those used in internal combustion engines, electronically controlled high-pressure fuel pumps are common and pressurize fuel (e.g., diesel fuel) for injection into the engine cylinders. High-pressure fuel injection has been shown to be effective for reducing emissions. In one design, the high-pressure fuel pump supplies a so-called common rail, which provides a fluid reservoir that stores a certain amount of pressurized fuel to be delivered to multiple fuel injectors. In other designs, the fuel pump is associated with a fuel injector individually, referred to as a unit pump.

[0003] To achieve a high level of control over moving parts within such pumps, electric actuators, such as solenoid actuators, are used to control valve positioning and fluid connection. When an electric current is applied, the solenoid generates a magnetic field that can produce a localized force with sufficient energy to actuate components within the fuel system hardware. Engineers have been experimenting with various electric actuators and pump designs over the years. As pressure increases and fuel injection quantity, fuel injection rate, and other characteristics are controlled, the electric actuators and associated valve components within the fuel pump tend to move relatively quickly and can impact valve seats, stops, or other surfaces with relatively high force. An exemplary fuel pump design is known from U.S. Patent No. 5,743,23 to Shorey et al. In the construction shown by Shorey et al., an electric actuator is used to control a valve that explicitly changes position to alternately allow or block fuel flow into the pumping chamber. Summary of the Invention

[0004] In one aspect, a valve assembly includes a valve member operably associated with a valve seat, wherein the valve member is movable along a valve central axis between a first open position and a second closed position, the valve member being spaced apart from the valve seat in the first open position, and the valve member engaging the valve seat in the second closed position to seal an opening in the valve assembly. An electric actuator includes a stator and an armature coupled to the valve member. The stator includes an annular outer stator portion and an annular inner stator portion, and an annular channel radially formed between the outer stator portion and the inner stator portion. A first radial channel extends through the annular outer stator portion between an outer surface of the outer stator portion and the annular channel. At least one second opening is disposed within the annular outer stator portion of the stator on the half of the stator opposite to the first radial channel. The stator is magnetically symmetrical along a line bisecting the first radial channel and perpendicular to the central axis. A winding and terminal assembly includes a conductive winding disposed within the annular channel and located between the outer stator portion and the inner stator portion, and conductive terminals electrically connected to the winding. A portion of the winding and terminal assembly extends through the first radial channel. The armature includes an armature plate that defines the armature's central axis, which is collinear with the valve's central axis, and is movable between a rest position and an actuated position to change the position of the valve member in response to changes in the energy state of the electric actuator. The armature plate includes a top armature surface facing the stator.

[0005] In another aspect, a valve assembly includes a valve member operably associated with a valve seat, wherein the valve member is movable along a valve central axis between a first open position and a second closed position, the valve member being spaced apart from the valve seat in the first open position and the valve member engaging the valve seat in the second closed position to seal an opening in the valve assembly. An electric actuator includes a stator and an armature coupled to the valve member. The stator includes an annular outer stator portion and an annular inner stator portion, and an annular channel radially formed between the outer and inner stator portions. A first radial channel extends through the annular outer stator portion between an outer surface of the outer stator portion and the annular channel. At least one second opening is disposed within the annular outer stator portion of the stator on the half of the stator opposite to the first radial channel. The stator is magnetically symmetrical along a line bisecting the first radial channel and perpendicular to the central axis. A winding and terminal assembly includes a conductive winding disposed within the annular channel and located between the outer and inner stator portions, and conductive terminals electrically connected to the winding. A portion of the winding and terminal assembly extends through the first radial channel. An insert-molded body extends around the stator and enters each of a first radial channel and at least one second opening. The armature includes an armature plate defining an armature central axis that is collinear with the valve central axis and is movable between a rest position and an actuated position to change the position of the valve member in response to changes in the energy state of the electric actuator. The armature plate includes a top armature surface facing the stator.

[0006] In another aspect, a pump includes a pump housing and a pumping element movable between a retracted position and an advanced position within a pumping chamber formed in the pump housing. The pump also includes a valve assembly for controlling the inflow or outflow of fluid from the pumping chamber. The valve assembly includes a valve member operably associated with a valve seat, wherein the valve member is movable along a valve central axis between a first open position and a second closed position, in the first open position the valve member is spaced apart from the valve seat, and in the second closed position the valve member engages the valve seat to seal an opening in the valve assembly. An electric actuator includes a stator and an armature coupled to the valve member. The stator includes an annular outer stator portion and an annular inner stator portion, and an annular channel radially formed between the outer stator portion and the inner stator portion. A first radial channel extends through the annular outer stator portion between an outer surface of the outer stator portion and the annular channel. At least one second opening is provided within the annular outer stator portion of the stator on the half of the stator opposite to the first radial channel. The stator is magnetically symmetrical along a line bisecting the first radial channel and perpendicular to the central axis. The winding and terminal assembly includes a conductive winding disposed within an annular channel and located between an outer stator portion and an inner stator portion, and conductive terminals electrically connected to the winding. A portion of the winding and terminal assembly extends through a first radial channel. The armature includes an armature plate defining an armature central axis, wherein the armature central axis is collinear with the valve central axis, and is movable between a rest position and an actuated position to change the position of the valve member in response to changes in the energy state of the electric actuator. The armature plate includes a top armature surface facing the stator. Attached Figure Description

[0007] Figure 1 This is a cross-sectional side view of a pump according to one embodiment;

[0008] Figure 2 This is a schematic diagram showing multiple parts of a valve assembly in a first state according to one embodiment;

[0009] Figure 3 yes Figure 2 A schematic diagram of the valve assembly in the second state;

[0010] Figure 4 This is a perspective view of an armature for an electric actuator according to one embodiment;

[0011] Figure 5 This is a bottom view of an electric actuator including a stator and an armature shown in dashed lines, according to one embodiment;

[0012] Figure 6 This is a bottom view of an alternative embodiment of the electric actuator;

[0013] Figure 7 yes Figure 6 Exploded perspective view of the actuator;

[0014] Figure 8 yes Figure 6 A perspective view of the stator of the actuator.

[0015] Figure 9 yes Figure 8 Top view of the stator.

[0016] Figure 10 yes Figure 8 Top view of the stator.

[0017] Figure 11 yes Figure 8 A schematic cross-sectional view of the stator, windings, and a portion of the armature interacting with the stator and windings; and

[0018] Figure 12 Is with Figure 7 A bottom view of an alternative embodiment of a stator used with actuators. Detailed Implementation

[0019] Reference Figure 1 The illustration shows a pump 10 according to one embodiment, comprising a pump housing 12 defining a longitudinal axis 13 of the pump housing. A pumping element having the characteristics of a plunger 14 is located within the pump housing 12 and is movable between an advancing position and a retracted position within a pumping chamber or plunger cavity 16. In the illustrated embodiment, the plunger 14 is movable between the advancing and retracted positions in response to rotation of a cam 18. The pump 10 may be a fuel pump for pressurizing, for example, fuel (e.g., diesel fuel) to deliver to a common rail (not shown), which supplies pressurized fuel to multiple fuel injectors in an internal combustion engine. Alternatively, the pump 10 may be a so-called unit pump associated with a single fuel injector. In other embodiments, the pump 10 may not be a fuel pump at all.

[0020] Piston 14 is in Figure 1 The only plunger visible in the cross-section is the piston 14; however, those skilled in the art will understand that one or more additional plungers are typically part of the pump 10 and reciprocate in phase or out of phase in response to rotation of the engine cam in a generally known manner. The plunger 14 pressurizes fuel within the plunger chamber 16 and transports fuel between the pump inlet 20 and the pump outlet 22. The valve member 26 of the valve assembly 24 is also located within the pump housing 12 and is movable between a rest position and an actuated position. In the rest position, the valve seat 28 is open and the pump inlet 20 is in fluid communication with the plunger chamber 16; in the actuated position, the valve member 26 blocks the valve seat 28 and the pump inlet 20 is blocked and cannot be in fluid communication with the plunger chamber 16. The valve member 26 can be positioned to block the valve seat 28 during the pressurizing stroke of the plunger 14.

[0021] Spring-biased outlet valve 19 blocks pump outlet 22 but opens in response to sufficient pressure to allow pressurized fuel to be supplied through fluid communication between plunger chamber 16 and the common rail or other components. Other valve positioning and operating strategies may be used. For example, valve assembly 26 may include a control valve that controls the position of another valve. Valve assembly 24 also includes an electro-actuator 30, the operation of which and its unique configuration are discussed further herein.

[0022] The electric actuator 30 includes a stator 32 positioned within or coupled to the pump housing 12, and an armature 44. The armature 44 may be coupled to a valve member 26, and in one embodiment may include an armature pin 47 attached to and / or integrally formed with the valve member 26. The valve member 26 and / or the armature pin 47 extend through an armature plate 46. Armature 44 and armature plate 46 are terms used interchangeably herein. Changing the energy state of the electric actuator 30 can cause the armature 44 to move relative to the stator 32 according to well-known principles. Changing the energy state typically involves energizing the electric actuator 30; however, embodiments in which changing the energy state includes de-energizing the electric actuator 30 are contemplated. Increasing the energy state of the electric actuator 30 from a first energy state to a higher energy state, or decreasing the energy state from a higher energy state to a lower energy state, can also be understood as changing the energy state as contemplated herein.

[0023] In the illustrated embodiment, the stator 32 includes an outer stator portion 34 having an annular shape and an inner stator portion 35 also having an annular shape. The outer stator portion 34 and the inner stator portion 35 may be arranged concentrically with respect to each other and centered on the longitudinal axis 13 of the pump housing; however, this disclosure is not limited thereto. An annular channel 36 is formed between the outer stator portion 34 and the inner stator portion 35. In the illustrated embodiment, the electric actuator 30 includes a solenoid electric actuator having a winding 38 positioned within or at least partially within the channel 36. The winding 38 comprises a conductive metallic material in a generally conventional manner. The electric actuator 30 may also include a non-metallic overmolded member 40 surrounding the winding 38. An electrical plug 42 is coupled to the pump housing 12 to provide electrical connection with the winding 38.

[0024] The stator 32 also includes a stator end face 52 (“stator face 52”) facing the armature 44 and formed in part by the annular end faces (not numbered) of each of the outer stator portion 34 and the inner stator portion 35 located in a common plane, and in an embodiment also in part by the winding 38. The overlay molding 40 thus forms the exposed portion of the stator face 52, the importance of which will become apparent from the following description.

[0025] Armature plate 46 defines the armature central axis 48. Figure 1In the illustrated state, the armature central axis 48 is substantially collinear with the longitudinal axis 13 of the pump housing. The armature 44, including the armature plate 46, can also move between a rest position corresponding to the rest position of the valve member 26 and an actuated position corresponding to the actuated position of the valve member 26. In the rest position of the armature 44, the armature plate 46 is spaced apart from the stator 32. In the actuated position of the armature 44, the armature plate 46 is adjacent to the stator 32, wherein the stroke of the armature 44 and the valve member 26 is generally stopped by contact between the valve member 26 and the valve seat 28. As described above, the armature 44 and the valve member 26 can move together in the aforementioned manner in response to changes in the energy state of the electric actuator 30. A return spring 68 may be provided to return the armature 44 and the valve member 26 to the rest position when the electric actuator 30 is de-energized or when the energy state changes appropriately.

[0026] Armature plate 46 includes a top armature surface 50, a bottom armature surface 54, and an outer peripheral surface 56 facing the stator 32, the outer peripheral surface extending circumferentially around the armature central axis 48 and axially between the top armature surface 50 and the bottom armature surface 54. See also Figure 2 The diagram illustrates several aspects and elements of the electric actuator 30. The top armature surface 50 has an inwardly stepped-up profile, forming a raised surface 58 in a radially inward position adjacent to the stator 32 in the actuated position, and a lower gap-forming surface 60 in a radially outward position, forming a gap 70 between the armature 44 and the stator 32 in the actuated position. The inward stepped-up profile implies a relatively abrupt rise in a radially inward direction toward the armature central axis 48, although the "step" is not necessarily sharp or angled. For example, a continuous change in height is unlikely to be fully understood as an inward stepped-up profile.

[0027] See also Figure 3 The diagram shows various aspects and elements of the electric actuator 30, as they may be present where the armature 44 is in the actuated position. In the actuated position, in some cases, the armature central axis 48 may be inclined relative to the longitudinal axis 13 of the pump housing, and in this case, the top armature surface 50 is inclined relative to the stator 32.

[0028] In the illustrated embodiment, an armature cavity 66 is formed in the pump housing 12 to accommodate the movement of the armature 44. During operation of the pump 10, the armature cavity 66 is typically filled with the working fluid transferred through the pump 10, although other fluids may also be used. When the armature 44 moves from its rest position (approximately...) Figure 2 (As shown) move to its actuation position (approximately as shown) Figure 3When the pump housing is moved to its actuated position (as shown), the fluid between the stator 32 and the armature 44 will be transferred. Specifically, when the armature 44 moves to its actuated position, the fluid is compressed between the top surface 50 and the stator surface 52. It can also be noted that a groove 72 is shown in the stator 32, and in the illustrated embodiment, the groove 72 extends inward from the stator surface 52. The groove 72 may have an annular shape, be concentric with the outer stator portion 34 and the inner stator portion 35, and generally be centered on the longitudinal axis 13 of the pump housing.

[0029] It has been observed that fluid compression between armature 44 and stator 32, and particularly between armature 44 and slot 72, can result in fluid velocity and energy sufficient, at least over time, to erode or otherwise damage the overmolded part 40. The inward stepped profile of the top surface 50 mitigates these corrosion phenomena by providing a more efficient escape path for the displaced fluid. As described above, the top surface 50 includes a raised surface 58 and a lower surface 60. In earlier designs lacking this inward stepped profile, no such fluid escape path was provided. Figure 3 In the diagram, the dashed line shows an example armature profile 160 that can be found in some known armature designs.

[0030] Recall that moving armature 44 to the actuated position may include tilting armature 44, ultimately causing the top surface 50 of armature 44 to tilt relative to stator surface 52. It is believed that tilting of armature 44 and some similar armatures can cause or exacerbate corrosion phenomena as described herein. It can be seen that when armature 44 reaches the actuated position, the known armature profile 160 can cause armature plate 46 to contact or nearly contact stator 32, and at least near the point of contact or close to the point of contact between armature 44 and stator surface 52, restrict or completely prevent the radial outward flow of fluid. As a result, the diverted fluid can be expected to be redirected inward, circumferentially, and upward into the groove 72, being accelerated in the process to the extent that a high-speed fluid jet can damage the relatively soft overmolded part 40.

[0031] Turn now Figure 4 The perspective view shows the armature 44, including the armature plate 46, and additional details are shown. It can be seen that the raised surface 58 is generally planar and circular, and an annular stepped surface or outer peripheral surface 69 extends between the raised surface 58 and the lower surface 60. The lower surface 60 is also generally planar and annular. The raised surface 58 and the lower surface 60 each extend circumferentially around the armature central axis 48, and will also be understood to extend circumferentially around the armature pin 47. From... Figure 4It will also be noted that the inward stepped rising profile of the top armature surface 50 is approximately symmetrical about the armature central axis 48. In one embodiment, the inward stepped rising profile includes a circumferentially uniformly rotating profile about the armature central axis 48, and each of the rising surface 58 and the lower surface 60 defines a circular periphery, wherein the circular peripheries are concentric. The armature plate 46 has a first axial thickness 112 located within the raised surface 58 and a second axial thickness 114 located within the lower surface 60. The first axial thickness 112 may be approximately twice or less than the second axial thickness 114. The outer peripheral surface 56 defines a first outer diameter dimension 116, and the raised surface 58 defines a second outer diameter dimension 118. The first outer diameter dimension 116 may be approximately twice or greater than the second diameter dimension 118.

[0032] Magnetic flux density tends to decrease non-linearly in the direction radially outward from the center of the solenoid coil. Therefore, removing or limiting the use of relatively more radially outward material in the armature according to this disclosure tends to have only a relatively mild effect (if any) on the magnitude of the electromagnetic force applied to the armature 44 when the electric actuator 30 is energized. It should be understood that, without departing from the scope of this disclosure, the following can be applied to… Figure 4 Various modifications are made to the geometry, proportions, and relative dimensions of the armature plate 46 shown. It is conceivable that a practical implementation includes forming the armature plate 46 such that when the armature 44 is in the actuated position, the gap 70 will be in fluid communication with the slot 72. Therefore, the position / size of the outer peripheral surface 69 may be slightly smaller than the outer diameter of the slot 72; however, this disclosure is not limited thereto.

[0033] In the illustrated embodiment, the electric actuator 30 includes a solenoid actuator having a winding 38 positioned within or at least partially positioned within a channel 36. The winding 38 comprises a conductive metallic material in a generally conventional manner. The electric actuator 30 may also include a non-metallic overlay molding 40 surrounding the winding 38. An electrical plug 42 is coupled to the pump housing 12 to provide electrical connection to the winding 38.

[0034] The stator 32 also includes a stator end face 52 (“stator face 52”) facing the armature 44 and formed in part by the annular end faces (not numbered) of each of the outer stator portion 34 and the inner stator portion 35 located in a common plane, and in an embodiment also in part by the winding 38. The overlay molding 40 thus forms the exposed portion of the stator face 52, the importance of which will become apparent from the following description.

[0035] To reduce or eliminate tilting of the armature 44, including the armature plate 46, and thus further reduce or eliminate wear along the lower surface of the insulator 40 surrounding the winding 38, the following methods can be used: Figure 6-11 An alternative embodiment of the electric actuator 130 depicted herein. The electric actuator 130 may be similar to... Figure 1-3 The actuator 30 is depicted in Figure 5, and the same elements in actuator 30 and actuator 130 may be identified by the same reference numerals. The electric actuator 130 includes a generally cylindrical stator 132, winding and terminal assemblies 187 at least partially disposed within the stator, a non-magnetic barrier 190 associated with the stator, and an overmolded body 192 at least partially disposed around the stator, winding and terminal assemblies, and barrier. An electrical connector 42 extends from the overmolded body 192.

[0036] See first Figure 6-7 The external profile or appearance of the stator of actuator 130 may be the same as or substantially the same as that of actuator 30 described above. Stator 132 includes an outer stator portion 134 having an annular shape and an inner stator portion 135 also having an annular shape. The outer stator portion 134 and the inner stator portion 135 may be concentrically arranged along the central axis 133 of the stator, which is also centered on the longitudinal axis 13 of the pump housing; however, this disclosure is not limited thereto. An annular channel 136 is formed between the outer stator portion 134 and the inner stator portion 135. Stator 132 may include an annular upper portion 180 interconnecting the outer stator portion 134 to the inner stator portion 135. See also Figure 10 The outer stator portion 134 includes an outer stator end face or lower surface 134a, and the inner stator portion 135 includes an inner stator end face or lower surface 135a. See also Figure 11 In one embodiment, the outer stator end face 134a and the inner stator end face 135a may be coplanar (i.e., located in a common plane). For example... Figure 1 As shown, the inner stator portion 135 may include a central opening to receive an armature pin 47 and a portion of the armature spring 68 therein.

[0037] A first radial channel 181 extends from the annular channel 136 through the outer stator portion 134 to the outer surface 137 of the outer stator portion. The first radial channel 181 may also extend upward through the upper portion 180. As described below, the first radial channel 181 provides a passage for a portion of the winding and terminal assembly 187 to pass through.

[0038] The second radial channel 182 extends from the annular channel 136 through the outer stator portion 134 to the outer surface 137 of the outer stator portion. The second radial channel 182 may also extend upward through the upper portion 180. In one embodiment, the second radial channel may be identical to the first radial channel 181. Furthermore, the second radial channel 182 may be configured to be radially opposite to the first radial channel 181. In other words, the first radial channel 181 and the second radial channel 182 are located on opposite sides of the stator central axis 133 and aligned along a line 184 bisecting the centers of the two channels, and also pass through or intersect the central axis perpendicularly to it.

[0039] In one embodiment, the upper portion 180 of the stator 132 may include a plurality of openings 185 configured to facilitate assembly of the actuator 130. In some embodiments, the openings 185 may be diametrically opposed and arranged along a line 186 perpendicular to line 184. In this case, the stator 132 is symmetrical about the bisecting line 184 passing through the first radial channel 181 and the second radial channel 182. In other embodiments, the openings 185 may be slightly offset from line 186. In this case, the lower surface of the stator 132 is symmetrical about the bisecting line 184 passing through the first radial channel 181 and the second radial channel 182. In other embodiments, the openings 185 may be omitted. The stator 132 may be formed of any desired magnetic material, such as a magnetic material with high permeability. In one embodiment, the stator 132 may be formed of a soft magnetic composite material and formed using powder metallurgy or molding processes. Other materials and processes for forming the stator 132 may be considered.

[0040] The winding and terminal assembly 187 includes a bobbin 188 and a coil 38. Figure 1 The insulator 40 is wound around the spool 188. The insulator 40 surrounds the assembly 38 and can be formed by overmolding the winding and spool 188. Electrical terminals 189 are electrically connected to the winding 38. Once assembled, the winding and terminal assembly 187 is inserted into an annular channel 136 between the outer stator portion 134 and the inner stator portion 135, wherein a portion of the winding 38, the insulator 40, the spool 188, and / or the terminals 189 extend through a first radial channel 181. The spool 188 can be formed from any desired material. In one embodiment, the spool 188 can be molded from polyphenylene sulfide, and the terminals 189 can be machined or formed from brass or a copper alloy. Other materials and manufacturing processes are also possible.

[0041] A non-magnetic barrier 190 can be provided between the stator 132 and the armature spring 68 to form a magnetic barrier and prevent the spring from being attracted to the stator and causing wear. The barrier 190 can be formed of any desired material. In one embodiment, the barrier 190 can be formed of stainless steel and can be formed of multiple parts that can be machined, stamped, and / or extruded. Other materials and manufacturing processes are also possible.

[0042] The overlay molding 192 may be formed around the stator 132, the winding and terminal assembly 190, and the non-magnetic barrier 190. For example... Figure 6 As shown, the molded body 192 and Figure 1 and 5Similar to the example shown, except that the overmolding material extends between the first radial channel 181 and the second radial channel 182. The overmolded body 192 can be formed of any desired material. In one embodiment, the overmolded body 192 can be formed of a thermosetting epoxy resin. Other materials are also contemplated.

[0043] After forming an overlay molding 192 around the stator 132, windings and terminal assembly 190 and non-magnetic barrier 190, the connector 42 can be secured to the overlay molding 192, wherein the terminals 189 extend into the cavity of the connector.

[0044] Reference Appendix Figure 10-11 Due to the symmetry of stator 132, particularly along the lower surface of the stator, the magnetic flux generated during actuation of the electric actuator 130 will be uniform, thereby attracting armature plate 46 in a uniform manner. This uniform attraction or magnetic symmetry can eliminate or reduce the possibility of armature plate 46 skewing or tilting and causing corrosion of the insulator 140 surrounding winding 138 when fluid is forced to flow out between the lower surface of stator 132 and armature plate 46.

[0045] Other ways of achieving magnetic symmetry in stator 132, particularly along the lower surface of stator 132, are conceivable. For example, instead of locating the second radial channel 182 along line 184, the second radial channel could be replaced by other openings in the stator such that the reduction in magnetic flux is equal to or substantially equal to the reduction caused by the presence of the first radial channel 181. Figure 12 In the depicted example, the second radial channel along line 184 can be omitted and replaced by a pair of additional openings 195 in the outer stator portion 134 that are equidistant from line 184. These openings 195 can be configured as radial channels or slots and extend completely or partially through the outer stator portion 134. The openings 195 can extend upward from the lower surface of the stator and, if desired, can extend through the upper portion or surface 180 of the stator 132, as shown by the openings 196 between the dashed lines.

[0046] The position and size of the opening 195 can be adjusted to balance the magnetic flux on opposite sides of lines 184 and 185. In one example, each pair of openings 195 and 196 can be configured as the same radial channel as the first radial channel 181. In this case, the first radial channel 181 and each of the pair of radial channels can be circumferentially spaced 120 degrees along the outer surface of the stator 132 to achieve magnetic symmetry of the stator.

[0047] Regardless of the shape and position of the openings 195 and 196, the overmolding material used to form the overmolded body 192 will fill the openings.

[0048] Those skilled in the art will understand that, since the opening 185 is located at the upper part 180 of the stator 132, the effect of any asymmetry caused by the opening 185 on the magnetic flux relative to the armature plate 46 will be reduced.

[0049] Actuator 130 can be used with an armature plate having a top surface with any desired configuration. In one embodiment, the top surface 50 can be as follows: Figure 1-4 The top surface is stepped, as shown. In another embodiment (not shown), the top surface may be flat. In yet another embodiment (not shown), the top surface may be curved.

[0050] Industrial applicability

[0051] Referring generally to the accompanying drawings, the operating valve assembly 24 may include changing the energy state of the electric actuator 30 as discussed herein, and moving the armature 44 from a rest position toward the stator 32 in response to the change in the energy state of the electric actuator 30. The armature 44 will move toward the actuated position and stop there, for example, by bringing the valve member 26 into contact with the valve seat 28, although the raised surface 58 may also contact the stator surface 52 depending on manufacturing tolerances, component wear, and the degree of tilt of the armature 44. In the actuated position, the lower surface 60 forms a gap 70, allowing fluid to transfer between the armature 44 and the stator 32 via the gap 70. The valve 26 moves in the manner described herein to change the fluid connection with the pumping chamber or plunger cavity 16 in the pump 10. When the electric actuator 30 is de-energized, the armature 44 may return to the rest position under the influence of the return spring 68.

[0052] See now Figure 5 The diagram shows a bottom view of the electric actuator 30, which may appear at the armature 44, indicated by dashed lines. It can be seen that the armature 44 is tilted generally to the left, away from the plug 42 and away from the space 74 formed by the gap in the outer stator portion 34. Circle 100 shows the area of ​​contact between the armature 44 and the stator surface 52, which can be observed in known designs. Location 102 is also shown, where corrosion or other damage may occur in addition to the outline of the armature 44 as described herein. It can also be noted that location 102 is located inside the slot 72. Different corrosion phenomena can be observed in other pump and / or electric actuator designs.

[0053] exist Figure 6 During the operation of the actuator 130, the stator 132 generates a uniform magnetic field, and thus the armature plate 46 is attracted to the stator in a uniform manner. This uniform attraction reduces the possibility of the armature plate deflecting or tilting. By avoiding tilting of the armature plate 46, high-speed fluid flow between the armature plate 46 and the stator 132 can be avoided.

[0054] This specification is for illustrative purposes only and should not be construed as limiting the scope of this disclosure in any way. Therefore, those skilled in the art will understand that various modifications can be made to the embodiments currently disclosed without departing from the full and reasonable scope and spirit of this disclosure. Other aspects, features, and advantages will become apparent from a study of the accompanying drawings and appended claims. As used herein, the article “a” is intended to include one or more items and is interchangeable with “one or more”. The term “one” or similar language is used where only one item is desired. Furthermore, as used herein, the terms “has”, “have”, “having”, etc., are intended to be open-ended terms. Additionally, the phrase “based on” is intended to mean “based, at least in part” unless otherwise explicitly stated.

Claims

1. A valve assembly, comprising: A valve member operably associated with a valve seat, the valve member being movable along a central axis between a first open position and a second closed position, the valve member being spaced apart from the valve seat in the first open position, and the valve member engaging the valve seat in the second closed position to seal the opening of the valve assembly; An electric actuator, the electric actuator including a stator and an armature coupled to the valve member; The stator includes an annular outer stator portion and an annular inner stator portion, and an annular channel formed radially between the outer stator portion and the inner stator portion; A first radial channel extends through the annular outer stator portion between the outer surface of the outer stator portion and the annular channel; and at least one second opening is provided in the annular outer stator portion of the stator on the half opposite to the first radial channel; the stator is magnetically symmetrical along a line that bisects the first radial channel and is perpendicular to the central axis; A winding and terminal assembly, the winding and terminal assembly including a conductive winding disposed within the annular channel and located between the outer stator portion and the inner stator portion, and conductive terminals electrically connected to the winding, a portion of the winding and terminal assembly extending through the first radial channel; and The armature includes an armature plate defining an armature central axis, the armature central axis being collinear with the central axis, and movable between a rest position and an actuated position to change the position of the valve member in response to a change in the energy state of the electric actuator, the armature plate including a top armature surface facing the stator.

2. The valve assembly of claim 1, wherein the at least one second opening includes a second radial channel extending through the annular outer stator portion between the outer surface of the outer stator portion and the annular channel, the second radial channel being radially opposite to the first radial channel.

3. The valve assembly of claim 1 further includes an insulating overlay molding that encloses the winding and is disposed in the annular channel.

4. The valve assembly of claim 1, wherein the outer stator portion includes an outer stator end face and the inner stator portion includes an inner stator end face, and the outer stator end face and the inner stator end face are located in a common plane.

5. The valve assembly of claim 1, wherein the winding and terminal assembly further comprises a bobbin assembly on which the winding is wound.

6. The valve assembly of claim 1, wherein the at least one second opening includes a second radial channel extending through the annular outer stator portion between the outer surface of the outer stator portion and the annular channel, the second radial channel being aligned with the first radial channel and located on the opposite side of the central axis.

7. The valve assembly of claim 1, wherein the stator has an upper surface and a lower surface, the lower surface being positioned closer to the armature plate than the upper surface, and the lower surface of the stator is radially symmetrical.

8. The valve assembly of claim 1, wherein the stator has an upper surface and a lower surface, the lower surface being positioned closer to the armature plate than the upper surface, the lower surface being symmetrical about a bisecting line passing through the first radial channel and intersecting the central axis and perpendicular to the central axis.

9. The valve assembly of claim 8, wherein the outer surface of the outer stator portion is symmetrical about the bisecting line.

10. The valve assembly of claim 8, wherein the stator is symmetrical about the bisecting lines.

11. The valve assembly of claim 1, further comprising a covering molded body extending around the stator and entering each of the first radial channel and the at least one second opening.

12. A valve assembly, comprising: A valve member operably associated with a valve seat, the valve member being movable along a central axis between a first open position and a second closed position, the valve member being spaced apart from the valve seat in the first open position, and the valve member engaging the valve seat in the second closed position to seal the opening of the valve assembly; An electric actuator, the electric actuator including a stator and an armature coupled to the valve member; The stator includes an annular outer stator portion and an annular inner stator portion, and an annular channel formed radially between the outer stator portion and the inner stator portion; A first radial channel extends through the annular outer stator portion between the outer surface of the outer stator portion and the annular channel; and at least one second opening is provided in the annular outer stator portion of the stator on the half opposite to the first radial channel; the stator is magnetically symmetrical along a line that bisects the first radial channel and is perpendicular to the central axis; A winding and terminal assembly, the winding and terminal assembly including a conductive winding disposed inside the annular channel and located between the outer stator portion and the inner stator portion, and a conductive terminal electrically connected to the winding, a portion of the winding and terminal assembly extending through the first radial channel; A covered molding body that extends around the stator and enters into each of the first radial channel and the at least one second opening; as well as The armature includes an armature plate defining an armature central axis, the armature central axis being collinear with the central axis, and movable between a rest position and an actuated position to change the position of the valve member in response to a change in the energy state of the electric actuator, the armature plate including a top armature surface facing the stator.

13. The valve assembly of claim 12 further includes an insulating overlay molding that encloses the winding and is disposed in the annular channel.

14. The valve assembly of claim 12, wherein the stator has an upper surface and a lower surface, the lower surface being positioned closer to the armature plate than the upper surface, and the lower surface of the stator is radially symmetrical.

15. The valve assembly of claim 12, wherein the stator has an upper surface and a lower surface, the lower surface being positioned closer to the armature plate than the upper surface, the lower surface being symmetrical about a bisecting line passing through the first radial channel and the second radial channel and intersecting the central axis.

16. The valve assembly of claim 15, wherein the outer surface of the outer stator portion is symmetrical about the bisecting line.

17. The valve assembly of claim 15, wherein the stator is symmetrical about the bisecting line.

18. The valve assembly of claim 15, wherein the overlay molding extends around the stator and enters into each of the first radial channel and the second radial channel.

19. A pump comprising: Pump housing; A pumping element that can move between a retracted position and an advanced position within a pumping chamber formed in the pump housing; A valve assembly for controlling the inflow or outflow of fluid from the pumping chamber, the valve assembly including... A valve member operably associated with a valve seat, the valve member being movable along a central axis between a first open position and a second closed position, the valve member being spaced apart from the valve seat in the first open position, and the valve member engaging the valve seat in the second closed position to seal the opening of the valve assembly; An electric actuator, the electric actuator including a stator and an armature coupled to the valve member; The stator includes an annular outer stator portion and an annular inner stator portion, and an annular channel formed radially between the outer stator portion and the inner stator portion; A first radial channel extends through the annular outer stator portion between the outer surface of the outer stator portion and the annular channel; and at least one second opening is provided in the annular outer stator portion of the stator on the half opposite to the first radial channel; the stator is magnetically symmetrical along a line that bisects the first radial channel and is perpendicular to the central axis; A winding and terminal assembly, the winding and terminal assembly including a conductive winding disposed inside the annular channel and located between the outer stator portion and the inner stator portion, and a conductive terminal electrically connected to the winding, a portion of the winding and terminal assembly extending through the first radial channel; The armature includes an armature plate defining an armature central axis, the armature central axis being collinear with the central axis, and movable between a rest position and an actuated position to change the position of the valve member in response to a change in the energy state of the electric actuator, the armature plate including a top armature surface facing the stator.

20. The pump of claim 19, further comprising a covering molding body extending around the stator and entering each of the first radial channel and the at least one second opening.

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