Lubricant vent valve with stepper motor drive

Abstract

Vent valve for a lubrication system (1), wherein the lubrication system (1) comprises a lubricant supply (2) and a lubricant dispenser (5), wherein the vent valve comprises the following: a valve body (12) with a flow passage (18), wherein the flow passage (18) has an inlet (19) fluid-connected to the supply and an outlet fluid-connected to the dispenser, and a vent passage (22) comprising an inlet opening (23) fluid-connected to the flow passage (18) and an outlet opening (24); a closure element (14) that is at least partially arranged in the vent passage (22), has a threaded section (26) and is linearly displaceable between an open position in which the vent inlet (23) and the vent outlet (24) are fluidly connected to allow lubricant to flow from the primary passage and from the valve body (12) through the vent outlet (24), and a closed position in which fluid flow between the vent inlet (23) and the vent outlet (24) is substantially prevented; and a motor (16) with a shaft (30) rotating around a central axis (A M ) is rotatable, wherein the shaft (30) has a threaded section (32) which is threaded in engagement with the threaded section (26) of the locking element (14), so that by rotating the shaft (30) in a first direction about the central axis (A M) the locking element (14) is moved towards the closed position, and by rotating the shaft (30) in a second, opposite direction around the axis the locking element (14) is moved towards the open position.

Description

[0001] The present invention relates to valves, in particular electric vent valves, used in lubrication systems.

[0002] Certain lubrication systems require a vent valve to release lubricant pressure after a lubrication cycle. Such a system may be a single-line lubrication system comprising one or more lubricant dispensers (e.g., injectors) for delivering lubricant to one or more devices (e.g., bearings), a lubricant supply, a supply line connecting the supply to the dispenser, and a pump to pressurize the lubricant in the supply line so that it flows from the supply to the dispenser(s). Typically, a control unit is provided to initiate pump operation when lubrication is required and to switch the pump off when a desired maximum lubricant pressure is reached in the dispenser(s), which is typically determined by a pressure switch.

[0003] The vent valve is also provided to release pressure in the supply line once the desired maximum lubricant pressure is reached and can be hydraulically, pneumatically, or electrically actuated. State-of-the-art electric vent valves typically comprise a coil driven by a solenoid that moves the coil between an open and a closed position. These valves are normally open and are driven to close when a lubrication cycle is initiated. Due to relatively high pressures reached in the lubricant supply line, especially when the lubricant is grease rather than a lower-viscosity oil, the solenoid must hold the coil in the closed position against a strong force acting on the coil, which pushes it toward the open position.The solenoid force required to hold the coil in the closed position against such high pressure is generally difficult to achieve with a typical low-voltage supply (e.g., 24 volts). Furthermore, due to the relatively short stroke of a typical solenoid, the valve orifices must be relatively small, resulting in rapid erosion of the valve's metal components, especially when using high-pressure grease.

[0004] DE 692 11 097 T2 is a valve controlled by a stepper motor and a thread.

[0005] EP 2 128 443 A1 discloses a piston pump driven by a stepper motor, which ensures venting by retracting the piston into a relief position.

[0006] A venting valve is known from DE 102 37 801 A1.

[0007] DE 199 04 647 A1 also reveals a vent valve.

[0008] In state-of-the-art solenoid-type valves, the flow of lubricating grease is restricted during the drain phase of the lubrication cycle due to the relatively small size of the openings. At low temperatures, especially with a relatively "stiff" lubricating grease, such small openings can prevent the grease from flowing back through the valve to the grease supply, thus preventing the drain phase from being reached.

[0009] If the discharge phase is not completed, the lubrication system cannot function. Typically, pressures in the lubrication system reach up to 3,500 psi, and a maximum of 5,000 psi to operate the lubrication valves (injectors), and must then be discharged to below 400 psi. Due to the small orifices, the valve is also susceptible to clogging if even small amounts of contaminants are present in the lubricating grease.

[0010] In one aspect, the present invention is a vent valve for a lubrication system, wherein the lubrication system comprises a lubricant supply and a lubricant dispenser. The vent valve comprises a valve body with a flow passage, the flow passage having an inlet fluid-connected to the supply and an outlet fluid-connected to the dispenser, and a vent passage comprising an inlet opening fluid-connected to the flow passage and an outlet opening.A closure element is at least partially located in the vent passage, has a threaded section, and is linearly displaceable between an open position, in which the vent inlet and outlet are fluidly connected to allow lubricant to flow from the primary passage and out of the body through the outlet, and a closed position, in which fluid flow between the vent inlet and outlet is substantially prevented. Furthermore, a motor has a shaft rotatable about a central axis, the shaft having a threaded section that engages with the threaded section of the closure element.In this way, by rotating the shaft in a first direction around the axis, the locking element is moved towards the closed position, and by rotating the shaft in a second, opposite direction around the axis, the locking element is moved towards the open position.

[0011] In another aspect, the present invention is again a vent valve for a lubrication system, wherein the lubrication system comprises a lubricant supply and a lubricant dispenser. The vent valve comprises a valve body with a flow passage, the flow passage having an inlet fluid-connected to the supply and an outlet fluid-connected to the dispenser, and a vent passage comprising an inlet opening fluid-connected to the flow passage and an outlet opening.A closure element is at least partially located in the vent passage and is linearly displaceable between a closed position, in which fluid flow between the vent inlet and outlet is substantially prevented, and an open position, in which the vent inlet and outlet are fluidly connected to allow lubricant to flow from the primary passage and out of the body through the outlet. A motor has a shaft rotatable about a central axis, the shaft being engaged with the closure element such that rotating the shaft in a first direction about the axis moves the closure element toward the open position, and rotating the shaft in a second, opposite direction about the axis moves the closure element toward the closed position.Furthermore, a controller is operatively connected to the motor and configured to receive first and second inputs to drive the motor so that it rotates the shaft in the first direction when the controller receives the first input and the locking element is in the open position, and to drive the motor so that it rotates the shaft in the second direction when the controller receives the second input when the locking element is in the closed position.

[0012] The introductory summary and the detailed description of preferred embodiments of the present invention are better understood in conjunction with the accompanying drawings. To illustrate the invention, currently preferred embodiments are depicted in the schematic drawings. However, it should be noted that the present invention is not limited to the exact arrangements and components shown. The drawings are Fig. 1 a schematic view of a lubrication system with a vent valve according to the present invention; Fig. 2 a perspective view of a first construction of the vent valve according to the present invention; Fig. 3 an axial cross-sectional view of the vent valve of Fig. 2; Fig. 4A and Fig. 4B, together Fig. 4, each a reduced view of the in Fig. 3 valve shown, wherein Fig. 4A an open valve configuration and Fig. 4B shows a closed valve configuration; Fig. 5 an enlarged, broken-up view of the lower section of Fig. 4A, which shows a coil locking element in an open position; Fig. 6 an enlarged, broken-up view of the lower section of Fig. 4B, which shows the coil locking element in a closed position; Fig. 7 a schematic diagram of the valve of the first construction, showing a preferred design of a valve control; Fig. 8 a more detailed schematic view of the in Fig. 7 shown control unit, which shows a preferred micro control unit; Fig. 9 a perspective view of a second construction of the vent valve according to the present invention; Fig. 10 an axial cross-sectional view of the vent valve of Fig. 9; Fig. 11A and Fig. 11B, together Fig. 11, each a reduced view of the in Fig. 10 shown valve, wherein Fig. 11A an open valve configuration and Fig. Figure 11B shows a closed valve configuration; Fig. 12 an enlarged, broken-up view of the lower section of Fig. 11A, which shows a plate locking element in an open position; Fig. 13 an enlarged, broken-up view of the lower section of Fig. 11B, which shows a plate locking element in a closed position; Fig. 14 a schematic diagram of the valve of the second construction, showing a preferred design of a valve control; Fig. 15 an exploded view of a third construction of the vent valve according to the present invention; Fig. 16 an axial cross-sectional view of the vent valve of Fig. 15; Fig. 17A and Fig. 17B, ​​together Fig. 17, each a reduced view of the in Fig. 16 shown valve, wherein Fig. 17A an open valve configuration and Fig. 17B shows a closed valve configuration; Fig. 18 an enlarged, broken view of the lower section of Fig. 17A, which shows a coil locking element in an open position; Fig. 19 an enlarged, broken view of the lower section of Fig. 17B, ​​which shows a coil locking element in a closed position; Fig. 20 an enlarged, broken-up view of the middle section of Fig. 16, which shows a gear drive of the motor shaft; and Fig. 21 an enlarged section of Fig. 15, which shows the gear drive of the motor shaft.

[0013] For convenience only, the following description uses a certain non-restrictive terminology. The words "lower," "upper," "upward," "downward," and "downward" denote directions in the drawings being referenced. The words "inner," "inward," and "outward," "outward," refer to directions toward and away from a designated centerline or geometric center of a described element, the specific meaning being readily apparent from the context of the description. As used here, the word "connected" is also intended to encompass direct connections between two elements, with no other elements positioned between them, and indirect connections between elements, with one or more other elements positioned between them. The terminology includes the words specifically mentioned above, derivatives thereof, and words of similar meaning.

[0014] Referring to the detailed drawings, in which numbers are consistently used to denote elements, it is in Fig. Figures 1-14 show a vent valve 10 for a lubrication system 1, which comprises a lubricant supply 2, a pump 3, a lubrication control unit 4, and at least one, and preferably a plurality, of lubricant dispensers 5, most preferably injectors 6, for supplying lubricant to bearings 7. The vent valve 10 essentially comprises a valve body 12, a movable closure element 14 arranged in the valve body 12, and a motor 16, which, as discussed below, is preferably a stepper motor and is operatively connected to the closure element 14. The valve body 12 has a primary flow passage 18, wherein the flow passage 18 has an inlet 19 fluidically connected to the lubricant supply 2 and an outlet 20 ( Fig. 2, Fig. 9 and Fig. 15) which is fluidly connected to the lubricant dispenser(s) 5, preferably via a supply line 8 and a valve passage 22. The valve passage 22 has an inlet opening 23, which is fluidly connected to the flow passage 18, and an outlet opening 24, which is preferably fluidly connected to the lubricant supply 2.

[0015] The closure element 14 is at least partially arranged in the valve passage 22 and has a threaded section 26, most preferably a bore 56 or 79 with an internal thread, as described below. The closure element 14 is oriented along a central axis A C between an open position P O , which in Fig. 3, Fig. 4A, Fig. 5, Fig. 10, Fig. 11A, Fig. 12, Fig. 16, Fig. 17A and Fig. 18 is shown, and a closed position P C , which in Fig. 5A, Fig. 6, Fig. 11B, Fig. 13, Fig. 17B and Fig. As shown in 19, it is linearly displaceable. When the locking element 14 is in the open position P O When the valve body is in the closed position P, the vent inlet opening 23 and the vent outlet opening 24 are fluidly connected to each other, so that lubricant can flow from the primary passage 18 and from the valve body 12 through the vent outlet opening 24 and preferably back into the lubricant supply 2. Furthermore, when the closure element 14 is in the closed position P C In this position, fluid flow between the vent inlet opening 23 and the vent outlet opening 24 is essentially prevented, so that all lubricant flowing into the primary passage 18 from the inlet 19 flows out of the outlet 20 and subsequently to the lubricant dispenser(s) 5.

[0016] Furthermore, the motor 16 is preferably contained in a housing 17 which is attached to the valve body 12 and has a shaft 30 which rotates about a central axis A M rotatable, preferably essentially aligned with axis A C the locking element is collinear. The shaft 30 has a threaded section 32 which engages with the threaded section 26 of the locking element. By rotating the motor shaft 30 in a first direction R1, such thread engagement Fig. 3 and Fig. 16) around axis A M the locking element 14 towards the closed position P C offset. Alternatively, by rotating shaft 30 in a second, opposite direction R2 ( Fig. 3 and Fig. 16) around axis A M the locking element 14 towards the open position P Ooffset. It should be noted that in two preferred valve designs 11A, 11B, as disclosed below, the first direction R1 is clockwise and the closing element 14 generally extends downwards along the central axis A C from the open position P O to the closed position P C is offset and vice versa. Alternatively, in a third preferred valve design 11C, the first direction R1 runs counterclockwise and the closure element 14 is generally moved upwards along the central axis A. C from the open position P O to the closed position P C offset and vice versa.

[0017] Furthermore, the threaded section 32 of the motor and the threaded section 26 of the sealing element are configured such that the engagement of the two threaded sections 32 and 26 essentially prevents displacement of the sealing element 14 when the sealing element 14 is subjected to lubricant pressure. That is, the engaged threads of the motor shaft 30 and the sealing element 14 are "locked" to prevent backward movement of the sealing element 14 when it is subjected to high lubricant pressure. Therefore, the motor 16 must be in a second valve assembly ( Fig. 9-14), which is described in detail below, do not exert a particularly strong torque to lock the locking element 14 in the closed position P C to maintain, even when the lubricant pressure in the vent inlet opening 23 reaches a relatively high level, since for the first valve design ( Fig. 2-8) and the third valve design (15-21) does not require torque, as explained below.

[0018] In relation to Fig. 3, Fig. 7, Fig. 8, Fig. 10 and Fig. 14 The vent valve 10 further preferably comprises a valve control 40 which is operatively connected to and configured with the motor 16 to drive it in order to move the closure element 14 between the open and the closed position P O , P C To be controllable and repositioned. Preferably, the controller is configured with 40, a first and a second input I1, I2 (see Fig. 10 and Fig. 14) to receive and drive the motor 16 so that it rotates the shaft 30 in response to the inputs I1, I2 in each of the opposite directions R1, R2. In particular, the valve control 40 is configured to drive the motor 16 to rotate the shaft 30 in the first direction R1 when the control 40 receives the first input I1 and the closing element 14 is in the open position P O is located so that the locking element 14 is in the closed position P C is displaced. The control unit 40 is also configured to drive the motor 16 to rotate the shaft 30 in the second direction R2 when the control unit 40 receives the second input I2 and the locking element 14 is in the closed position P. C is located so that the locking element 14 is in the open position P C is offset. Preferably, the first input is a voltage signal S. Vfrom a power supply (not shown) and the second input I2 a combination of the power supply voltage signal S V and a control signal S C the lubrication control unit 4, as described in detail below.

[0019] Furthermore, motor 16 is a stepper motor (as mentioned above) configured to make a predetermined number of rotations around the motor axis A of motor shaft 30. M to rotate the locking element 14 between the open and closed positions P O , P C to displace. In particular, in the preferred valve control 40, the control 40 is configured to drive the motor 16 so that it makes a predetermined number of rotations about the axis A. M in the first direction R1, when the control 40 receives the first input I1 and the locking element is in the open position P OThe controller 40 is also configured to drive the motor 16 so that it makes a predetermined number of rotations around axis A. M in the second direction R2, when the control 40 receives the second input I2 and the locking element 14 is in the closed position P C is located.

[0020] With reference to Fig. In Figures 3-6, 10, 11, and 18-20, the threaded section 32 of the motor shaft 30 is preferably provided by an outer circumferential surface 34 with at least one external thread 35, which, as described below, can engage with an internal circumferential surface thread 54A of the closure element 14. Preferably, the motor shaft 30 has a rotor shaft 31 with an outer end 31a and a drive element 36, which is connected to the outer end 31a of the shaft and provides the threaded section 32 of the shaft. In the first and second valve designs 11A and 11B, the drive element 36 is mounted directly on the outer end 31A of the shaft, as shown in Figure 1. Fig. 3 and Fig. 10 shown, and in the third valve assembly 11C the motor shaft 31 and the drive element 36 are connected to each other by a gear drive 130, as in Fig. 16 and Fig. 20 shown and described in detail below. Furthermore, the drive element 36 preferably has a generally cylindrical mounting section 37 with a bore 37a for receiving the shaft end 31a (see e.g. Fig. 3 and Fig. 10) or a shaft section 135a of a gear drive output element 135, as well as a drive rod section 38 that provides the outer surface 34 and the one or more threads 35. Alternatively, the motor shaft 31 can have an integrated threaded section (not shown) that provides the threaded section 32 of the shaft. As a further alternative, the drive wheel 36 (or the shaft 31) can have an internal threaded bore that can engage with an external threaded section of the locking element 14 (structure not shown).

[0021] Now, with reference to Fig. In a preferred design, the vent valve 10 (2-6) is a coil-type valve 11A, wherein the closure element 14 is a coil 50. The coil 50 comprises a cylindrical rod 52 with a centerline 53, respective inner and outer circumferential surfaces 54A and 54B, and two ends 55A and 55B spaced apart along the centerline 53. The inner surface 54A is threaded to form a threaded bore 56 extending inward from the upper, open end 55A, generally along the centerline 53, to the lower, closed end 55B. The threaded bore 56 provides, as described above, the threaded section 26 of the closure element and is dimensioned and configured to engage threadedly with the drive rod section 38 of the preferred motor shaft drive element 36.Thus, the rotation of the motor shaft 30 drives the coil 50, which, as described above, due to the interaction of the thread(s) on the rotating drive element 36 with the thread(s) of the threaded bore 56 along the axis A. C to move.

[0022] In the coil-type valve 11A, the valve body 12 preferably further comprises a sleeve 60 with respective inner and outer circumferential surfaces 61A, 61B, wherein the inner surface 61A defines a central bore 62 that provides a section of the vent passage 22. The sleeve 60 further has first and second openings 63, 64, each extending between the inner and outer surfaces 61A, 61B. The first opening 63 is fluidly connected to the vent inlet opening 23, and the second opening 64 is fluidly connected to the vent outlet opening 24. Preferably, the sleeve 60 is made of hardened steel (e.g., approximately 54 on the Rockwell C scale), and the openings 63, 64 have relatively large dimensions, for example, a diameter of approximately 25 hundredths of an inch (0.25").Such relatively large openings 63, 64 minimize wear of the valve components, increase valve reliability by ensuring sufficient flow of stiffer lubricants, such as high-viscosity grease, and reduce the clogging potential of the valve 10. Furthermore, in such a valve sleeve 60, the coil rod 52 of the closure element is at least partially arranged in the sleeve bore 62, wherein the bore 62 and the rod 52 are preferably dimensioned relative to each other to provide a radial clearance in the range of three to five micrometers (0.001 mm - 0.003 mm). Due to this minimal clearance, leakage of lubricant between the coil 50 and the sleeve 60 is essentially prevented.

[0023] Furthermore, the spool rod 52 is positioned to essentially block at least one of the first and second openings 63, 64 when the locking element 14 is in the closed position P C is located, and preferably only the first opening 63, as in Fig. 4B and Fig. 6 shown. Due to the lubricant pressure in the first opening 63, which acts on the coil 50 in a direction perpendicular to the axis A C When pressure is exerted on the locking element, the pressure cannot drive the locking element 14 back, so the motor 16 does not have to exert any torque on the locking element 14 to keep the element 14 in the closed position P. C to hold. When the locking element 14 is in the open position P OThe coil rod 52 is positioned at an upward distance from both sleeve openings 63, 64. Thus, the vent inlet and vent outlet openings are fluidly connected to each other through the openings 63, 64 and a section of the sleeve bore 62, as shown in Fig. 3, Fig. 4A and Fig. 5 shown.

[0024] With reference to Fig. In a second preferred embodiment, the vent valve 10 is a disc-type valve 11B, wherein the closing element 14 is a disc valve 70 and the valve body 12 has a seat surface 72 that extends circumferentially around a section of the valve vent passage 22. The disc valve 70 comprises an elongated rod 73 with a center line 74, an outer circumferential surface 75, and first and second ends 73a, 73b, which are spaced apart from each other along the center line 74. The outer surface 75 has a tapered surface 76 at the first, lower end 73a of the rod, which can engage with the valve seat surface 72 when the closing element 14 is in the closed position P. CThe valve 70 is located to essentially prevent flow through the vent passage 22. Furthermore, the poppet valve 70 also includes a generally cylindrical actuator 78, which is attached to the second, upper end 73b of the elongated rod 73. The actuator 78 has a threaded bore 79 that provides the threaded section 26 of the closure element and has a circular flange 80 that slides in an inner guide surface 81 of the valve body 12.

[0025] Preferably, the valve body 12 comprises a generally cylindrical insertion element 82, which is arranged in the vent passage 22 and has two opposite upper and lower ends 82a, 82b and a central bore 84 extending between the two ends 82a, 82b. The vent inlet and vent outlet openings 23, 24 are fluidically connected through the bore 84 when the poppet valve 70 is in the open position P. Ois located, as in Fig. 10, Fig. 11A and Fig. Figure 12 shows that the upper end 82a of the insertion element 82 has an annular surface that extends circumferentially around the central bore 84 and provides the valve seat surface 72. With this structure, the lower end 73a of the poppet valve stem 73 penetrates when the closing element 14 is in the closed position P. CThe valve body 70 is inserted into the upper end of the insertion bore 84 until a portion of the tapered section 76 abuts the insertion surface 85 to substantially seal the vent passage 22. Preferably, the poppet valve 70 and the valve insertion element 82 are made of hardened steel, most preferably with a hardness of approximately 55 on the Rockwell C scale (55 RC) to minimize erosion of these valve components. Furthermore, in the poppet-type valve 11B, the valve body 12 preferably comprises a generally cylindrical guide element 86 with a central opening 87 dimensioned to receive the poppet valve stem 73. Thus, the opening 87 guides the sliding movement of the stem 73 as the stem 73 moves between the open and closed positions P. O , P C the locking element is linearly offset.

[0026] With reference to Fig. In a third, currently most preferred design, the vent valve 10, as described in Figures 15-21, is again a coil-type valve 11C, similar to the first valve design 11A, wherein the closing element 14 is a coil 100. The coil 100 comprises a cylindrical rod 102 with a centerline 103, respective inner and outer circumferential surfaces 104, 105, and two ends 106A, 106B spaced apart along the centerline 103. The inner surface 104 is threaded to form a threaded bore 108 extending inward from the upper, open end 106A, generally along the centerline 103, to the lower, closed end 106B. The threaded bore 108 provides, as described above, the threaded section 26 of the locking element and is dimensioned and configured to engage in threaded engagement with the drive rod section 38 of the preferred motor shaft drive element 36.Thus, the rotation of the motor shaft 30 drives the coil 100, which, as described above, due to the interaction of the thread(s) on the rotating drive element 36 with the thread(s) of the threaded bore 108 along the axis A. C to move.

[0027] Furthermore, the rod 102 is preferably formed with an undercut central section 110, which is defined between upper and lower radially larger closure sections 112, 114. Each of the upper and lower closure sections has a surface section 113, 115, which is dimensioned to fit relatively tightly (i.e., by sliding fit) into the inner circumferential surface 118A of a valve sleeve 116, as described below. The undercut rod section 110 has a surface section 111, which is spaced radially inward from the inner surface 118 of the sleeve to define an annular flow channel 120, as described in more detail below.

[0028] In the coil-type valve 11C, the valve body 12 preferably comprises a generally tubular sleeve 116 with respective inner and outer circumferential surfaces 118A, 118B, wherein the inner surface 118A defines a central bore 122 that provides a section of the vent passage 22. The sleeve 116 further comprises first and second openings 124, 126, each extending between the inner and outer surfaces 118A, 118B. The first opening 124 is fluidly connected to the vent inlet opening 23, and the second opening 126 is fluidly connected to the vent outlet opening 24. Preferably, the sleeve 116 is made of hardened steel (e.g.,approximately 54 on the Rockwell C scale), and the orifices 124, 126 have relatively large dimensions, for example a diameter of approximately 25 hundredths of an inch (0.25''), in order to minimize wear of the valve components, increase valve reliability and reduce the risk of clogging described above in connection with the first valve design.

[0029] In such a valve sleeve 116, the coil rod 102 of the closure element is at least partially arranged in the sleeve bore 122, wherein the bore 122 and the rod 102 are preferably dimensioned relative to each other to provide a radial clearance in the range of three micrometers and five micrometers (0.001 mm - 0.003 mm) between each of the closure surface sections 113, 115 and the inner sleeve surface 118A. This minimal clearance essentially prevents lubricant from escaping between the coil 100 and the sleeve 116. However, the valve 11C preferably includes upper and lower circular sealing elements 128, 129 (e.g., O-ring seals) arranged around the upper and lower closure sections 112, 114 to provide additional leakage protection.

[0030] Furthermore, the spool rod 102 is positioned to essentially block at least one of the first and second openings 124, 126 when the locking element 14 is in the closed position P C is located, and preferably only the first opening 126, as in Fig. 17B and Fig. Figure 19 shows that, unlike the coil valve of the first design 11A, a quantity of lubricant remains in the annular flow channel 120 and exerts uniform pressure on the upper and lower sealing sections 112, 114 of the rod. Thus, the lubricant cannot drive the coil 100 back or otherwise displace it when the coil 100 is in the closed position P. C is located so that no torque is required to move the coil 100 into the closed position P C to hold. When the locking element 14 is in the open position P OThe spool rod 102 is positioned such that the undercut section 110 extends over both of the first and second sleeve openings 124, 126, as shown in Fig. Figure 18 best shows this. Thus, the vent inlet and outlet openings 23, 24 are fluidly connected to each other via the sleeve openings 124, 126 and the annular flow channel 120, as shown in Fig. 16, Fig. 17A and Fig. 18 shown. Unlike the first two valve designs 11A, 11B, the coil 102 of the third valve design 11C is still preferably generally displaced in an upward direction when it is between the open position P O ( Fig. 18) and the closed position P C ( Fig. 19) is moved.

[0031] With reference to Fig. 15-17, 20 and 21, the motor shaft 30 of the third valve assembly 11C is provided for the improved use of high-viscosity lubricants, preferably with a gear drive 130, to enhance the torque transmission from the rotor shaft 31 to the drive element 36 and the coil 100. As in Fig. 20 and Fig. As best shown in Figure 21, the gear transmission 130 is preferably a planetary gear transmission with a sun gear 132 mounted on an input element 133 attached to the motor rotor shaft 31, and a plurality of planet gears 134, preferably three gears 134. The planet gears 134 are arranged around and thus meshed with the sun gear 132 and are rotatably mounted on an output element 135. The output element 135 has a shaft section 135 connected to the input element 36, and a fixed ring gear 136 is arranged around and thus meshed with all the planet gears 134. The gear train 130 is configured such that rotation of the motor shaft 131 rotates the input element 131 and the fixed sun gear 132, causing the engaged planet gears 134 to rotate around the sun gear 132 and within the fixed ring gear 136.Since the planet gears 134 rotate around the sun gear 132, the fixed output element 135 rotates around the central axis A. C the shaft rotated, which in turn rotates the drive element 36 around the axis A C is rotated to rotate the coil 100 along axis A C to be displaced linearly. Preferably, the gear drive 130 is contained in a gearbox 138 which is mounted on the motor 16, wherein the drive element 36 extends through a gearbox opening 140 and is connected to the output element 135.

[0032] With reference to Fig. 7, Fig. 8 and Fig. In all three valve designs 11A, 11B, and 11C, the control unit 40 preferably comprises a microcontroller 90, first and second input terminals 92A and 92B connected to the microcontroller 90, and at least one, and preferably two, motor coil driver circuits 94. Each driver circuit 94 is connected to the microcontroller 90, to a separate coil (not shown) of the motor 16, and to the power supply 42, so that the driver circuits 94 continuously receive an electrical voltage (preferably at 24 V). The first terminal 92A is connected to the power supply (not shown), and the second terminal 92B is connected to the lubrication control unit 4. In this configuration, the first input I1 is a voltage signal S. V , which is received by the microcontrol unit 90 via the first terminal 92A, and the second input I2 a combination of the voltage signal S Vvia the first connection 92A and a control signal S C , which is received by the micro control unit 90 through the second connection 92B.

[0033] Furthermore, the microcontroller 90 is programmed to operate the motor coil driver circuits 94 such that electrical current is conducted to flow through the motor coils (not shown) in one direction when the microcontroller 90 receives the first input I1, and current is conducted to flow through the motor coil in the opposite direction when the microcontroller 90 receives the second input I2. More precisely, the relief valve 10 is preferably a "normally open" valve, with the closing element 14 in the open position P. Ois arranged and the controller 40 continuously receives the first input I1, in particular twenty-four volts (24 V), whereby the motor driver circuit(s) 94 are always energized. When a lubrication cycle is initiated by the lubrication system 1, the relief passage 22 must be closed so that the lubrication control unit 4 receives a control signal S C The signal is sent to the microcontroller 90, which is received via the second input terminal 92B, so that the microcontroller 90 receives the second input I2. The microcontroller 90 then operates the driver circuit(s) 94 to supply current to the motor coils in the first current direction until the motor shaft 30 has completed the predetermined number of rotations to move the locking element 14 into the closed position P. C to move.

[0034] In the disc-type valve 11B, the motor 16 preferably includes an integrated encoder 95, which is connected to and configured with the controller 40 to detect the rotary movement of the motor shaft 40. The controller 40 is configured by the encoder 95 to determine, based on inputs received from the encoder 96, whether the closing element 14 is in the closed position P. C is located to ensure that the poppet valve 70 is engaged with the valve seat surface 72. When the poppet valve 70 is engaged, the encoder 95 sends a signal to the microcontroller 90 to indicate that the closed position P is reached. Cwas achieved, and preferably the microcontrol unit 90 then drives the driver circuit(s) 94 to provide a substantially lower current for the motor coil(s), sufficient to cause the motor 16 to exert a minimal torque on the poppet valve 70. Such a minimal torque may be required to prevent the poppet valve 70 from being forced back, as the lubricant pressure in the bore 84 of the insertion element increases in a direction along axis A. C of the locking element and towards the open position P O is applied to the plate valve 70.

[0035] When the lubrication system 1 reaches a certain pressure, the lubrication control unit 4 sends a signal to the pump 3 so that it stops pumping lubricant from supply 2 and stops sending the control signal S. Cto the vent valve control 40. Thus, the micro control unit 90 determines that the only input is the first input I1, and that the closing element 14 is in the closed position P. C is located. In response, the microcontrol unit 90 then drives the driver circuit(s) 94 to provide current to the motor coils in the second current direction until the motor shaft 30 has made the predetermined number of rotations to move the locking element 14 into the open position P. O to move.

[0036] In coil-type valve designs 11A and 11C, the valve 10 further comprises a sensor 96, preferably a switch, which is connected to and configured with the control 40 to sense whether the coil 50 is in the open position P O (first construction 11A, Fig. 3) or in the closed position P C (third construction 11A, Fig. 16). As in Fig. 3 and Fig. As shown in Figure 16, the switch 96 is preferably a reed switch comprising a detector magnet 97 connected to the coil 50 and a switching element 98 arranged in the valve body 12 to be activated by the magnet 97 when the coil 50 is in the open position P O ( Fig. 3) or alternatively in the closed position P C ( Fig. 16). This allows the microcontrol unit 90 to reliably determine whether the coil-type valve 11A is in one of the predetermined positions P O or P C is located, and then drive the preferred stepper motor 16 so that it rotates the shaft 30 a suitable number of turns to move the locking element 14 linearly to the other position P C , P Oto be moved. Subsequently, with one of the valve types 11A, 11B or 11C, the control unit 40 continues to receive the first input I1 from the power supply 42 and the valve closure element 14 is in the open position P. O remain until another lubrication cycle is initiated in lubrication system 1.

[0037] Those skilled in the art will understand that modifications can be made to the embodiments described above without departing from their broad inventive concept. It is therefore self-evident that this invention is not limited to the specific disclosed embodiments, but is intended to cover modifications within the scope of the spirit and protection of the present invention in accordance with the present general definition and the accompanying claims.

Claims

[1] Vent valve for a lubrication system (1) wherein the lubrication system (1) comprises a lubricant supply (2) and a lubricant dispenser (5) wherein the vent valve comprises: a valve body (12) with a flow passage (18), wherein the flow passage (18) has an inlet (19) fluid-connected to the supply and an outlet fluid-connected to the dispenser, and a vent passage (22) comprising an inlet opening (23) fluid-connected to the flow passage (18) and an outlet opening (24); a closure element (14) that is at least partially arranged in the vent passage (22), has a threaded section (26) and is linearly displaceable between an open position in which the vent inlet (23) and the vent outlet (24) are fluidly connected to allow lubricant to flow from the primary passage and from the valve body (12) through the vent outlet (24), and a closed position in which fluid flow between the vent inlet (23) and the vent outlet (24) is substantially prevented; and a motor (16) with a shaft (30) rotating around a central axis (A M ) is rotatable, wherein the shaft (30) has a threaded section (32) which is threaded in engagement with the threaded section (26) of the locking element (14), so that by rotating the shaft (30) in a first direction about the central axis (A M) the locking element (14) is moved towards the closed position, and by rotating the shaft (30) in a second, opposite direction around the axis the locking element (14) is moved towards the open position. [2] Venting valve according to claim 1, wherein the threaded section (32) of the motor (30) and the threaded section (26) of the closure element (14) are configured such that the engagement of the two threaded sections (26, 32) substantially prevents the closure element (14) from being displaced when the closure element (14) is subjected to a lubricant pressure. [3] Venting valve according to claim 1, further comprising a control (40) which is operatively connected to the motor (16) and configured to drive it in order to controllably move the closure element (14) between the open and closed positions. [4] Vent valve according to claim 3, wherein the control (40) is configured to receive a first and a second input to drive the motor (16) to rotate the shaft (30) in the first direction (R1, R2) when the control (40) receives the first input and the closure element (14) is in the open position, and to drive the motor (16) to rotate the shaft (30) in the second direction (R1, R2) when the control (40) receives the second input and the closure element (14) is in the closed position. [5] Venting valve according to claim 4, wherein the first input is a voltage signal (S V ) from a power supply and the second input is a combination of the power supply voltage signal and a control signal (S C ) from a lubrication system control unit. [6] Vent valve according to claim 4, wherein the motor (16) is a stepper motor and the controller (40) is configured to drive the motor (16) to perform a predetermined number of rotations about the axis in the first direction (R1, R2) when the controller (40) receives the first input and the closure element (14) is in the open position, and to drive the motor (16) to perform a predetermined number of rotations about the axis in the second direction (R1, R2) when the controller (40) receives the second input and the closure element (14) is in the closed position. [7] Vent valve according to claim 4, wherein the control (40) comprises a micro control unit (90), a first and a second connection which are connected to the micro control unit (90), wherein the first connection is connectable to a power supply and the second connection is connectable to a lubrication control unit (4), and at least one motor coil driver circuit (94) which is connected to the micro control unit (90) and a coil of the motor (16). [8] Venting valve according to claim 7, wherein: the first input is a signal received by the control unit via the first port, and the second input is a combination of a signal received by the control unit via the first port and a signal received by the control unit via the second port; and the micro control unit (90) is programmed to actuate the motor coil driver circuit (94) so ​​that current is conducted to flow through the motor coil in one direction (R1, R2) when the controller (40) receives the first input, and current is conducted to flow through the motor coil in another, opposite direction (R1, R2) when the controller (40) receives the second input. [9] Vent valve according to claim 4, further comprising a sensor (96) which is connected to the control (40) and configured to sense whether the closure element (14) is in the open position or in the closed position. [10] Vent valve according to claim 1, wherein the motor (16) is a stepper motor configured to rotate the motor shaft (30) a predetermined number of turns about the axis so that it moves the closure element (14) between the open and closed positions. [11] Venting valve according to claim 3, wherein the motor (16) comprises an encoder (95) which is connected to and configured with the control unit (40) to detect the rotational displacement of the motor shaft (30), wherein the control unit (40) is configured to determine, based on an input received from the encoder (95), whether the closure element (14) is in the closed position. [12] Venting valve according to claim 1, wherein one of the threaded section (32) of the motor (16) and the threaded section (26) of the closure element (14) has an outer circumferential surface (34) with at least one external thread (35), and the other of the threaded section (32) of the motor (16) and the threaded section (26) of the closure element (14) has an inner circumferential surface with at least one internal thread. [13] Venting valve according to claim 1, wherein the motor shaft (30) has a rotor shaft (31) with an outer end (31a) and a drive element (36) which is connected to the outer end (31a) of the shaft and provides the threaded section (32) of the shaft (30). [14] Venting valve according to claim 13, wherein the motor shaft (30) comprises a gear drive (130) connecting the rotor shaft to the driver element. [15] Vent valve according to claim 1, wherein the closure element (14) comprises a cylindrical rod with a center line (53), two ends (55A, 55B) spaced apart from each other along the center line (53) and a threaded bore (56) extending inwards from one of the two ends (55A, 55B) substantially along the center line (53) to the other of the two ends (55A, 55B), wherein the threaded bore (56) provides the threaded section (26) of the closure element (14). [16] Venting valve according to claim 15, wherein: the valve body (12) a sleeve (60) with an inner and an outer circumferential surface (61A, 61B), wherein the inner surface (61A, 61B) defines a central bore (62) providing a section of the vent passage (22), and comprises a first and a second opening (63, 64) extending between the inner and outer surfaces (61A, 61B), respectively, wherein the first opening (63, 64) is fluidly connected to the vent inlet opening (23) and a second opening (63, 64) is fluidly connected to the vent outlet opening (24); and the rod of the locking element (14) is at least partially arranged in the sleeve (60) so that it substantially blocks at least one of the first and second openings (63, 64) when the locking element is in the closed position. [17] Venting valve according to claim 1, wherein: the valve body (12) comprises a valve seat surface (72) which extends circumferentially around a section of the valve vent passage; and the closure element (14) comprises an elongated rod, the rod having a center line (53), a first and a second end (55A, 55B) spaced apart from each other along the center line (53), the first end (55A, 55B) having a tapered surface which can engage with the valve seat surface (72) when the closure element (14) is in the closed position to substantially prevent flow through the vent passage (22), and comprising a cylindrical drive element (36) which is attached to the second end (55A, 55B) of the elongated rod and which has a threaded bore (56) which provides the threaded section (26) of the closure element (14). [18] Vent valve according to claim 17, wherein the valve body (12) comprises a generally cylindrical insertion element (82) arranged in the vent passage (22) and having two opposite ends (82a, 82b) and a central bore (84) extending between the two ends (82a, 82b), wherein the bore (84) fluidly connects the vent inlet opening (23) and the vent outlet opening (24), and wherein one end (82a, 82b) of the insertion element (82) has an annular surface extending circumferentially around the central bore (84) and providing the valve seat surface (72). [19] Vent valve for a lubrication system (1) wherein the lubrication system (1) comprises a lubricant supply (2) and a lubricant dispenser (5), wherein the vent valve comprises: a valve body (12) with a flow passage (18), wherein the flow passage (18) has an inlet (19) fluid-connected to the supply and an outlet fluid-connected to the dispenser, and a vent passage (22) comprising an inlet opening (23) fluid-connected to the flow passage (18) and an outlet opening (24); a closure element (14) that is at least partially arranged in the vent passage (22) and is linearly displaceable between a closed position in which fluid flow between the vent inlet opening (23) and the vent outlet opening (24) is substantially prevented, and an open position in which the vent inlet opening (23) and the vent outlet opening (24) are fluidly connected to allow lubricant to flow from the primary passage and out of the body through the vent outlet opening (24); a motor (16) with a shaft (30) rotating around a central axis (A M ) is rotatable, wherein the shaft (30) is engaged with the locking element (14), such that by rotating the shaft (30) in a first direction (R1, R2) about the axis the locking element (14) is moved towards the open position, and by rotating the shaft (30) in a second, opposite direction (R1, R2) about the axis the locking element (14) is moved towards the closed position; and a controller (40) which is operatively connected to and configured with the motor (16) to receive a first and a second input in order to drive the motor (16) so that it rotates the shaft (30) in the first direction (R1, R2) when the controller (40) receives the first input and the locking element (14) is in the open position, and to drive the motor (16) so that it rotates the shaft (30) in the second direction (R1, R2) when the controller (40) receives the second input when the locking element (14) is in the closed position. [20] Venting valve according to claim 19, wherein the closure element (14) has a threaded section (32) and the motor shaft (30) has a threaded section (32) which engages with the threaded section (26) of the closure element (14) so ​​that by rotating the motor shaft (30) the closure element (14) is linearly displaced.

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