SE536848C2 - Valve for controlling fat supply - Google Patents

Abstract

18 ABSTRACT According to an aspect of the invention, a valve (1) for controlling supply ofgrease is provided. A gap (140) is defined between a circumference of aclosing member (130) and an inner wall of a chamber (105) for admitting aflow of grease when the closing member moves between a closed positionand an open position. Further, a passage (135) extends through the closingmember and/or in the housing for admitting a flow of grease betweenopposite sides of the closing member when the closing member movesbetween the closed and open positions. The valve is adapted such that a flowof grease occurs in the gap when the closing member moves towards one ofthe closed and open positions, which flow is larger than a flow of grease inthe gap occurring when the closing member moves towards the other one ofthe closed and open positions. A circulation ofgrease is created in thechamber for reducing accumulation of grease in dead spaces. (Figure 1a)

Description

AWAPATENT AB Kontor/HandläggareStockholm/Åsa Hagström/AHM PMC Lubrication AB Vår referens SE-21059573 VALVE FOR CONTROLLING SUPPLY OF GREASE Field of the invention The present invention generally relates to the field of valves for controlling supply of grease.

Backqround of the invention Lubrication systems are used in various machines and vehicles to supplylubrication to moving mechanical parts. Such lubrication systems normallycomprise electrically controlled valves for controlling supply of lubricanttowards the points where lubrication is desired (also referred to as lubrication points).

Grease is commonly used as lubricant in such lubrication systems. Whengrease is accumulated in dead spaces of the lubrication system (i.e. spaceswithout a constant flow of grease) and subjected to high pressures, it tends toseparate into its two basic components: oil and soap. Such dead spaces maybe present e.g. in the valves for controlling the supply of lubricant, and soapfrom separated grease may clog the valve, thereby interfering, or even interrupting, the operation of the valve.

US6260664 shows a lubrication valve comprising vents for preventingaccumulation of grease residue in the valve, which grease residue mayinterfere with the closing of the valve. A drawback with such a lubricationvalve is that one or more additional venting bodies (or parts) comprising thevents has to be mounted to the existing valve, thereby increasing the numberof additional components required in the lubrication valve. Further, such alubrication valve requires an arrangement for gathering drained grease from the vents, which renders the implementation even more difficult.

Summary of the invention Thus, there is a need for providing alternatives and/or new devices that wouldovercome, or at least alleviate or mitigate, at least some of the abovementioned drawbacks. lt is with respect to the above considerations that thepresent invention has been made. An object of the present invention is toprovide an improved alternative to the above mentioned technique and priorart. More specifically, it is an object of the present invention to provide a valvefor controlling supply of grease with a reduced risk of operation failure.

These and other objects of the present invention are achieved by means of avalve having the features defined in the independent claim. Preferableembodiments of the invention are characterized by the dependent claims.

Hence, according to an aspect of the present invention, a valve for controllingsupply of grease is provided. The valve comprises a housing, in which achamber is defined, and a closing member movably arranged within thechamber between an open position, in which a main flow of grease isadmitted, and a closed position, in which the main flow of grease is blocked.A gap is defined between the circumference of the closing member and aninner wall of the chamber for admitting a flow of grease when the closingmember moves between the closed and open positions. Further, at least onepassage extends through the closing member and/or in the housing foradmitting a flow of grease between opposite sides of the closing memberwhen the closing member moves between the closed and open positions. Thevalve is adapted such that a flow of grease occurs in the gap when theclosing member moves towards one of the closed and open positions, whichflow is larger than a flow of grease in the gap occurring when the closing member moves towards the other one of the closed and open positions.

Movement of the closing member (which also may be referred to as a sealingmember or closing body) in the chamber causes movement of grease in thechamber. When the closing member moves between the closed and open positions, a flow of grease is induced (or created) in the gap and/or in the 3passage in a direction opposite to the direction of movement of the closing member, as grease is displaced in front of the moving closing member.

The present invention uses the concept of creating a circulation of grease inthe chamber for reducing accumulation ofgrease in dead spaces. The valveis adapted such that the flow of grease in the gap created when the closingmember moves in one direction (i.e. towards one of the closed and openpositions) is larger than the flow of grease in the gap occurring when theclosing member moves in the opposite direction (i.e. towards the other one ofthe closed and open positions), which flow even may be zero. For example,the valve may comprise means for reducing (alternatively increasing) the flowof grease in the gap in a first flow direction compared to a flow of grease inthe gap in a second direction opposite to the first direction. Hence, the flow ofgrease in the gap is larger in one direction compared to the oppositedirection, which in the following may be referred to as an asymmetric flow.The asymmetric flow in the gap may further create a correspondingasymmetric flow in the passage. A larger flow in the gap in one direction(such as from one side to an opposite side of the closing member) may implya correspondingly smaller flow in the passage in the same direction (i.e. fromsaid one side to the opposite side of the closing member). As the size of theflow in the gap, and consequently also in the passage, is direction dependent,circulation of grease in the chamber is facilitated. The grease is forced tocirculate through the gap and then through the passage in a certaincirculation direction, instead of merely reciprocating back and forth in the gapand/or the passage. Hence, a repeated movement of the closing member causes the grease to circulate in the chamber (and the passage).

The circulation ofgrease reduces dead space in the valve, where grease maybe accumulated and subjected to high pressure. This reduces the risk ofgrease separating into oil and soap, which in turn reduces the risk of soap clogging the valve possibly causing operation failure.

Further, the present invention is advantageous in that additional venting parts(as used in prior art) for draining accumulated grease from the chamber maynot be required. 4The passage (which also may be referred to as a channel) may be arranged to fluidly connect (i.e. allow a flow of grease between) portions (orcompartments) of the chamber located at opposite sides of the closingmember, and may thus be defined in the closing member and/or in thehousing. lt will be appreciated that the main flow of grease may be a flow of greasetowards a lubrication point (e.g. in a lubrication system), which main flow iscontrolled by the valve according to the present invention. ln the following, several embodiments will be described for facilitating theabove described asymmetric flow in the gap.

According to an embodiment of the present invention, the gap may be at leastpartially tapered, thereby facilitating flow of grease in the gap in the taperingdirection (i.e. the direction in which the gap gets narrower). The taperedshape of the gap may further inhibit flow of grease in the direction opposite tothe tapering direction. Hence, the flow of grease in the gap in the taperingdirection created when the closing member moves towards one of the closedand open positions is larger (as it is facilitated) compared to the flow ofgrease in the gap in the direction opposite to the tapering direction createdwhen the closing member moves towards the other one of the closed andopen positions. ln the present specification, the term “tapered” is to be widely interpreted andmay not just include a continuous narrowing conical shape, but any shapebeing gradually (or stepwise) narrower in a certain direction. ln an embodiment, the closing member may have an at least partially taperedshape in order to define a tapered gap between the closing member and theinner wall of the chamber. The present embodiment is advantageous in thatmanufacturing of the valve is facilitated, as the closing member with an atleast partially tapered shape may be used together with a housing having astandard cylindrical chamber. Alternatively, or as a complement, at least aportion of the chamber may be tapered in order to define the tapered gap. 5An alternative (or complementing) way of influencing the flow in the gap is to influence the flow of grease in the passage. ln a particular direction ofmovement of the closing member, a smaller flow in the passage implies alarger flow in the gap, as a constant amount of grease is displaced by theclosing member. When the flow of grease is inhibited in the passage, a largerflow is forced through the gap. Hence, the size of the flow in the passage maybe direction dependent (asymmetric), thereby also making the flow in the gap direction dependent.

For example, the passage (in the closing member and/or in the housing) maybe at least partially tapered, thereby facilitating flow of grease in the passagein the tapering direction (i.e. the direction in which the passage getsnarrower). The tapered shape of the passage may further inhibit flow of grease in the direction opposite to the tapering direction.

According to another example, a check valve may be arranged in thepassage so as to inhibit flow of grease in one direction in the passage.Several passages may be defined in the closing member and/or in thehousing, wherein merely one may be provided with a check valve foradmitting a total flow of grease in the passages being larger in one direction compared to the opposite direction.

According to an embodiment of the present invention, an edge may bearranged at the inner wall of the chamber, the edge being adapted to inhibitflow of grease in the gap when the closing member moves towards said otherone of the closed and open positions (i.e. in the movement direction of theclosing member wherein the flow of grease is reduced in the gap). The edgemay be adapted to remove (or scrape off) grease from the closing member in one of the movement directions of the closing member. ln an embodiment of the present invention, the circumference of the closingmember and an inner wall of the chamber may be shaped such that the innerwall of the chamber is adapted to guide the closing member towards theclosed position. Hence, the size and shape of the gap may be adapted so asto admit a flow of grease in at least one direction while still allowing a guided 6movement of the closing member towards (and preferably also away from) the closed position.

According to an embodiment of the present invention, a first compartment (orspace) of the chamber may be defined between a first end of the closingmember and the inner wall of the chamber and a second compartment (orspace) of the chamber may be defined between a second end of the closingmember (e.g. opposite to the first end) and the inner wall of the chamber.Further, an in|et for the main flow of grease to the second compartment of thechamber and an outlet for the main flow of grease from the secondcompartment of the chamber are defined in the housing. ln other words, theclosing member divides the chamber into two compartments. The closingmember may thus close the main flow of grease by closing the in|et to and/or outlet from the second compartment. ln an embodiment, the gap and the passage may be adapted to admit flow ofgrease between the first and second compartments when the closing membermoves between the closed and open positions. Hence, when the closingmember moves towards the closed position, grease flows through the gapand/or the passage to the first compartment, and when the closing membermoves towards the open position, grease flows through the gap and/or thepassage to the second compartment, whereby grease is moved (or displaced)between the first and second compartments. Due to the asymmetrical flow inthe gap, grease will be forced to circulate through the gap, the firstcompartment, the passage and the second compartment (or in the reversedorder), as the closing member moves back and forth.

According to an embodiment of the present invention, a lubrication system isprovided. The lubrication system comprises a valve as defined in any one of the preceding embodiments.

Further objectives of, features of, and advantages with, the present inventionwill become apparent when studying the following detailed disclosure, thedrawings and the appended claims. Those skilled in the art realize that 7different features of the present invention can be combined to create embodiments other than those described in the following.

Brief description of the drawinqs The above, as well as additional objects, features and advantages of thepresent invention, will be better understood through the following illustrativeand non-limiting detailed description of preferred embodiments of the presentinvention, with reference to the appended drawings, in which: Figures 1a and 1b show a valve according to an embodiment of the present invenfion; Figures 2a and 2b show a valve according to another embodiment of the present invention; Figures 3a and 3b show a valve according to yet another embodiment of the present invention; and Figure 4 shows a valve according to yet another embodiment of the present invenfion.

All the figures are schematic, not necessarily to scale, and generally onlyshow parts which are necessary in order to elucidate the invention, wherein other parts may be omitted or merely suggested.

Detailed description of embodiments With reference to Figures 1a to 3b, three valves for controlling supply ofgrease according to different embodiments of the present invention will bedescribed. Each valve has a closing member and Figure 1a, 2a and 3aillustrate when the closing member moves towards a closed position andFigure 1b, 2b and 3b illustrate when the closing member moves towards an open position. ln order to clearly illustrate the function of each valve, the illustrations aresimplified and may not be according to scale, e.g. some dimensions may be exaggerated in order to illustrate certain features. 8A valve 1 according to a first embodiment of the present invention will be described with reference to Figures 1a and 1b.

The valve 1 comprises a housing 100, in which a chamber 105 is defined.The closing member 130 is movably arranged within the chamber 105 anddivides the chamber 105 into a first compartment 110, defined between a firstend 131 of the closing member 130 and an inner wall of the chamber 105,and a second compartment 120 defined between a second end 132 of theclosing member 130 and an inner wall of the chamber 105. The secondcompartment 120 has an in|et 121 and an outlet 122 for admitting a main flowof grease to enter and exit the second compartment 120, respectively.

The closing member 130 is arranged to reciprocate between an openposition, in which the main flow of grease is admitted through the in|et 121and outlet 122 of the second compartment 120, and a closed position, inwhich the main flow of grease is blocked. For example, the closing member130 may be adapted to seal (or block) the outlet 122 in order to block themain flow of grease. When the closing member 130 is in the open position,the main flow of grease is admitted towards a lubrication point. The outlet 122may also be referred to as the valve seat.

A gap 140 is defined between the circumference of the closing member 130and an inner wall of the chamber 105 for admitting a flow of grease betweenthe first and second compartments 110, 120 (i.e. between opposite sides ofthe closing member 130). The gap 140 may partially or entirely surround theclosing member 130. Further, at least one passage 135 is defined in theclosing member 130 extending between the first and second compartments110, 120 for admitting a flow of grease there between (i.e. between oppositesides of the closing member 130). The passage may alternatively (or as acomplement) be arranged in the housing for admitting a flow of greasebetween the first and second compartments (not shown). Hence, the passagemay extend in the housing from the first compartment to the second compartment. 9When the closing member 130 moves in the chamber 105, grease is displaced, and a flow of grease is created in the chamber 105. The valve 1 isadapted such that a flow (indicated by arrows 162 in Figure 1a) ofgreaseoccurs in the gap 140 when the closing member 130 moves towards one ofthe closed and open positions, which flow is larger than a flow (indicated byarrows 165 in Figure 1b) of grease in the gap 140 occurring when the closingmember 130 moves towards the other one of the closed and open positions.Hence, the flow of grease in the gap 140 is larger in one direction comparedto the opposite direction, which may be referred to as an asymmetric flow.The asymmetric flow may be obtained by facilitating flow of grease in the gap140 or in the passage 135 in one direction compared to the oppositedirection. ln the present embodiment, the asymmetric flow is obtained by the gapentrance from the second compartment 120 being wider than the gapentrance from the first compartment 110, whereby the flow of grease(indicated by arrows 162 in Figure 1a) in the gap 140 created when theclosing member 130 moves towards the closed position (i.e. the flow indirection from the second compartment 120 to the first compartment 110) isfacilitated and the flow ofgrease (indicated by arrows 165 in Figure 1a) in thegap 140 created when the closing member 130 moves towards the openposition (i.e. the flow in direction from the first compartment 110 to the secondcompartment 120) is inhibited (or restrained). As the total flow of greasebetween the first and second compartments is the same for both movementdirections of the closing member 130, the flow of grease in the passage 135is consequently larger when the closing member 130 moves towards theopen position compared to when the closing member 130 moves towards theclosed position (as indicated by arrow 164 and arrow 161, respectively, inFigures1a and 1b).

For example, the gap 140 may have a tapered section 136, which is tapered(i.e. gets narrower) in direction from the second compartment 120 towards thefirst compartment 110. ln order to obtain the tapered section 136 of the gap 140, the closing member 130 may be at least partially tapered towards the second end 131. Alternatively (or as a complement), the inner walls of the Chamber may be inclined in order to define a tapered gap between thecircumference of the closing member and the chamber (not shown).Preferably, the tapered section 136 of the gap 140 may be continuouslytapered, such as conically tapered.

A valve 2 according to a second embodiment of the present invention will bedescribed with reference to Figures 2a and 2b. The valve 2 may be equallyconfigured as the valve described with reference to Figures 1a and 1b, exceptthat the asymmetric flow is obtained by the passage entrance from the firstcompartment 210 being wider than the passage entrance from the secondcompartment 220, whereby flow of grease is facilitated in the passage 235from the first compartment 210 to the second compartment 220 and inhibited(or restrained) in the opposite direction. For example, the passage 235 maybe at least partially tapered (i.e. get narrower) in direction from the firstcompartment 210 towards the second compartment 220.

When the closing member 230 moves towards the open position, the flow ofgrease (indicated by arrow 264 in Figure 2b) in the passage 235 is largercompared to the flow of grease (indicated by arrow 261 in Figure 2a) inducedwhen the closing member 230 moves towards the closed position due to thetapered shape of the passage 235. As previously described, in a particulardirection of movement of the closing member 230, a smaller flow in thepassage 235 implies a larger flow in the gap 240, as a constant amount ofgrease is to be displaced by the closing member 230. Hence, when theclosing member 230 moves towards the open position, the flow of grease(indicated by arrows 265 in Figure 2b) in the gap 240 is smaller compared tothe flow of grease induced when the closing member 230 moves towards theclosed position (which flow is indicated by arrows 262 in Figure 2a).

A valve 3 according to a third embodiment of the present invention will bedescribed with reference to Figures 3a and 3b. The valve 3 may be equallyconfigured as the valve described with reference to Figures 1a and 1b, exceptthat the asymmetric flow is obtained by having a check valve 338 arranged inthe passage 336. ln the present embodiment, several passages 336, 337 are 11defined in the closing member 330 connecting the first and second compartments 310, 320. The check valve 338 is arranged in one of thepassages 336 in order to facilitate flow of grease in that passage 336 from thefirst compartment 310 to the second compartment 320 and inhibit flow ofgrease in the opposite direction. Alternatively, a single passage may bedefined in the closing member, wherein a check valve may be arranged inthat passage (not shown). ln similarity with the previously described embodiment (described withreference to Figures 2a and 2b), the flow in the gap 340 is influenced byinfluencing the flow of grease in the passages 336, 337. When the closingmember 330 moves towards the open position, the flow of grease (indicatedby arrows 366, 367 in Figure 3b) in the passages 336, 337 is larger comparedto the flow of grease (indicated by arrow 361 in Figure 2a) induced in thepassages 336, 337 when the closing member 230 moves towards the closedposition, as the check valve 338 opens up by the flow ofgrease in directionfrom the first compartment 310 to the second compartment 320 and closes bythe flow of grease in the opposite direction. Consequently, when the closingmember 330 moves towards the open position, the flow of grease (indicatedby arrows 365 in Figure 3b) in the gap 340 is smaller compared to the flow ofgrease (indicated by arrows 362 in Figure 3a) induced when the closing member 330 moves towards the closed position. ln the above described embodiments, the flow of grease in the gap is larger indirection from the second compartment to the first compartment (which isinduced when the closing member moves towards the closed position)compared to the opposite direction (which is induced when the closingmember moves towards the open position) in order to create a circulation ofgrease in the chamber. Hence, a net flow of grease is forced to circulate fromthe second compartment through the gap to the first compartment and thenthrough the passage back to the second compartment. However, it will beappreciated that the valve alternatively may be arranged such that the flow ofgrease in the gap is larger in direction from the first compartment to thesecond compartment compared to the opposite direction. The net flow of 12grease then circulates in the opposite direction, i.e. from the second compartment through the passage to the first compartment and then throughthe gap back to the second compartment. The means for inducing thecirculation (the tapered gap, the tapered passage and the check valve in thepassage) may then be reversely arranged (i.e. being tapered in the oppositedirection or having the check valve arranged to inhibit flow in the oppositedirection compared to what is described above with reference to Figures 1a to3b).

With reference to Figure 4, a valve 4 according to an embodiment of thepresent invention will be described. The valve 4 may be similarly configuredas the valve described with reference to Figures 1a and 1b.

The valve 4 comprises a housing (or valve body) 400 adapted to be installedin a lubrication system for controlling a main flow of grease from a lubricationsource towards a lubrication point in a machinery. The housing 400comprises a chamber 405, in which a closing member 430 adapted to admitor block the main flow of grease is arranged. ln the present embodiment, thevalve 4 is an electrically controlled solenoid valve having a magnet core 402for controlling the valve 4. The magnet core 402 may be arranged to enclosethe closing member 430 in the chamber 405. Further, an isolation ring 401made of non-magnetic material may be arranged to concentrate magnet flowin the gap between the magnet core 402 and the closing body 430. Theisolation ring 402 reduces the risk of short-cutting magnet flow from themagnet core to the housing 400.

The closing member 430 is fitted within the chamber 405 and is movablebetween a closed position and an open position. Preferably, the closingmember 430 is a cylindrical piston and the chamber 405 has a correspondingcylindrical shape, wherein the closing member 430 may reciprocate in thechamber 405.

The closing member 430 divides the chamber 405 into a first compartment410 defined by a first end 431 of the closing member 430 and the inner wall ofthe chamber 405 and a second compartment 420 defined by a second end 13432 of the closing member 430 and the inner wall of the chamber 405. The main flow of grease enters the second compartment 420 via an in|et 421 andexits the second compartment 420 via an outlet 422. The closing member 430comprises a protruding portion 434 disposed at the second end 432 of theclosing member 430 for biocking (or sealing) the outlet 422, thereby biockingthe main flow of grease.

A spring 403 (or any other resi|ient means) is arranged to force the closingmember 430 towards the closed position. The spring 403 may e.g. bearranged between the magnet core 402 and the closing member 430. Whenthe magnet core 402 is activated, the force of the spring 403 is counteractedand the closing member 430 is pu||ed towards the magnet core 403, wherebythe protruding portion 434 is removed from the outlet 422 and the closingmember 430 is positioned in its open position. When the magnet core 402 isdeactivated, the closing member 430 is pushed back to the closed position bythe spring 403.

The diameter (or cross section) of the closing member 430 is slightly smallerthan the diameter (or cross section) of the chamber 405, whereby a narrowgap 440 is defined between the circumference of the closing member 430 andthe inner wall of the chamber 405 for admitting a flow of grease therebetween. The gap 440 may entirely or partially surround the closing member430. For example, the gap 440 may be confined to a (narrow) channelbetween the closing member 430 and the inner wall of the chamber 405 andthe remaining circumference of the closing member 430 may be arranged in(close) abutment to the inner wall of the chamber 405. However, it isadvantageous to have the gap 440 (at least almost) entirely surrounding theclosing member 430, as grease then is allowed to flow around the entireclosing member 430.

Further, the width of the gap 440 may preferably be adapted such that a flowof grease is admitted in the gap 440 while the inner walls of the chamber 405still guides the closing member 430 in its movement between the closed andopen positions. ln the present embodiment, the gap 440 may not be visible inFigure 4, as it is rather narrow. However, the gap 440 is still wide enough to 14admit a flow of grease between the closing member 430 and the inner wall of the chamber 405. Further, the closing member 430 has a tapered section436, whereby the gap 440 is partially tapered. The tapered portion of the gap440 gets narrower in direction from the second compartment 420 to the firstcompartment 430. For example, the narrowest portion of the gap 440 mayhave a width in the order of 0.1 mm.

An edge 470 is arranged in the gap 440 at the inner wall of the chamber 405.The edge 470 provides a sharp transition between a wider cross section to anarrower cross section of the chamber 405 (in direction from the firstcompartment 410 towards the second compartment 420).

The closing member 430 further comprise a passage 435 extending from thefirst end 431 of the closing member 430 to the second end 432 of the closingmember 430, thereby fluidly connecting the first and second compartments410, 420. Optionally, the spring 403 may be supported, and partiallyarranged, within the passage 435. For example, the narrowest portion of thepassage 435 may have a diameter of around 2 mm. ln the following, operation of the valve 4 will be described. When the closingmember 430 moves towards its closed position (i.e. downwards in Figure 4)grease is displaced in the chamber 405 and a flow of grease is induced in thegap 440 in the tapering direction of the gap 440, from the secondcompartment 420 to the first compartment 410. As the gap 440 is wider at itsentrance from the second chamber 420, flow of grease in direction from thesecond compartment 420 to the first compartment 410 is facilitated. lnaddition, a flow of grease is induced in the passage 435 from the secondcompartment 420 to the first compartment 410. Accordingly, grease istransferred from the second compartment 420 to the first compartment 410through the gap 440 and the passage 435.

When the closing member 430 moves towards its open position (i.e. upwardsin Figure 4) grease is again displaced in the chamber 405. However, as thegap 440 is narrower at its entrance from the first compartment 410 due to thetapered shape of the gap 440, in particular at the edge 470 at the inner wall of the Chamber 405, flow of grease from the first compartment 410 to the second compartment 420 in the gap 440 is inhibited (such as completely or partiallyblocked). The edge 470 removes (or scrapes of) grease from the closingmember 430 when it moves towards the closed position. As the same amountof grease is displaced by the closing member 430 when it moves from theclosed position to the open position as when it moves from the open positionto the closed position, the total flow of grease between the first and secondcompartments 410, 420 is the same in both directions. However, as the flowin the gap 440 is reduced (inhibited) when the closing member 430 movestowards the open position, the flow of grease induced in the passage 435from the first compartment 410 to the second compartment 420 is correspondingly increased. ln conclusion, grease is transported in the gap 440 (i.e. at the circumferenceof the closing member 430) to the first compartment 410 and then transportedthrough (within) the closing member 430 via the passage 435 back to thesecond compartment 420. Thus, a circulation of grease is obtained, whichreduces dead space in the chamber 405. ln particular, accumulation ofstagnated grease in the first compartment 410 is reduced, thereby reducingthe risk of soap, separated from oil in the grease, to cause mal function of thespring 403.

While specific embodiments have been described, the skilled person willunderstand that various modifications and alterations are conceivable within the scope as defined in the appended claims.

For example, the embodiments described above may be combined with eachother in order to create further embodiments. For example, a tapered gapmay be combined with a check valve in the passage and/or a tapered passage etc.

Claims (1)

1. A valve (1) for controlling supply of grease, the valve comprising: a housing (100), in which a Chamber (105) is defined, and a closing member (130) movably arranged within the chamberbetween an open position, in which a main flow of grease is admitted,and a closed position, in which the main flow of grease is blocked, wherein a gap (140) is defined between the circumference of theclosing member and an inner wall of the chamber for admitting a flowof grease when the closing member moves between the closed andopen positions, wherein at least one passage (135) extends through the closingmember and/or in the housing for admitting a flow of grease betweenopposite sides of the closing member when the closing member movesbetween the closed and open positions, and wherein the valve is adapted such that a flow (162) of greaseoccurs in the gap when the closing member moves towards one of theclosed and open positions, which flow is larger than a flow (165) ofgrease in the gap occurring when the closing member moves towards the other one of the closed and open positions. _ The valve as defined in claim 1, wherein the gap is at least partially tapered. _ The valve as defined in claim 1 or 2, wherein the closing member has an at least partially tapered shape. _ The valve as defined in any one of the preceding claims, wherein the passage (235) is at least partially tapered. _ The valve as defined in any one of the preceding claims, wherein a check valve (338) is arranged in the passage (336) so as to inhibit flowof grease in one direction in the passage. 17 _ The valve as defined in any one of the preceding claims, wherein an edge (470) is arranged at the inner wall of the chamber, the edgebeing adapted to inhibit flow of grease in the gap when the closingmember moves towards said other one of the closed and openpositions. _ The valve as defined in any one of the preceding claims, wherein the circumference of the closing member and an inner wall of the chamberare shaped such that the inner wall of the chamber is adapted to guidethe closing member towards the closed position. _ The valve as defined in any one of the preceding claims, wherein a first compartment (110) ofthe chamber is definedbetween a first end (131) of the closing member and the inner wall ofthe chamber and a second compartment (120) of the chamber isdefined between a second end (132) of the closing member and theinner wall of the chamber, and wherein an inlet (121) for the main flow of grease to the secondcompartment of the chamber and an outlet (122) for the main flow ofgrease from the second compartment of the chamber are defined inthe housing. _ The valve as defined in claim 8, wherein the gap and the passage are adapted to admit flow of grease between the first and secondcompartments when the closing member moves between the closedand open positions. 10_Lubrication system for supplying grease, the lubrication system comprising a valve as defined in any one of the preceding claims.