ELECTRIC VALVE

An electric valve, comprising a housing and an end cover. A cavity and a valve port are formed in the housing. The electric valve further comprises a rotor assembly, a rod assembly, and a valve core assembly; the rotor assembly is connected to one end of the rod assembly; and the other end of the rod assembly is connected to the valve core assembly. The electric valve further comprises a sealing component, and the sealing component is distant from the valve port with respect to the valve core assembly; the sealing component comprises a first cylindrical portion, a membrane portion, and an annular sealing portion; by providing the sealing component, the first cylindrical portion is connected to the rod assembly and a connection position is sealed.

This disclosure is a national phase application of PCT international patent application PCT/CN2020/134380, filed on Dec. 8, 2020, which claims priorities to the following two Chinese patent applications, both of which are incorporated herein by reference in their entireties, Chinese Patent Application No. 201911250887.9, titled “ELECTRIC VALVE”, filed with the China National Intellectual Property Administration on Dec. 9, 2019; and 2) Chinese Patent Application No. 201911250889.8, titled “ELECTRIC VALVE”, filed with the China National Intellectual Property Administration on Dec. 9, 2019.

BACKGROUND

1. Field of the Disclosure

The present application relates to the technical field of flow regulation, and in particular to an electric valve.

2. Discussion of the Background Art

An electric valve is widely used in fluid-medium pipeline systems and is configured to regulate the flow of medium. Taken the application of the electric valve in the automotive field as an example, the electric valve is applied in an air conditioning system, an engine cooling system, a battery cooling system or a fuel supply system.

The electric valve includes a valve core part movable relative to a housing, and the valve core part is driven by a driving portion. In some applications of the electric valve, the driving portion can be corroded by the fluid, and it is necessary to prevent the fluid in a valve cavity from leaking to the driving portion.

SUMMARY

An electric valve is provided according to the present solution, where the electric valve includes a housing and an end cover, a first cavity and a valve port are provided in the housing. The electric valve further includes a rotor assembly, a rod assembly and a valve core assembly. The rotor assembly is connected to one end of the rod assembly, and the other end of the rod assembly is connected to the valve core assembly. The electric valve further includes a sealing member, and the sealing member is away from the valve port with respect to the valve core assembly;the sealing member includes a first cylindrical portion and a membrane portion, where the first cylindrical portion has a second through hole, another part of the rod assembly passes through the second through hole; the first cylindrical portion is connected to the rod assembly and a junction between the first cylindrical portion and the rod assembly is sealed, and an outer peripheral side of the membrane portion is sealed with the housing and/or the end cover.

By providing the sealing member, the first cylindrical portion is connected with respect to the rod assembly and the junction between the first cylindrical portion and the rod assembly is sealed, and the outer peripheral side of the membrane portion is sealed with the housing and/or the end cover, which can well prevent the fluid from contacting the rotor assembly and prevent the fluid from corroding the rotor assembly. In addition, the membrane portion is arranged without obstructing the rod assembly from moving up and down.

In a specific solution, the sealing member further includes an annular sealing portion, and the membrane portion is located between the annular sealing portion and the first cylindrical portion. The annular sealing portion is caught between the end cover and the housing, so that the annular sealing portion is in a compressed state, so as to well seal the housing and cover by the sealing portion.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments are described in detail below with reference to the accompanying drawings.

As shown inFIG.2, the electric valve includes a housing26and an end cover16, where a first cavity1and a valve port265are provided in the housing26. The electric valve further includes a rod assembly14and a valve core assembly33. One end of the rod assembly14is connected to the valve core assembly33, and the other end of the rod assembly14is connected to a rotor assembly10. The rod assembly14and the valve core assembly33can be moved up and down in an extending direction of the rod assembly14to open or close the valve port265. The housing26includes a first passage261and a second passage262, the first passage261is in communication with the first cavity1, and the valve port265is configured to communicate the second passage262with the first cavity1.

As shown inFIG.2, the electric valve further includes a coil assembly31and a sleeve3. The sleeve3is fixed to the end cover16and a junction between the sleeve3and the end cover16is sealed, and a second cavity36is formed inside of the sleeve3, and at least a part of the rotor assembly10is arranged in the second cavity36. The coil assembly31is sleeved on the sleeve3.

The end cover16includes a first through hole163penetrating the end cover16. A part of the rod assembly14passes through the first through hole163of the end cover16and is drivingly connected to the rotor assembly10. The rod assembly14is slidably fitted to an inner wall corresponding to the first through hole163. The rotor assembly10further includes a screw rod8and a permanent magnet4, a nut part12is threaded on the periphery of the screw rod8, and the nut part12is screw-thread fitted to the screw rod8. The nut part12is fixed to the end cover16, and the screw rod8can move up and down with respect to the nut part12, and the screw rod8is configured to drive the rod assembly14to move. An elastic member11is provided between the rod assembly14and the screw rod8.

The first passage261and the second passage262of the electric valve can be in communication with a pipeline of a fuel cell system with relatively higher pressure. In order to prevent the fluid with higher pressure in the first cavity1from entering the rotor assembly10or reduce leakage risk, as shown inFIG.2toFIG.4, the electric valve further includes a sealing member19, which is away from the valve port265with respect to the valve core assembly33. The sealing member19includes a first cylindrical portion192and an annular membrane portion191, the first cylindrical portion192is located on the inner peripheral side of the membrane portion191, and the first cylindrical portion192includes a second through hole193, and the other part of the rod assembly14passes through the second through hole193of the sealing member19and is connected to the valve core assembly33. An outer peripheral side of the membrane portion191is connected to the housing26and the end cover16, and junctions between them are sealed. The sealing member19may be made of rubber material or metal material, and the sealing member19has elasticity. As shown inFIG.4, the membrane portion191includes a first flat portion196connected to an annular sealing portion195, a second flat portion197connected to the first cylindrical portion192, and a corrugated portion located between the first flat portion196and the second flat portion197. The corrugated portion198is stretchable under external forces, so as to adapt to the up and down movement of the rod assembly14. As shown inFIGS.2to4, a part of the sealing member19in contact with the rod assembly14is stationary with respect to the rod assembly14, and a part of the sealing member19in contact with the housing26is stationary with respect to the housing26. Compared with dynamic sealing, static sealing can be adopted to reduce the risk of leakage. In other embodiments, the outer peripheral side of the membrane portion191may only be connected to the housing26or the end cover16, and a junction between them is sealed.

As shown inFIG.3andFIG.4, the electric valve further includes an annular jacket20, the annular jacket20surrounds the outer periphery of the first cylindrical portion192and surrounds the second through hole193. The first cylindrical portion192includes an outer wall portion and an inner wall portion located at an inner side of the second through hole193, the inner wall portion and the outer wall portion are located on the inner and outer sides of the first cylindrical part192, respectively. The annular jacket20and the outer wall portion of the first cylindrical portion192are in an interference fit, and the annular jacket20can exert a pressure on the cylindrical portion192towards the rod assembly14, so that the first cylindrical portion192and the outer circumference of the rod assembly14are closely fitted, which can reduce leakage at the second through hole193, thereby preventing the fluid with higher pressure in the first cavity1from entering the rotor assembly10in order to prevent the fluid from corroding the rotor assembly10, and also prevent the fluid from entering the second cavity36and freezing at a low temperature, causing the rotor assembly10to fail to rotate.

As shown inFIGS.2to3, the electric valve further includes a first position-limiting member21, the first position-limiting member21is located at one end of the annular jacket20away from the first through hole163, and the outer diameter of at least a part of the first position-limiting member21is greater than the inner diameter of the annular jacket20. The first position-limiting member21abuts against the annular jacket20, and the first position-limiting member21is fixed to the rod assembly14, so that the end of the annular jacket20abutting against the first position-limiting member21is axially position limited. In this embodiment, the first position-limiting member21is a retaining ring. The rod assembly14has a groove142recessed in an outer peripheral surface of the rod assembly14, the groove142corresponds to the first position-limiting member21, and a part of the first position-limiting member21extends into the groove142, so that the first position-limiting member21is axially position limited, and the other part of the first position-limiting member21extends outward in radial direction of the rod assembly14and abuts against an end of the sleeve20. The retaining ring may be an E-shaped retaining ring, and the inner diameter of the retaining ring can vary, so that the retaining ring can pass through the thicker part of the rod assembly14to reach the groove142during installation. In other embodiments, the first position-limiting member21may also be a nut, and the first position-limiting member21can be fixed to the rod assembly14by internal threads. However, the structure of the retaining ring is simpler than that of the nut, and the cost is lower. In other embodiments, the first position-limiting member21may also be a part of the rod assembly14.

As shown inFIG.3, the electric valve further includes a second position-limiting member18, the second position-limiting member18is located at an end of the sealing member19close to the first through hole163, and the outer diameter of at least a part of the outer diameter of the second position-limiting member18is greater than the diameter of the second through hole193. The sealing member19abuts against the second position-limiting member18. The second position-limiting member18is fixedly connected to the rod assembly14or integrated with the rod assembly as a whole, so that an end of the first cylindrical portion192can be axially position limited. The second position-limiting portion18can be axially position limited by a fifth step portion141of the rod assembly14. In other embodiments, the second position-limiting portion18may be a part of the rod assembly14.

As shown inFIGS.3and4, the annular jacket20includes an outer extension portion201extending outward in radial direction of the rod assembly14and a second cylindrical portion202extending axially along the rod assembly14. The second cylindrical portion202is sleeved on the first cylindrical portion192, and the outer diameter of the second position-limiting portion18is greater than the outer diameter of the second cylindrical portion202. The second flat portion197of the membrane portion191is caught between the second position-limiting portion18and the outer extension portion201, the outer extension portion201extending outward in radial direction of the rod assembly14and the second position-limiting member18can increase the area of a caught portion of the sealing member19, and further reduce the deformation of the first cylindrical portion192caused by pulling while increasing the area of a sealing surface so as to reduce the leakage at the second through hole193. The annular jacket20also has a horn-shaped flaring or chamfer203located at a junction between the outer extension portion201and the second cylindrical portion202, and the horn-shaped flaring or chamfer203gradually expands toward the second position-limiting member18. In case that the annular jacket20is not arranged on the outer periphery of the first cylindrical portion192, the outer diameter of the first cylindrical portion192may be slightly greater than the inner diameter of the annular jacket20, and the flaring or chamfer can be configured as a guide during inserting first cylindrical portion192into the annular jacket, so that the first cylindrical portion192can be more easily inserted into an inner side of the annular jacket20. The chamfer can be rounded. The annular jacket20can be formed by pressing, which is lower in cost.

As shown inFIGS.3and4, the sealing member19further includes an annular protrusion194, which protrudes from an inner side of the first cylindrical portion192toward the rod assembly114and surrounds the rod assembly14. The rod assembly14has an annular groove144, which is recessed in an outer circumference of the rod assembly14and surrounds the rod assembly14. The annular groove144corresponds to the annular protrusion194, at least a part of the annular protrusion194extends into the annular groove144, and the annular protrusion194abuts against the annular groove144, so that not only the first cylindrical portion192can be axially position limited but also the sealing performance can be improved. In case that the first cylindrical portion192is not under pressure, a height of the annular protrusion194protruding from the inner side of the first cylindrical portion192is greater than a depth of the annular groove144. In case that the first cylindrical portion192is sleeved on the outer periphery of the rod assembly14, the annular protrusion194is in a compressed state, which could reduce the leakage at the second through hole193. In other embodiments, the rod assembly14may also have an annular protrusion protruding from the outer peripheral surface of the rod assembly14and surrounding the rod assembly14, and the sealing member19has an annular groove recessed in the inner side surface the first cylindrical portion192and surrounding the rod assembly14. At least a part of the annular protrusion extends into the annular groove, and the annular protrusion abuts against the annular groove.

As shown inFIGS.4and6, the sealing member19further includes an annular sealing portion195located at the outer peripheral edge of the membrane portion191. The annular sealing portion195surrounds the first through hole163of the end cover16, and the thickness of the annular sealing portion195is greater than that of a junction between the membrane portion191and the annular sealing portion195. The end cover16includes a first step portion165, and the housing26includes a second step portion263, where the first step portion165and the second step portion263both surround the first through hole163. The first step portion165and the second step portion263are arranged opposite to each other, and an accommodating cavity is formed between the first step portion165and the second step portion263. The annular sealing portion195is located between the first step portion165and the second step portion263, and is in a compressed state, so that fluid leakage into the rotor assembly10from the first cavity1via the peripheral edge of the sealing member19is reduced. The annular sealing member195can also reduce fluid leakage from the first cavity1to the outside and/or the stator assembly31via a space between the end cover16and the housing26. The first flat portion196is caught between the first step portion165and the second step portion263, and the first flat portion196can be in a compressed state, which can further reduce leakage.

It can be seen that the sealing arrangements for at least one of the outer peripheral side of the membrane portion191of the sealing member19, the housing26and the end cover16can just obtain the object of reducing the fluid leakage to the outside and/or the stator assembly31from the first cavity1via a space between the end cover16and the housing26. Further, the membrane portion191can be stretchable, which will obstruct the vertical movement of the rod assembly14connected to the sealing member19. In this embodiment, the outer periphery of the membrane portion191is further provided with an annular sealing portion195, which is pressed in between the end cover16and the housing26so as to indirectly seal the end cover16and the housing26with the membrane portion191. It should be understood that the outer peripheral side of the membrane portion191can also be directly connected to and sealed with the end cover16and the housing26.

As shown inFIG.6, the end cover16includes a third step portion164, where the third step portion164corresponds to a fourth step portion264of the housing26. The third step portion164and the fourth step portion264are arranged opposite to each other, and an accommodating cavity is formed there between. The electric valve further includes an annular sealing member17, which is arranged between the third step portion164and the fourth step portion264and is in a compressed state. The third step portion164is away from the first cavity1with respect to the first step portion165. The annular sealing member17can reduce external leakage of the first cavity1and form a double sealing with the annular sealing member195. The end cover16can be welded and fixed to the housing26, and a junction there between is sealed, and the external leakage of the first cavity1can be further reduced by welding.