Patent Publication Number: US-2023160497-A1

Title: Electric valve and assembly method therefor

Description:
This disclosure is a national phase application of PCT international patent application no. PCT/CN2021/077996, filed on Feb. 26, 2021, which claims the benefit of priorities to the following two Chinese patent applications, both of which are incorporated herein by reference,
         1) Chinese Patent Application No. 202010179491.6, titled “ELECTRIC VALVE AND ASSEMBLY METHOD THEREFOR”, filed with the China National Intellectual Property Administration on Mar. 23, 2020; and   2) Chinese Patent Application No. 202020380324.3, titled “ELECTRIC VALVE AND ASSEMBLY METHOD THEREFOR”, filed with the China National Intellectual Property Administration on Mar. 23, 2020.       

    
    
     FIELD 
     The present disclosure relates to an electric valve and an assembly method therefor. 
     BACKGROUND 
     An electric valve can be applied to a vehicle thermal management system or an air conditioning system. The electric valve includes a stator assembly, a rotor assembly and a sleeve which is located between the rotor assembly and the stator assembly. How to reduce the external moisture entering the stator assembly through a gap between the sleeve and the stator assembly is a technical problem. 
     SUMMARY 
     An electric valve is provided according to the present disclosure, which is beneficial to reducing the external moisture entering a stator assembly through a gap between a sleeve and the stator assembly. An assembly method for the electric valve is further provided according to the present disclosure. 
     To achieve the above object, the following technical solutions are provided according to the present disclosure: 
     an electric valve includes a stator assembly, a valve component, a valve body and a sleeve, the stator assembly is located at an outer circumference of the sleeve, the stator assembly is position-limitedly connected or fixedly connected to the valve body, the electric valve further includes a first sealing member, the stator assembly has a first recessed portion, at least part of an opening of the first recessed portion is arranged toward the valve body, the first sealing member is located in the first recessed portion, the first recessed portion is located at the outer circumference of the sleeve, and the first sealing member is located between the valve body and the stator assembly; the first recessed portion has a first mounting surface and a second mounting surface, an inner side portion of the first sealing member abuts against an outer circumferential surface of a side wall of the sleeve and an outer side portion of the first sealing member abuts against the second mounting surface in a radial direction; and a position of the first sealing member is position limited by the first mounting surface in an axial direction. 
     An assembly method for an electric valve includes the following steps: 
     assembling a valve component with a sleeve so as to form a sleeve assembly; 
     assembling the sleeve assembly with a valve body, position-limitedly connecting the sleeve assembly with the valve body by screwing a compression nut so as to form a valve seat assembly; 
     positon limiting a supporting pad to the compression nut; 
     assembling a first sealing member, which includes of sleeving the first sealing member from one end of the sleeve to abut against the supporting pad; and 
     positon-limitedly connecting a stator assembly with the valve body, which includes of fixedly connecting a pressure plate with the stator assembly, aligning a second cavity of the stator assembly with the sleeve, aligning a first recessed portion with a position of the first sealing member, pressing the stator assembly with a downward force until the stator assembly abuts against the valve body and the first recessed portion is located in the first recessed portion, and then position-limitedly connecting the pressure plate with the valve body with a screw. 
     In the electric valve according to the present disclosure, the first sealing member is arranged between the stator assembly and the valve component, and the position of the first sealing member is position limited by the first recessed portion formed in the stator assembly, the sleeve and the corresponding valve body, which is beneficial to reducing the external moisture entering the stator assembly through the gap between the stator assembly and the sleeve to a certain extent. 
     The assembly method for the electric valve according to the present disclosure is beneficial to the assembly of the first sealing member, which has a simple assembly process. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic cross-sectional view of a first embodiment of an electric valve; 
         FIG.  2    is a schematic partially enlarged view of  FIG.  1   ; 
         FIG.  3    is a schematic cross-sectional view of a stator assembly; 
         FIG.  4    is a partially enlarged view of I portion in  FIG.  3   ; 
         FIG.  5    is a schematic perspective view of a supporting pad; 
         FIG.  6    is a schematic perspective view of a compression nut; 
         FIG.  7    is a schematic perspective view of a second embodiment of the compression nut and the supporting pad; and 
         FIG.  8    is a schematic partially enlarged view of a third embodiment of the electric valve. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The present disclosure will be further described as follows in conjunction with the drawings and specific embodiments. 
       FIGS.  1  to  7    show a first embodiment of an electric valve  100 , the electric valve  100  can be used in a vehicle thermal management system or an air conditioning system for flow adjustment and on/off control of the system. The electric valve  100  includes a stator assembly  1 , a circuit board  2 , a valve component  3 , a valve body  4 , a rotor assembly  31  and a sleeve  9 . The stator assembly  1  may be located at an outer circumference or an inner circumference of the rotor assembly  31 . In this embodiment, the stator assembly  1  is located at the outer circumference of the rotor assembly  31 , and the stator assembly  1  and the rotor assembly  31  can directly or indirectly drive the valve component  3  to move. The stator assembly  1  is located at an outer circumference of the sleeve  9 , and the sleeve  9  is located between the stator assembly  1  and the rotor assembly  31 . The stator assembly  1  is position-limitedly connected or fixedly connected to the valve body  4 , and the stator assembly  1  is electrically connected or signally connected to the circuit board  2 . The stator assembly  1  includes a winding  12  that is located inside the stator assembly  1 . The valve component  3  includes a valve core  32  and a valve seat  33 , and the electric valve further includes a valve port  331 . In this embodiment, the valve port  331  is located in the valve seat  33 . As other embodiment, the valve port may be directly arranged in the valve body, and the valve seat may be omitted. During the operation of the electric valve  100 , the circuit board  2  controls the winding  12  of the stator assembly  1  to be energized and controls the current passing through the winding  12  to be varied according to a predetermined rule, so as to control the stator assembly  1  to generate a varying excitation magnetic field. The rotor assembly  31  rotates under the action of the excitation magnetic field, and the rotor assembly  31  is able to directly or indirectly drive the valve core  32  to move relative to the valve port  331  and adjust an opening degree of the valve port  331  in order to realize flow adjustment and on/off control of the system. It is explained herein that the stator assembly  1  located at the outer circumference of the sleeve  9  refers to that the stator assembly is located outside a wall of the sleeve, not in the wall of the sleeve. Other references to the outer circumference herein should be understood in the same way. 
     The stator assembly  1  further includes a stator housing  11 , a frame  13 , an injection molding portion  14 , and the winding  12 . The frame  13  is located inside the stator housing  11  and provides support for the winding  12 , the injection molding portion  14  is integrally injection molded with the winding  12 , the frame  13  and the stator housing  11  as inserts, the injection molding portion  14  has a first cavity  141  and a second cavity  142 , which are not not in communication with each other. The first cavity  141  is located above the winding  12 , the second cavity  142  is located in the middle of the stator assembly  1 , and the first cavity  141  is separated from the second cavity  142  by a first cover  143  of the injection molding portion  14 . The circuit board  2  is located in the first cavity  141 , the winding  12  is electrically connected or signally connected to the circuit board  2 , a cover plate  15  is provided above the first cavity  141 , and the cover plate  15  is fixed to the injection molding portion  14  by welding. A second sealing ring  6  is arranged between the cover plate  15  and the injection molding portion  14  to seal the first cavity  141 , so as to prevent external water vapor and impurities from entering the first cavity  141  and affecting the normal operation of the circuit board  2 . 
     Referring to  FIG.  2   , the valve component  3  further includes a connecting member  35 , a nut  36  and a screw rod  37 , and at least part of the valve component  3  is located in the second cavity  142 . The sleeve  9  is located in the second cavity  142 , and part of the sleeve  9  is located between the rotor assembly  31  and the stator assembly  1 , which plays an isolation role. The rotor assembly  31  is fixedly connected to one end of the screw rod  37 . An inner wall of the nut  36  has an internal thread section  361 , and the other end of the screw rod  37  passes through the nut  36  and is connected to the valve core  32 . An outer circumferential wall of the screw rod  37  has an external thread section which is meshed with the internal thread section  361 , the external thread of the screw rod  37  and the internal thread of the nut  36  cooperate with each other to convert a circumferential rotation of the rotor assembly into an axial movement of the valve core  32 . In this embodiment, the nut  36  is fixedly connected to the connecting member  35 , the valve seat  33  is connected to the connecting member  35 , the valve seat  33  is located in the valve body  4 , and at least part of the valve core  32  is located in the valve seat  33 . 
     The electric valve further includes a compression nut  38 . The connecting member  35  has a flange portion  351 , a lower end surface of the flange portion  351  abuts against the valve body  4 , the compression nut  38  is sleeved at a radial outer circumference of a main body side wall of the connecting member  35 , the compression nut  38  is in contact with an upper end surface of the flange portion  351 , and the compression nut  38  is threaded to the valve body  4 , so that the connecting member  35  is fixedly connected with the valve body  4 . The electric valve further includes a pressure plate  7 , the stator assembly  1  is fixedly connected to the valve body  4  by the pressure plate  7 , a cross section of the pressure plate  7  is substantially L-shaped, a part of the pressure plate  7  is fixedly connected to the stator assembly  1 , and another part of the pressure plate  7  is fixedly connected to the valve body  4  by means of screw connection and the like. When the stator assembly  1  of the electric valve generates an excitation magnetic field, the rotor assembly  31  drives the screw rod  37  to rotate together under the action of the excitation magnetic field, while the screw rod  37  threadedly cooperates with the nut  36  to drive the valve core  32  to move axially. The valve core  32  changes a flow cross-sectional area of the working medium at the valve port  331  by approaching or moving away from the valve port  331 , thereby forming throttling and/or on/off of the working medium at the valve port  331 . 
     Referring to  FIG.  1    to  FIG.  4   , the stator assembly  1  further has a first recessed portion  144  that is located in the injection molding portion  14 , the first recessed portion  144  is formed by injection molding, and at least part of an opening of the first recessed portion  144  is arranged toward the valve body  4 . Viewed from a radial direction of the electric valve, the first recessed portion  144  is located between the valve component  3  and the stator assembly  1 ; and viewed from an axial direction of the electric valve, the first recessed portion  144  is located between the valve body  4  and the stator assembly  1 . Specifically, the first recessed portion  144  is located at a position where the injection molding portion  14  is close to the valve body  4  and the sleeve  9 , and the first recessed portion  144  is located at the outer circumference of the sleeve  9 . The electric valve  100  further includes a supporting pad  34  and a first sealing member  5 , and the supporting pad  34  is position-limitedly connected or fixedly connected to the compression nut  38 . Viewed from the axial direction of the electric valve, the first recessed portion  144  is located between the supporting pad  345  and the injection molding portion  14 ; viewed from the radial direction of the electric valve, the first recessed portion  144  is located between the sleeve  9  and the injection molding portion  14 , and the first sealing member  5  is located within the first recessed portion  144 . In this embodiment, the first sealing member  5  is an O-shaped ring. As other embodiments, the first sealing member  5  may be an irregular sealing ring or a sealing assembly formed by two or more sealing members. Referring to  FIG.  4   , the first recessed portion  144  has a first mounting surface  1441 , a second mounting surface  1442  and a connecting portion  1443 , the first mounting surface  1441  is substantially perpendicular to the main body side wall of the sleeve  9 , the first mounting surface  1441  is arranged opposite to the valve body  4 , the second mounting surface  1442  is arranged opposite to an outer circumferential surface of the main body side wall of the sleeve  9 , the second mounting surface  1442  is connected to the first mounting surface  1441  by the connecting portion  1443 , which is arc-shaped. Of course, the first recessed portion  144  may not be provided with the connecting portion, and the second mounting surface  1442  may be directly connected to the first mounting surface  1441 . In the radial direction, an outer side portion of the first sealing member  5  abuts against the second mounting surface  1442  and an inner side portion of the first sealing member  5  abuts against the outer circumferential surface of the side wall of the sleeve  9 . In the axial direction, a position of the first sealing member  5  is limited by the first mounting surface  1441 , the first sealing member  5  is located above the supporting pad  34  and abuts against an upper surface of the supporting pad  34 , and the first sealing member  5  is deformed by extrusion of the sleeve  9 , the stator assembly  1  and the valve body  4 . The supporting pad  34  is supported on the compression nut  38 , which is fixedly connected to the valve body, and the first sealing member  5  is supported on the supporting pad  34 , that is, part of the first sealing member  5  is indirectly position-limited to the valve body  4 , and the valve body  4  provides at least partial support for the first sealing member  5 . 
     A structure of the compression nut  38  is as shown in  FIG.  6   , an external thread (not shown in the  FIG.  6   ) is formed on an outer circumferential wall of the compression nut  38 , and the compression nut  38  has two second recessed portions  381 . A function of these two second recessed portions  381  is that a tooling can act on the two second recessed portions  381  during assembly so as to threadedly fix the compression nut  38  to the valve body  4 . In order to change the structure of the original electric valve as little as possible, the supporting pad  34  is provided in this embodiment based on the structure of the compression nut  38 , and the structure of the supporting pad  34  is as shown in  FIG.  5   . The supporting pad  34  mainly supports the first sealing member  5 , so that the first sealing member  5  indirectly abuts against the valve body  4 , and the first sealing member  5  is more stable and firm. In order to limit the rotation of the supporting pad  34  relative to the compression nut  38 , a lower end of the supporting pad  34  further has two positioning bosses  341 , the two positioning bosses  341  are matched with the second recessed portions  381  of the compression nut  38 , and the positioning bosses  341  of the supporting pad are pressed into the second recessed portions  381  of the compression nut  38 , which can limit a position of the supporting pad  34 , and reduce the damage to the first sealing member  5  caused by the shaking or rotation of the supporting pad  34  during the vibration of the electric valve. 
     The first mounting surface  1441  and the second mounting surface  1442  are flat surfaces in this embodiment, an included angle α is formed between the second mounting surface  1442  and the main body side wall of the sleeve, and the included angle α is greater than 0 degree and is less than 90 degrees. The second mounting surface  1442  is located on a side away from the sleeve  9 . In the direction shown in the drawings, one end, close to the winding  12 , of the first recessed portion  144  is narrow, and the other end, close to the supporting pad  34  of the valve body  4 , of the first recessed portion  144  is wide, showing a structure with a narrow upper end and a wide lower end. In the structure of the electric valve shown in  FIG.  1   , in order to keep the other structural dimensions of the electric valve unchanged as much as possible and meet the requirement that the first sealing member  5  reaches a certain compression rate, such as a compression rate ranging from 25% to 35%, the included angle α can be selected to range from 5 degrees to 18 degrees under the condition that the structural constraints are satisfied. The included angle α can be adjusted according to the structural dimensions of different electric valves. 
     Specially, the included angle α in  FIG.  4    is 10 degrees, and some lines existing in  FIG.  3    are omitted in  FIG.  4   . Of course, the first mounting surface  1441  and the second mounting surface  1442  are not limited to flat surfaces (the flat surfaces herein are generalized flat surfaces, including smooth flat surfaces, flat surfaces with roughness observed by the naked eye, etc.), or may be curved surfaces with radians, in this case the included angle α between the second mounting surface and the main body side wall of the sleeve is an included angle between a tangent plane of the second mounting surface and the main body side wall of the sleeve. 
     An assembly method for the above electric valve is further provided according to the present disclosure, which includes the following steps: 
     assembling the valve component  3  with the sleeve  9  to form a sleeve assembly; 
     assembling the sleeve assembly with the valve body  4 , and position-limitedly connecting the sleeve assembly with the valve body  4  by screwing the compression nut  38  to form a valve seat assembly; the specific operations of the assembling the sleeve assembly with the valve body  4 , and position-limitedly connecting the sleeve assembly with the valve body  4  by screwing the compression nut  38  to form a valve seat assembly are in that: sleeving the compression nut  38  from an upper end of the sleeve  9  to abut against the valve body  4 , and threadedly fixing the compression nut  38  to the valve body  4  by acting on second recessed portions  381  of the compression nut  38  with a tooling, so as to fix the valve body  4  to the sleeve assembly. 
     Position limiting the supporting pad to the compression nut; the specific operation of the limiting the supporting pad to the compression nut is in that: sleeving the supporting pad  34  from the upper end of the sleeve  9  to contact with the compression nut  38 , and inserting positioning bosses  341  of the supporting pad  34  into the second recessed portions  381  of the compression nut  38  to position limit the supporting pad  34  to the compression nut  38 . 
     The assembly of the first sealing member includes sleeving the first sealing member  5  from the upper end of the sleeve  9  to abut against the supporting pad  34 . 
     The position-limitedly connecting the stator assembly with the valve body includes: fixedly connecting the pressure plate  7  with the stator assembly  1 , aligning the second cavity  142  of the stator assembly  1  with the sleeve  9 , aligning the first recessed portion  144  with a position of the first sealing member  5 , pressing the stator assembly  1  with a downward force until the stator assembly  1  abuts against the valve body  4  and the first recessed portion  5  is located within the first recessed portion  144 , and then fixedly connecting the pressure plate  7  with the valve body  4  with a screw  8 . 
     The assembly of the electric valve further includes the following step: completing the assembly of the stator assembly  1  with the circuit board  2 , and sealing a cover plate  15  to an injection molding portion  14  by a second sealing ring  6  and fixing the cover plate  15  to the injection molding portion  14  by welding, and this step is performed before or after the stator assembly is position-limitedly connected with the valve body. 
     By arranging the included angle α in this embodiment, it is convenient to discharge the air in the first recessed portion  144  during pressing the first sealing member  5  into the first recessed portion  144 , which reduces the assembly difficulty and reduces the wear of the first sealing member  5  during assembly. The assembled first sealing member  5  can isolate the metal material in the injection molding portion  14  of the stator assembly from the external environment to a certain extent, reduce the possibility of external moisture or impurities entering the stator assembly  1 , and reduce the risk of corrosion of metal materials such as the winding  12  and the stator housing  11  and damage to the circuit board  2 . If the second mounting surface  1442  of the first recessed portion  144  does not deviate from the sleeve by the included angle α, when the stator assembly  1  is sleeved down toward the valve seat assembly during mounting the stator assembly  1 , it is prone to form an air spring between the first recessed portion  144  of the stator assembly and the valve seat assembly, and thus it is more and more difficult to sleeve the stator assembly  1  down. The formed air spring may cause the stator assembly and the valve seat assembly to have a mutual disengagement force for a long time after the stator assembly  1  is assembled with the valve seat assembly and the screw  8  of the pressure plate  7  is screwed tightly, so that the pressure plate  7 , which fixes the stator assembly  1  to the valve body  4 , will continue to be stressed. In the long term, the pressure plate  7  will deform and the relative distance between the stator assembly and the valve seat assembly will become larger. 
     A second embodiment of the electric valve is further provided according to the present disclosure, different from the first embodiment, the compression nut  38  and the supporting pad  34  in this embodiment are integrally configured, as shown in  FIG.  7   , the compression nut and the supporting pad in integral configuration herein refer to as an integral member  38   a , a lower end of which is equivalent to the compression nut in the first embodiment, an upper end of which is equivalent to the supporting pad in the first embodiment. The whole integral member is also provided with two second recessed portions  381   a , which have the same function with the second recessed portions  381  in the first embodiment. During assembly, the tooling can act on the two second recessed portions  381   a  to threadedly fix the integral member  38   a  to the valve body  4 . By configure the compression nut and the supporting pad into the integral member, the assembly steps can be simplified (the position limit connection between the supporting pad and the compression nut can be omitted), and the assembly efficiency can be improved. 
     A corresponding assembly method for the electric valve includes the following steps: 
     assembling the valve component  3  with the sleeve to form a sleeve assembly, assembling the sleeve assembly with the valve bod  4 , and position-limitedly connecting the sleeve assembly with the valve body  4  by screwing an integral member  38   a  to form a valve seat assembly, 
     assembling of the first sealing member, which includes: sleeving the first sealing member  5  from the upper end of the sleeve  9  of the sleeve  9  to abut against an upper end (equivalent to the supporting pad in the first embodiment) of the integral member  38   a;    
     position-limitedly connecting the stator assembly with the valve body, which includes: fixedly connecting the pressure plate  7  with the stator assembly  1 , aligning the second cavity  142  of the stator assembly  1  with the sleeve  9 , aligning the first recessed portion  144  with a position of the first sealing member  5 , pressing the stator assembly  1  with a downward force until the stator assembly  1  abuts against the valve body  4  and the first recessed portion  5  is located in the first recessed portion  144 , and then fixedly connecting the pressure plate  7  with the valve body  4  with a screw  8 . 
     Referring to  FIG.  8   ,  FIG.  8    shows a third embodiment of the present disclosure, compared with the first embodiment, the first sealing member  5 ′ in this embodiment is an irregular sealing ring, a cross-sectional shape of the first seal  5 ′ is shown in  FIG.  8   , and an outer contour of this cross section is formed by four arcs. It can be understood that, the first sealing member  5 ′ is not limited to the shape shown in  FIG.  8   , and may be other regular or irregular sealing members. A top of the first sealing member  5 ′ abuts against the first mounting surface  1441  and is position limited by the first mounting surface  1441 , an outer side portion of the first sealing member  5 ′ abuts against the second mounting surface  1442 , an inner side portion of the first sealing member  5 ′ abuts against the outer circumferential surface of the side wall of the sleeve  9 , and a bottom of the first sealing member  5 ′ abuts against the supporting pad  34 . 
     The above embodiments are only used to illustrate the present application rather than limit the technical solutions described in the present application. Although the present application is described in detail in this specification with reference to the above embodiments, those of ordinary skill in the art should understand that those skilled in the art may still modify or equivalently replace the present application, and all technical solutions and improvements thereof that do not depart from the spirit and scope of the present application shall be covered within the scope of the claims of the present application.