Direct-action-type electrically-operated valve and assembly method therefor

Abstract

A direct-action-type electrically-operated valve comprises a valve base ( 30 ) provided with a valve cavity, a motor ( 10 ) disposed on the upper end the valve base, and a screw rod ( 312 ). The screw rod ( 312 ) is fitted and connected to a nut ( 41 ) by means of threads. The nut is connected to a spool ( 42 ). Axial positions of a rotor ( 12 ) of the motor and the valve base are relatively fixed. The upper end of the screw rod is fixedly connected to the rotor. Driven by the nut, the spool moves along the axial direction of the valve cavity to open or close a valve opening ( 30 a ) disposed on the valve base. The spool is a tubular structure provided with a balancing channel, and a seal piece for dividing the valve cavity into two independent cavities is disposed on the periphery of the spool. A gear system is removed from the electrically-operated valve, so that unnecessary rotations are reduced, friction loss is reduced, and a response is direct, reliable and sensitive; the axial positions of the rotor and the valve base are relatively fixed, that is, the relative fixation of the rotor and a coil element during the working enables driving force to be stable; and obviously, for valve openings with a same size, the size of the motor using the valve opening is smaller than that in the background technology, which can meet requirements of miniaturization and large capacity.

1 - 12 . (canceled) 
     
     
         13 . A direct-acting electric valve, comprising a valve seat provided with a valve cavity, a motor arranged at an upper end of the valve seat, and a screw rod, wherein the screw rod is cooperated with and connected to a nut by means of screw threads, the nut is connected to a valve core, wherein axial positions of a rotor of the motor and the valve seat are fixed with respect to each other, and an upper end of the screw rod is fixedly connected to the rotor, and the valve core is movable in an axial direction of the valve cavity as the nut moves, so as to open or close the valve port arranged on the valve seat, the valve core is a column structure with an balancing passage, and a sealing member, which separates the valve cavity into two independent cavities, is provided outside an circumferential surface of the valve core,
 the direct-acting electric valve comprising a valve core assembly, a lower valve seat assembly and an upper valve seat assembly, wherein the upper valve seat assembly comprises an upper valve seat, a screw rod and a rotor of a motor, and the upper valve seat is fixedly connected to a lower valve seat of the lower valve seat assembly, and inner cavities of the upper valve seat and the lower valve seat are communicated with each other, and the rotor is sleeved on an upper end of the upper valve seat, and axial positions of the rotor and the upper valve seat are relatively fixed with respect to each other, and an upper end of the screw rod passes through the upper valve seat and is fixedly connected to the rotor, and a lower end of the screw rod is cooperated with the nut by screw threads, a valve core of the valve core assembly is movable axially in an inner cavity of the lower valve seat as the nut moves, so as to open or close a valve port arranged on the lower valve seat.   
     
     
         14 . The direct-acting electric valve according to  claim 13 , wherein the screw rod is fixed to the rotor via an annular connecting sheet by welding, and a peripheral edge of a through hole of the annular connecting sheet extends axially to form a protrusion. 
     
     
         15 . The direct-acting electric valve according to  claim 13 , wherein the rotor is a permanent magnet rotor, and the ratio of an outer diameter of the rotor to the diameter of the valve port ranges from 0.8 to 1.8. 
     
     
         16 . The direct-acting electric valve according to  claim 13 , wherein an inner cavity of the upper valve seat is separated into an upper cavity and a lower cavity by an annular plate, and a bearing is provided in the upper cavity, the axial positions of the screw rod and the upper valve seat are fixed with respect to each other via the bearing. 
     
     
         17 . The direct-acting electric valve according to  claim 16 , wherein a housing is sleeved on the upper valve seat, and a coil component of the motor is sleeved on the housing, and is supported by a fixing rest sleeved on the housing, and axial central lines of the coil component, the bearing and the rotor are coincident. 
     
     
         18 . An assembling method for a direct-acting electric valve according to  claim 13 , comprising steps:
 mounting an assembled valve core assembly to an assembled lower valve seat assembly;   screwing a screw rod of an assembled upper valve seat assembly into a nut of the valve core assembly, and fixing an upper valve seat of the upper valve seat assembly to a lower valve seat of the lower valve seat assembly by welding; and   mounting a housing and a fixing rest by pressing, and assembling a coil component of a motor.   
     
     
         19 . The assembling method according to  claim 18 , wherein the assembling of the upper valve seat assembly comprises:
 mounting a screw rod, a bearing and an upper valve seat by pressing;   mounting a spacer to an upper end of the bearing, and riveting or welding the spacer to the upper valve seat;   clamping a bush between the screw rod and the spacer, which allows the bush to abut against an upper end of the bearing and be fixed to the screw rod by welding; and   sleeving a rotor of a motor on an upper end of the upper valve seat, and fixedly connecting the rotor of the motor to the screw rod.