US2915077A

US2915077A - Diaphragm-flapper assembly

Info

Publication number: US2915077A
Authority: US
Inventors: Robert L Wehrli; Cecil A Crafts; Maynard D Mcfarlane
Original assignee: Robertshaw Fulton Controls Co
Current assignee: Robertshaw Controls Co
Priority date: 1957-01-30
Filing date: 1957-01-30
Publication date: 1959-12-01
Anticipated expiration: 1976-12-01
Also published as: DE1069972B

Description

DeC- 1, 1959 R. L. wEHRLl ETAL 2,915,077

DIAPHRAGM-FLAPPER ASSEMBLY Filed Jan. 30, 1957 MaynardlZA/IFarlane. EY

e Amma.

mAPHRAGM-FLAPPER ASSEMBLY Robert L. Wehrli, Santa Ana,fCecil A. Crafts, vla'sailena,

Application January 30, 1957,Serial No. 637,183 r s claims. (ci. 137-82), l

This invention relates to flow control means for a hydraulic transfer valve and more particularly to a dual purpose diaphragm-dapper assembly that is used in a hydraulic transfer valve to control the passage of high pressure hydraulic fluid `through a pair of orifices in thev'alve and to prevent the direct flow of hydraulic fluid between` a pair of chambers in the valve.

The present invention is concerned with and forms an integral partof only two of the three main components of a hydraulic transfer valve: the motor and the hydraulic amplifier. The diaphragm-dapper assembly is shown and described herein as forming a component part of a hydraulic transfer valve in which the valve motor is comprised of a magnetic circuit and the hydraulic amplifier is comprised of a pair of fluid passage orifices adapted to be intermittently covered and uncovered by a flapper.

lThe diaphragm-dapper assembly, a flexible diaphragm or plate with a apper rigidly mounted thereon, is positioned in the valve so that the diaphragm forms a component part of the magnetic motor circuit in addition to preventing a direct flow of hydraulic l iiuid over and around the other components of the magnetic motor circuit. Being so positioned, the diaphragm not only supports the flapper for rotation between a plurality of controlling positions relative to the uid passage orifices, but also prevents contamination of the hydraulic uid disposed in the magnetic motor circuit of the valve and prevents contamination of the hydraulic fluid surrounding the fluid passage orifices. The primary object of the present invention is to mount a hydraulic transfer valve flapper on a flexible diaphragm or plate.

Another object of the invention is to prevent contamination of the fluid in the magnetic motor circuit in a hydraulic transfer valve.

Another object of the invention is to use allexible diaphragm or plate as a component part of the magnetic motor circuit in a hydraulic transfer valve.

Another object of the invention is to prevent contamination of the uid around the hydraulic amplifier fluid passage orifices in a hydraulic transfer valve. 1 Another object of the invention is to mount the flapper member of a hydraulic transfer valve on a exible diaphragm or plate and utilize the. ilapper as a component part of the hydraulic transfer valve motor and the hydraulic amplifier.

These and other objects ofthe invention will become apparent from the following A,description taken in connection with the accompanying drawings wherein:

Fig, l is a schematic illustration of one environmental I application of the diaphragm-dapper assembly;

Fig. 2 is a top plan View of the preferred embodiment of the diaphragm-dapper assembly;

Fig. 3 is a section taken along the line III-Ill in Fig. 2; Fig. 4 is a side elevation of the preferred embodiment of one of the components shown in Figs. 2 and 3;

Fig. 5 is an end elevation of the component of the diaphragm-dapper assembly shown in Fig. 4;

2,915,077 I vPatented Dec. 1, 1959 ICC provided with arelatively large chamber 12 and a relatively small chamber 14 therein. Chamber 12 defines a floor or flat surface16 within the bodyv ofcasing 10 and chamber 14 defines av pair lof opposed walls v18 and'20V therein.` ,r Y r,

Walls 18 and 20 have mounted therein a pair ofspaced and opposed nozzles 22 and` 24 which communicate with a pair of uid passages 26 and 28, respectively, in casing 10. Nozzles 22 and 24are provided with a pair of uid passages or orifices 30 Vand 32, respectively, therein which accommodate the passage therethrough of pressurizedl hydraulic fluid from casing passages 26 and 28,. Pres-l surized hydraulic'fluidlowing through orifices 30 andl 32 is discharged into4 casing chamber 14 from whereit is conducted by a passage 33 (shown in outline) inv casing 10 to another component ofthe hydraulic transfer valve which is, likewise, shownin outline in Fig. 1.

Since a part'of the hydraulic transfer .valve is shown in outline and thus will not be structurally and functionally describedV in detail herein, it might be noteworthy to state the general purpose and function of the two orifices 30 and 32 in relation to the overall function of the hydraulic transfer valve.A Orifices 30fand 32 are adapted to be differentially covered or uncovered in part by one of the components ofthe subject diaphragm-dapper assembly to alternately produce a pressure drop across one yor the other ofthe orifices.` `The pressure drop across one or the other oftheorices 30 or 32 creates a pair of control pressures upstreamof each orifice in passages 26 and 28. The control pressures thus created are then applied by any suitable means to another component of the valve, such as the spring-biased flow Vcontrol piston 35, shown in outline. The orifices30 and 32, therefore, serve` as an integral part of a control means to accurately adjust the rate of flow of pressurized uid through the hydraulic transfer valve.

Cooperating with the orifices 30 and 32 `and positioned between casing chambers 12 and 14 is adiaphragmflapper assembly, generally designated by the reference numeral 34, and best shown in Figs. 1 and 3. The structural details of the preferred embodiment of the diaphragmapper assembly 34 .are best shown, however, in Figs. 3, 4 and 5 wherein the assembly includes a flexiblemagnetic material plate or diaphragm 36 provided with a pair of

opposed faces

38 and 40 thereon. Rigidly attached to plate 36 at the approximate geometric center thereof is a apper member or bar generally designated by the reference numeral 42.

The preferred embodiment of the flapper `42 comprises a two-piece, axially aligned construction including an upper portion 44 and a lower portion 46 extending substantially laterally of plate 36 from

faces

38 and 40, respectively. The two

flapper portions

44 and 46 are retained in assembled ,engagementby a threadedconnection, portion 44 being provided with a threaded shank 48 and portion 46 beingv provided ,with a threaded passage 50 thereon. A centrally disposed aperture S2 in plate 36 permits assembly of the two flapper portions `44 and 46 and enables the fiapper 42 to be rigidly mounted on the plate. t

As shown in Pigs. 2, 4 and 5, the two

apper portions

44 and 46 are rectangular in cross-section adjacent their outer extremities and are provided with circular collars 54 and 56, respectively, at the inner extremities thereof. The circular collars. 54 and 56 define` a pair of flat circular end walls 58 and 60, respectively, and thus provide a pair 4vof bearing surfaces which engage

faces

38 and 40,

stress' concentrations" in plate 36 when tlapper' 42 is` rotated relative to plate 36',v as will be explained more in detail hereinafter. r

Asl shown in` Fig;` l', the plate- 36 with' apper `42 mountedfthereon is seated'l with a recess' 62 formed in casing floo'r`16l and isv thusl positioned betweenY casing chambersl 12 and 14. Being so positioned, plate 36 forms a wall between" the twochambersv 12 and 14 and prevents'the direct' ow of hydraulic' uid therebetween. With the plate 36 in this position, itwill also be noted that the lower portion 46 of the apper is positioned between the two orifices 30 and 32 while the upper portion 44 of. the dapper. extends upwardly intol casing chamber-12. l

Casing' chamber 1'2, as best' sho'w'n in Fig.v 1, houses a magnetic circuiti motor. or powermeans'which vincludes a ma'gneticlmaterial plate or `shunt 64, with permanent magnet`66, and an electrically energized coil 68. Shunt 64 isV mounted on top of plate"36 and is provided with a centrally disposed aperture 70 therein tov accommodate the' passage therethrough of iiapper portion 44. The

permanent magnet 66 has yone end seated in conductive l relationship with shunt 64 and at the opposite end is providedA with an open space o'r void 72 thereinwhich defines a pair of' opposite magnetic poles 74 and 76.

The electrically energized' coil 68 is disposed around the flapper'portion 44 intermediate the ends thereof and being so positionedl pro'videsa short terminal end 78 on flapper portion 44 which is disposedvbetween the poles 74 and`76 of the magnet 66. The upper iapper portion 44 thus becomesthe armature of the hydraulic transfer valve motor.

In order to equalize the hydraulic fluid pressure on both sides of plate 36 to prevent' deformation thereof, casing 10 is provided with a passage 80 therein which connects the casing chambers 12` and 14.' Passage 80 permits uid flow in one direction only at any one time and prevents a continuous flow of fluid between the chambers. AsV a` practical matter, the flow of luid'between the chambers 12 and 14 will lcease When chamber 12 becomes lled'w'ith fluid.

The prevention ofk a continuous or direct'flow of uid betweenV chambers 12 and 14 is particularly important from .the standpoint of preventing contamination ofthe fluid in chamber 12'. Since contaminants present in the hydrauliciiuid, notably ferrous particles, adversely eiect the functioning of the magnetic circuit motor, it becomes extremely important'to limit the flow of hydraulic uid between the chambers 12 and 14l so as to prevent a build-up or 'concentration of'contaminants in the magnetic ux within chamber 12.

Operation When coil 68 is energized, theterminal end 78 of flapper 42 will bedrawn towardsone or the other of the magnetic poles 74 or 76 andthelower portion46 of the dapper will be' simultaneously moved in the opposite direction to partiallycover or uncover one or the other of the oriiices 30 or 32. It will be noted that the movement of the flapper 42 between the magnetic poles 74 and 76 produces a rotation of the flapper 42 about its mountingon plate 36.l This 'pivotal movement of the liapper 42 is permitted by the flexibility of plate 36, the rotation ofiiapper' 42 being accompanied' by a corresponding deflection of plate 36 adjacent the point of connection between the' flapper and the plate.

Under most-operating conditions, it will be desirable to operate the hydraulic valve so that the apper 42 is oscillatedbetween the' magnetic poles 74 and' 76 andthe orifices 30 and 32'iin' response Atosom'e 'characteristic of theinput signal to the 'coil 68. With the iiapper 42 being oscillated, rtheflw of iiuidthrough orifices 30 and 32 will beproportionately relatedto the' input signal to the coil 68l Stating the relationship between Huid 110W and the input signal in another manner, the fluid fiow ratev through orifices 30 and 32 will be a linear function of some characteristic of the input signal to the coil 68, for example, a characteristic such as the amplitude of the input signal.

In addition to preventing a direct flow of hydraulic fluid between casing chambers 12 and 14 and thus preventing contamination of the magnetic motor [circuit in and around permanent magnet 66 and coil 68, plate 36 also prevents' contamination of the magnetic motor c'i'rn cuit adjacent the orifices 30 and 32. The plate 36 forms an integral part of thel magnetic motor circuit since it is made of a magnetic-material and is juxtaposed the magnetic shunt 64. Because of the construction' and position of the plate 36, the intensity of the magnetic flux around orifices 30 and 32 is very low and, thus, the contamination of the hydraulic fluid around orifices 30 and 32 is negligible. It is particularly important to prevent contamination of the magnetic motor circuit around orificesv 30 and 32 since'the presence of contaminants in the hydraulic fluid at this point adversely effects the iiow control characteristics of the orifices.

Figs." 6 and 7 show another embodiment of the dapper which may be used as a component part of the diaphragm-iapper assembly.' In this embodiment, the flapper comprises an' elongated rectangular-shaped bar 82 provided with an annular threaded portion 84 and an annular ange 86 intermediate the ends thereof. The flapper 82 in this embodiment is a one-piece construction which is adapted to be retained in assembled engagement with a` diaphragm (not shown) by threaded portion 84.

While only two embodiments of the present invention have'been shown and described herein, it will be apparent that various changes may be made in the form and arrangement of parts and the details of construction herein disclosed without departing from the scope of the inventionvas defined inthe appended claims.

It is claimed'and desired to secure by Letters Patent:

l. In a ow control device including a casing having a pair of chambers therein, magnetic means in one of said chambers producing a magnetic flux, and liuid passage means for pressurized fluid in another of said chambers, the combination of flexible means for preventing the passage of fluid between the chambers and for providing a component of a magnetic circuit for the magnetic ilux, and a member carried by said flexible means with a portion of the member extending into each of the said chambers, one portion of said member being cooperable with the magnetic means and the other portion thereof being positioned between the fluid passage means whereby one portion of said member is rotated relative to said ilexible means by the magnetic flux to move the other portion of said member between a plurality of controlling positions relative to the fluid passage means for controlling the passage of fluid therethrough, said magnetic circuit component providedv by said exible means being operative to reduce the intensity of the magnetic ilux in the chamber housing the uid passage means and thereby being operable to substantially eliminate the contamination of the fluid around the fluid passage means.

2. In a iiow control device including a casing having a pair of chambers therein connected by a flow passage with an electrically energizable coil and magnetic means in one of said chambers and iluid passage means in the other of said chambers, saidvmagnetic means producing a magnetic flux, the combinationl of a flexible plate for preventing the direct ow of fluid between the chambers and for providing a component of a magnetic'ux circuit, and a' member mounted on said plate with portions extending substantially laterally of said plate, one portion of said member being surrounded by the coil and juxtaposed the magnetic means and another portion of said member being positioned between the fluid passage means, said member rotated relative to said plate by the magnetic flux when the coil is energized to thereby move one portion of said member between a plurality of controlling positions relative to the fluid passage means to produce a pressure drop across the uid passage means.

3. A fiow control device including a casing having a pair of chambers therein connected by a fiow passage with a two-pole magnet and an electrically energized coil in one of said chambers and a pair of orifices for pressurized fluid in the other of said chambers, characterized by a flexible diaphragm for preventing the direct flow of fluid between the chambers and for providing a component of a magnetic circuit for the magnetic iiux produced by the magnet, said diaphragm in preventing the direct fio-w of liud between the chambers thereby being operative to prevent the contamination of the fluid in the magnetic circuit in the chamber housing the magnet and the coil, and a iiapper rigidly mounted on said diaphragm with portions thereof extending substantially laterally of the said diaphragm, one portion of said flapper being surrouned by the coil and positioned between the poles of the magnet and another portion of said rflapper being positioned between the pair of orifices, one portion of said flapper being moved between the poles of the magnet when the coil is energized and thereby being rotated relative to said diaphragm to move the other portion of said flapper between a plurality of controlling positions relative to the orifices to produce a pressure drop thereacross, the component of the magnetic circuit provided by said diaphragm being operable to reduce the intensity of the magnetic flux in the chamber housing the orifices and thereby being operable to eliminate the contamination of the fluid around the orifices.

4. In a iiow control device as claimed in claim 3 wherein said flapper is comprised of two parts held in assembled engagement by a threaded connection and having opposed anges engageable with said diaphragm to reduce stress concentration.

5. In a flow control device as claimed in claim 3 wherein said flapper is comprised of an elongated bar provided with an annular flange and an annular threadedportion intermediate the ends thereof.

6. In a iiow control device having a pair of chambers therein and provided with a plurality of orifices in one of said chambers for pressurized fluid, a flexible plate positioned between said chambers for preventing the ow of fluid therebetween, a relatively iniiexible member mounted on said plate and having a portion thereof projecting into each of said chambers, a magnetic circuit motor operatively associated with said member relative to said plate whereby one portion of said member is moved between a plurality of controlling positions relative to said orifices to control the passage of fluid therethrough, and means to equalize the tiuid pressures in both of said chambers, said magnetic-material plate comprising a part of said magnetic circuit motor and thereby being operative to prevent contamination of the fluid around said orifices by reducing the intensity of the magnetic flux around said orifices.

7. In a flow control device having a pair of chambers therein and provided with a pair of orifices in one of said chambers for pressurized fluid, a magnetic-material plate separating said pair of chambers and preventing the ow of viiuid therebetween, a member carried by said plate and having portions thereof projecting into each of said chambers, and magnetic means in one of said chambers including a magnetic circuit operatively associated with one portion of said member for rotating said member and moving another portion of said member between a plurality of controlling positions relative to said orifices for producing a uid pressure drop across said orifices, said magnetic-material plate forming `a component of said magnetic circuit and thereby being operative to prevent contamination of the fluid around said orifices by reducing the intensity of the magnetic flux around said orifices.

8. In a fiow control device having a pair of chambers therein and provided with a pair of orifices in one of said chambers for pressurized fluid, a flexible magneticmaterial plate positioned between said chambers for preventing the iiow of uid therebetween, a magnetic-material member mounted on said plate and having a portion thereof projecting into each of said chambers, means to equalize the uid pressure in said chambers, a two-pole magnet and an electrically energizable coil in the other of said chambers, one portion of said member having a part thereof surounded by said coil and having a part thereof positioned between the poles of said magnet, and a magnetic iiux circuit operatively associated with one portion of said member for rotating said member when said coil is energized and moving the other portion of said member between a plurality of controlling positions relative to said orifices to produce a fluid pressure drop across said orifices, said magnetic-material plate also forming a part of said magnetic flux circuit and thereby being operative to prevent contamination of said fluid in said chamber housing said coil and said magnet in addition to preventing contamination of the fluid around said orifices by reducing the intensity of the magnetic flux around said orifices.

' References Cited in the file of this patent UNITED STATES PATENTS 1,920,764 Nickle Aug. 1, 1933 2,526,804 Carpenter O ct. 24, 1950 2,767,689 Moog Oct. 23, 1956 2,775,254 Stanbury Dec. 25, 1956 2,790,427 Carson Apr. 30, 1957 2,806,480 Bowditch Sept. 17, 1957 OTHER REFERENCES Control Engineering, McGraw-Hill, Moog Valve Co., Inc., May 1955, p. 21, New York City.