US3526246A - Concentric suction and delivery valve for high pressure compressors and pumps - Google Patents

Description

United States Patent [72] Inventor Anton Leitgeb Aesoh, Switzerland [21] Appl. No. 708,291 [22] Filed Feb. 26, 1968 [45] Patented Sept.1,l970 [73] Assignee Maschinenfabrik Burckhardt AG Basel, Switzerland a Swiss company [54] CONCENTRIC SUCTION AND DELIVERY VALVE FOR HIGH PRESSURE COMPRESSORS AND PUMPS 7 Claims, 3 Drawing Figs.

[52] U.S. Cl l37/5l2.3,

137/516.l3, 137/516.15; 230/231 [51] Int. Cl ..F16k 15/08, F04b 39/ 10 [50] Field ofSearch 137/102, 516.1 l,516.l3,5l6.l5,512.3; 230/230, 231; 251/282 [56] References Cited UNITED STATES PATENTS RE.25,899 11/1965 Waibel l37/5l6.15X

Primary Exan1inerWilliam F. ODea Assistant Examiner-David J. Zobkiw A ttorney- Wenderoth. Lind and Ponack ABSTRACT: A concentric suction and delivery valve for high pressure compressors and pumps wherein a valve body in a housing has oblique suction channels and a central delivery channel. A suction valve lift-limiting member has an obturating member cooperating with the suction channels. A delivery valve seat is provided in the housing with an obturating member cooperating with the delivery valve seat. An intermediate ring is located between the valve body and the delivery valve seat having a through bore of a form for high flow efficiency receiving the lift-limiting member. There is a delivery valve lift-limiting member. The valve body with the intermediate ring, the suction valve lift-limiting member, the delivery valve seat and the delivery valve lift-limiting member form a unit which can be inserted in and removed from the 2,703,217 3/1955 Ashton etal... 251/282 housing. The unit on its external surface is exposed to the ac- 3,106,169 10/1963 Prosser et al. 230/231X tion ofthe delivery pressure at least in the zone corresponding 3,180,277 4/1965 Thresher 230/231X to the region ofoutflow ofthe suction channels.

0 l4 24 9 R Q k\ v CONCENTRIC SUCTION AND DELIVERY VALVE FOR HIGH PRESSURE COMPRESSORS ANDPUMPS A concentric suction and delivery valve for high pressure compressors and pumps has been proposed in which there are no steps and projections on the valve body which would give rise to stress concentrations through changes in cross section, and which at the same time enables rapid mounting and dismounting in the high pressure cylinder.

According to that proposal, oblique suction channels and a central delivery channel are provided in the valve body of the concentric suction and delivery valve, the valve body being combined with a lift-limiting member to form a unit.

Atthe same time an element, e.g. a central tube is set in the bore in the valve body forming the central delivery channel, the flow bore in which element has a form permitting efficient flow, the element unitingthe valve body with the complete suction valve and the lift' limiting member thereof into a common'mountable and removable unit.

Any stress-raising changes of cross section in the parts of the valve body exposed to alternating pressures are to a great extentavoided in the concentric suction and delivery valves.

constructed in this manner. Further after releasing a cover or a closing screw provided on the cylinder head the valve can be mounted in or removed from the compressor or pump in a very short time without any further dismounting operations.

An object of the present invention is to improve the concentric suction and delivery valve for high pressure compressors and pumps according to the above mentioned proposal, that easier assembly results from a simplified construction and possible dangers attaching to the prior valve, e.g. through fracture of the central tube, are eliminated. The concentric suction and delivery valve according to the present'invention is characterised in that an intermediate ring for accommodating a suction valve lift-limiting member having'a through bore of a form for high flow efficiency, is incorporated between the valve body and the delivery valve seat, and that the valve body with the intermediate ring with inset suction valve lift-limiting member, and the delivery valve seat together with the delivery valve lift-limiting member are built together into a unit which as a whole can be inserted in and removed from the valve housing, which unit on its external surface is exposed to the action of the delivery pressure at least in the zone corresponding to the region of outflow of the suctionchannels.

Examples of the invention are illustrated in the accompanying drawing, wherein:

FIG. I shows a cross-section of the concentric suction and a delivery valve;

FIG. 2 is a partial view indicating a modified arrangement of -a'packing ring; and

FIG.3 is a partial cross-sectional view showing another arrangement ofa packing ring.

' According to FIG. I the concentric suction and delivery valve is set into a valve housing I having a cylindrical bore 2. The valve housing I having a suction duct s and a delivery ductzr can he formed by the cylinder head ofa high pressure compressor or a high pressure pump. The valve body marked 3 on the left hand side is provided with suction channels 4 extending from its periphery, which run obliquely to a flat, conical'ordomed suction valve seating surface of the suction valve with which co-operates an annular obturating member 5, and are arranged surrounding a central bore 6 which serves for the through flow of the medium during the suction and delivery strokes. In the region of the entries to the oblique channels 4 an annular chamber 7 is provided between the channels and the housing 1 for the inflow ofthe medium. The central bore 6 in the valve body 3 leads through a central bore 10 in a suction valve lift-limiting member 9 and a central bore 11 in a delivery valveseat 12 to the obturating member 13 of the delivery valve, the chamber of which is connected through bores I4 with the pressure chamber 15 out of which the medium brought under pressure can flow away. To achieve efficient flow conditions, the entry openings to the central bores are well rounded.

In the arrangement illustrated during the suction stroke the medium to be compressed flows under the suction pressure in the direction of the arrow through the annular chamber. 7 into the oblique bores 4 and the obturating member 5 of the suction valve opens against theforce of the spring 5a. The obturating member 13 of the delivery valve is held closed during suction by the delivery pressure acting on it. During the delivery stroke the medium drawn in is compressed by a piston (not shown) working in a bore 27, the suction valve obturating member 5 being closed by the. pressure acting through a bore 5b and the delivery valve obturating member 13 being opened by the pressure acting directly on the latter.

An annular packing 16 of known kind is mounted on the left hand part of the valve body 3 at the inner end of the bore 18 in the housing 1, between the chamber 15 which is under delivery pressure and the chamber 7 which is under suction pressure.

Between the valve body 3 and the delivery valve seat 12 is an intermediate ring 8 which has a smooth bore 17. The liftlimiting member 9 for limiting the lift of the annular obturating member 5 is set in the bore 17.

So that the changes of form of the ring 8 as a result of the constant compression pressure acting on the outside cylindrical surface of the ring 8 and the suction and compression pressures acting alternately inside the bore 17, which changes can give rise to damaging friction corrosion on the abutment surfaces which can serve at the same time as seating surfaces, may be reduced, the ring 8 is made of a material which has a substantial higher modulus of elasticity and compressive strength than the material of the adjoining valve body 3and delivery seat 12. The changes of form of the ring 8 under the pressure action are reduced by the higher modulus of elasticity, and by corresponding choice of the internal and external diameter of the ring, the changes of form can be so related to those of the adjacent abutment surfaces of the valve body 3. and the delivery valve seat 12 that the relative movements under the internal and external pressure actions are reduced to a minimum at the abutment surfaces and thus the danger of harmful friction corrosion is reduced to a considerable extent.

So that the harmful effect of alternating stresses in the range of tension in the region of the oblique bores 4 arranged surrounding the central bore 6 in the valve body 3, which stresses increase as the bores 4 run nearer to the seating surfaces 19 for the annular suction valve obturating member 5 may be substantially reduced, the outer cylindrical surfaces of the valve body 3 is exposed to the constant delivery pressure over a short portion din the region of the zone in which the oblique bores 4 lie in the immediate neighbourhood of the outlet from the central bore 6. Thereby the stresses in the valve body 3 produced by the alternating pressure in the zone of the outlet from the central bore and the outlets of the oblique bores 4 are displaced into the range of compressive stresses.

In FIG. 1 this is achieved by the housing bore being stepped. The bore 18 of larger diameter than the bore 2, is carried in so deeply that the valve body 3 has the seating surface I9 projecting so far beyond the step 20 formed at the junction of the two housing bores 2 and 18 that after mounting of the packing 16 against the annular surface 20, the outer cylindrical surface of the suction end of the valve body 3 is brought over the predetermined length under the action of the constant delivery pressure. By this means the stresses arising from the alternating pressures acting in the central bore '6 and the out;

lets from the oblique bores 4 lying in the same neighbourhood are displaced into the range of compressive stresses.

The arrangement illustrated in FIG. I has the disadvantage that the cylindrical bore of the valve housing 1 must have a shoulder to receive the packing 16. FIG. 2 illustrates how this disadvantage can be removed. In this example the shoulder for receiving the packing 16 is provided on the valve body 3 and the bore in the housing I can be made without a step. The effect of the action of the delivery pressure on the suction valve end of the valve body 3 obtained in this way is similarto that obtained in the arrangement of FIG. 1.

It is however easily possible for both the bore in the valve housing 1 and the cylindrical external surface of the valve body 3 to be made without steps. Such an embodiment is illustrated in FIG. 3. In this case a cylindrical intermediate sleeve 26 which has a through opening 26a for the sucked in medium is inserted between the valve housing 1 and the valve body 3. The packing ring 16 bears against the outer end surface of the intermediate sleeve 26.

The valve body 3, the intermediate ring 8 with inserted suction valve lift-limiting member 9, the delivery valve seat 12 and the delivery valve lift-limiting member 21 are centred and combined into a common insertable and removable unit by an external sleeve 22.

As shown by way of example in FIG. 1 the sleeve 22 for effecting this has a shoulder 23 at the right hand end and an internal screw thread 24 at the left hand end which is screwed on to corresponding external threads on the right hand end of the valve body 3. Obviously other securing means could be used on the valve body 3.

lclaim:

l. A combined suction and delivery valve for high pressure compressors and pumps, comprising a housing 1 with a bore having a suction duct (s) and a delivery duct (x) leading thereto, a valve body 3 located within said housing boreand having a central bore 6 and suction channels 4 communicating with said suction duct, said suction channels extending obliquely from the periphery of said valve body to a side face of said valve body forming a suction valve seating surface 19, an intermediate ring 8 having a central bore 17 located adjacent the peripheral portion of said seating surface 19, a suction valve located coaxially within said central bore 17 and having a central bore 10, said suction valve comprising a coaxially located annular suction valve obturating member 5, means biasing said suction valve obturating member onto said valve seating surface to block said suction channels and an annular valve lift limiting member 9 cooperating with said obturating member, a delivery valve located adjacent said suction valve and said intermediate ring comprising an annular valve seat member 12 having a central bore 11 communicating with said delivery duct and a lift limiting member 21 located coaxially with respect to said valve seat member 12, an obturating member 13 guided in said lift limiting member to obturate said central bore 11 of said valve seat member 12, means biassing said obturating member 13 against said valve seat member 12, said central bores 6, 10, 11 forming a unitary bore for communicating with the working bore 27 of a piston, the fluid to be compressed enters said housing through said suction duct (s) and said oblique suction channels 4 to fill said central bores 6, 10, 11 and is then delivered, during the delivering stroke of said piston through said delivery valve and said delivery duct (x), said valve body (3) with said intermediate ring 8, said suction valve 9, 5 and said delivery valve 12, 13, 14 constituting a unit which can be inserted in and removed from said housing as a Whole.

2. A valve according to claim 1 wherein said valve body, said intermediate ring, said delivery valve seat member 12 and said delivery valve lift-limiting member 21 are held together by a sleeve fitting said bore in said housing, said sleeve at one end having a shoulder engaging said delivery valve lift-limiting 21 member and at the other end is connected to said valve body.

3. A valve according to claim 1 wherein said intermediate ring is made of a material of higher modulus of elasticity and higher compressive strength than the material of said valve body and said delivery valve seat member 12.

4. A valve according to claim 1 wherein a packing ring is arranged on the periphery ofsaid unit.

5. A valve according to claim 4 wherein a shoulder is provided in said bore in said housing against which said packing ring bears.

6. A valve according to claim 4 wherein a shoulder is provided on the periphery of said valve body against which said packing ring bears.

7. A valve according to claim 4 wherein an intermediate sleeve is inserted between said housing and said valve body serving as an abutment for said packing ring.

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