GB2268999A

GB2268999A - Rotary valve assembly

Info

Publication number: GB2268999A
Application number: GB9314030A
Authority: GB
Inventors: Simon Richard Stone
Original assignee: Meco Mining Equipment Ltd
Current assignee: Meco Mining Equipment Ltd
Priority date: 1992-07-23
Filing date: 1993-07-07
Publication date: 1994-01-26
Also published as: ZA935083B; DE4324666A1; AU4191293A; GB9215637D0; GB9314030D0

Abstract

A rotary valve assembly, particularly for use in mining equipment, comprises a valve body 10 and a valve member 21 rotatable in the valve body about an axis 22. The valve member has an annular, part spherical surface extending about the axis 22, first, second, third and fourth angularly spaced ports 32, 33, 34 and 35 in the part spherical surface and a fifth port 36, 37 in the valve member. The fifth port is axially spaced from the first to fourth ports. The first and second ports are connected by first passage means 38 in the valve member and the third, fourth and fifth ports are connected by second passage means 39, 43, 44 in the valve member. The valve body 10 has four angularly spaced annular valve seats 27, 29 which co-operate with the valve member and which, according to the angular position of the valve member relative to the valve body, sealingly communicate each of at least three of the first to fourth ports with one of at least three ports 15, 16 and 17 in the valve body, the fifth port in the valve member being in permanent communication with a further port 18 in the valve body. In addition to being openable to switch the direction of flow to and from a hydraulic ram 50, the valve may be set to connect both sides of the ram to supply P (Fig. 6) so that the ram will extend more slowly, or to connect both sides to tank R. <IMAGE>

Description

2268999 ROTARY VALVE ASSEMBLY This invention relates to a rotary valve

assembly and more particularly, but not exclusively, to 5 such an assembly for operating an hydraulic ram.

There is sometimes a requirement to operate hydraulic rams in any one of four different modes, namely extend under full pressure, extend under differential pressure (with both sides of the piston connected to pressure), retract and float (with both sides of the piston connected to drain). Known valve assemblies for operating rams in this manner make use of at least two valve members and are complex and expensive.

According to the present invention there is provided a rotary valve assembly comprising a valve body, a valve member angularly movable within the valve body about an axis, the valve member having an annular, part spherical surface extending about said axis, first, second, third and fourth angularly spaced ports in said annular, part spherical surface and a fifth port in the valve member, the fifth port being axially spaced from said first to fourth ports, the first and second ports being connected by first passage means in the valve member and the third, fourth and fifth ports being connected by second passage means in the valve member and the valve body having four angularly spaced annular valve seats which co-operate with the valve member and which, according to the angular position of the valve member relative to the valve body, serve to sealingly communicate each of at least three of the first to fourth ports with one of at least three ports in the valve body, the fifth port in the valve member being in permanent communication with a further port in the valve body.

The valve member of such a rotary valve assembly can be angularly moved between any one of four positions to give four different modes of operation of an hydraulic device connected to the valve member.

is Preferably, the first and second ports in the valve member are angularly adjacent to one another and the third and fourth ports in the valve member are angularly adjacent to one another.

Advantageously, the first to fourth ports in the valve member are equiangularly spaced about said axis of the valve member. In this case, preferably, the four valve seats are mounted in the valve body in equiangularly spaced relationship relative to said axis of the valve member.

Preferably, the first to fourth ports in the valve member are arranged in a common plane substantially perpendicular to said axis. In this case, advantageously, the first passage means is arranged substantially to one side of said common plane and the second passage means is arranged substantially to the other side of said common plane.

Preferably, the fifth port in the valve member is provided in a generally cylindrical portion of the valve member and between two axially spaced annular seals.

Typically, the rotary valve assembly is used to operate a double acting hydraulic rain. In this case the three ports and the further port in the valve body are each connected to one of a source of pressurised fluid, drain, and opposite sides of the ram.

The invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which:- Figure 1 is a section taken through one embodiment of a rotary valve assembly according to the present invention, Figure 2 is a section taken along line II-II of Figure 1 but showing part only of the rotary valve assembly, Figure 3 is a schematic view of the rotary valve assembly of Figures 1 and 2 in combination with an hydraulic ram, the rotary valve assembly being shown in a first operative position to extend the ram under full pressured.

Figure 4 is a schematic view similar to Figure 3 but showing the rotary valve assembly in a second operative position to retract the ram, Figure 5 is a schematic view similar to Figures 3 and 4 but showing the rotary valve assembly in a third operative position connecting both sides of the piston of the ram to drain, Figure 6 is schematic view similar to Figures 3, 4 and 5 but showing the rotary valve assembly in a fourth operative position connecting both sides of the piston to pressure, Figure 7 is a view similar to Figure 1, but showing another embodiment of a rotary valve assembly according to the invention, and Figure 8 is a section taken along line VIIIVIII of Figure 7.

Referring firstly to Figures 1 and 2, a rotary ball valve assembly is shown therein and comprises a valve body 10 having f our removable bushes 11, 12, 13 and 14 def ining ports 15, 16, 17 and 18, respectively, and a removable plug 19 blanking of f an opening 20. The bushes 11 to 14 and the plug 19 are all screw threadably engaged with the valve body 10.

The rotary ball valve assembly also comprises a valve member 21 rotatable in the valve body 10 about an axis of rotation 22. The valve member 21 has a portion 23 protruding from the valve body 10 f or the attachment of a handle, two generally cylindrical portions 24 and 25 and an annular, part spherical portion 26 intermediate the cylindrical portions 24 and 25.

The valve body 10 is equipped with four equi angularly spaced, annular valve seats 27, 28, 29 and 30 which co-operate with the annular, part spherical portion 26 of the valve member 21. The valve seat 27 is supported by a collar 31 and is in f luid communication with the port 15 in the bush 11. The seats 28 and 29 are supported by the inner ends of the bushes 12 and 13, respectively, and are in fluid communication with the ports 16 and 17, respectively. The seat 30 is supported by the inner end of the plug 19.

The annular, part spherical portion 26 of the valve member 21 has four equi-angularly spaced ports 32, 33, 34 and 35 and the generally cylindrical portion 25 of the valve member 21 has two ports 36 and 37. The ports 32, 33, 34 and 35 are disposed in a common plane perpendicular to the axis 22 and, with the valve member 21 in the position shown in Figures 1 and 2, these ports 32, 33, 34 and 35 communicate respectively with the ports 15, 16 and 17 and with the blanked off opening 20. Ports 32 and 33 are connected by a first generally Lshaped passage 38 arranged substantially above the aforesaid common plane and ports 34 and 35 are connected by a second generally L-shaped passage 39 arranged substantially below the aforesaid common plane.

The ports 36 and 37 communicate with an annular chamber in the valve body 10 between two 0-ring seals (not shown) located in grooves 40 and 41 in the cylindrical portion 25 of the valve member 21 and the aforesaid annular chamber communicates with the port 18 in the bush 14 by way of a passage 42 in the valve body 10. The ports 36 and 37 are interconnected by a passage 43 extending diametrically across the cylindrical portion 25 of the valve member 21 and the passage 43 communicates with the second generally Lshaped passage 39 by way of an axially extending passage 44 in the portions 25 and 26 of the valve member 21.

The two ports 36 and 37 could be replaced by a single port.

The ports 36 and 37 remain in permanent communication with the port 18, but the valve member 21 is rotatable between four operative, angularly spaced positions in which the ports 32, 33, 34, and 35 and the passages 38 and 39 in the valve member 21 connect the ports 15, 16 and 17 and the blanked of f opening 20 in different ways.

In one specific example, the rotary ball valve assembly is used to control the operation of a double acting hydraulic ram 50 (see Figures 3 to 6). The port 15 is connected to drain, the port 16 is connected to the annular area of the ram 50, the port 17 is connected to a source of f luid under pressure and the port 18 is connected to the full (or head) area of the ram.

With the valve member 21 in the position shown in Figure 3, fluid under pressure is supplied to the full area of the ram 50 and the annular area of the ram is connected to drain. The ram 50 will therefore extend under full pressure.

With the valve member 21 in the position shown in Figure 4, the annular area of the ram 50 is connected to fluid under pressure and the full area of the ram 50 is connected to drain. The ram 50 will therefore retract.

With the valve member 21 in the position shown in Figure 5, the annular area and the full area of the ram 50 are connected to drain. The ram 50 will therefore float.

With the valve member 21 in the position shown in Figure 6, the annular arba and the full area of the ram 50 are connected to fluid under pressure and the ram 50 will extend more slowly than when the valve member 21 is in the position shown in Figure 3 because the piston of the ram will be subjected to the differential pressure across it.

It is particularly useful to be able to provide these four modes of operation of an hydraulic ram in some mining applications. For example, the ability to extend a ram under full pressure and under differential pressure has particular application in operating side flaps on the canopies of mine roof supports. Extension of the ram under differential pressure can be used to seal the f lap or f laps of one canopy against an adjacent canopy in order to prevent roof debris from falling into the roof supports whereas extension of the ram under full pressure can be used to steer one roof support relative to an adjacent roof support as it is advanced towards a mine face being worked.

It is envisaged that there may be applications for the rotary ball valve assembly described above in which the opening 20 is not blanked off by a plug 19 and the plug 19 is replaced by a bush having a port therein communicating with the annular seat 30. Such an arrangement is included within the scope of the invention.

It is also envisaged that the generally cylindrical portion 24 of the valve member 21 could have one or more ports, similar to ports 36 and 37, which communicate with an annular chamber in the valve body 10 between two further 0-ring seals, for connecting the passage 38 to another port in the valve body 10.

Also, the ports 32, 33, 34 and 35 need not be equi-angularly spaced about the axis 22. For example, they could be spaced apart over an angle of about 1800.

Figures 7 and 8 show another embodiment of a rotary ball valve assembly. In this embodiment, the arrangement of the ports 151, 161, 171 and 181 is different. Ports 151, 171 and 181 are provided in the valve body 101 rather than in removable plugs. Also ports 361 and 371 are provided in the upper and lower surfaces of the part spherical portion 261 of the valve member 211. These ports 361 and 371 communicate with the L-shaped passage 391 by way of a passage 431 in the part spherical port 261 and with the port 181 by way of a chamber 51 and an annular passage 421 in the valve body 101. one of these ports 361 and 371 could be omitted. The operation of this rotary ball valve assembly is, however, similar to the operation of the ball valve assembly shown in Figures 1 and 2.

Claims

C L A I M S

A rotary valve assembly comprising a valve body, a valve member angularly movable within the valve body about an axis, the valve member having an annular, part spherical surface extending about said axis, first, second, third and fourth angularly spaced ports in said annular, part spherical surface and a f ifth port in the valve member, the f ifth port being axially spaced from said f irst to fourth ports, the f irst and second ports being connected by first passage means in the valve member and the third, fourth and fifth ports being connected by second passage means in the valve member and the valve body having four angularly spaced annular valve seats which co-operate with the valve member and which, according to the angular position of the valve member relative to the valve body, serve to sealingly communicate each of at least three of the first to f ourth ports with one of at least three ports in the valve body, the fifth port in the valve member being in permanent communication with a further port in the valve body.
2. A rotary valve assembly as claim in claim 1, wherein the first and second ports in the valve member are angularly adjacent to one another and the third and fourth ports in the valve member are angularly adjacent to one another.
3. A rotary valve assembly as claimed in claim 1 or claim 2, wherein the f irst to fourth ports in the valve member are equi-angularly spaced about said axis 5 of the valve member.
4. A rotary valve assembly as claimed in claim 3, wherein the four valve seats are mounted in the valve body in equi-angularly spaced relationship relative to said axis of the valve member.
5. A rotary valve assembly as claimed in any one of the preceding claims, wherein the f irst to fourth ports in the valve member are arranged in a common plane substantially perpendicular to said axis.
6. A rotary valve assembly as claimed in claimed in claim 5, wherein the first passage means is arranged substantially to one side of said common plane and the second passage means is arranged substantially to the other side of said common place.
7. A rotary valve assembly as claimed in any one of the preceding claims, wherein the f ifth port in the valve member is provided in a generally cylindrical portion of the valve member and between two axially spaced annular seals.
8. A rotary valve assembly as claimed in any one of claims 1 to 6, wherein the valve member comprises two substantially cylindrical portions and a part spherical portion between the two cylindrical portions and the fifth port in the valve member is provided in one end of the part spherical portion.
9. A rotary valve member as claimed in any one of the preceding claims, in combination with a double acting hydraulic ram, the three ports and the further port in the valve body being each connected to one of a source of pressurised fluid, drain, and opposite sides of the ram.
10. A rotary valve member substantially as hereinbefore described with reference to the accompanying drawings.

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