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Compact seal for reciprocating shaft
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Compact seal for reciprocating shaft
94~1 ~ 98, 110 )
Tide: Rotary reciprocating seals with exterior metal band Patent number: US5979904 Date: 9 November 1999 Inventor: P J Balsells Assignee: Bal Seal Engineering Co Inc A seal fitted to a reciprocating shaft is subjected to forces which tend to distort it. The seal must be flexible, but it must retain its shape at the sealing surfaces on the shaft and the stationary housing. A conventional seal assembly has an outer metal ring for fitting into the stationary housing, and the seal is fixed to the ring using an adhesive. The outside diameter of the seal must be considerably larger than the shaft diameter, so that the seal has enough flexibility. The seal assembly described in this patent has grooves in the outer ring, and it uses a spring within the seal to provide flexibility. This design means that the outer diameter can be less, making the assembly more compact.
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92
/
46 140
......
28 90
Sealing Technology No. 75
24, 32
/48
50
Figure 1 shows the construction of the assembly. The seal 12 is located in the outer ring 26. Spring 28 fits in between the inner flange 18 and the outer flange 20, and it presses the flanges onto the sealing surfaces of the shaft and stationary housing. The outer ring has a groove around its inner surface and also a number of grooves which are parallel to the shaft. On assembly the seal is pushed into the outer ring and is held in place by the grooves. The grooves parallel to the shaft prevent the seal rotating.
Tide: Rotatable valve assembly Patent number: US597445 Date: 7 September 1999 Inventors: Z Wang, J A Tomasko, S P Farwell Assignee: BS&B Safety Systems Inc
n the outer ring 26
130
88 /
90 ___
142 92, 128
5~0.0 /
92, 124
22
100, 122
can be used for pressure relief. Rotatable valves have been used in this way, but the high level of friction in the valve seals means that a large torque is needed to operate them, and they do not always open at the required pressure. As an example, the patent describes a butterfly valve. The improved design has a lowfriction seal, and the mechanism which operates the valve is more reliable and can be set accurately. Figure 2 shows the seal acting on the disc of a butterfly valve which opens by rotating about shaft 28. Seal 114 is in the form of a ring and has a small area of contact with the
Rotatable pressure relief valve
Figure 1: Compact seal lor reciprocating shaft. Sprinq 28 presses flanqes 18 and 20 onto the
J
L I O 0 , 112
,/o
70
54
This patent shows how a rotatable valve (which is opened and closed by rotating the valve spindle), such as a butterfly valve or a ball valve,
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Compact seal for reciprocating shaft
94~1 ~ 98, 110 )
Tide: Rotary reciprocating seals with exterior metal band Patent number: US5979904 Date: 9 November 1999 Inventor: P J Balsells Assignee: Bal Seal Engineering Co Inc A seal fitted to a reciprocating shaft is subjected to forces which tend to distort it. The seal must be flexible, but it must retain its shape at the sealing surfaces on the shaft and the stationary housing. A conventional seal assembly has an outer metal ring for fitting into the stationary housing, and the seal is fixed to the ring using an adhesive. The outside diameter of the seal must be considerably larger than the shaft diameter, so that the seal has enough flexibility. The seal assembly described in this patent has grooves in the outer ring, and it uses a spring within the seal to provide flexibility. This design means that the outer diameter can be less, making the assembly more compact.
rt~
"~J/e//~
92
/
46 140
......
28 90
Sealing Technology No. 75
24, 32
/48
50
Figure 1 shows the construction of the assembly. The seal 12 is located in the outer ring 26. Spring 28 fits in between the inner flange 18 and the outer flange 20, and it presses the flanges onto the sealing surfaces of the shaft and stationary housing. The outer ring has a groove around its inner surface and also a number of grooves which are parallel to the shaft. On assembly the seal is pushed into the outer ring and is held in place by the grooves. The grooves parallel to the shaft prevent the seal rotating.
Tide: Rotatable valve assembly Patent number: US597445 Date: 7 September 1999 Inventors: Z Wang, J A Tomasko, S P Farwell Assignee: BS&B Safety Systems Inc
n the outer ring 26
130
88 /
90 ___
142 92, 128
5~0.0 /
92, 124
22
100, 122
can be used for pressure relief. Rotatable valves have been used in this way, but the high level of friction in the valve seals means that a large torque is needed to operate them, and they do not always open at the required pressure. As an example, the patent describes a butterfly valve. The improved design has a lowfriction seal, and the mechanism which operates the valve is more reliable and can be set accurately. Figure 2 shows the seal acting on the disc of a butterfly valve which opens by rotating about shaft 28. Seal 114 is in the form of a ring and has a small area of contact with the
Rotatable pressure relief valve
Figure 1: Compact seal lor reciprocating shaft. Sprinq 28 presses flanqes 18 and 20 onto the
J
L I O 0 , 112
,/o
70
54
This patent shows how a rotatable valve (which is opened and closed by rotating the valve spindle), such as a butterfly valve or a ball valve,
@