초록 ▼

A seal assembly between a rotatable hollow outer shaft and a rotatable inner shaft for sealing a high pressure fluid reservoir from a low pressure fluid reservoir. Axially spaced radially extending first and second runners are attached to the inner shaft. An annular seal ring surrounds and is radial

A seal assembly between a rotatable hollow outer shaft and a rotatable inner shaft for sealing a high pressure fluid reservoir from a low pressure fluid reservoir. Axially spaced radially extending first and second runners are attached to the inner shaft. An annular seal ring surrounds and is radially spaced from the inner shaft and disposed between the runners. Fluid flow from the high pressure reservoir to the low pressure reservoir in a path defined by spaces formed between the seal ring and the shafts and runners, and axially through passages in the seal ring. The hydrostatic forces imposed on the seal ring tend to maintain it in its proper position. Radially extending grooves are machined in the opposed surfaces of the runners generating a hydrodynamic lift force between the seal ring and runners proportionate to relative rotation between the shafts, for axially sliding the seal ring relative to the outer shaft in response to relative axial movement between the shafts and for maintaining the flow of fluid and preventing rubbing contact between the seal ring and the runners.

대표청구항 ▼

A seal assembly positioned between a rotatable hollow outer shaft and a rotatable inner shaft within the outer shaft, for sealing a high pressure fluid reservoir from a low pressure fluid reservoir, comprising: axially spaced radially extending first and second runners attached to the inner shaft an

A seal assembly positioned between a rotatable hollow outer shaft and a rotatable inner shaft within the outer shaft, for sealing a high pressure fluid reservoir from a low pressure fluid reservoir, comprising: axially spaced radially extending first and second runners attached to the inner shaft and radially spaced from the outer shaft, the runners having opposed, radially extending side surfaces, the first runner disposed adjacent to the high pressure fluid reservoir; an annular seal ring surrounding and radially spaced from the inner shaft, a portion of the seal ring extending radially to slidably contact the outer shaft, the seal ring being disposed between the runners and having side surfaces that are spaced from the opposed side surfaces of the runners; an annular spacer attached to the inner shaft and extending axially between the runners a predetermined distance greater than the axial width of the seal ring and being radially spaced from the seal ring; hydrostatic means, including seal ring flow passage means including a plurality of flow passages extending axially through the seal ring for admitting the fluid to flow axially through the seal ring, for utilizing the pressure differential between the high pressure fluid reservoir and the low pressure fluid reservoir to create hydrostatic forces on the seal ring that tend to maintain the side surfaces of the seal ring substantially uniformly spaced from the respective radially extending side surfaces of the runners, said hydrostatic means further including a plurality of flow passages extending axially through the first runner and located radially proximate the space between the seal ring and the spacer, whereby the radially-inward axially-extending surface of the seal ring is subjected to fluid at the high pressure, wherein the seal ring flow passage means further includes a first annular recess formed in the side surface of the seal ring adjacent the first runner and a second annular recess formed in the opposite side of the seal ring, the plurality of the flow passages in the seal ring extending between and being in fluid communication with the first and second recesses, the recesses being dimensioned and configured to create substantially uniform pressure adjacent to the recesses; and hydrodynamic means, including means formed in the opposed radially extending side surfaces of the runners, for generating a hydrodynamic lifting force proportionate to relative rotation between the inner and outer shafts to axially slide the seal ring relative to the outer shaft in response to relative axial movement between the inner and outer shafts and thereby prevent the seal ring from contacting the runners.