Seal for piston rods and pistons of piston machines

Claim 2

A composite seal for a reciprocable member of reciprocable piston machines for sealing a high pressure side relative to a low pressure side, which includes: a first group of sealing units for use at the high pressure side, and a second group of sealing units for sealing units for sealing at the low pressure side, said groups being in substantially axial alignment with each other, and each of the sealing units of each of said groups having a supporting ring and a split sealing ring for sealing engagement with the reciprocable member to be sealingly engaged, the supporting rings having their inner diameter so dimensioned as to engage the reciprocable member to be sealingly engaged without radial play, the sealing rings having a substantially cylindrical mantle surface, and a resilient covering ring biased inwardly and surrounding said sealing ring, said covering ring having a split arranged substantially diametrically opposite the split of said sealing ring.

Claim 3

A composite seal according to claim 1, in which the inner diameter of said supporting rings is undersized actually only slightly less than the outer diameter of the reciprocable member to be sealingly engaged thereby, a circumferential portion of said supporting rings having a break therein for sliding the same into position, said supporting rings accordingly serving double function of sealing and support.

Claim 4

A composite seal according to claim 1, in which said sealing rings of said first group are resilient and biased inwardly.

Claim 5

A composite seal according to claim 1, in which the sealing rings of said second group consist of soft packing material requiring no run-in period.

Claim 6

A composite seal for a reciprocable member of reciprocable piston machines for sealing a high pressure side relative to a low pressure side, which includes: a first group of sealing units for use at the high pressure side, and a second group of sealing units for sealing at the low pressure side, said groups being in substantially axial alignment with each other, and each of the sealing units of each of said groups having a supporting ring and a sealing ring for sealing engagement with the reciprocable member to be sealingly engaged, sealing rings having a split with plane surfaces which together with the tangential plane to the contour of the inner periphery of the respective sealing ring through the line of section of said plane surfaces with the inner contour of the pertaining sealing ring form an angle of from 20* to 60*, the distance between said plane surfaces of the respective split having a magnitude corresponding to the difference in the thermal longitudinal extension of the sealing ring during the manufacturing temperature thereof and the thermal longitudinal extension of the reciprocable member to be sealingly engaged at the maximum temperature of operation and the distance equaling substantially zero between said pLane surfaces at the same maximum speed of operation of said reciprocable member.

Claim 7

A composite seal for a reciprocable member of reciprocable piston machines for sealing a high pressure side relative to a low pressure side, which includes: a first group of sealing units for use at the high pressure side, and a second group of sealing units for sealing at the low pressure side, said groups being in substantially axial alignment with each other, and each of the sealing units of each of said groups having a supporting ring and a sealing ring for sealing engagement with the reciprocable member to be sealingly engaged, sealing rings having a split with plane surfaces which together with the tangential plane to the contour of the inner periphery of the respective sealing ring through the line of section of said plane surfaces with the inner contour of the pertaining sealing ring form an angle of from 20* to 60*, the distance between said plane surfaces of the respective split having a magnitude corresponding to the difference in the thermal longitudinal extension of the sealing ring during the manufacturing temperature thereof and the thermal longitudinal extension of the reciprocable member to be sealingly engaged at the maximum temperature of operation and the distance equaling substantially zero between said pLane surfaces at the same maximum speed of operation of said reciprocable member.