FR2492035A1 - MECHANICAL JOINT ASSEMBLY - Google Patents

Abstract

THE PRESENT INVENTION CONCERNS AN ASSEMBLED MECHANICAL SEAL 10 INTENDED TO BE USED SPECIFICALLY IN CHEMICAL INDUSTRIES, OR A SLEEVE 36 SEALED TO THE CHEMICALS INVOLVED SURROUNDED BY A SPRING MEANS 24 WHICH REQUESTS THE SEALING FACES 20, 22 TOWARDS ONE. OTHERWISE, THE SPRING IS CAPABLE OF TRANSMITTING TORQUE AND PROVIDING AXIAL SUPPORT OF THE SLEEVE.

Description

1.

  The present invention relates to mechanical seals

  what assembled. We know in the prior art seals

  assembled mechanical seals between fluids

  des, which are associated with a fixed housing and a ro-

  tative. The housing may contain a pump rotor connected to the rotary shaft. In order to substantially eliminate the leakage of the pump fluid in the housing, use is made

  an assembled mechanical seal. Generally, these mechanical seals

  niques include a sealing ring connected to the housing

  and a sealing ring connected to the shaft, the rings

  having opposite sealing faces and one of these fa-

  these being urged elastically towards the other or the two faces being both urged elastically towards one another. Such a construction can leave the elastic means exposed to one of the fluids, i.e. 1) to the

  pumped fluid and 2) air or other fluid. If the fluid

  pump is chemically active, it can corrode and damage

  mage the elastic means and / or other parts of the assembly

  corn. The present invention relates to an assembled mechanical seal, specially constructed for use in

  chemical applications where corrosive fluids are handled

  strips, which has a coating impermeable to chemical bodies

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  and intended to protect the various parts of the whole

  ble against contact with corrosive fluids. More specific

  specifically, the assembly includes a ring seal

  tative and a classic fixed sealing ring between the

  which is mounted a coil spring which biases them

  towards each other. Preferably, a tube made of plastic material

  a heat shrinking tick surrounds the spring and one end thereof is sealed at one end of a spring retainer, and at its other end at one of

  sealing rings, the tube being made of fluorine-ethylene-propy-

  lene. Other elastomers can be used to enclose

  sea spring, in which case other methods will have to be used

  of the junction of this sleeve, or shirt, to the parts of

extremity.

  The present invention will be well understood during-

  the following description made in relation to the drawing below

joint in which:

  The figure is a view in longitudinal section, through

  part of a mechanical seal assembled according to this in-

vention.

  The assembled mechanical seal shown in 10

  takes a fixed sealing ring 12 sealed to a housing

  14 in several parts by an O-ring 16 and a ba-

  rotary seal 18, the rings 12 and 18 comprise

  both facing faces 20 and 22, respectively. The plac-

  that 18 is biased towards the ring 12 by a spiral spring 24, one end of which surrounds a reduced part of

  the ring 18 and is in friction contact with this part

  tie, and the other end surrounds a reduced part 20 of a spring retaining member 30 and is in friction contact with this part, the latter being intended to be

  connected to a rotary shaft 32 by a stop screw 34 and

  due watertight by an O-ring 35 .. As a result of the connection

  sound of the retaining member 32 with the shaft 32 and the res-

  comes out 24, the sealing ring 18 can rotate with the shaft 32. A sleeve, or jacket, 36 surrounds the spring 24 and

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  extends over parts of the sealing ring 18 and of the spring retaining member 30. One end of the sleeve 36 is received in an annular groove 38 of the ring 18 and is fixed there by an O-ring 40. The other end of the sleeve 36 is received in an annular groove 42 formed in the retaining member 30 and is fixed there by a seal

toric 44.

  Preferably, the sleeve 36 consists of a tu-

  be heat shrinking to fluorine-ethylene-propylene.

  Part of the seal 10 can be constructed as a cartridge

  che, that is to say that a retaining member 30, a sealing ring 18 and a spring can be mounted in a mandrel. A section of the fluorine-ethylene-propylene tube is slid over the mounted parts, then the O-rings 40 and 44 are put in place in the appropriate grooves 38 and 42, respectively. Hot air is then directed onto the tube, which causes it to shrink and gives it the shape shown in the drawing. The parts can then be extracted from the mandrel to then be mounted with the

sealing ring 12.

  For uses where high pressure prevails,

  multiple sleeves can be used in layers.

  It will be understood that other types of elastomers can

  can be used to enclose the spring 24, in which case other methods of joining the sleeve, or liner, to the end pieces would be necessary, The spring 24 serves to support the sleeve, or liner, and allows the use of the joint assembled at much higher pressures in the absence of radial support,

  The present invention is not limited to the examples

  ples of realization which have just been described, it is on the contrary susceptible of modifications and variants which will appear to the person skilled in the art,

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Claims (5)

  1 - Mechanical seal assembled, more adaptable   especially in the chemical industries and associated with a rotary shaft and a fixed housing which can contain chemically active fluids, characterized in that it comprises: - a fixed sealing ring (12) associated with the housing; - a rotary sealing ring (18) associated with the shaft; - the sealing rings comprising sealing faces (20, 22) facing each other;   - an elastic means (24) urging one of the bases   gues towards each other; and - a fluid-tight means (36) consisting of   plastic shrink shirt.   2 - Mechanical seal assembled according to the claim   tion 1, characterized in that the plastic material   heat-shrinking is fluoroethylene-propylene.   3 - Assembled mechanical seal according to claim 1, characterized in that the elastic means is a spring, and in that it further comprises a spring retaining member (30) for positioning one end of the   second seal ring at one end of the seal.   4 - Assembled mechanical seal, intended for more   especially to be used with chemically active fluids, characterized in that it comprises: - a fixed sealing ring (12) intended to be connected to a housing; - a rotary sealing ring (18) intended to be connected to a rotary shaft; - a sealing ring comprising two opposite faces (20, 22); - a spiral spring (24) urging the rotary sealing ring towards the fixed sealing ring; - a retaining member (30) intended to be connected to the rotary shaft so as to position one end of the spring; 5. 2492035   - a fluid-tight jacket (36) surrounding the spring; - Means (38, 40, 42, 44) sealingly sealing the ends of the envelope to the retaining member and to the fixed sealing ring respectively; - the fluid-tight shirt being made up   of heat shrinking ethylene propylene.