Mechanical seal incorporating a pusher ring for safe

Mechanical seal incorporating a pusher ring for safe

An improved mechanical seal incorporating a pusher ring to hold the integral parts of the seal together, in lieu of a typical retaining ring and snap ring aligning and compressing the gland plate. The improvement consists of a pusher ring, fixedly attached to the seal body gland face with cap screws, which retains the gland plate, allowing for easy and safe repair and assembling.

A mechanical seal provides a hydraulic seal between a rotatable element, typically, a shaft and a stationary housing of the apparatus. Such seals are associated with a fluid pump having a shaft extending through a pump housing wall, handling fluids of varying viscosity. The lower the viscosity of the fluid being handled, the tighter the seal required within the pump design.

Although these seals are most commonly employed on pump equipment, other fluid handling equipment also utilize mechanical seals. So, although the present invention is addressed in terms of pump applications, the invention is not restricted therein, but may be employed on all such equipment having mechanical seals.

The pump shaft is typically coupled to a motor through a motor shaft. The mechanical seal forms a seal between the pump shaft and the outer surface of the pump housing. Mechanical seals for such applications are commercially available and have been available for more than 25 years.

Seals, Generally

Seals, in their most common and most basic form, are known in the art and comprise rotatable components and stationary components which contact to form a seal at opposing sealing surfaces. The rotatable components include a shaft attachment means. Such a means is typically a sleeve having an inner perimeter surface which sealingly fits over the outer perimeter surface of the shaft and is connected to the shaft, by connecting means such as set screws. An “O” ring typically provides a seal between the shaft and the sleeve. There is a rotatable circumferential seal element interconnected to the sleeve so as to rotate when the shaft and sleeve rotate. The sleeve extends axially along the shaft.

The stationary components comprise a gland which extends circumferentially around the shaft. The gland abuts against the outer housing surface around the shaft. There is typically a sealing gasket interconnected to the gland and located between the gland and the housing. The gland functions as a base by which the seal is attached to the housing. The connection is typically accomplished by bolts extending from the outer housing wall. The bolts pass through slots or connecting extensions extending radially from the gland through the connecting slots or connecting extensions and secured with nuts. A stationary seal element is located between the inner circumferential surface of the gland facing the shaft (i.e. the gland inner surface) and the shaft. The stationary seal is directly or indirectly connected to the stationary gland. There are suitable means such as described in U.S. Pat. Nos. 4,832,351 and 4,989,882 to axially center the various stationary elements on the shaft. A circumferential spacing is maintained between the stationary elements, and the shaft and various of the rotating elements.

Mechanical Seals, Specifically

The mechanical seal also comprises rotatable components and stationary components. The rotatable components are interconnected to the shaft and rotate with the shaft. The stationary components are interconnected to the housing and do not rotate. The rotatable components and stationary components are positioned relative to each other so that a rotatable seal surface sealingly engages a stationary seal surface. Such a mechanical seal is particularly useful to form seals on machines which have rotatable shafts extending therefrom and fluid inside such as fluid pumps, i.e., water pumps, which have close tolerances, particularly in applications requiring the handling of caustic chemicals or flammable liquids. They are also widely used in nuclear reactor cooling systems to contain radioactive liquids. Typical mechanical seals are designed for leakage of less than one one-thousandth of one percent of the volume of the liquid pumped, per unit time.

The prior art mechanical seals date back to the early 1980′s. They have existed for many years, as relative to this art. There has existed, however, safety concerns over a number of the seals because they generally employ snap rings on the seal which, while being installed or removed, can become projectiles which pose a threat to the mechanics.

Original designs used a heavy duty snap ring just inside the gland to hold the integral parts of the seal together. This snap ring was rated at upwards of 80,000 ft. lbs. of axial thrust load. This is more axial thrust load than any pump would ever experience with these seals, and was extreme for a snap ring as applied to these seals. Therefore, when the snap ring was removed, special pliers had to be employed, and risk of severe injury was possible because of the loaded spring causing the threat of projectiles.

Mechanical seals known in the art have at least one “O” ring associated with the sealing element being acted on, and in most instances, acted on by the spring. The spring forces this element toward the opposing element to form a seal. The “O” ring must form a seal not withstanding the axial movement and is known as a “dynamic-O” ring. Additionally, the dynamic “O” ring is located in an “O” ring slot which can clog. The spring must, therefore, provide force to cause the sealing elements to come together under sufficient pressure to form a seal while overcoming the resistance of the dynamic-O ring.

It would be desirable to eliminate the metal spring installed in concert with the dynamic “O” ring, and that is the present sense of the invention disclosed and claimed herein. The present invention retains all the favorable characteristics of the “O” ring, but without the disadvantages of snap ring and retaining rings, the mechanisms which create the dangerous tendency of the spring mechanisms in current art.

Additionally, the means to connect the mechanical seal to the housing is integrated into the structure of the stationary components. The mechanical seal is often set in place and removed in the small space between the pump and motor. The means to attach the seal takes up space and make access to the mechanical seal difficult for both installation and removal. A design with easier access to the seal elements at the location where the shaft extends from the housing is desirable, also an attribute of the present invention.

Seals and Sealing Handbook, Fifth Edition

Seals and Sealing Handbook, Fifth Edition

Wherever machinery operates there will be seals of some kind ensuring that the machine remains lubricated, the fluid being pumped does not leak, or the gas does not enter the atmosphere. Seals are ubiquitous, in industry, the home, transport and many other places. This 5th edition of a long-established title covers all types of seal by application: static, rotary, reciprocating etc. The book bears little resemblance to its predecessors, and Robert Flitney has re-planned and re-written every aspe

List Price: $ 180.00

Price:

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More Mechanical Seals Products

Principles and Design of Mechanical Face Seals

Principles and Design of Mechanical Seal

Examines the fundamentals and practice of both the design and operation of mechanical seal

, ranging from washing machines to rocket engine turbopumps. Topics include materials, tribology, heat transfer and solid mechanics. A variety of simple and complex models are proposed and evaluated and specific problems such as heat checking, blistering and instability are considered. Offers 64 tables and 364 references plus

useful recommendations regarding the future of mechanical seal design.

List Price: $ 365.00

Price: $ 333.40

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Stokes Vacuum Oil Pump Mechanical Seal

Stokes Vacuum Oil Pump Mechanical Seal

A Stokes Vacuum Oil Mechanical Seal is a device used on a Stokes Vacuum Pump model number 085-029-600.  The Stokes Vacuum Pump could also be known as model number 900-212-11 and also a 412 Microvac Pump.  This post has been written to provide further information on the mechanical seal.

This Mechanical Seal is also a replacement for 085-037-799, 085-038-766 and A-427-121-002.  The seal works by trapping a thin film of fluid on the faces.  This micro-amount of fluid lubricates the rotary face against the static face thus creating a seal.

Acumen Seals based in Manchester, England have successfully manufactured and supplied this Mechanical Seal since the year 2000.

Mono Pumps based in Denton, Manchester England, have a range of pumps as listed on this post.
Acumen Seals who are also based in Manchester England, can supply a complete range of mechanical seals to suit all of these pumps.

Mono Pump Model E13D has a mechanical seal fitted which is, Mono seal reference M032139G ,Acumen Seals have a mechanical seal which will interchange with the existing Mono seal. Acumen Seal reference is 0320/XXVFF/A33/AS04, Acumen Seals can supply this mechanical seal for this Mono Pump at a very competitive price. Operating limits ,Pressure 170 psi,Speed 15 m/s.

Mono Pump Model EE1XD has a mechanical seal fitted which is, Mono seal reference M035139G ,Acumen Seals have a mechanical seal which will interchange with the existing Mono seal. Acumen Seal reference is 0350/XXVFF/A33/AS04, Acumen Seals can supply this mechanical seal for this Mono Pump at a very competitive price. Operating limits ,Pressure 170 psi,Speed 15 m/s.

Mono Pump Model E14D has a mechanical seal fitted which is, Mono seal reference M045139G ,Acumen Seals have a mechanical seal which will interchange with the existing Mono seal. Acumen Seal reference is 0450/XXVFF/A33/AS04, Acumen Seals can supply this mechanical seal for this Mono Pump at a very competitive price. Operating limits ,Pressure 170 psi,Speed 15 m/s.

Mono Pump Model E15D has a mechanical seal fitted which is, Mono seal reference M055139G ,Acumen Seals have a mechanical seal which will interchange with the existing Mono seal. Acumen Seal reference is 0550/XXVFF/A33/AS04, Acumen Seals can supply this mechanical seal for this Mono Pump at a very competitive price. Operating limits ,Pressure 170 psi,Speed 15 m/s.

Mono Pump Model E16D has a mechanical seal fitted which is, Mono seal reference M065139G ,Acumen Seals have a mechanical seal which will interchange with the existing Mono seal. Acumen Seal reference is 0650/XXVFF/A33/AS04, Acumen Seals can supply this mechanical seal for this Mono Pump at a very competitive price. Operating limits ,Pressure 170 psi,Speed 15 m/s.

Mono Pump Model E17D and E18D  has a mechanical seal fitted which is, Mono seal reference M085139G ,Acumen Seals have a mechanical seal which will interchange with the existing Mono seal. Acumen Seal reference is 0850/XXVFF/A33/AS04, Acumen Seals can supply this mechanical seal for this Mono Pump at a very competitive price. Operating limits ,Pressure 170 psi,Speed 15 m/s.