US3740057A - Shaft seal - Google Patents

Shaft seal Download PDF

Info

Publication number
US3740057A
US3740057A US00148027A US3740057DA US3740057A US 3740057 A US3740057 A US 3740057A US 00148027 A US00148027 A US 00148027A US 3740057D A US3740057D A US 3740057DA US 3740057 A US3740057 A US 3740057A
Authority
US
United States
Prior art keywords
pressure
compartment
fluid
sealing
chamber
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00148027A
Other languages
English (en)
Inventor
E Doyle
Feuvre T Le
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Thermo Fisher Scientific Inc
Original Assignee
Thermo Electron Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Thermo Electron Corp filed Critical Thermo Electron Corp
Application granted granted Critical
Publication of US3740057A publication Critical patent/US3740057A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J15/00—Sealings
    • F16J15/16—Sealings between relatively-moving surfaces
    • F16J15/40—Sealings between relatively-moving surfaces by means of fluid
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S277/00—Seal for a joint or juncture
    • Y10S277/927—Seal including fluid pressure differential feature
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S277/00—Seal for a joint or juncture
    • Y10S277/929—Seal feature where change in operation or condition induces additional leakage control
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S417/00—Pumps
    • Y10S417/901—Cryogenic pumps

Definitions

  • a rotary shaft seal is characterized by a buffer compartment filled with fluid maintained at a pressure which equals or exceeds the pressures along the shaft with which the seal is associated.
  • the relatively high buffer pressure within the seal is effective to prevent passage of material along the shaft from one side of the seal to the other.
  • a rotary driveshaft passes through the expander casing and engages the device to be driven.
  • pressure within the expander casing fluctuates over a wide range extending above and below the pressure surrounding the casing, which is typically the ambient atmosphere.
  • the pressure in the casing falls to a substantially subatmospheric level due in part to the cooling attending shut-down of the engine. It is essential to prevent passage of fluid within the expander into the atmosphere and to prevent the passage of air into the expander.
  • Fluids contained within the expander casing include a lubricant,or lubricants, and the working fluid for the Rankine cycle engine. Both fluids are present at the location where the shaft passes through the expander casing.
  • the working fluid is sufficiently expensive that its conservation becomes an extremely important matter in efficient operation of the Rankine cycle engine. Further, a pre-determined optimum amount of working fluid must be maintained within the system to enable it to operate at peak efficiency.
  • the pressure in the casing is above atmospheric pressure, fluids in the casing continually tend to be forced out into the atmosphere along the driveshaft. Loss of these fluids is accompanied by a substantial reduction in operating efflciency and a substantial increase in operating expense.
  • the present invention relates to a seal for preventing movement of material either into or out of a casing along a rotary shaft.
  • the sealing elements include a first means mounted on the shaft forming a first pair of sealing surface areas and a second means mounted on the casing forming a second pair of sealing surface areas in sealing engagement with the first sealing surface areas.
  • a buffer fluid chamber containing pressurized buffer fluid surrounds the sealing elements. Buffer fluid pressure is maintained sufficiently high that the tendency of buffer fluid to pass between the sealing surfaces at least equals the tendency of material to pass between the sealing surfaces from either inside or outside of the casing. Thereby, passage of material past the sealing surface areas either into or out of the casing is effectively prevented.
  • the buffer fluid may pass the sealing surfaces and enter the casing or the environment surrounding the casing. Accordingly, the buffer fluid is selected so as not to be harmful to material within the casing or harmful when present in the environment.
  • the buffer fluid may be a suitable lubricating fluid.
  • the seal is particularly effective when used on the expander driveshaft in a sealed Rankine cycle engine.
  • the buffer fluid pressure is constantly maintained at a pressure level equaling or above both atmospheric pressure and any anticipated crankcase pressure.
  • the buffer fluid pressure is maintained at the desired level by apparatus responsive to both atmospheric pressure and the pressure within the expander casing.
  • a further object of this invention is to provide a rotaryshaft seal for the expander of a Rankine cycle engine which is responsive to both the pressure within the expander and atmospheric pressure for maintaining within the seal a buffer pressure which equals or exceeds both the pressure within the expander and the atmospheric pressure.
  • FIG. 1 illustrates a preferred embodiment of the rotary shaft seal of this invention
  • FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1;
  • FIG. 3 illustrates an alternate embodiment of the apparatus shown in FIG. 2;
  • FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 1;
  • FIG. 5 presents an alternate embodiment of the rotary shaft seal shown in FIG. 1;
  • FIG. 6 illustrates an alternate embodiment of the apparatus shown in FIG. 4;
  • FIG. 7 illustrates another alternate embodiment of the apparatus shown in FIG. 4;
  • FIG. 8 is a schematic view of a Rankine cycle system according to this invention.
  • FIG. 9 is a sectional view of a reciprocating piston expander constructed according to this invention.
  • FIG. 10 is a schematic view showing a turbine expander constructed according to this invention.
  • a rotary shaft 10 to which a driven member 8 is attachable, extends through a casing 12, the casing being comprised of parts 14 and 16.
  • a structure 11 establishes a seal between the shaft and the casing.
  • the sealing structure 11 includes a first sealing element in the form ofa ring 18 and a pair of sealing elements 26 and 26'.
  • the sealing ring 18 is affixed to shaft 10 near an outer portion of the casing 12.
  • the sealing ring 18 may be formed of any suitable material such as hardened steel, cast iron or the like.
  • Mounted on the casing 12 are substantially identical sealing elements 26 and 26', each of which sealing engages a separate sealing area of the sealing ring 18, as will be more fully described below.
  • the interface between the sealing ring 18 and the driveshaft 10 is sealed hermetically by static O-ring seal 20.
  • the interface between the casing 12 and the sealing elements 26 and 26 is provided with hermetic O-ring seals 27 and 27'.
  • sealing elements 26 and 26 are substantially identical, only sealing element 26 will be described.
  • sealing element 26' like primed numerals designate like parts.
  • the sealing element 26 comprises an outer enclosure 28 supporting a sealing ring 30 of suitable material such as carbon, an O-ring 32, spring means 34, means 36 for confining the O-ring 32, and means 38 for confining the carbon sealing ring 30.
  • the carbon sealing ring 30 is positioned for direct engagement with the sealing ring 18 and is pressed into continuous firm sealing engagement by the spring means 34.
  • the O-ring 32 establishes a static seal between the carbon sealing ring 30 and the enclosure 28 to prevent passage of material between the carbon sealing ring and the enclosure.
  • the means 36 maintains the O-ring in proper sealing engagement with the carbon sealing ring and the enclosure 28.
  • the means 38 confines the carbon sealing ring 30 to maintain it in fixed position relative to the enclosure 28, thereby avoiding movement of the carbon sealing ring 30 relative to the shaft 10 when the shaft 10 and the mating ring 18 rotate.
  • the means 38 may engage the carbon sealing ring 30 in a detent, not shown, or in any other suitable manner.
  • the elements 18, 26 and 26' of the sealing structure .11 are mounted adjacent the journal box where the driveshaft 10 passes through the casing 12.
  • the sealing ring 18 is firmly pressed against a shoulder 22 of the driveshaft by a threaded retaining member 24.
  • the sealing element 26 abuts a journal bearing 40.
  • the bearing face 42 of the carbon sealing ring 30 associated with the sealing element 26 is positioned in sealing engagement with one surface area of the sealing ring 18.
  • the sealing element 26 is positioned so that its bearing surface 42' sealingly engages an opposite surface area of the sealing ring'l8.
  • the sealing element 26 is firmly secured in position by a retaining ring 44.
  • a compartment 48 for containing a buffer fluid Surrounding the points of sealing engagement between the sealing elements 26, 26 and 18 is a compartment 48 for containing a buffer fluid.
  • the compartment is so formed that buffer fluid contained therein will be continuously present at the interface between the sealing ring 18 and the sealing rings 30 and 30.
  • pumping action is produced by cooperation between the sealing element 18 and the buffer fluid compartment 48 in a manner which is best described with reference to FIG. 2.
  • the buffer fluid compartment 48 is formed eccentrically within the casing 12 so that the central axes of the sealing ring 18 and of the buffer fluid compartment 48 do not coincide.
  • the sealing ring 18 acts as an impeller within the compartment 48 to build a relatively high pressure adjacent the outlet 52 and a relatively low pressure adjacent the inlet 56.
  • the small pressure differential created in this manner is enough to establish the required flowof buffer fluid through the loop 55.
  • the heat exchange which takes place along the lines forming the loop is sufficient to maintain the temperature of the buffer fluid at the appropriate level.
  • FIG. 3 An alternate embodiment of buffer fluid pump is illustrated in FIG. 3.
  • the sealing ring 18 and the buffer fluid compartment 48 are concentri- 'cally formed within the casing 10.
  • the sealing ring 18 has formed thereon a series of vanes 60 which serve as impellers to build a pressure differential between the inlet 56 and the outlet 52.
  • the pressure of the buffer fluid must constantly be maintained at a level equal to or higher than the pressure surrounding the shaft at opposite sides of the sealing elements 26 and 26.
  • a pressure source 62 joined by a connecting line 64 to the loop 55.
  • the pressure source 62 may operate in a number of ways to maintain the required pressure level in the buffer fluid compartment 48.
  • a housing 65 comprises support means 66, a first end section 68 and a second end section 70.
  • a hermetically sealed buffer fluid reservoir 72 is defined by a first flexible diaphragm means 74 and a second flexible diaphragm means 76.
  • the flexible diaphragm means 74 and 76 include within their central portion rigid plates 78 and 80, respectively.
  • a buffer fluid level indicator 108 bearing indicia 109 extends from plate 78 through chamber 84.
  • a port 82 which communicates with the connecting line 64.
  • Adjacent one side of the reservoir is a first pressure chamber 84 formed by first end section 68; adjacent the other side of the reservoir is a second pressure chamber 86 formed by the second end section 70.
  • a compression spring 88 is interposed between plate 78 and surface 90 of the first end section 68.
  • lnterposed between the plate 80 and surface 94 of the second end section 70 is a compression spring 92. The springs constantly exert pressure on the plates and thus on the buffer fluid within the reservoir 72.
  • pressure is applied to the buffer fluid within the reservoir 72 by pressure within the pressure chambers 84 and 86.
  • the additional pressure applied to the buffer fluid is substantially equivalent to either the pressure in the first pressure chamber 84 or the second pressure chamber 86, as will be explained in more detail below.
  • a stop 96 for limiting movement of the plate 78; within the second pressure chamber 86 is a stop 98 for limiting movement of the plate 80.
  • the first and second pressure chambers are provided for applying pressure to the buffer fluid in response to the pressure surrounding the driveshaft on opposite sides of the sealing elements 26 and 26'.
  • the sealing element 26' is exposed to a zone of pressure outsidethe casing 12 and the sealing element 26 is exposed to pressure inside the casing 12.
  • the first pressure chamber 84 is constructed to respond to pressure outside the casing by direct communication through ports 100 and 102.
  • a line 104 extends from the second pressure chamber 86 to the interior of the casing 12 to enable the second pressure chamber to respond to pressure within the casing '12.
  • the sealing structure 11 depicted in FIGS. 1, 2 and 4 prohibits communication between thefirst pressure zone on one side of the sealing elements 26 and 26' and a second pressure zone on the opposite side of these sealing elements, regardless of pressurefluctuations or of which pressure is higher than the other.
  • the buffer fluid chamber 48, the loop .55, the line 64, and the reservoir 72 are all filled with buffer fluid.
  • the pressure applied to the reservoir 72 by the springs 88 and 92 is transmitted to the'buffer fluid within the compartment 48 by means of the line 64 and the loop 55.
  • the springs thus constitute a pressure source constantly acting on the buffer fluid.
  • the first pressure chamber 84 is at a first pressurelevel corresponding to the pressure level outside the casing 12 and the second pressure chamber 86 is at the pressure level of the interior of the casing.
  • a pressure equivalent to the higher pressure of the pressures within the chambers 84 and 86 is applied to the reservoir 72, in addition to the pressure applied to the reservoir by opposed springs 88 and 92. That is, when pressure in the second pressure chamber 86 exceeds pressure in the first chamber 84, the first and second flexible diaphragm means 74 and 76 flex so that the reservoir 72 advances toward the stop 96 until the stop is abutted by the plate 78.
  • the springs continue to act upon the reservoir while a force equivalent to the pressure in the second pressure chamber 86 is applied thereto.
  • the first and second flexible diaphragm means flex to permit the reservoir 72 to advance toward the stop 98 until this stop is abutted by the plate 80.
  • pressure substantially equivalent to the relatively high pressure in the chamber 84 is applied to the buffer fluid in addition to the pressure applied thereto by the springs.
  • the springs 88 and 92 are preferably calibrated so that pressure on the buffer fluid within the compartment 48 always exceeds pressures surrounding sealing elements 26 and 26'. However, the springs may be calibrated to apply a minimum force effective only to overcome any frictional resistance within the pressure source 62 or eliminated entirely. In the latter event, the buffer fluid pressure will substantially equal the highest of the pressures surrounding the sealing elements 26 and 26. Since the pressure across the sealing faces of elements 18, 26 and 26 is always characterized by either equilibrium or relatively high buffer fluid pressure, there is never a tendency for material to pass along the shaft 10 from one side of the sealing elements 26 and 26' to the other side of these sealing elements.
  • buffer fluid there is a tendency for a small amount of buffer fluid to pass between the sealing faces of the sealing ring 18 and the carbon sealing rings 30 and 30. In event of passage, a small portion of the buffer fluid may be lost either to one side or the other of the sealing elements 26 and 26'. Fluid which passes from the buffer fluid compartment 48 is replenished from the reservoir 72. As the fluid is exhausted from the reservoir, flexible diaphragm means 74 and 76 advance toward each other to reduce reservoir volume. The reservoir may or may not need periodic recharging of buffer fluid depending on the life of the system within which the sealing structure 11 is used. Within the practical limits of reservoir size, the supply of buffer fluid has been found sufficient for extended periods.
  • the sealing structure 11 operates in the manner described, whether or not the driveshaft 10 is rotating within the casing 12, and is therefore equally effective when the system in which it is used is operating and when the system is not operating.
  • the amount of buffer fluid in reservoir 72 at any given time is measured by reading indicia 109 on the buffer fluid indicator means 108 with respect to a reference point, such as the surface of housing 65.
  • the indicator means 108 To obtain a reading, the indicator means 108 must be in the fully advanced position so that the plate 80 abuts the stop 98. In this position, the indicia 109 provides a reading of the distance between the plates 78 and 80 and therefore of the volume of fluid within the reservoir 72.
  • the pressure in the chamber 84 exceeds the pressure in the chamber 86, the plate 80 will be caused to I abut the stop 98 so that the position of the indicator 108 inherently provides a reading of the reservoir contents.
  • the indicator means 108 is prohibited by the resistance of the stop 98 and the buffer fluid within the reservoir 72.
  • the indicator means is advanced against a resistance level which is a function of the pressure differential between the two pressure chambers.
  • a second resistance level resulting from engagement of the plate with the stop 98 is encountered, the indicator means 108 is fully advanced and a reading may be taken.
  • FIG. 5 operates substantially in the same manner as the one described in connection with FIGS. 1, 2 and 4 except that the static sealing elements are mounted on the casing 12 and rotary sealing elements are mounted on the driveshaft 10.
  • FIG. 6 shows one embodiment of pressure source 62 for applying force to the buffer fluid independent of pressures surrounding the driveshaft 10.
  • a housing 65 is provided with a flexible bellows diaphragm 140 which divides the interior of the housing 65 into a buffer fluid reservoir 142 and a pressure chamber 144.
  • the housing 65 is provided with a port 82,for connection to the line 64 to establish communication with the loop 65.
  • Compressed gas admitted through port 146 fills the pressure chamber 144 to provide sufficient pressure on buffer fluid within the buffer fluid reservoir 142 to maintain the buffer fluid within the buffer fluid compartment '148, shown in FIG. 1, at a level which equals or exceeds the pressures surrounding the driveshaft 10 on opposite sides of the elements 26 and 26.
  • the pressure applied to the reservoir 142 by the source of compressed gas is calibrated to always provide at least the minimum pressure required for compartment 148.
  • the pressure source 62 shown in FIG. 7 includes a housing 65 divided into three sections by a first flexible diaphragm means 150 and a second flexible diaphragm 152.
  • the flexible diaphragm means 150 and 152 provide hermetic sealing between the three sections of the interior of the housing 65.
  • a chamber 154' is provided with ports 156 which establish communication with one pressure zone.
  • a chamber 158 communicates through line 104 with another pressure zone.
  • a buffer fluid reservoir 160 communicates through a port 82 and the line 64 with the loop 55 and thence with the compartment 48.
  • the diaphragm means 150 includes a rigid plate-like structure 162. From structure 162, a sleeve 164 projects into chamber 158 and a projection 164 extends through the chamber 154. The projection 164 forms a fluid level indicator. Indicia 166 thereon serves to indicate the amount of fluid present within the buffer fluid reservoir 160.
  • the diaphragm means 152 includes a second plate-like structure 168 from which projection 170 extends upward into the chamber 158 and telescopes within the sleeve 164.
  • a retaining means 172 is mounted within the chamber 158. Opposed between the retaining means 172 and the structure 168 is a compression spring 174.
  • the spring 174 continuously applies pressure to buffer fluid within the reservoir 160 and thus to fluid within the compartment 48.
  • the diaphragms and 152 are urged apart from each other.
  • the diaphragm 150 as shown in FIG. 7, is in the transitory state, moving away from the diaphragm 152.
  • the diaphragm 150 advances to the partition 176 and the diaphragm 152 is pressed firmly against buffer fluid in the reservoir 160. Under this condition, the pressure of the fluid within the chamber 158 is imparted to buffer fluid within the reservoir in addition to the pressure applied thereto by the spring 174.
  • the diaphragm 150 advances toward the diaphragm 152. This advancement continues until the terminal portion 178 of the sleeve 164 engages the terminal portion 180 of the projection 170. When this occurs, the projection and the sleeve are effectively coupled together so that pressure within the chamber 154 is applied to buffer fluid within the reservoir 160 in addition to pressure applied thereto by the spring 174.
  • the fluid level indicating means 164 provides for the determination of the amount of buffer fluid within the reservoir 160.
  • the diaphragms are effectively coupled as described above, and the indicia 166 on the projection 164 will indicate the amount of fluid within the reservoir 160.
  • the projection 154 will not be susceptible of further downward movement into the housing 65.
  • the pressure in chamber 168 exceeds that in chamber 154, the diaphragm 150 will be pressed against the member 176 and the indicia 166 on the projection 164 will indicate that the reservoir is full.
  • the projection 164 When the reservoir is indicated full, to determine that this is actually a correct reading, the projection 164 must be pressed inwardly of the housing 165, against the force applied thereto by the pressure differential between the chambers 158 and 154, until a second level of resistance is encountered beyond which the projection is no longer movable. The reading at the second level of resistance is the correct indication of the amount of fluid within the reservoir 160. If upon pressing the projection 164 inwardly on the housing 165, it is immediately immovable, the reservoir 160 is full of buffer fluid.
  • FIGS. 8 and 9 there will be described a Rankine cycle system constructed according to this invention to prevent passage of the fluid from the system into the atmosphere and passage of material from the atmosphere into the system.
  • the Rankine cycle system is described briefly in connection with FIG. 8.
  • a vapor generator 182 heats organic working fluid fed thereto by a pump 184.
  • the vaporized working fluid is then directed to an expander 186 which expands the vapor through a substantial temperature and pressure drop to produce work and rotate the driveshaft 10.
  • the working fluid then passes from the expander 186 through a separator 188 which removes any lubricants from the organic working fluid,
  • the working fluid then enters the vapor side 192 of a regenerator 194 and gives up some of the heat energy remaining therein to working fluid passing through the liquid side 196 of the regenerator. From the vapor side 192 of the regenerator, the working fluid passes through the condenser 198 and is fully condensed.
  • the pump 184 then drives the condensed working fluid through the liquid side 196 of the regenerator 194 and back to the vapor generator 182.
  • the working fluid is heated as it is driven through the liquid side of the regenerator by exhaust vapor passing through the vapor side of the regenerator.
  • the vapor generator 182 vaporizes the working fluid and the cycle is repeated.
  • FIG. 9 illustrates a reciprocating expander for a Rankine cycle system of the type shown in FIG. 8.
  • the expander is provided with a casing 200 comprising parts 202 and 204.
  • a vapor inlet manifold 206 and valves 208 and 210 cooperatively arranged with respect to reciprocatingpistons 212 and 214.
  • Each of the pistons have associated therewith a When the Rankine cycle expander is operating and ments 26 and 26', it is replenished from the reservoir piston rod 216 and 218.
  • the piston rods are connected to a crankshaft 220 which is supported within the casing 200 at one end by a journal box 222.
  • a driveshaft 10 extends from the opposite end of the crankshaft and is supported in the casing 200 by a journal box 224. Adjacent the journal box 224 are sealing elements 18, 26 and 26' surrounded by a buffer fluid compartment 48. The sealing elements, compartment and other associated parts are constructed and mounted in substantially the same fashion as described above in connection with FIG. 1.
  • Lines 50 and 54 extend from the compartment 48 to form the loop 55 which is connected by line 64 to the pressure source 62.
  • Extending from the pressure source 62 is a line 104 establishing communication between pressure source and the interior of the casing 200. The line 104 should enter the casing 200 at a place relatively near the journal 224 so that it may enable the pressure source 62 to accurately sense the pressure adjacent the sealing element 26.
  • the expander 186 is characterized by wide variations of internal pressures.
  • the pressure in the casing 200 may extend to levels well above atmospheric pressure under certain conditions and, under other conditions, drop substantially below atmospheric pressure. Consequently, the shaft seal is required to prevent passage of material from within the casing to the atmosphere when the casing pressure is relatively high and to prevent passage of material from the atmosphere into the casing when the casing pressure is relatively low.
  • Vaporized working fluid admitted into the inlet manifold 206 from the vapor generator 182 is alternately directed first into cylinder 211 and then into cylinder 213 by valves 208 and 210, respectively, in a typical manner understood in the art.
  • Working fluid is exhausted from the cylinders through exhaust ports of the type.
  • the casing pressure is transmitted through line 104 to the second pressure chamber 86 of the pressure source 62. This pressure is then applied by the pressure source 62 to the buffer fluid system. There is also applied to the buffer fluid system the pressure resulting from compression springs 88 and 92. The result is that the pressure of the buffer fluid within the buffer fluid compartment 48 is equal to the pressure in the casing 200 plus the pressure from the compression springs 88 and 92. On the other hand, during long periods of shut-down of the Rankine cycle system, the pressure within the casing 200 typically drops below atmospheric pressure.
  • the first pressure chamber 84 which communicates with the atmosphere by means of ports 100 and 102 is subjected to a relatively [high pressure which overcomes the influence of the pressure within the second pressure chamber 86.
  • the atmospheric pressure is then applied to the buffer fluid system together with the pressure of compression springs 88 and 92 so that buffer fluidwithin the buffer fluid compartment 48 is subjected to a pressure equal to the atmospheric pressure plus the pressure applied by the compression springs.
  • Expanders are characterized by sealing arrangements between the pistons and cylinders which permit passage of working fluid past the pistons and cylinders into the portion of the expander casing which contains lubricant, with the result that working fluid becomes intermixed with the lubricant.
  • the tendency of material to pass from the interior of the epxander to the exterior thereof along the driveshaft establishes the potential loss of both working fluid and lubricant.
  • working fluid tends to pass between the cooperating piston and cylinder assemblies to the portion 201 of the casing 200 which serves as a lubricant containing crankcase.
  • the crankcase 201 thus contains a mixture of lubricant and working fluid which passes through the journal 224 and would tend to pass between the sealing element 18 and sealing elements 26 and 26' except for the pressure of buffer fluid within the compartment 48.
  • FIG. 10 is a schematic view showing a turbine 300 embodying this invention.
  • the sealing structure 11 is interposed between the casing of the turbine 300 and its driveshaft 10 to prevent passage of material from one side of the sealing structure to the other along the driveshaft. It should be understood that this invention is not limited to expanders but may be' used on pumps and other apparatus wherein an effective shaft seal is required.
  • first sealing means mounted in fixed relationship to said shaft means and forming first and second sealing surface areas each surrounding said shaft means;
  • second sealing means mounted in fixed relationship to said casing wall means and forming first and second sealing surface areas, said first and second surface areas formed by said second sealing means mating in sealing engagement with said first and second sealing surface areas of said first sealing means, respectively;
  • a shaft seal according to claim 1 wherein said pressure applying means is responsive to the pressures in both said first and second pressure zones.
  • a shaft seal according to claim 1 wherein said pressure applying means comprises:
  • said pressure applying means further comprises means for constantly applying pressure to said expansible chamber and thereby to said compartment in addition to the pressure applied thereto by said means responsive to the pressures in said first'and second pressure zones, whereby the pressure applied to said compartment exceeds the greater of either the pressure in said first pressure zone or'the pressure in said second pressure zone.
  • a shaft seal according to claim 1 wherein said means responsive to said first and second communicating means is'in hermetically sealed fluid connection with said buffer fluid compartment.
  • a shaft seal comprising:
  • second sealing means in fixed, fluid tight relationship to said means forming said working fluid chamber and having first and second sealing surface areas in sealing engagement with said first and second sealing surface areas, respectively, of said first sealing means;
  • d. means in hermetically sealed fluid communication with said compartment constantly applying pressure to buffer fluid therein which at least equals the greater of either the pressure in said working fluid chamber or the pressure in said environmental zone, said pressure being applied during both operating and non-operating conditions of the Rankine cycle system, thereby to eliminate the tendency of material to pass along said shaft from said working fluid chamber into said environmental zone when pressure in said working fluid chamber is above environmental zone pressure and from said environmental zone into said working fluid chamber when pressure in said working fluid chamber is below environmental zone pressure.
  • a shaft seal wherein said pressure applying means applies to buffer fluid within said compartment a pressure greater than either the pressure of said working fluid chamber or the pressure of said environmental zone.
  • said first sealing means comprises an annular flange surrounding said rotary shaft
  • said second sealing means comprises a pair of annular sealing surfaces for sealing engagement with opposite sides of said annularflange;
  • said buffer fluid compartment surrounds said annular flange along and between the points of engagement of said annular flange with said pair of annular sealing surfaces.
  • a shaft seal further comprising means forming a fluid inlet and a fluid outlet for said buffer fluid compartment wherein said buffer fluid compartment surrounds said annular flange, eccentrically thereof, whereby rotary movement of said annular flange within said buffer fluid compartment during operation of the Rankine cycle system produces a pumping action for drawing buffer fluid into said compartment through said inlet and expelling buffer fluid from said compartment and through said outlet.
  • a shaft seal further comprising:
  • reservoir means communicating with said closed loop for providing a continuing supply of buffer fluid to replenish any buffer fluid which passes from said compartment into said working fluid chamber or said environmental zone.
  • said reservoir means comprises a flexible, hermetically sealed buffer fluid confining means
  • said means constantly applying pressure applies pressure to said flexible, hermetically sealed fluid confining means for exerting pressure on buffer fluid in said compartment.
  • a shaft seal wherein said means constantly applying pressure is responsive to the pressure in said environmental zone and the pressure in said working fluid chamber.
  • a shaft seal wherein said means constantly applying pressure comprises:
  • a shaft seal further comprising:
  • a shaft seal wherein said pressure applying means comprises:
  • first means communicating with pressure external of said chamber
  • a Rankine cycle system including an expander casing means forming a chamber to contain fluid lubricant and organic Rankine cycle working fluid, the interior and exterior of said chamber being characterized by different pressure levels, and
  • a shaft seal comprising:
  • first sealing means in fixed, fluid tight relationship to said shaft means and having a first surface portion and a second surface portion;
  • second sealing means in fixed, fluid tight relationship to said expander casing means and in sealing engagement with both said first and second surface portions of said first sealing means
  • hermetically sealed compressible reservoir means in fluid communication with said compartment
  • said second pressure applying means applies pressure to said buffer fluid which is at least substantially as great as the greater of either the pressure within said chamber or the pressure without said chamber, whereby the pressure applied to said buffer fluid within said compartment is always greater than either the pressure within said chamber or the pressure without said chamber.
  • a shaft seal further comprising means for indicating the amount of buffer fluid in said reservoir.
  • said second pressure applying means comprises:
  • first means communicating with pressure external of said chamber for applying to said reservoir means a first pressure level having a magnitude substantially equal to said external pressure
  • second means communicating with pressure internal of said chamber for applying to said reservoir means a second pressure level having a magnitude substantially equal to said internal pressure
  • first sealing means mounted in :fixed relationship to said shaft means and forming first and second sealing surface areas each surrounding said shaft means;
  • d. means in hermetically sealed fluid communication with said compartment for continuously applying to buffer fluid within said compartment, under all conditions, a pressure which at least substantially equals the greater of the pressures in said first and second pressure zones, thereby to inhibit passage of material along said shaft means from either of said pressure zones to the other under all conditions.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Sealing Devices (AREA)
  • Turbine Rotor Nozzle Sealing (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
  • Mechanical Sealing (AREA)
  • Sealing Of Bearings (AREA)
US00148027A 1971-05-28 1971-05-28 Shaft seal Expired - Lifetime US3740057A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US14802771A 1971-05-28 1971-05-28

Publications (1)

Publication Number Publication Date
US3740057A true US3740057A (en) 1973-06-19

Family

ID=22523916

Family Applications (1)

Application Number Title Priority Date Filing Date
US00148027A Expired - Lifetime US3740057A (en) 1971-05-28 1971-05-28 Shaft seal

Country Status (8)

Country Link
US (1) US3740057A (de)
JP (1) JPS5338373B1 (de)
CA (1) CA1017378A (de)
DE (1) DE2225259C3 (de)
FR (1) FR2139980B1 (de)
GB (1) GB1368875A (de)
IT (1) IT955926B (de)
SE (1) SE388919B (de)

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3979104A (en) * 1974-01-17 1976-09-07 Westinghouse Electric Corporation Shaft sealing device for a butterfly valve
DE2625153A1 (de) * 1976-06-04 1977-12-15 Leybold Heraeus Gmbh & Co Kg Wellenabdichtung
US4078809A (en) * 1977-01-17 1978-03-14 Carrier Corporation Shaft seal assembly for a rotary machine
US4307889A (en) * 1980-01-25 1981-12-29 Nl Industries, Inc. Apparatus utilizing rotary motion of a member as the motive force for a pump
US4384724A (en) * 1978-08-17 1983-05-24 Derman Karl G E Sealing device
US4460181A (en) * 1980-06-26 1984-07-17 Toyo Denki Kogyosho Co., Ltd. Method and mechanism for controlling the pressure at shaft-sealing part of an apparatus
US4497172A (en) * 1981-12-08 1985-02-05 Rolls-Royce Limited Bearing chamber pressurization system for a machine
US5529314A (en) * 1993-09-13 1996-06-25 Ekstam; Charles L. Pump shaft lubricated bearing fluid seal assembly
US5803463A (en) * 1996-08-29 1998-09-08 Durametallic Corporation Grease seal
US5865441A (en) * 1995-02-02 1999-02-02 Orlowski; David C. Emission seal
US20040011338A1 (en) * 2001-02-20 2004-01-22 Ekstam Charles L. Fuel delivery system
US20040250544A1 (en) * 2001-07-10 2004-12-16 Masahiko Minemi Rankine cycle system
WO2010009358A1 (en) * 2008-07-17 2010-01-21 Lawrence Pumps, Inc. Apparatus for simultaneous support of pressurized and unpressurized mechanical shaft sealing barrier fluid systems
US20130160450A1 (en) * 2011-12-22 2013-06-27 Frederick J. Cogswell Hemetic motor cooling for high temperature organic rankine cycle system
NL2010696C2 (en) * 2013-04-24 2014-10-27 Ihc Holland Ie Bv Pressure compensator.
NL2010697C2 (en) * 2013-04-24 2014-10-27 Ihc Holland Ie Bv Pressure compensation device.
US20180058597A1 (en) * 2016-08-23 2018-03-01 Onesubsea Ip Uk Limited Barrier fluid pressure system and method
US20200347726A1 (en) * 2017-12-28 2020-11-05 Tocircle Industries As Sealing arrangement

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3227234A1 (de) * 1982-07-21 1984-01-26 Klein, Schanzlin & Becker Ag, 6710 Frankenthal Gleichdruck-sperrfluessigkeitsbehaelter fuer gleitringdichtungen
DE3227235A1 (de) * 1982-07-21 1984-01-26 Klein, Schanzlin & Becker Ag, 6710 Frankenthal Druckuebersetzer fuer sperrfluessigkeitssysteme von gleitringdichtungen
AT387267B (de) * 1986-05-12 1988-12-27 Stoeller Walter Gleitringdichtung
DE4003214C2 (de) * 1990-01-31 1994-06-30 Mannesmann Ag Verfahren und Einrichtung zum Ausgleich von Leckflüssigkeitsverlusten einer Sperrflüssigkeitsanlage
DE4343389A1 (de) * 1993-12-18 1995-06-22 Koellemann A J Gmbh Welleneinheit für Überdruck-Prozeßmaschinen
DE29614698U1 (de) * 1996-08-23 1996-10-10 Feodor Burgmann Dichtungswerke GmbH & Co., 82515 Wolfratshausen Drucküberwachungseinrichtung

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2226001A (en) * 1938-05-06 1940-12-24 Bour Harry E La Gland
US3268232A (en) * 1962-04-25 1966-08-23 Nat Res Dev Shaft seal assemblies

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2226001A (en) * 1938-05-06 1940-12-24 Bour Harry E La Gland
US3268232A (en) * 1962-04-25 1966-08-23 Nat Res Dev Shaft seal assemblies

Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3979104A (en) * 1974-01-17 1976-09-07 Westinghouse Electric Corporation Shaft sealing device for a butterfly valve
DE2625153A1 (de) * 1976-06-04 1977-12-15 Leybold Heraeus Gmbh & Co Kg Wellenabdichtung
US4128248A (en) * 1976-06-04 1978-12-05 Leybold-Heraeus Gmbh & Co. Kg Shaft seal
US4078809A (en) * 1977-01-17 1978-03-14 Carrier Corporation Shaft seal assembly for a rotary machine
US4384724A (en) * 1978-08-17 1983-05-24 Derman Karl G E Sealing device
US4307889A (en) * 1980-01-25 1981-12-29 Nl Industries, Inc. Apparatus utilizing rotary motion of a member as the motive force for a pump
US4460181A (en) * 1980-06-26 1984-07-17 Toyo Denki Kogyosho Co., Ltd. Method and mechanism for controlling the pressure at shaft-sealing part of an apparatus
US4497172A (en) * 1981-12-08 1985-02-05 Rolls-Royce Limited Bearing chamber pressurization system for a machine
US5529314A (en) * 1993-09-13 1996-06-25 Ekstam; Charles L. Pump shaft lubricated bearing fluid seal assembly
US5865441A (en) * 1995-02-02 1999-02-02 Orlowski; David C. Emission seal
US5803463A (en) * 1996-08-29 1998-09-08 Durametallic Corporation Grease seal
US6729310B2 (en) 2001-02-20 2004-05-04 Charles L. Ekstam Fuel delivery system
US20040011338A1 (en) * 2001-02-20 2004-01-22 Ekstam Charles L. Fuel delivery system
US20040250544A1 (en) * 2001-07-10 2004-12-16 Masahiko Minemi Rankine cycle system
US6948316B2 (en) * 2001-07-10 2005-09-27 Honda Giken Kogyo Kabushiki Kaisha Rankine cycle system
WO2010009358A1 (en) * 2008-07-17 2010-01-21 Lawrence Pumps, Inc. Apparatus for simultaneous support of pressurized and unpressurized mechanical shaft sealing barrier fluid systems
US20100015000A1 (en) * 2008-07-17 2010-01-21 Lawrence Pumps, Inc. Apparatus for simultaneous support of pressurized and unpressurized mechanical shaft sealing barrier fluid systems
US9689281B2 (en) * 2011-12-22 2017-06-27 Nanjing Tica Air-Conditioning Co., Ltd. Hermetic motor cooling for high temperature organic Rankine cycle system
US20130160450A1 (en) * 2011-12-22 2013-06-27 Frederick J. Cogswell Hemetic motor cooling for high temperature organic rankine cycle system
NL2010696C2 (en) * 2013-04-24 2014-10-27 Ihc Holland Ie Bv Pressure compensator.
WO2014175733A1 (en) 2013-04-24 2014-10-30 Ihc Holland Ie B.V. Pressure compensation device
WO2014175734A1 (en) * 2013-04-24 2014-10-30 Ihc Holland Ie B.V. System with pressure compensator
NL2010697C2 (en) * 2013-04-24 2014-10-27 Ihc Holland Ie Bv Pressure compensation device.
US20180058597A1 (en) * 2016-08-23 2018-03-01 Onesubsea Ip Uk Limited Barrier fluid pressure system and method
US10550949B2 (en) * 2016-08-23 2020-02-04 Onesubsea Ip Uk Limited Barrier fluid pressure system and method
US20200347726A1 (en) * 2017-12-28 2020-11-05 Tocircle Industries As Sealing arrangement
US11668300B2 (en) * 2017-12-28 2023-06-06 Tocircle Industries As Sealing arrangement

Also Published As

Publication number Publication date
FR2139980A1 (de) 1973-01-12
SE388919B (sv) 1976-10-18
DE2225259C3 (de) 1975-05-07
FR2139980B1 (de) 1973-07-13
CA1017378A (en) 1977-09-13
GB1368875A (en) 1974-10-02
IT955926B (it) 1973-09-29
DE2225259B2 (de) 1974-09-19
DE2225259A1 (de) 1972-12-07
JPS5338373B1 (de) 1978-10-14

Similar Documents

Publication Publication Date Title
US3740057A (en) Shaft seal
US4305592A (en) Gas seal bushing
US3559398A (en) Hot-gas piston engine
US4669736A (en) Stirling engine with improved sealing piston ring assembly
US4093239A (en) Piston rod sealing arrangement for a stirling engine
US3848877A (en) Seal for piston rod of stirling engine
US3810634A (en) Reciprocating rod sealing means for hot gas engines
GB1313392A (en) Device comprising two coaxial elements of which one is reciprocable within the other
US2831325A (en) Pump for liquefied gases
US3951419A (en) Seal between members which are rotatable relative to each other
GB1391787A (en) Oscillating or reciprocating device
US4335884A (en) Device for ensuring dynamic tightness, particulary for Stirling engine
US3216651A (en) Seal
US4248050A (en) Double-yoke balanced compressor
JPS6119953A (ja) スタ−リングエンジン
US5938207A (en) Heat engine rod seal system
US3783745A (en) Gas-supported rolling diaphragm seal for piston and cylinder assembly
US4308001A (en) Heat pump compressor integrated in an internal-combustion engine
US1859039A (en) Packing
KR830002538B1 (ko) 냉동 모터 압축기 장치를 위한 지지 및 밀봉 시스템
US3299828A (en) Reciprocating cryogenic pump
US3508393A (en) Low friction stirling engines and chemical heating means
NO172510B (no) Sperrevaeske-tetningsanordning for akseltetning i en turbokompressor
GB1341112A (en) Device comprising two relatively reciprocable components
JPS629069A (ja) シ−ル装置