US2247074A - Sealing arrangement - Google Patents

Description

June 24, 1941.

D. FZWARNER 2,247,074

SEALING ARRANGEMENT Original Filed Dec. 1-0, 1937 Inventor.- Dorwald F. Warner,

His Attorney.

Patented June 24, -1 941 SEALING ARRANGEMENT Donald F. Warner, Swampscott, Mass, assignor to General Electric Company, a corporation of New York Original application December 10, 1937, Serial No. 179,169, now Patent No. 2,177,544, dated October 24, 1939. Divided and 1939, Serial No. 287,042

4 Claims.

The present invention relates to sealing arrangements to reduce leakage along a stem or rod for positioning a valve or the like, and is a division of my application on Valve mechanism, Serial No. 179,169, filed December 10, 1937, now Patent No. 2,177,544 issued October 24, 1939, and assigned to the same assignee as this application.

The object of my invention is to provide an improved sealing arrangement for valve stems and the like whereby such stems are effectively sealed and cramping or jamming in the bore of a casing due to expansion during operation is substantially prevented.

For a consideration of what I believe to be novel and my invention, attention is directed to the following description and the claims oppended thereto in connection with the accompanying drawing.

The single figure of the drawing illustrates a sealing arrangement for a valve mechanism in accordance with my invention.

The arrangement comprises a valve body having a lower cylindrically-shaped flanged portion l and an upper cylindrically-shaped flanged portion H secured together by bolts l2. The body forms a cylindrical valve chamber or chest l3 to which elastic fluid is conducted through a conduit I4 ecured to the lower body portion In and from which fluid is discharged through a plurality of openings l5, I6, l7 and I8 leading to a consumer such as separate first stage nozzles of an elastic fluid turbine, not shown. Each of the openings to 18 communicates with the chamber l3 through a pair of vertical bores 23,14. The flow of fluid from the chamber Hi to the vertical bores is controlled by a plurality of pairs of valves 33, 34 located in the chamber 73 and loosely supported by means including a disk 37 having a central portion rigidly secured to the lower end of a lifting rod or stem 45, which latter has an upper end arranged for connection to a governing or control mechanism, not shown.

The lifting rod 45 is of considerable length and sealed and guided within the upper body portion H. The sealing and guiding means in accordance with my invention comprises a plurality of sleeves, in the present instance three sleeves 46, 47 and 48, surrounding the tem 45 and disposed within a bore 49 in the upper body portion II. The sleeve 47 which is intermediate the sleeves 46 and 48 forms a slight clearance in the bore and slides with its entire outer surface along the bore 49 and thus forms a guide sleeve, which may float laterally to accommodat for slight move this application July 28,

ment of the stem with changes in temperature, thus minimizing the risk of cram-ping and jamming of the stem and the packing. The sleeves 46 and 48 have short portions or annular projections 58 and 5| tightly engaging the inner surface of the bore 49 to form rocking sleeves, permitting slight rocking of the lifting rod 45 about the intermediate sleeve 47 and to prevent leakage along the bore 49. Each sleeve has one or more breakdown grooves 52 to form a number of separate packing surfaces and thus gradually to reduce the pressure from the lower or high pressure end of the sleeve 46 to the upper or atmospheric end of the sleeve 48. Any fluid passing from the valve chamber along the stem towards said upper end is discharged through lateral openings 53 in the upper end of the sleeve 48 and a drain or bleed-off pipe 54 secured to the upper body portion II.

The three leeves or packing cylinders are separated by rings or spacers 55 and 55, each engaging the bore and forming a clearance with the rod 45. These rings are preferably made from corrosion-resisting material, such as chrome iron, and the sleeves and the stem are preferably nitrided.

The portion of the stem above the bleed-01f pipe 54 is sealed to the body by means of a soft packing 57, preferably made of graphite and asbestos to prevent leakage of fluid past the upper end of the stem. The soft packing 57 is held in place by means of an end plate 58 secured to the body by bolts 59. The upper sleeve 48 abuts with its end face against a projection 60 formed in the bore 49 of the upper body portion and the lower sleeve 46 is prevented from downward sliding movement by an end ring Bl secured to the upper body portion I I by bolts 62. The stack of sleeves and spacers i assembled with a small axial clearance sufficient to allow freedom for the intermediate sleeve to float with misalinement of the stem.

What I claim as new and desire to secure by Letters Patent of the United States, is,

1. The combination of a body having a bore, a rod projecting through the bore, and means for sealing the rod in the bore comprising a floating sleeve having sealing contact with the rod and a slight clearance with the bore and a rocking sleeve on each side of the floating sleeve having sealing contact with the rod and an outer relatively narrow projection engaging the bore to permit slight rocking movement of the rod.

2. The combination of a body having a bore, a rod projecting through the bore, and sealing 3. The combination of a casing having a bore,

a stem passing centrally through the bore, and sealing means to reduce leakage of fluid along the stem, said sealing means comprising a floating sleeve having sealing contact with the stem and forming slight clearance with the opening, and a rocking sleeve on each side of the floating sleeve having sealing contact with the stem and a short annular portion with a tight fit in the bore.

4. The combination of a casing having a bore, a stem passing through the bore, and sealing means to reduce leakage of fluid along the stem, said sealing mean comprising a plurality of floating and rocking sleeves alternating, all of j the sleeves having sealing contact with the stem,

the floating sleeves being slightly spaced from the bore and the rocking sleeves having axially short outer portions in rocking contact with the bore and other long outer portions spaced from the bore.

DONALD F. WARNER.

Images