US1795546A

US1795546A - Doll-head bearing for drying cylinders

Info

Publication number: US1795546A
Application number: US406142A
Authority: US
Inventors: Evans William Parsonage
Original assignee: Individual
Current assignee: Individual
Priority date: 1928-11-26
Filing date: 1929-11-09
Publication date: 1931-03-10
Anticipated expiration: 1948-03-10

Description

March 10, 1931.

w. PTEVANS 1,795,546

DOLL HEAD BEARING FOR DRYING CYLINDERS Filed Nov. 9 1929 2 Sheets-Sheet 1 Q 1) 3 g d C N A2 a A c I A 1 a 131 By @AW HTTORNEV March 10, 1931. w,-p EVANS 1,795,546

DOLL HEAD BEARING FOR DRYING CYLINDERS Filed Nov. 9. 1929 2 SheetsSheet 2 4 2 A1 A s E 411) A? T v if u i i mvnvrop $00M Patented Mar. 10, 1931 PATENT OFFICE WILLIAM PARSONAG-E EVANS, OF SWIN'ION, ENGLAND DOLL-HEAD BEARING FOR DRYING CYLINDERS Application filed November 9, 1929, Serial No. 406,142, and in Great Britain. November 26, 1928'.

This invention relates to improvements in the bearings for the trunnions or hollow shafts of steam heated revolving cylinders used in machines for. drying textile fabrics U and paper such as are known as doll head bearings.

Owing to theexpansion of .such cylinders it isnec'essary to provide a yielding joint between thefixed pipe supplying the steam to the cylinder and it 1s also necessary to provide means whereby the joint will be broken when the supply of steam is cut off to prevent the formation of a partial vacuum in the cylinder. Joints for'this purpose are already known in 1 5 which the closure device-bearing against the end of the hollow trunnion is carried at the centre of a flexible diaphragm rigidly held around its periphery, the action of the steam pressure on the diaphragm being such that 10 it moves at the centre towards the cylinder trunnion and holds the closure device tightly against the end thereof. When the supply of steam iscut off however the contraction of the cylinder causes the end of the trunnions to move away from the closure device and opens the inside of the cylinder to the atmosphere thereby preventing the formation ofa partial vacuum within the cylinder. Accordingto the present invention the diaphragm is anchored at the centre to a hollow support separate frombut aflixed to the doll head casting through which the steam passes and is attached at its periphery to the closure device which can move relatively to the fixed support, the closuremember being of such shape that a hollow steam chamber is formed between its inner surface and the diaphragm. V

By this arrangement the whole of the closure member is entirely free from thefixed doll head casting and the steam in the steam chamber since it acts in one direction in the diaphragm and in the opposite direction on the inner face of the closure member maintains the whole in a state of equilibrium. The area of the diaphragm on which the steam acts may be less than the area of the closure member so that the difference between these two areas forms the effective area for makingthe joint thus bringing about a closure without causing a great amount of friction between the closure member and the end of the trunnion and so reducing the wear between the closure member and the end of the revolving trunnion. If desired a spring or a number of springs arranged circumferentiallymay be employed to keep the closure member normally against the end of the trunnion and the steam pressure acting on the effective area cause the face of the closure 00 member to'make a steam tight jointwith the end of the trunnion.

Instead of the area of the diaphragm being less than the area of the closure member it could be equal thereto or greater than the 5 area of the closure member. In the former case the steam in the chamber would keep the closure member in equilibrium and in the latter would tend to move the member away from the cylinder end. In both cases the steam tight joint between the closure member and the end of the cylinder shaft would be maintained by the pressure of the spring.

The invention will be described with reference to the accompanying drawings Fig. 1 is a transverse section through one form of the invention.

Fig. 2 is a section on line 22 Fig. 1.

F ig. 3 is a transverse section through anotherform of the invention.

Fig. 4 is a transverse section through a modification of the invention having two'diaphragms.

Fig. 5 is a transverse section through the bearing of a paper drying cylinder. 35

In the form of the invention shown in Figs.

1 and-2 an elbow casting A having a steam passage a is mounted on top of the doll head casting B. A screwed sleeveA is screwed into the outlet end of the steam passage a and an annular diaphragm C is clamped between the flanged end of the sleeve A and the end of the casting A. The closure member D D is aifixed bybolts d to the diaphragm G near the periphery thereof. The closure member D is formed in two parts D, D aifixed together by-the bolts (Z with a chamber D between them, into which chamber steam from the passage a can enter. The part D has a passage d for steam to enter the hollow shaft E and is formed with a machined face (l1 which bears against the end of the shaft E to make a steam tight joint therewith. The other member D has an extending flange d surrounding the elbow casting A and forming a housing for a spring A which bears at one end against the member D and at the other against the casting A. The whole of the closure member D D is thus entirely supported at the periphery of the diaphragm C and can move relatively to the casting A so that the face al can be pressed up against the end of the shaft E.

The inner diameter of the annular diaphragm C is greater than the bore of the passage (Z through which the steam passes to the shaft E so that the area of the member D acted on by the pressure of the steam in the chamber D is greater than the area of the diaphragm C acted on by the steam pressure. Since the pressure of the steam tends to move the member D towards the shaft E and to move the diaphragm C in the opposite direction the diflerence between these two areas is the effective area the pressure on which forces the face d of the closure member against the end of the shaft.

Although the spring A might be omitted and the pressure on the effective area be employed alone for making the joint it is preferred to employ the spring A which is of sufficient strength to hold the face (Z of the closure member against the end of the shaft and to employ the pressure on the effective area to ensure a tight joint between the face (Z and the shaft without causing a great amount of friction as the shaft rotates.

The elbow casting A is formed with a flange a which is bolted to a flange on the doll head B so that the closure member D D and the casting A. can be readily removed from the doll head bearing for the purpose of replacement or repair.

In the form of the invention shown in Fig. 3 the construction of the closure member 13 ,13 is the same as that described with reference to Figs. 1 and 2. The diaphragm C is clamped at the centre between the screwed sleeve A and a tube F which is screwed into the doll head B and locked in position by the nut Thus by slacking off the nut f the tube F and closure member I), D can be removed from the doll head or adjusted relatively to the end of the shaft E.

5 shows the invention applied to the doll head bearing of a paper drying machine. The construction of the closure members D D is similar to that described with reference to Fig. 1. The bearing face (Z however bears against a shoulder e on the shaft E instead of against the end thereof. The sleeve A clamping the diaphragm C at the centre is screwed into a sleeve A surrounding the shaft E and bolted to the doll head casting B.

In the arrangement shown in Fig. ti: the

two members D D of the closure device are separated by aring d and a second annular diaphragm C is clamped between the memher I) and the ring (P. A ring d is affixed to the second annular diaphragm C and the face oil of this ring makes contact with the end of the shaft E. The inner diameter of the diaphragm C is less than that of the diaphragm C so that the effective area acted on. by the steam to hold the ring d" against the end of the cylinder is the difference between the areas of the two diaphragn'is. The diaphragm C is clamped at the centre to an elbow casting k as described with reference to Fig. 1. A spring A presses the member D against the diaphragm C to keep it pressed forward towards the end of the shaft E.

Although in the drawings the area of the closure member ID is shown and described as being larger than the area of the diaphragm C its area may be equal to or less than that of the diaphragm in which cases the steam tight joint between the closure member and the end of the cylinder shaft would be maintained by the pressure of the spring and in the latter case the steam pressure would tend to move the closure member away from the cylinder end.

The closure member maybe provided with a readily detachable seating either of metal or fibrous material to make a steam tight joint. The seating may be spherical or flat and may have a different diameter of bore to the passage through the shaft E to suit or balance various steam pressures.

If desired two or more of the diaphragms may be arranged one behind the other each diaphragm being carried on a central tube supported from the preceding diaphragms.

Where two doll heads are employed one at either end of a drying cylinder the one may be constructed so that the steam will assist to force the closure member against the end of the cylinder and the other to move it away from the cylinder end.

VJ hat I claim as my invention and desire to protect by Letters Patent is 1. In a doll head bearing for the trunnion of a steam heated cylinder the combination with the closure member forming a steam tight joint with the end of the shaft of a non-rotating diaphragm to the periphery of which the closure member is affixed, and a central support independent of but affixed to the doll head casting to which the diaphragm is anchored at its centre.

2. In a doll head bearing for the trunnion of a steam heated cylinder the combination with the closure member forming a. steam tight joint with the end of the shaft of a nonrotating diaphragm to the periphery of which the closure member is affixed, a central hollow sleeve aiiixed to the doll head casting to which the diaphragm is anchored at its centre and a spring to assist the pressure of the steam in keeping the closure member against the end of the shaft.

3. In a doll head bearing for the trunnion of a steam heated cylinder the combination with the closure member forming a steam tight oint With the end of the shaft of a nonrotating diaphragm, a central support independent of but aflixed to the doll head casting to which the diaphragm is anchored at its centre, a second diaphragm afiixed at its periphery to the first diaphragm and carrying the closure member at its centre.

In testimony whereof I have hereunto set my hand.

WILLIAM PARSONAGE EVANS.