Pneumatic And Hydraulic Equipment Page 1102

FIXED CENTERLINE MOUNTS Centerline mounts are generally considered to be the best type of fixed mounting since the thrust from the piston rod is taken at a mounting surface that is coincident with the cylinder centerline. Use of this type of mount can eliminate possible problems resulting from cylinder sway and flexure of cylinder components. FLANGE MOUNTS Although flange mounts are considered to be of the centerline type, caution must be exercised as they can be applied in such manner as to cause them to be of a non centerline nature. Whenever a cylinder is mounted by the backside of a flange, a condition exists where flexure of the flange resulting in fatigue failure of the mounting bolts or flange retainer fasteners is possible. See Fig. A The only type of flange recommended for backside mounting is the style where the full thickness of the head or the cap serves as the flange styles FHF or RHF. Selection of a flange mounting style depends, in part, upon whether the major force applied to the machine member will result in tension or compression of the cyl- inder rod. Rear flange mounting styles are best for thrust loads (rod in compression) and front flange mounting styles are best where the rod is stressed in tension. Rectangular flange mounts styles FF and RF are not recommended for use with pressures in excess of 1000 psi nor should they be used with strokes longer than 36 inches. Regardless of mount, whenever a long stroke cylinder is em- ployed, consideration should be given to additional support. Where the larger size of the square flange can be accom- modated Styles FFX and RFX, they may be used with full pressure rating of the cylinder and with longer strokes. The best styles of flange mount, regardless of application, are the FHF and RHF mounts. The RHF mount has the same mounting hole pattern and the same rectangular flange dimensions as the RF mount. Therefore, with longer mounting screws and consideration for a slightly shorter overall length, the RHF mount can be substituted for the RF. The FHF mount has the same hole pattern and rectangular flange dimensions as the FF mount. To substitute the FHF mount for that of the FF, it may be necessary to use spacers to fill in the dimensions previously occupied by the flange. (See separate Accessories Section) for Front Head Flange Spacer Bars. Spacers are employed as shown in Fig. B. CENTERLINE LUG MOUNT This style of mount is one of the best fixed mounts. It is not, however, one of the more popular mounts since it is not the most convenient to utilize. When used at higher pressure ranges or under shock condi- tions, the lugs should be doweled to the machine. This style of mount has room for dowel pins in the mounting lugs. Doweling should be done at one end of the cylinder only, especially important on long strokes, due to the deflection that takes place under load. Cylinders should never be pinned across corners. This can result in severe warping when the cylinder is subjected to operating temperatures and pressures. TIE ROD EXTENDED MOUNTS Tie Rod Extended cylinders are available with the tie rods extended front (style FX), with the tie rods extended rear (Style RX) or both ends (Style BX). Frequently cylinders are ordered with tie rods extended on one end in addition to another mount. The extended tie rods are then utilized for the mounting of other systems or machine components. Should the mounting be such that the overhung weight of the cylinder is borne by the extended tie rods, additional support may be required, especially if the cylinder has a long stroke. From a thrust standpoint, tie rod extended mounts are good, stable ones. REAR FLANGES STYLES RF & RFX REAR HEAD FLANGE STYLE RHF FRONT FLANGES STYLES FF & FFX CENTERLINE LUG STYLE CL TIE ROD EXTENDED STYLES FX, RX & BX FIGURE A BACKSIDE FLANGE MOUNT FRONT HEAD FLANGE STYLES FHF FIGURE B FF MOUNT FHF MOUNT WITH SPACER BARS SPACER BAR ONE EACH SIDE ENGINEERING-MOUNTING INFORMATION Sheffer cylinders (314) 427-0600 800-444-0522 (FAX) 314-427-3502 www. j hf.com JHF Catalog [ Volume 7 ] 1102 Prices Subject to Change Without Notice John Henry Foster pneumatic and hydraulic equipment

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