Airail Springs Design Guide Rail
52Pages

Rail Applications Design Guide

Rail Applications Design Guide TABLE OF CONTENTS History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 Advantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 Terms – Air Springs & Suspensions . . . . . . . . . . . . . . . . . . . . . . . .4 Construction Of Air Springs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 Styles of Air Springs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 Bead Rings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....

HISTORY In the early 1930’s, the Firestone Tire and Rubber Company began experiments to develop the potential of pneumatic springs. In 1938, the country’s largest manufacturer of motor coaches became interested in using air springs on a new design bus they were developing. Working with Firestone engineers, the first buses were tested in 1944 and the inherent ride superiority of air suspensions was clearly documented. Development continued into other vehicular applications. Firestone made huge in-roads into the automotive, heavy truck and trailer markets. With the invention of the reversible...

ADVANTAGES Passenger Comfort Suspension systems designed with Airail™ springs provide a uniformly smooth ride for passenger comfort. The rail car is cushioned by air springs from the jolts and vibration experienced by the rail truck. By incorporating an auxiliary air reservoir, the frequency and spring rate characteristics of the air spring can be modified to the exact specifications of the suspension designer. Utilizing Firestone’s extensive computer modeling programs, the effect of orifice damping can be determined for controlled shock absorption. Constant Floor Height With the use of a...

TERMS – AIR SPRINGS & SUSPENSIONS PRESSURE & PROCESS TERMS Bead Ring. A metal ring incorporating a shaped cross-section that grips the bead of the flexible member and provides a means of attaching and sealing the bead to a plate or other structure. Absolute Pressure. The pressure in a vessel located in a complete vacuum. Usually determined by adding 14.7 pounds per square inch (psi) to the gauge pressure. Absolute pressure = gauge pressure + atmospheric pressure. Bead Skirt. A bead ring (see above description) that has a profile such that it controls the lateral movement of the spring. A...

SUSPENSION RELATED TERMS Compression Stroke (Jounce). The reduction in height from the normal design height of the spring as it cycles in dynamic operation. Height Sensor. An electronic device that senses the position of a suspension or other mechanical device. The output signal from this device is sent to a control circuit which then exhausts or adds air to the air spring through a solenoid valve. Design Load. This is the normal maximum static load the air spring suspension is expected to support. It is the rated axle load divided by the number of air springs working with the axle and...

Outer Cover Inner Liner FLEXIBLE MEMBER CONSTRUCTION Although the two-ply air spring is available, most Firestone air springs for rail applications are built with four-ply rated construction. An air spring is a carefully designed rubber and fabric flexible member which contains a column of compressed air. The flexible member itself does not provide force or support load; these functions are performed by the column of air. Each air spring’s flexible member is identified by a style number, which is molded-in during the curing (vulcanization) process. Examples would be 29, 218, 1T60, etc. This...

STYLES OF AIR SPRINGS REVERSIBLE STYLE AIR SPRING WITH BEAD SKIRT C Flexible Member. See page 6 for flexible member A Bead Plate. A metal component, typically steel, D Piston. A metal component, typically aluminum, plated for corrosion resistance, bolted to the bead skirt to create an airtight assembly that allows for leak testing before the unit leaves the factory. plated for corrosion resistance whose profile, along with the bead skirt, can further influence the vertical and lateral characteristics of the spring per the designer's requirements. construction information. B Bead Skirt. A...

C Upper Bead Plate. 6-gauge (.194”) carbon steel, CONVOLUTED AIR SPRINGS – ROLLED PLATE ASSEMBLIES plated for corrosion resistance. Permanently attached to the flexible member with a clamp ring (D) to form an airtight assembly. Allows for leak testing before the assembly leaves the factory. Convoluted parts are available with bead rings or permanently attached plates called “rolled plates.” Rolled plate assemblies may offer an advantage over bead ring parts because installation is much easier. D Clamp Ring. This ring is crimped to the bead plate to permanently attach it to the flexible...

F Bead Ring. Aluminum ribbed neck type shown. CONVOLUTED AIR SPRINGS – BEAD RING ASSEMBLIES May also be of a second stamped steel variety or made of aluminum (see page 10). A Mounting Plate. Not included. See page 10 for material, machining recommendations and installation instructions. SERVICE ASSEMBLY B Bead Ring Bolt. Some assemblies may include The flexible member is available separately as a replacement on convoluted bead ring assemblies. one of three varieties included with air spring assemblies. See chart on page 10. C Nuts & Lock Washers. Included with air spring Note: No convoluted...

BEAD RINGS THREE TYPES OF BEAD RINGS STEEL COUNTERSUNK BEAD RING ALUMINUM RIBBED NECK BEAD RING ALUMINUM SOCKET HEAD BEAD RING* Customer Supplies Plate Bolt Length Effective Length Bolt Length Effective Length Customer Supplies Plate Customer Supplies Plate Optional Shorter Length Ribbed Neck Bolt Standard Bolt Length (in) 15⁄8 Standard Bolt Length (in) 17⁄8 Standard Bolt Length (in) 11⁄4 Standard Effective Length (in) 1.22 Standard Effective Length (in) 1.28 Optional Effective Length (in) 0.66 Standard Order Number (bolt only) Standard Order Number (bolt only) Optional Order Number (bolt...