Garter Springs are helical extension or compression springs whose ends are connected so that each spring becomes a circle and exerts radial forces. Their primary application is in oil seals. Other uses include small motor belts, electrical connectors and piston-ring expanders.
Design methods for garter springs are continuations of methods developed for helical compression and extension springs. Generally, they are designed with as low a rate as possible to provide a nearly constant force on a seal as it wears.
The garter is essentially a helical extension spring formed into a circular ring with the ends connected on the inside diameter. Thus a garter spring is an endless spring, ignoring that its ends are joined which does not affect the results and is easily identified in that it looks like a circle made up of a spring.
Joint Design and Considerations for Garter Springs Garter spring ends may be fastened together by interlocking loops, staking one coil of the female end into the rib end, soldering (for belt applications) or by screwing one end into the other.
When considering garter spring design, its strength must be such that the joint will not separate when the spring is extended to its maximum diameter regardless of the connecting joint used.
Specifications for Garter Springs
Give The Following Information As Completely As Possible:
Assembled I.D. (extension) or O.D. (compression):
Installed I.D. or O.D.:
Circumferential Load Required:
Direction of Coil:
Type of end connection:
O.D. Body Coil Diameter:
Number of Coils:
Number of Active Coils:
Initial Tension P:
Radial Load P: Max.
Rod or Shaft Diameter for Spring Expansion:
Tolerances (specified either on assembled length or I.D. but not on both):