Nitrile Butadiene (Buna N) Rubber is a flexible elastomer material that is oil resistant, resembles natural rubber in resilience and elasticity and operates effectively in temperature range of -40° to 212° F (-40° to 100° C). Good resistance to oil. Standard elastomer. (Also applies to SXB Cushions.)
Elastomers in Compression
ElastomersinCompression
Lovejoy offers four types of elastomer designs to allow for additional flexibility in addressing specific application requirements. One piece designs are used in the “L” and “AL” models (referred to as spiders) and multiple part “load cushions” are used in the “C” and “H” model couplings. The load cushions are in sets of 6 to 14 pieces depending on coupling size.
Solid Center Spider
The solid center design is commonly used design when shafts of the driver and driven equipment can be kept separate by a standard gap
Open Center Spider
The open center design allows for the shafts of the driver and driven to be positioned within a short distance
Open center spiders offer shaft positioning flexibility but have a lower RPM capacity (1,750 RPM maximum for NBR, 3,600 maximum for Urethane/Hytrel®)
Cushions
Used exclusively for the C and H Type couplings
Load cushions are held in place radially by a steel collar which is attached to one of the hubs
Snap Wrap Flexible Spider
Design allows for easy removal of the spider without moving the hubs
Allows for close shaft separation all the way up to the hubs maximum bore
Maximum RPM is 1,750 RPM with the retaining ring, but if used with the LC Type (with collar) the normal RPM rating of the coupling applies
Style is available in NBR and Urethane only, and in limited sizes
Note
Notes
NBR standard shore hardness is 80A ±5A – Except L035=60A. Other softer or harder designs are available in NBR material; consult Lovejoy.
