bronze bushings
- January 16, 2018
Gallagher Fluid Seals is a distributor of CIP Composites full product line. CIP Composites are laminated polymer materials made by impregnating textile with thermoset resins. The physical properties of CIP materials make them superior bearing materials. CIP Composites offer design engineers an attractive, cost effective alternative to the traditional material used for bushings, bearings, wear pads, and thrust washers. The following describes the physical characteristics and application factors to replacing bronze bearings with CIP Composites.
Physical Characteristics
Coefficient of Friction
CIP Composites have lower coefficients of friction than bronze in both static and dynamic situations. It is common to achieve 50% lower coefficients of friction when transitioning to composites. Bronze bearings pose a risk for metal to metal contact if grease is non-existent or not sufficient to support the shaft, and may develop high break-away torque requirements after prolonged periods of rest. CIP Composites are self-lubricated, minimizing the concerns with lubrication systems, specifically in high load, slow speed, or oscillating applications. CIP Composites eliminate noisy stick-slip problems, extend operating life and reduces wear, making for better operating efficiency.
Moisture Absorption
There can be concerns with moisture absorption for non-metallic materials. Moisture absorption can create swell and expansion of the bearing material and potentially premature failure. Some common plastics in use today have water absorption rates as high as 5-7%, which can lead to bore closure of the bearing and seizing on the shaft. CIP Composites have a negligible absorption of less than 0.1%, and effectively eliminate this concern when moving away from a metallic solution.
- December 21, 2017
Vesconite Hilube is a thermopolymer, designed for particularly difficult operating environments. Hilube is specifically recommended for moist and underwater applications. These include the pump and marine industry, where regular maintenance is not practically feasible or cost-effective. Displaying superior wear life, especially in poorly lubricated and dirty conditions, Vesconite Hilube has been shown to offer up to ten times the life of bronze bushings.
Vesconite Hilube incorporates an internal lubricant that translates into an exceptionally low friction coefficient. Combined with excellent dimensional stability, low wear rates and a high load-bearing capacity. Hilube has a PV rating (pressure x velocity) four times that of nylon bushings.
Vesconite is available in a wide range of rods, bushings, plates, and machined custom parts.
Hilube Key Features
No Water Swell
Fully saturated, Vesconite Hilube has a negligible moisture absorption rate (0.5%). Its linear swell rate of 0.07% allows for fine clearances in the majority of applications. By way of contrast, nylons absorb moisture by as much as 9% of total mass – resulting in high swell rates and critical loss of clearance, which can lead to seizures.
