Composite Bushings

HEF’s Composite / Polymer Bushings are designed to operate under conditions which include (a) the need for maintenance and grease/lubricant-free operations; (b) low friction in the joint; (c) high to medium loads; (d) corrosive environment; and (e) the ability to absorb shock and vibrations.

HEF’s family of H-Liner bushings has a woven structure made of PTFE and epoxy resin, which provides tensile strength vastly superior to injection molded polymer bushings – and is significantly more resistant to high loads, seizure and galling.

These composite bushings are well-suited for both rotation and oscillation applications, and can be used at high-speeds. In addition, these bushings are chemically inert, and have low water absorption. Their maximum working temperature is 320°F (160°C). They are widely used for handling misalignment situations.

	Dyn Load (N/mm2)	Max Speed (m/s)	Max Temp (°C)	Low Maintenance	Water Resistance	Low Water Absorption
H-Liner M	80	0.5	+130°C	+++	++	+++
H-Liner S	100	0.5	+160°C	+++	++	+
H-Liner S1	140	0.5	+160°C	+++	+++	+

The H-Liner S and H-Liner S1 bushings are also available with a patented ‘lip’ option, as illustrated below. This unique integrated lip prevents dirt from entering the joint and minimizes the wear of the guiding pin, which is typically enhanced with an urethane seal.

Mechanical Properties	Unit	H-Liner M	H-Liner S (with or without lip)	H-Liner S1
Static Compression Resistance (Max)	N/mm2	350	400	400
Dynamic Compression Resistance (Max)	N/mm2	80	100	140
Elastic Modulus of Compression	N/mm2	3300	12380	12380
Density	gm/cm3	1.3	1.6	1.6
Water Absorption	%	0.07	0.16	0.16
Temperature Range of Use	°C	-40/+130	-40/+160	-40/+160

Tribological Properties	Unit	H-Liner M	H-Liner S (with or without lip)	H-Liner S1
Dynamic Pressure (Max)	N/mm2	80	100	140
Max Linear Speed	m/s	0.5	0.5	0.5
PV Factor (Max)	N/mm2 *m/s	1	1.2	1.2
Dry Coefficient of Friction		0.05 - 0.10	0.06 - 0.12	0.03 - 0.09
Optimal Pin Roughness (Ra)	µm	0.2 - 0.6	0.2 - 0.6	0.2 - 0.6

For optimal performance, we recommend using a grinded pin with a roughness lower than Ra 0.4 µm and hardness higher than 400 HB. HEF DURFERRIT PEL^® OX pins are particularly appropriate with H-Liner Bushings.