POM Composite Bushings
Heavy-duty self-lubricating bearings with acetal (POM) lining and integrated grease pockets for marginal lubrication applications.
Tri-Layer Composite Structure
POM composite bushings (also known as boundary lubricating bearings or DX-type bushings) are engineered for heavy-duty applications requiring marginal lubrication. Unlike fully self-lubricating PTFE bearings, POM bushings are designed to operate with periodic grease application, delivering superior performance under high loads, shock loading, and edge loading conditions.
JBM POM composite bushings feature a precision-engineered tri-layer structure that combines the mechanical strength of steel with the excellent sliding properties of modified polyoxymethylene (acetal copolymer).
POM (Acetal) Lining
Modified polyoxymethylene layer (0.30-0.50mm) with integrated grease pockets. Provides high wear resistance, low friction, and excellent damping properties.
Porous Bronze Interlayer
Sintered bronze powder (0.20-0.35mm) bonds the POM to the steel backing. Provides maximum thermal conductivity and serves as a mechanical anchor.
Steel Backing
Low-carbon steel base delivers exceptionally high load-carrying capacity, excellent heat dissipation, and structural rigidity for press-fit installation.
Technical Specifications
| Max Load (Static) | 250 N/mm² |
| Max Load (Dynamic) | 70 N/mm² |
| Max Speed (Greased) | 2.5 m/s |
| PV Limit (Greased) | 3 N/mm²·m/s |
| Temperature Range | -40°C to +110°C |
| Friction Coefficient | 0.05 - 0.20 |
| Thermal Conductivity | 50 W/(m·K) |
Cross Reference
Equivalent to DX® type bushings, SF-2 series, and other boundary lubricating plain bearings.
Integrated Grease Pockets
The defining feature of POM composite bushings is the pattern of circular indentations (grease pockets) machined into the bearing surface. These oil storage indents are critical for boundary lubrication performance.
Lubricant Reservoir
Grease pockets store lubricant and release it gradually during operation, maintaining a consistent lubrication film between bearing and shaft surfaces.
Extended Intervals
Oil indent design significantly extends re-lubrication intervals, reducing maintenance frequency and associated labor costs.
Debris Collection
Indentations also capture wear particles and contaminants, preventing abrasive damage to the bearing surface and shaft.
Machinability
Unlike PTFE, POM lining can be machined after installation to achieve precise tolerances and optimal clearance fits.
Why Choose POM over PTFE?
| Characteristic | POM Composite | PTFE Composite |
|---|---|---|
| Load Capacity | Higher (70 N/mm² dynamic) | Standard (60 N/mm² dynamic) |
| Shock Resistance | Excellent damping | Good |
| Edge Loading | Superior tolerance | Moderate |
| Machinability | Can machine after install | Not recommended |
| Lubrication | Requires initial grease | Fully dry running |
| Temperature Range | -40°C to +110°C | -195°C to +280°C |
| Best For | Heavy loads, dirty environments | Dry running, high temps |
Key Advantage: POM composite bushings excel in heavy-duty applications with shock loading, misalignment, and contaminated environments where PTFE bearings may not perform optimally.
POM Composite Bushing Benefits
High Load Capacity
Supports static loads up to 250 N/mm² and dynamic loads up to 70 N/mm², ideal for heavy-duty machinery.
Shock Resistant
Excellent damping properties absorb shock loads and vibration, protecting both bearing and mating components.
Edge Loading Tolerance
Superior resistance to misalignment and edge loading conditions common in heavy equipment applications.
Water Resistant
POM absorbs virtually no water, ensuring dimensional stability and consistent performance in humid environments.
Low Maintenance
Grease pocket design extends re-lubrication intervals significantly, reducing maintenance costs and equipment downtime.
Post-Install Machining
POM lining can be bored or reamed after press-fitting to achieve precise clearance or interference fits.
Quiet Operation
POM's natural damping characteristics reduce operational noise and vibration for smoother equipment performance.
Contamination Tolerant
Performs reliably in dirty, dusty environments where contaminants may enter the bearing area.
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Get a QuoteWhere POM Composite Bushings Excel
POM composite bushings are specifically designed for heavy-duty, low-speed applications with marginal lubrication. They perform best in demanding environments where standard bearings fail.
Construction & Earthmoving
- Excavator boom & arm pivots
- Crane slewing rings
- Loader bucket pins
- Bulldozer track rollers
- Backhoe swing bearings
- Forklift mast bushings
Agricultural Machinery
- Tractor front axle pivots
- Harvester header bushings
- Baler trip mechanisms
- Wheel caster swivels
- Implement lift linkages
- PTO shaft bearings
Automotive & Trucks
- Kingpin bushings
- Steering linkage joints
- Suspension pivot points
- Chassis hinge pins
- Tailgate pivots
- Fifth wheel plates
Industrial Machinery
- Machine tool spindles
- Press ram guides
- Hydraulic cylinder pivots
- Conveyor idler shafts
- Mill roll chocks
- Grinding machine slides
Available Configurations
Cylindrical Bushings
Standard straight bushings for radial loads. Press-fit into housing bore. Available in metric and imperial sizes.
- ID range: 6mm - 150mm
- Wall thickness: 1mm - 3mm
- Radial loads only
Flanged Bushings
Integrated thrust flange handles combined radial and axial loads in a single component.
- ID range: 8mm - 100mm
- Flange OD: +4mm to +20mm
- Combined load capacity
Thrust Washers
Flat ring bearings for axial thrust loads. Used alone or paired with cylindrical bushings.
- ID range: 10mm - 200mm
- Thickness: 1.5mm - 4mm
- Axial loads only
POM Composite Bushing Range
Need Help Selecting the Right POM Bushing?
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