PTFE Composite Bushings for Hydraulic Pumps
Solutions / Hydraulic pumps and actuators
PTFE composite bushings for hydraulic pumps use a metal backing and a polymer-containing sliding layer. BONIU BEARING reviews steel-backed SF-1 / DU-type bushing enquiries for pump-shaft and actuator locations against the drawing and fluid duty. A general composite-bushing description does not establish pump-specific performance.
Fluid-lubricated shaft bearings require attention to working clearance, start-up, pressure loading and compatibility with the hydraulic fluid. Pump noise, leakage and shaft position depend on the assembly. A quotation needs the bearing duty and liner specification rather than only the outside diameter and length.
Application positions and bearing choices
| Position | Product family to review | Critical enquiry details |
|---|---|---|
| Gear-pump shaft support | Specified steel-backed PTFE composite sleeve | Fluid, viscosity, shaft speed, bearing load and installed clearance |
| Hydraulic-actuator guidance | PTFE composite bushing | Oscillation or stroke, side load, operating fluid and alignment |
| Flange-guided mechanism | Flanged composite bushing | Separate radial and axial duty plus flange geometry |
| Drawing-defined metallic alternative | Plain copper-alloy bushing for review | Lubrication design and differences from the composite liner |
Material, fit and operating conditions
For a steel-backed PTFE bushing for a gear pump, send the exact layer construction and any pump-specific material designation. SF-1 and DU-type are descriptions used in enquiries; they do not establish equivalence to a branded material. Define both steady operation and start-stop conditions. Keep hydraulic-fluid pressure separate from calculated bearing contact pressure.
Assembly requirements
Do not ream or machine a standard PTFE sliding layer without checking the selected product instructions. Some specialty pump liners are designed for machining; that feature cannot be transferred to every composite bushing. No direct interchangeability with a named OEM pump part or proprietary grade is claimed.
Compare the specified alloy with our brass and bronze grade information. Send a required grade or standard explicitly; similar alloy names do not establish automatic equivalence.
Related BONIU BEARING products
Steel-backed PTFE composite bushings
Metal-backed polymer sliding layer; review the required liner and fluid duty.
Plain copper-alloy bushings
Drawing-based copper-alloy sleeve; specify the alloy and lubrication plan.
What to send for a quotation
- Pump or actuator drawing and the bearing’s precise location
- Hydraulic-fluid type, viscosity range and minimum/maximum temperature
- System pressure, shaft speed, start-stop duty and radial bearing load
- Installed bore clearance, housing fit, shaft finish and lining specification
- Required testing, quantity, drawing revision and first-article approval
We review drawings or samples before confirming material, dimensions, availability and lead time. Agree first-article and inspection requirements at the enquiry stage so both sides use the same acceptance criteria.
Frequently asked questions
Is every SF-1 bushing suitable for a hydraulic gear pump?
No. Fluid compatibility, erosion exposure, load-speed conditions, clearance and liner construction must match the pump requirements. Review the specified grade before substitution.
Can you supply a metal-polymer bearing for a pump shaft from a sample?
We review sample-based enquiries, but the original liner specification and unworn dimensions should be confirmed. A worn sample alone cannot establish the required clearance.
Should a DU-type hydraulic-actuator bushing run dry?
Follow the actual application and material specification. A dry-running capability in a catalogue does not mean the hydraulic system should operate without its required fluid.
Further selection guidance
Read the related technical guide or explore all bushing selection guides.
Industry reference: GGB: Metal-polymer bearing requirements for internal gear pumps. This reference provides application context; its branded material specifications, certifications and performance claims are not specifications for BONIU BEARING products.