PI Bearings Manufacturers

As a PI Bearings manufacturer based in Yancheng, Jiangsu, Jiangsu Yinghong Transmission Technology Co., Ltd. produces polyimide bearings under the registered YHU brand inside a wider plastic bearing family that also covers POM, PP, UPE, PEEK, PTFE, PVDF, PA66 and specially modified grades.

PI bearings address rotating points where lubricated steel is the wrong answer: sustained heat, vacuum, aggressive media, radiation exposure, or a demand for electrical insulation and non-magnetic behaviour. We manufacture them on the same platform as the rest of our bearing product range, using Japanese precision manufacturing technology, automated production lines and high-precision inspection equipment, with IATF 16949, RoHS, CE and SGS certification behind the process.

Our PI Bearing Range and Supply Formats

Polyimide parts leave our works in several formats, each matched to the housing and shaft interface in the customer's assembly.

• Plain PI sleeve bearings — press-fit or slip-fit into a housing, running directly on a hardened shaft with no grease circuit.
• Flanged PI bushings — radial and axial location from a single component; comparable mounting geometry is also produced across our flanged bearings range in bearing steel and stainless steel.
• PI cages, retainers and thrust washers — separate polymer components assembled into rolling bearing stacks and precision instrument mechanisms, frequently alongside our deep groove ball bearings.
• Custom non-standard PI parts — shaped, thin-wall or non-circular profiles produced to drawing or sample as part of our custom non-standard range.

Where PI Bearings Fit in the Line

Polyimide earns its place wherever heat, vacuum or cleanliness removes the option of an oil or grease film. Typical duty on our customers' lines includes:

• Semiconductor equipment and vacuum handling, where low outgassing and dry running matter more than load capacity.
• Medical devices and instruments that pass through sterilisation cycles or repeated cleaning.
• Electric motors, power tools and pneumatic tools with hot housings and an insulation requirement.
• Robotics, drones, household appliances and precision instruments needing quiet, non-magnetic rotation.
• Marine, aerospace, textile and financial equipment where chemical or humidity exposure shortens steel life.

Critical Specifications We Work To

A PI bearing is defined by the interface around it. The parameters below drive both the drawing and the process route.

• Geometry: bore, housing diameter, wall thickness, length, flange diameter and flange thickness, with the tolerance class agreed per interface.
• Working point: radial and axial load, sliding speed, duty cycle and the resulting pressure-velocity combination.
• Counterface: shaft hardness, surface finish and material, since polymer wear behaviour depends on the steel it runs against.
• Thermal envelope: continuous and peak temperature, plus the expansion and contraction the part must absorb.
• Environment: chemicals, moisture, cleaning agents, vacuum level and radiation exposure.
• Functional behaviour: electrical insulation value, magnetic neutrality, clearance and running fit.

PI Positioned Against Our Other Plastic Grades

Because we mould and machine the full plastic family in-house, the material recommendation comes from the working point rather than from a single available grade.

Configuration and Custom Development

Our engineering team designs and optimises bearing structure, material grade and performance parameters for specific industry conditions. For PI work this normally means confirming the dry-running envelope first, then fixing the geometry around it.

• Grade and blend selection for the temperature, media and friction target.
• Dimension, wall thickness and tolerance class to suit press-fit or slip-fit installation.
• Flange, groove, pocket or chamfer features that simplify assembly and retention.
• Prototype production followed by mass delivery once the sample is approved.
• Failure analysis and technical support where an existing part is wearing or deforming in service.

Quality Control and Acceptance

Yinghong operates a closed-loop quality management system from raw material warehousing through production to finished goods, supported by high-precision inspection and testing equipment. We are a National High-Tech Enterprise holding invention and utility model patents, certified to IATF 16949, RoHS, CE and SGS.

• Incoming material verification and batch traceability through to shipment.
• In-process control on machining and assembly precision.
• Performance checks covering precision, noise, vibration, sealing, wear and corrosion resistance.
• SGS test reports available for the plastic bearing materials we supply.
• Sample approval before serial production, with dimensional records issued against the agreed drawing.

Information We Use to Configure Your Solution

We prepare a configuration and quotation from the working point, not from a catalogue line alone. The following inputs let us size the part correctly on the first pass.

• Shaft and housing diameters with tolerances, plus available axial space.
• Radial and axial load, speed, duty cycle and expected service life.
• Continuous and peak operating temperature.
• Media, cleaning or sterilisation process, vacuum level and any radiation exposure.
• Insulation and magnetic requirements at the installed position.
• Drawing or physical sample, annual quantity, packing preference and delivery scope.

Installation, Maintenance and Serviceability

PI bearings install with a controlled press or a light interference fit, depending on the retention the housing provides. Because the material expands and contracts more than steel, we state the fitting allowance on the drawing rather than leaving it to the assembly floor.

There is no lubrication schedule to maintain and no grease to migrate into a clean process. The part is treated as a wear component: replacement intervals are set from the duty cycle, and we supply the same geometry as a spare so that a rebuilt unit returns to its original running clearance. Documentation, drawings and assembly guidance are issued with the order, and technical support continues after delivery.

Frequently Asked Questions

What is a PI bearing used for?

Polyimide bearings are used where heat, vacuum, chemicals or radiation rule out a lubricated steel bearing, and where electrical insulation or non-magnetic behaviour is required. They run dry on a hardened shaft, so they also suit applications that cannot tolerate grease contamination.

Do PI bearings need lubrication?

No. They are supplied as self-lubricating components and are designed to run without an oil or grease film, which is one of the reasons they are specified close to semiconductor, medical and vacuum equipment.

Can you produce PI bearings to our drawing or sample?

Yes. We undertake standard and non-standard bearing customisation and can work from a drawing or a physical sample. The usual route is review of the working point, prototype production, sample approval, then mass delivery.

How does PI compare with PEEK or PTFE for the same position?

PI offers the highest stiffness and heat performance of our plastic group together with radiation and vacuum tolerance. PEEK is often the choice where fatigue life dominates, and PTFE where the lowest possible friction matters more than load capacity. We hold all three, so the recommendation follows the duty cycle.

What acceptance documents come with a PI bearing order?

Orders are supported by dimensional inspection records against the approved drawing, material and batch traceability, and RoHS documentation. Our quality system is certified to IATF 16949, with CE and SGS evidence available for the relevant materials and processes.

Which quantities can you handle?

Our automated production lines support standardised, large-scale mass production, and the same facility handles prototype and small-batch custom work. Send the annual volume with the enquiry so that tooling and packing are planned around the real requirement.