HZ-EP Engineering plastic bearing Manufacturers

What HZ-EP Engineering Plastic Bearings Are

HZ-EP bearings are plain sliding elements formed from engineering thermoplastics by injection moulding, with fibre reinforcement and solid lubricant fillers where the duty demands it. Because the geometry comes from a mould rather than a machining cycle, we can produce ribs, flanges, oil or grease pockets, snap features and non-circular bores that would be costly in bronze or steel.

The material matrix carries the lubricant, so the bearing runs dry or with only boundary lubrication. Friction stays low in both dry and lubricated conditions, and the polymer tolerates humid, saline and mildly chemical environments where a metal bush would corrode. The low density also reduces rotating mass and transmitted noise.

Where the Range Fits

• Automotive components — seat hinges, pedal pivots, latch and linkage points, motor mounts and interior mechanisms.
• Industrial machinery — conveyor drives, packaging and labelling lines, cam followers and low-speed rotary joints.
• Medical and laboratory equipment — humidity-controlled assemblies, centrifuges and instruments where lubricant contamination is unacceptable.
• Agricultural and outdoor equipment — pivot points and linkages exposed to dust, washdown and weather.

Our HZ-EP Product Range

The HZ-EP family is organised by motion type and mounting style, so a project can be matched to the closest standard geometry before any tooling is discussed.

Materials and Critical Specifications

Standard HZ-LIN film and precision grades use a high-strength engineering plastic matrix such as POM or PA66, reinforced with fibres and loaded with solid lubricants including PTFE and graphite. The lubricant is released progressively under motion, which keeps the friction coefficient in the region of 0.05–0.15 across roughly −40 °C to 120 °C and supports dynamic PV values up to about 1.5 MPa·m/s.

• Static compressive strength — up to approximately 120 MPa for the reinforced film grades.
• Precision bore tolerance — HZ-LIN precision bushes are held to about ±0.02 mm with bore roughness Ra ≤ 0.8 µm to suppress stick-slip.
• Moisture absorption — below 0.5% for the precision grade, keeping dimensions stable in humidity-controlled equipment.
• Housing fit — precision bushes are dimensioned for H7 housings and press-fit installation.
• Load ratings — catalogue tables list dynamic and static load capacity per bore size, for example LIN-00-20 at 1125 N dynamic and 7875 N static.

Because the polymer is chemically inert and non-porous, it resists oxidation, dilute acids and saline exposure, and does not support microbial growth — relevant for food-adjacent and medical assemblies. Hard contaminants embed into the surface instead of scoring the shaft.

Speed, Load and Thermal Behaviour

Thermoplastics behave differently from bronze under speed. Heat generated at the sliding interface must leave through the shaft and housing, so the allowable PV falls as continuous speed rises and as ambient temperature approaches the material limit. We size the bearing so the product of contact pressure and sliding velocity stays inside the material envelope at the actual duty cycle, not at a nominal peak.

Dimensional stability under heat is a genuine advantage: the polymer does not expand like metal, so clearance stays predictable and seizure risk from thermal growth is reduced. The structure also damps harmonic vibration, which lowers noise and resonance in precision machinery.

Configuration Options

Within the HZ-EP family we adjust material grade, wall thickness, bore tolerance band, flange form, lubrication pockets, sealing lips and end chamfers to suit the assembly. Typical configuration decisions include:

• Base resin and filler package — unfilled, fibre-reinforced, or solid-lubricant loaded.
• Bore and outside diameter tolerance class matched to the shaft fit and housing bore.
• Plain, flanged, sealed or linear sliding geometry.
• Oil holes, grease grooves or diamond-pattern pockets where boundary lubrication is available.
• Colour and marking for assembly-line identification.

Where a standard catalogue size does not fit, we review a drawing and confirm whether an existing mould can be adapted or a new tool is required. Mould tooling is held in-house, which shortens the path from drawing to first article.

Installation, Assembly and Line Integration

HZ-EP bearings are designed for straightforward press-fit assembly with minimal pressure, which reduces the risk of bore distortion on the line. Precision grades are compatible with H7 housings; the sliding film grades are supplied with base-hole assembly drawings so the housing bore, groove width and retention features can be machined to match.

For automated assembly we can define lead-in chamfers, retention shoulders and orientation features, and supply the dimensional report needed to set press force and stroke. Shaft finish matters as much as the bearing: a ground, hardened shaft in the Ra 0.2–0.8 µm range gives the most stable friction behaviour, while very rough shafts accelerate wear.

Quality Control and Acceptance

Production runs on more than 280 sets of special equipment with 50 automatic production lines, supported by in-house moulds and a technical team of over 150 people. Dimensional inspection covers bore diameter, outside diameter, wall thickness, flange geometry and length against the agreed drawing.

• First-article inspection and dimensional report before batch release.
• Material and batch traceability through moulding and finishing.
• Sampling plans agreed per project for critical characteristics.
• Certification documentation available for automotive and industrial programmes, including IATF16949 and quality management system records.

Acceptance criteria are fixed in the drawing and inspection plan before production, so both sides measure the same characteristics the same way.

Information We Use to Configure Your Solution

To move from an enquiry to a firm configuration and quotation, we work from the operating data below. Where a value is not yet fixed, we can propose a starting point and confirm it against the application.

Maintenance, Spares and Serviceability

Self-lubricating HZ-EP bearings remove the grease line, the re-lubrication interval and the associated downtime. In service, wear is progressive and predictable; replacement is a press-out and press-in operation using the same housing bore. We retain mould records so repeat orders reproduce the original geometry, and we can supply replacement batches against the original drawing reference.

For high-volume programmes we recommend holding a defined spare quantity at the customer's site rather than relying on emergency shipments, and we can package parts in line-ready kits or bulk containers to suit the receiving process.

Documentation, Packaging and Delivery Scope

Each order is accompanied by the documentation agreed at the quotation stage: dimensional reports, material declarations and certification copies where the programme requires them. Packaging is specified per part — bulk bags, layer trays or individual protection for precision bores — so that parts arrive without surface damage.

Delivery scope is confirmed in writing before production, covering quantity, packaging, marking and the inspection documents included. Samples are produced in three days for standard configurations, which allows a fit and function check before committing to a full batch.

Frequently Asked Questions

Can HZ-EP bearings run completely dry?

Yes. The solid lubricant in the polymer matrix provides the sliding interface, so no external grease or oil is required. Dry running is the normal condition for the film and precision grades; where a grease groove or oil hole is present, it is there to extend life under higher PV duty, not as a mandatory requirement.

What shaft finish and tolerance should the mating shaft have?

A ground shaft in the Ra 0.2–0.8 µm range gives the most stable friction and wear behaviour. Shaft tolerance must be read together with the bore tolerance band in the catalogue table, because the running clearance is the difference between them. We confirm the pair against the drawing before release.

How do I choose between the precision bush and the sliding film?

The precision bush is a moulded or machined component with a tight bore tolerance and a thick wall, suited to press-fit installation in an H7 housing and to oscillating or micro-motion duty. The sliding film is a thin-wall wrapped element for larger housing bores and lower-cost assemblies, and is available in plain and sealed versions.

Can you produce a non-standard size or geometry?

Yes. With in-house mould tooling and a technical team of more than 150 people, we adapt existing moulds or develop new ones for non-circular bores, flanges, retention features and sealing lips. Send the drawing with the operating data and we will confirm feasibility and the tooling route.

What is the typical lead time for samples and production?

Samples for standard configurations are produced in three days. Production timing depends on whether existing tooling can be used or a new mould is required, and is confirmed in the quotation once the drawing and annual volume are fixed.

Which documents accompany a shipment?

Documentation is agreed per programme and can include dimensional inspection reports, material declarations and certification copies. The exact set is listed in the order confirmation so that receiving inspection knows what to expect.