Slide Bearings.

What are Slide Bearings?

Slide bearings, also known as sleeve bearings, are one-piece plain bearings that support a rotating or oscillating shaft through direct sliding contact rather than rolling elements. The shaft turns inside a close-fitting polymer sleeve, so the bearing carries radial load in a compact form with no balls, races or cages to assemble. 

Accu supplies slide bearings moulded from self-lubricating iglidur G, a tribologically optimised polymer that runs dry. There’s no oil or grease to apply, top up or contaminate the surrounding assembly. That makes them a maintenance-free choice for engineers who need dependable plain bearings without a lubrication schedule.

How Plastic Slide Bearings Work.

A plastic slide bearing works by sliding, not rolling. Solid lubricants are built into the iglidur G polymer during moulding, so as the shaft turns, it transfers a microscopically thin film onto the running surface. That film keeps the coefficient of sliding friction low, between 0.08 and 0.15 against a steel shaft, so the bearing runs smoothly from the first rotation with no run-in period and no added lubricant. Because the load is spread across a sliding surface rather than concentrated at rolling contact points, the bearing also damps vibration and runs quietly.

Sliding bearings are governed by pressure and surface speed rather than by rolling-element fatigue, so each size has a maximum recommended surface pressure of 80 MPa at +20°C for iglidur G, alongside a working temperature band that runs from -40°C to +130°C, with short peaks to +220°C. Within those limits, they suit low-speed and oscillating duties like providing a pivot in a packaging mechanism, a linkage on agricultural machinery or a guide bush in office equipment, where freedom from grease and quiet running matter more than the very high speeds a rolling bearing would reach. For rolling-element options across the wider range, see the bearings parent category that covers ball and roller types.

Materials Plastic Sleeve Bearings Are Made From.

Accu's plastic sleeve bearings are produced in a single tribologically optimised polymer. For a plain bearing the choice of material must balance load, speed and temperature rather than pointing to one universal best material.

• Plastic - Nylon Blend: A nylon-based compound with solid lubricants blended right through the wall rather than laid on as a surface coat, so it keeps running smoothly even as it wears. That blend strikes a practical middle ground on wear life, mechanical strength and cost for everyday engineering, taking surface pressures to 80 MPa at +20°C and running continuously anywhere from -40°C to +130°C.

Every bearing is supplied in its natural, unpigmented finish, with the material itself providing the running surface.

Sleeve Bearings Sizes and Types.

The range covers 143 sizes, all metric. 

• Inside diameter (the shaft bore): Runs from 1.5 mm to 18 mm, outside diameter from 3 mm to 20 mm and overall length from 1.5 mm to 50 mm, so most low-speed shaft-support tasks can be matched to a stock size without a special order. 
• Outside diameters: Held to an h13 tolerance for a reliable press fit into the housing, while the bore is finished to an E10 class once fitted. 

For correct running clearance, pair each bearing with an h9 shaft and an H7 housing bore. Sizes are identified by the GSM part reference, which encodes the bore, outside diameter and length.

Every size here is a straight cylindrical sleeve. Where a design needs an integral locating flange or a flat face to take axial thrust, the flanged sleeve and thrust washer forms cover those jobs, while the plain slide bearings and wider bearings ranges cover related sliding and rolling duty. 

FAQs.

Q: Are slide bearings better than ball bearings?

A: It depends on the job, but for low-speed rotating or oscillating shafts a self-lubricating sleeve bearing is often the better choice. It runs dry, absorbs shock and vibration, tolerates dirt well and costs less, all without the balls, races and grease a rolling bearing needs. Ball bearings still win where speeds and precision climb, because a plain bearing is limited by pressure and surface speed rather than built for high rotation. 

For a great many everyday mechanisms, though, the simpler, quieter, cheaper sleeve is all the design needs.

Q: What are the disadvantages of sleeve bearings?

A: Plain sleeve bearings suit sliding rather than high-speed rotation, so they are bounded by pressure-velocity limits and a maximum temperature rather than by rolling-element wear. In practice that means respecting the 80 MPa surface-pressure limit and the +130°C continuous temperature ceiling when you specify one.

Q: Do plastic slide bearings need grease or lubrication?

A: No. iglidur G slide bearings are self-lubricating and designed to run completely dry. Solid lubricants are built into the polymer and release gradually during motion, so the bearing needs no oil, no grease and no re-greasing over its life. That keeps the surrounding assembly clean and is exactly why they suit applications where lubricant would attract dirt or cause contamination.

Q: Are plastic sleeve bearings any good?

A: For the right duty, very. Polymer sleeve bearings match many metal bushes on load while adding corrosion resistance, quiet running, light weight and complete freedom from lubrication. They will not replace a precision ball bearing at high speed, but for low-speed pivots, linkages and guides they are often the more sensible, lower-cost and lower-maintenance choice. Engineers who have not used them often are surprised how much duty a good polymer bearing will take.

Q: Are slide bearings quiet?

A: Yes, noticeably so. Sliding contact and the shock-absorbing polymer make sleeve bearings much quieter than ball bearings, which have moving elements that can rattle and hum. That quiet running is a large part of why they suit office equipment, medical devices and other noise-sensitive assemblies, on top of the fact that they need no lubrication.

Q: How are plastic slide bearings installed?

A: Plastic slide bearings are press-fitted into a clean housing bore machined to an H7 tolerance, after which the shaft runs directly in the bearing with no further lubrication or running-in. Keep the bore clean and press the bearing in square so it is not pinched, then check that the shaft turns freely with the correct clearance.

Bespoke Slide Bearings Manufacture.

High precision, bespoke manufacture of Slide Bearings to customer specification. State of the art facilities specialising in both small batch prototyping and large scale manufacture.