The bearing housing presses into the end of a conveyor roller, idler or drum motor shell and carries the bearing that lets the roller turn under belt load. It has to hold the bearing square, keep grease in and dust out, and survive continuous running in mines, quarries, ports and recycling plants. Ningbo Ruican casts the housing near net shape and machines the bearing bore, seal seat, shell press fit and circlip groove so the bearing seats concentrically and the sealing system works from the first rotation.
Specifications
| Parameter | Specification |
|---|---|
| Casting process | Silica sol lost wax investment casting; water glass process for larger housing sizes |
| Material options | EN-GJS-500-7 / 65-45-12 ductile iron; EN-GJS-600-3; AISI 1020; AISI 1045; AISI 4140 / 42CrMo4; AISI 304 on request |
| Dimensional tolerance (ISO 8062-3 CT grade) | CT7 as-cast standard; CT6 on bearing bore and seal seat after tooling review |
| Machining | CNC turning of bearing bore, seal seat, outer press fit diameter and circlip groove; bore to H7 or J7 |
| Surface finish (Ra) | Ra 1.6 on bearing bore and seal seat; Ra 3.2 on press fit diameter; Ra 6.3 as-cast |
| Hardness / heat treatment | 170-230 HBW ductile iron as-cast or normalized; 28-34 HRC for AISI 4140 quench and tempered; stress relieving standard |
| Weight range | 0.4 kg to 9.5 kg per housing |
| Typical lead time | Tooling 4-6 weeks; first article samples 2-3 weeks after tooling approval; production 5-7 weeks |
Key features
- Bearing bore and seal seat machined in one setup, holding concentricity inside 0.04 mm so the roller turns without runout and bearing life is not cut by misalignment.
- Press fit diameter turned to your shell tolerance band, giving a consistent interference fit that resists loosening under belt tension and vibration.
- Multi-labyrinth seal groove profiles cast and machined in place, keeping water, dust and fine material away from the bearing without adding separate parts.
- Circlip and retaining grooves machined to depth and width tolerances that hold the bearing axially through shock loading on impact zones.
- Fine-grained, porosity-free cast structure verified by pressure testing, so housings do not weep grease through the wall in service.
- Available with corrosion-resistant coatings or in stainless for washdown, quarry dust, coastal and food handling environments.
Applications
- Conveyor idler rollers in belt conveyor systems for mining and quarrying.
- Drum motors and motorised pulleys driving packaged handling lines.
- Troughing, impact and return rollers on overland and yard conveyors.
- Belt conveyor platforms in ports, terminals and bulk material stockyards.
- Recycling and waste sorting plant conveyors handling mixed municipal material.
- Food, packaging and pharmaceutical conveyor lines requiring washdown duty housings.
Images
Quality & compliance
Conveyor roller bearing housings are produced under the Ningbo Ruican IATF 16949 certified process control system, with controlled melt chemistry, monitored pouring and documented heat treatment for every batch. Material certification to EN 10204 3.1 or ASTM equivalents, plus heat treatment charts, accompany each shipment. Hardness mapping is carried out on the press fit wall, seal seat and bore land to confirm consistent properties, and tensile testing is performed on test bars from the same heat for ductile iron grades. CMM and air gauge dimensional reports confirm bearing bore size, concentricity and groove geometry against the approved drawing. Air decay pressure testing or kerosene leak testing is available to prove the cast structure is free of through-wall porosity. FAI reports and PPAP Level 1 to Level 5 packages are prepared on request, and capability studies on the bearing bore are run for high volume roller programs.
FAQ
Q1. Can you hold the bearing bore to a specific bearing fit?
Yes. We routinely machine bearing bores to H7, J7 or K7 depending on your bearing size and load case, and we confirm the chosen fit against your bearing supplier’s recommendation before production tooling is cut. Bore roundness is held within a few micrometres.
Q2. How do you keep the seal seat concentric with the bearing bore?
Both features are turned from a single datum in one fixture setup, so there is no re-chucking error between operations. We routinely hold concentricity inside 0.04 mm and report the measured value on every first article and on agreed production samples.
Q3. Can you match our existing roller shell press fit dimensions?
Send the shell drawing or a sample roller and we will machine the outer diameter to your tolerance band, usually a controlled interference fit of a few hundredths of a millimetre. We can also advise on knurl or rib patterns that resist rotation in thin-walled shells.
Q4. Do you test for porosity in the housing wall?
We offer air decay pressure testing and kerosene leak testing on request, plus radiographic inspection of sample castings for high volume programs. Investment casting in itself gives a fine, dense grain structure, so through-wall porosity is rarely encountered on these housings.
Q5. What volumes can you support for roller programs?
We support both development runs and high volume production. Tooling for a new housing takes four to six weeks, and we design multi-cavity tooling so unit cost falls significantly once annual volume rises above a few thousand pieces per part number.
Q6. Can you supply the housing machined and ready to assemble?
We can. We deliver fully machined housings, cleaned, deburred and protected against corrosion, and on request we press bearings and fit seals and circlips in our own shop, so your roller line receives a finished sub-assembly ready to install rather than a loose machined casting.
CTA
Send your conveyor roller bearing housing drawings, bearing fit requirements or a sample housing and Ningbo Ruican will return a tooling, casting and machining proposal, normally within three working days. Contact Wendy She at sales@cnsandcasting.com or on WhatsApp +86-13777124360, or visit cnsandcasting.com to discuss your roller program.
