Main Bearing

Assembly

Deep Groove Ball Bearing.jpg · Commons ↗ Report photo

A three-row roller bearing several meters in diameter that lets the cutterhead turn while carrying its thrust, its weight and the overturning moment from uneven face loads. Replacing it underground is a major job, so it is sized and sealed to last the whole drive; makers keep its diameter as large as the tunnel allows, because bearing life drops when it is small relative to the bore.

Type	Three-row axial-radial cylindrical roller bearing
Rows	Main thrust, reverse thrust and radial
Lubrication	Dry sump, filtered and recirculated gear oil
Protection	Multi-row lip seals with grease-purged labyrinths on both sides
Direct parts	4
Total parts	4
Used in	1 assembly
Class	Assembly

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Main Bearing parts and their functions

4 top-level parts · 4 parts in total · full bill of materials below

Main Bearing parts diagram: 1 main bearing rings, 2 main thrust roller row, 3 reverse thrust roller row, 4 radial roller row. 4 parts in 4 top-level items. — Main Bearing parts diagram. Numbers match the table below; each box is one top-level part or assembly with what it contains.

#	Part	Qty	What it does
1	Main Bearing Rings	1×	Hold the roller rows and bolt to the support and the cutterhead. Set
2	Main Thrust Roller Row	1×	Carries the cutterhead thrust
3	Reverse Thrust Roller Row	1×	Carries reverse axial load and part of the overturning moment
4	Radial Roller Row	1×	Carries the cutterhead weight and side forces

3D model

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Build & assembly graph

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Bill of materials for Main Bearing

4 top-level lines · 4 rows shown · 4 parts total · indented to 3 levels

#	Item / sub-assembly	Part no.	Qty/assy	Ext. qty	Parts	Type
1	Main Bearing Rings	main-beam-tbm-bearing-rings	1×	1	·	part
2	Main Thrust Roller Row	main-beam-tbm-thrust-roller-row	1×	1	·	part
3	Reverse Thrust Roller Row	main-beam-tbm-reverse-thrust-roller-row	1×	1	·	part
4	Radial Roller Row	main-beam-tbm-radial-roller-row	1×	1	·	part

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Where the main bearing is used

1 product across 1 domain contain it, directly or inside a sub-assembly

Construction & Earthmoving 1 Main Beam Tunnel Boring Machine

Used in 1 assembly

Cutterhead Support and Main Drive

Sourcing: possible vendors

Browse the supplier directory → Prices, MOQ, and lead times are algorithmic estimates, not quotes, and not claims about these companies. Company mappings are curated by keyword; est. price band $0.50–$80. How estimates work

Vendor	HQ	Specialty	MOQ	Lead time
🇨🇳ZWZ Bearing zwz.com.cn ↗	Wafangdian, CN	Bearings	2,000 pcs	6–10 wks
🇮🇳NBC Bearings nbcbearings.com ↗	Jaipur, IN	Bearings (NEI)	2,000 pcs	6–10 wks
🇨🇳HRB Bearing hrbbearing.com ↗	Harbin, CN	Bearings	2,000 pcs	6–10 wks
🇮🇳NRB Bearings nrbbearings.com ↗	Mumbai, IN	Needle & auto bearings	2,000 pcs	6–10 wks
🇨🇳LYC Bearing lyc.com.cn ↗	Luoyang, CN	Bearings	2,000 pcs	6–10 wks