Mounted Bearing
Mounted bearing units from FULI: a sealed ball bearing insert in a cast iron pillow block or flange housing, ready to bolt on. Types, selection and quotes.
A mounted bearing unit is a bearing supplied ready to install: an insert bearing already fitted in a housing, so it bolts or slides into place without machining a bearing seat. FULI supplies these units from Linqing, Shandong in three styles, each covered on its own page with the full size range, dimensions and model list. This page covers what separates them, how to choose between them, and what to send with an inquiry.
Types of mounted ball bearing units
The housing decides how the unit mounts to the machine; the insert inside it is the same UC, SB or SA bearing family used across all three styles.
| Housing style | Mounts | FULI page |
|---|---|---|
| Pillow block (UCP) | Bolts flat to a frame parallel to the shaft, two-bolt base | Pillow block bearing |
| Flange (UCF square; UCFL oval) | Bolts to a wall or plate perpendicular to the shaft | Flange bearing |
| Take-up (UCT) | Slides in a frame so the shaft can be moved to tension a belt or chain | Take up bearing |
The insert itself — UC, SB or SA — can also be ordered on its own as a spare for an existing housing; see insert bearing for the full size range and how the three locking types differ.
How to choose a housing style
Start from the machine, not the bearing. If the shaft sits in open air above a frame, a pillow block bolts straight to the frame. If the shaft passes through a wall, a plate or the side of a machine, a flange unit bolts to that surface instead: the square UCF suits a wide mounting area, and the 2-bolt flange UCFL suits a narrow one, such as a side plate or a conveyor stringer. If the shaft needs to move along its length to tension a belt or chain — most often a conveyor tail pulley — a take-up unit is the right choice, because it slides in a frame rather than bolting in a fixed position.
Two units of the same size, in different housing styles, take the same insert. A UCP205, UCF205 and UCT205 all fit a 25 mm shaft and all use a UC205 insert; only the housing differs, so a spare insert can serve more than one unit if the sizes match.
How a mounted ball bearing works
The insert is a deep groove ball bearing whose outer ring is ground to a sphere. It sits in a matching bore, so the unit is self-aligning: it accepts small misalignment between the shaft axis and the mounting surface. The balls carry radial and thrust loads, with the thrust kept moderate. The locking mechanism fixes the insert to the rotating shaft. UC and SB inserts are fixed by screws; SA inserts use an eccentric locking collar. Heavy machines use mounted roller bearing units.
Where mounted bearings are used
Typical industrial applications:
- Belt conveyors and screw conveyors, which also need hanger bearings between the end supports. See conveyor bearings.
- Farm machinery, see agricultural machinery bearings.
- Fans driven by electric motors, see fan and blower bearings.
- Food and beverage lines, where washdown calls for stainless steel or thermoplastic housings that resist corrosion. See grain and food processing bearings.
- Power transmission line shafts with pulleys and sprockets.
Lubrication and wear
Most units have a grease fitting, so the sealed insert can be topped up without removal. How often to lubricate depends on speed, temperature and dirt: high-speed, hot or dusty service needs shorter intervals. The grease fill calculator gives a starting quantity. Premature wear usually comes from loose locking screws, misalignment beyond the limit or too much grease. A correctly mounted unit with clean grease gives a long service life and less downtime.
Specifications FULI supplies
| Item | FULI specification |
|---|---|
| Housing styles | Pillow block (UCP), flange (UCF / UCFL), sliding frame (UCT) |
| Insert | UC type, sealed, spherical outside diameter, set-screw locking; SB and SA also available |
| Insert material | GCr15 chrome bearing steel |
| Housing material | Cast iron |
| Precision | P0 standard |
| Radial clearance | C0 standard; C3 on request |
| Supply | Complete unit; insert or housing quoted separately on request |
To get a quotation, send the designation (for example UCP205, UCF205-16 or UCT206), the quantity per size and the destination port to sales@fuli-bearings.com or use the request a quote form.
FAQ
What is a mounted bearing?
It is a complete bearing unit: a ball bearing insert already fitted in a cast iron housing, ready to bolt onto a frame, wall or sliding rail without machining a separate bearing seat. On this site a mounted bearing unit is a pillow block (UCP), flange (UCF or UCFL) or sliding UCT unit; each uses the same UC, SB or SA insert in a different body.
Which housing type do I need: pillow block, flange or take-up?
It depends on how the shaft meets the mounting surface. A pillow block bolts to a flat surface along the shaft. A flange bolts to a wall or plate that the shaft passes through at right angles. A UCT unit slides in a frame so the shaft position can be adjusted, which is for belt or chain tensioning rather than a fixed mount.
Can I order just the insert or just the housing?
Yes. The insert bearing can be quoted on its own as a replacement for an existing housing; see the insert bearing page for UC, SB and SA sizes. A housing on its own, without the insert, can also be quoted — state this in your inquiry with the designation.
What is the difference between UC, SB and SA inserts in a mounted bearing unit?
All three have a curved outer ring that seats in a matching bore. UC inserts lock to the shaft with two set screws in a wide inner ring. SB inserts lock the same way but are narrower. SA inserts lock with an eccentric collar. The pillow block, flange or UCT body is the same whichever insert is fitted, as long as the size matches.
What is the difference between mounted and unmounted bearings?
An unmounted bearing is a bare bearing, such as a deep groove ball bearing, pressed into a bore machined in the machine. A mounted bearing arrives as an assembly with its own housing, so there is no bearing seat to machine and a replacement is a bolt-on job.
Are inch bore mounted bearing units available?
Yes. Inch bore versions such as UCP205-16 or UCF205-16 use the same housing as the metric unit of the same size; only the bore is different. The full inch size list is on each housing type's page.