Bearing Housing and Housing Units
Bearing housing from FULI: UCP, UCF, UCFL and UCT housings that hold and align the insert, keep out dirt and simplify maintenance. With or without insert.
A bearing housing is the body of a mounted bearing unit: the part that bolts or slides onto the machine and holds the insert bearing in its spherical seat. FULI supplies housings from Linqing, Shandong both as complete units, with a UC, SB or SA insert already fitted, and on their own for replacing just the housing on an existing unit.
The housing design does three jobs. It carries the load from the shaft into the machine frame, it keeps the insert in line, and it holds the grease and keeps dirt and water out. Protecting bearings this way is what gives a unit a long operating life in dusty or wet plants.
Which type of bearing housing FULI supplies
| Housing | Mounts | FULI page |
|---|---|---|
| Pillow block (UCP) | Bolts flat to a frame, two-bolt base | Pillow block bearing |
| Flange (UCF, four-bolt; UCFL, two-bolt) | Bolts to a wall or plate the shaft passes through | Flange bearing |
| Take-up (UCT) | Slides in a frame for belt or chain tensioning | Take up bearing |
All three take the same family of UC, SB and SA inserts; see insert bearing for insert sizes, and mounted bearing for how to pick a housing type. The housing type selector compares them by mounting surface, bolt count and adjustability.
One-piece units and split plummer block housings
Housings fall into two broad groups. Housing units, the type on this site, are one-piece castings that hold a deep groove ball insert. The insert locks to the shaft with set screws or an eccentric collar, so no shoulder or nut is needed. These units suit light and medium loads on conveyors, fans, farm machines and other rotating machinery, where easy mounting matters more than high loads.
Plummer block housings are the heavier group. A split plummer block housing has a cap bolted to a base, so the cap can come off for inspection without taking the shaft out; unsplit plummer block housings are one piece. They usually carry a spherical roller or self-aligning ball bearing on an adapter sleeve and take heavy loads in mining equipment, crushers and large fans. Standard series are grey iron castings, with spheroidal graphite iron or cast steel where there are shock loads.
Where one rotor runs in two of these housings, one is the locating bearing: locating rings in its housing hold the outer ring and take the axial loads. The other is a non-locating bearing, free to move in its housing as the shaft grows with heat. A wrong bearing arrangement, with both outer rings held, is a common cause of short service life.
FULI lists one-piece units on this site. We also supply split plummer block housings (SN / SNL style); send the designation and we will confirm the details with the quote.
Housing material, seals and corrosion
Standard housings are grey iron with a paint coating. Where corrosion is the main risk, as in food plants or outdoor washdown, users choose a stainless steel or thermoplastic housing and accept a lower load rating.
On an insert unit the seal is part of the insert, and the housing carries a grease fitting for lubrication in place. On a split housing the seals sit in the housing itself, and the type (felt, labyrinth or lip) is chosen by speed and dirt. For grease intervals, see how often to regrease.
Housing-only orders and bearing replacement
A housing is sold on its own in two common cases: replacing a housing that has cracked or corroded while the insert is still serviceable, or building a unit from a housing and insert bought as separate line items (useful when standardizing on one insert type across several housing styles). State the full designation and whether the insert should be included — the quotation and packing list differ depending on whether a bearing is fitted.
In most cases the insert wears out before the housing. Before you fit a new insert, check the housing bore for cracks and fretting marks, because a worn seat lets the outer ring turn. Bolt spacing can differ between the JIS and ISO 3228 versions of the same designation, so measure it on the old housing. The housing matcher pairs each insert with its P, F and FL housings, and the installation checklist covers alignment and set screw order.
Specifications FULI supplies
| Item | FULI specification |
|---|---|
| Material | Cast iron |
| Styles | Pillow block, flange (square and oval base), take-up |
| Bore seat | Spherical, matched to UC/SB/SA insert outside diameter |
| Mounting | Bolt holes (UCP, UCF, UCFL) or slide ways (UCT) |
| Supply | With insert fitted, or housing only on request |
To get a quotation, send the housing designation, whether the insert should be fitted, the quantity per size and the destination port to sales@fuli-bearings.com or use the request a quote form.
FAQ
What is a bearing housing?
It is the body that holds a bearing and bolts or slides onto a machine. On its own it is just the housing, with no bearing fitted; fitted with a UC, SB or SA insert it becomes a complete mounted bearing unit such as a UCP, UCF or UCT.
Can I order the housing without the insert?
Yes. A housing can be quoted on its own, for example when only the bearing inside a unit has worn out and the housing is still good. State the housing designation (such as UCP205 or UCF208) and whether you want it with or without the insert.
What housing types does FULI supply?
Two-bolt base housings (UCP), square four-bolt (UCF) and oval two-bolt (UCFL) flanges, and sliding housings (UCT) that adjust belt or chain tension. Each is covered on its own page with the full size range and model list; the mounted bearing page compares all three. We also supply split plummer block housings (SN / SNL style); send the designation and we will confirm the details with the quote.
What is the housing made of?
Cast iron, machined for the bore that takes the insert's spherical outside diameter and for the bolt holes or slide ways that mount it to the machine.
Is a plummer block the same as a bearing housing?
It is one type of bearing housing: the kind with a base that bolts to a surface parallel to the shaft. The name is used most for split housings that carry a roller bearing on an adapter sleeve. For insert units the same shape is usually called a pillow block.
How do you install a bearing into a housing?
An insert is turned 90 degrees, pushed in through the two loading slots in the housing bore, then turned upright into its seat. On the machine, bolt the housing down first and tighten the set screws or collar last, so the insert is not pulled out of line.