Hanger Units

What is a hanger unit?

A hanger unit is a bearing unit designed to be suspended from above, rather than bolted to a frame or foot. The housing has a threaded hole in the top, so it can hang from a pipe, rod, or hanger bracket, supporting a long shaft part-way along its length. Hanger units are most commonly used in screw conveyors and augers, where the shaft is too long to be supported only at the ends.

A standard hanger unit is made up of:

• A cast iron hanger housing with a threaded hole in the top for suspension
• A self-aligning insert bearing, seated in a spherical bore in the housing
• A locking method, usually two grub screws, that fixes the insert to the shaft
• A fully sealed insert, and a grease nipple for relubrication.

The hanging design suits long, enclosed shafts.

• The unit hangs inside the conveyor trough or casing, supporting the shaft from above while leaving room for material to pass underneath.
• The compact housing takes up very little space around the shaft, so it interferes as little as possible with the flow of material.

Hanger units are sold as complete units with the insert fitted, or as housings on their own, and the insert can be removed and replaced when it wears.

Why are hanger units essential?

Long screw conveyors and augers need support along their length, or the shaft and flights will sag, whip, and wear against the trough. A hanger unit provides that support from above, without needing a frame or foot under the shaft, where it would block the material being conveyed.

The self-aligning insert bearing copes with small misalignment between the hanger and the end bearings, and with movement of the shaft under load. Because the insert is sealed and can be regreased, it stands up well to the dusty, dirty conditions found in bulk handling.

Typical applications include:

• Screw conveyors
• Augers and feeders
• Grain and agricultural handling equipment
• Cement, aggregate, and bulk powder handling
• Animal feed and food processing plants
• Waste and recycling equipment
• Wastewater and sludge handling
• Overhead line shafts and drive shafts

The main types of hanger units

• Normal duty cast iron hanger units - The standard design for most screw conveyors, with a cast iron housing, a threaded suspension hole, and a grub screw locking insert.
• Hanger units with other housing shapes - Some ranges use a different hanger housing shape or mounting arrangement, while still taking a standard insert bearing.
• Metric and inch bore hanger units - Both are widely available. Inch sizes are common because many screw conveyors are built to standard inch shaft and pipe sizes.
• Stainless steel and thermoplastic hanger units - Corrosion-resistant versions for food, washdown, and wet or chemical applications.

How to choose the right hanger unit?

• Shaft size - Match the insert bearing bore to the conveyor shaft, and check whether the shaft is metric or inch.
• Suspension thread - Check the size and type of thread in the top of the housing matches the pipe, rod, or hanger it will hang from.
• Housing size - Check the overall height and width fit inside the conveyor trough or casing, with enough clearance around the screw flights.
• Load - Consider the weight of the shaft, flights, and material, as well as any shock from lumpy material. For heavier duty, choose a larger housing or a heavier insert.
• Conditions - Screw conveyors are often dusty or wet, so choose a unit with good sealing and a grease nipple. Use stainless steel or thermoplastic units for corrosive or food-grade applications.

Essential references and specialised ranges

How the numbering works:

Hanger unit references combine the insert bearing and the housing:

UC = insert bearing with grub screw locking and an extended inner ring

HA = hanger housing

The digits = the series and bore code. Multiply the last two digits by five to get the bore in mm.

Examples:

UCHA205 = hanger unit for a 25mm shaft

UCHA208 = hanger unit for a 40mm shaft

HA205 = the hanger housing on its own, which takes a UC205 insert

Inch bore units add a suffix showing the bore in sixteenths of an inch:

UCHA205-16 = 1 inch shaft

UCHA208-25 = 1-9/16 inch shaft

UCHA212-37 = 2-5/16 inch shaft

Some manufacturers use other hanger codes, such as UCHB, for different housing shapes.

Suffixes:

-16, -25, -37 and similar = inch bore in sixteenths of an inch

E = eccentric collar locking insert

Suffix codes vary between manufacturers, so check the supplier’s catalogue for the exact meaning.

FAQ - All you need to know about hanger units

Where are hanger units used?

They are mainly used in screw conveyors and augers, where they hang from above to support the shaft part-way along its length. They are also used on overhead line shafts and other long shafts that need support between the end bearings.

How is a hanger unit suspended?

The housing has a threaded hole in the top. A pipe, threaded rod, or hanger bracket screws into this hole and is fixed to the top of the conveyor or frame, so the unit hangs below it.

How many hanger units does a screw conveyor need?

It depends on the length of the conveyor and the shaft size. Longer conveyors need hanger units at regular intervals along the shaft. Follow the conveyor maker’s recommended hanger spacing.

Do hanger units need lubrication?

Yes. Hanger units are supplied greased and have a grease nipple for relubrication. Because screw conveyors are often dusty, regular regreasing helps push out dirt and keeps the bearing running. Add grease slowly until fresh grease just appears at the seals.

How do I fit a hanger unit?

Screw the suspension pipe or rod into the top of the housing and fix it to the conveyor. Slide the unit onto the clean, burr-free shaft, check the shaft is centred in the trough, and then tighten the grub screws to lock the insert to the shaft.

How do I identify a hanger unit I need to replace?

The reference is usually cast on the housing and marked on the insert bearing. If it cannot be read, measure the shaft diameter, the overall height and width of the housing, and the size of the threaded hole in the top. Also note the locking method.

What are the signs that a hanger unit needs replacing?

Look out for:

• Grinding, squealing, or knocking noises from the conveyor
• The screw rubbing or wearing against the trough
• Increased vibration or shaft whip
• The housing running hot
• Play or wobble in the shaft
• Grease and dirt pushing out of the seals
• A cracked housing or damaged suspension thread