What is a Mast Bearing?

Mast bearings are found on fork lift trucks. They carry the forks (carriage) up the mast and they also enable the various stages of the mast to extend.

There are four main types of Mast Bearings:

  1. Mast guide bearings – these bearings guide the mast stages up as the forks are raised beyond the first stage. They also attach the fork carriage to the mast rails.
  2. Carriage bearings – these provide lateral guidance to the fork carriage as it travels up the mast. They are typically smaller than the mast guide bearings.
  3. Side thrust rollers – these bearings transfer the lateral (sideways) loads to the mast and help to prevent twist. Typically they are mounted on a shaft (pin).
  4. Chain roller bearings – these guide the leaf chain that raises & lowers the mast. The bearings are usually flanged like a pulley to ensure the chain is captive.

Sometimes the mast guide bearings and side thrust rollers are fitted as a complete assembly, known as a Combined Roller Bearing.

What features do Mast Bearings have?

  • Thick Outer Ring: Mast bearings operate at relatively low speeds. They travel along the rail as a track bearing (like a wheel) and consequently experience high loads. The outer ring (steel tyre) of a mast bearing is much thicker than a standard bearing, to enable this load to be transmitted.
  • Inseparable Design: The components of the bearings are held together to form an inseparable ‘wheel’.
  • Balls or Rollers: Due to the high loads, mast bearings usually have balls or rollers as their rolling element.
  • Seals: Mast bearings are usually to sealed to prevent the grease from escaping and to keep debris out. The seal can be rubber (RS) or metal (ZZ), or sometimes a combination of both (ZRS).

How to Identify a Mast Bearing?

Our Technical Sales team are very experienced in identifying mast bearings. To help them, you will need to provide the following information:

  1. Make of the fork truck (e.g. Toyota)
  2. Part numbers or brands stamped on the bearing, or a part number from the parts book. Everything helps.
  3. The dimensions as accurately as possible. That is the ID (shaft size), OD (outside diameter) & width. The width of the outer ring and the inner ring are likely to be different. It is important to know both to ensure the bearing will fit back on the shaft. For side thrust rollers, the length of the shaft and the hole centres is also critical.
  4. The shape of the bearing & whether is has rollers or balls inside. Choose the nearest type from our drawing list or send us some photos.
Mast Bearings - mast guide bearing, chain roller bearing, side thrust roller and carriage bearing.
A typical set of Mast Bearings
(Clockwise from back left: Chain Roller Bearing, Mast Guide Bearing, Side Thrust Roller & Carriage Bearing)

Oversize or Custom Mast Bearings

If the bearing you need is no longer in production or you have a special requirement, Euro-Bearings Ltd can manufacture bespoke mast bearings to suit your needs. Typically we would need a sample or pattern to quote and lead times can be as short as 24 hours.

Contact Us

If you need help to identify a mast bearing or want a quotation, please contact our technical sales team by email or telephone.

Did you know…?

Combined roller bearings can be used in a huge variety of applications. In the simplest arrangement (4 bearings & 2 rails) they can be used to make a forklift mast (vertically), a telescopic slide (horizontally) or just to slide something from A to B.

combined bearings and rails
Combined Roller Bearings and Mating Steel Profiles (Rails)

The main advantage of a combined roller bearing is the small axial roller that helps to keep the system running parallel and prevent it from jamming or crabbing. The combi bearings come complete with a weldable hub so they can be welded directly to your structure or, for ease of maintenance, they can be purchased pre-welded to a mounting plate. This mounting plate is simply bolted on with 4 bolts.

Used together with the mating steel channels (rails), the combined roller bearings offer a simple and cost effective way to make a heavy duty linear slide system. The smallest bearing diameter is 52mm, and the largest Jumbo bearing is 390mm. The rails are available in both C and H (or I) sections.

What Products are Available?

Standard Range
standard combined roller bearings rails for combi bearings mounting plates for combined bearings flanged clamps for CR rails eccentric adjustable CR bearings
Precision Range Jumbo Range
standard combined roller bearings rails for combi bearings mounting plates for combined bearings flanged clamps for CR rails eccentric adjustable CR bearings

Precision Range: For heavy duty applications requiring high precision, the Precision Combined Roller Bearings offer a reduced clearance between the bearing & the rail and consequently minimise the play in the system. The rail is machined in the web and the bearing diameter is increased to match this, with a tolerance of 0.2mm – 0.4mm.Click on an image to visit the relevant webpage.

Jumbo Range: For ultra heavy duty applications, the Jumbo bearings can offer an affordable solution.

Corrosion Resistance: In some environments (e.g. Offshore) it can be beneficial to use a corrosion resistant system. The Thin Dense Chromium coating withstands salt spray and can considerably improve the operating life. We can offer all of the ranges with coating.

Please visit our website for full details. Datasheets & pdf catalogues are available to download.

Advantages

+ Very heavy load capacities. See Hertzian Pressure for system capability.

+ Side (axial) roller prevents crabbing. Channel (rail) is self supporting in many applications.

+ Easy to engineer, assemble and set up. Low maintenance.

+ Tolerant of dirty / dusty environments.

+ Bearing diameters from 52mm to 390mm.

Applications

– Access Equipment

– Handling Equipment, including forklift trucks & scissor lifts

– Palletising Machines

– Lifts for goods, personnel and wheelchairs

– Paying Out Systems

 

– Agricultural Machinery

– Primary Food Processing Equipment

– Furnace Loading Equipment

– Production Lines

– And lots more…

Why Euro-Bearings Ltd?

– Large UK-based stock of Combined Roller Bearings

– Over 30 years in the industry

– Always speak to Technical Sales

– Fast delivery

– Family business who value their customers

– Ability to offer custom plates or special diameter bearings

Welcome to our Blog!

Euro Bearings Products
Some of our products

Hello, and welcome to our blog.

This blog is being developed to provide you with more information about our product range. Each blog will focus on a product range. The aim is to highlight the advantages it offers and give you an overview of typical applications.

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