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.

The Best Linear Motion System?

horizontal and vertical system

Combined Roller Bearings & Mating Steel Profiles are one of the most versatile linear motion systems. Originally used on forklift trucks, the bearings are designed to carry both the axial and radial loads in one unit. The bearings and rails can be used horizontally and vertically, and can also be arranged telescopically to allow for full extension.

The main advantage of Combined Roller Bearings over other track rolling systems is that the smaller axial rollers contact the web of the profiled rails. This helps to keep the system running parallel and consequently prevents it from jamming.

The bearings can be supplied pre-welded to a mounting plate and then simply bolted onto the carriage or they can be welded directly to the structure for a more compact configuration.

Here are some of the possible arrangements:

horizontal linear motion applicationhorizontal and vertical systemSimple cantilever using combined roller bearings
Simple Horizontal
System
Combined Horizontal
/ Vertical
Horizontal Cantilever
Telescopic heavy duty linear motionThree stage telescopic linear systemcantilevered systems using an I or H section
2 Stage Telescopic
System
3 Stage Telescopic
System
I Beam
Cantilevered
System

Click on an image for further information.

With good resistance to dirt and heat, Combined Roller Bearings can be used in many industrial applications: from packaging machines to furnace loaders, brick makers to offshore pipe and cable laying devices, to name just a few.

If you have a heavy duty linear motion application, please contact our technical sales team for help and advice.

Details on how to select the correct size of bearing can be found here.

Stainless Steel Anti-Vibration Engine Mounts

stainless steel marine mount

Our latest product is a stainless steel anti-vibration mount. It is available in two sizes – SS MCM 01 and SS MCM 02. This captive mount can be used to mount engines & generators in marine environments. The mounting hole is captive between the top and bottom plates to ensure that the AV mount remains failsafe should the rubber shear.

We also have a range of Male-Male (MMSS) and Female-Female (FFSS) mounts in Stainless Steel.

A Fresh Look

We are pleased to announce that we have launched our new website. The new layout is better suited to viewing on mobiles phones and tablets whilst remaining just as informative as ever. We hope that you find it easy to navigate. Please do give us your feedback on it (good or bad).

euro-bearings new website
New Website from Euro-Bearings Ltd

Linear shafts – now on stock!

We can supply both standard hardened & ground (Cf53) shaft AND also stainless linear shaft (X90CrMoV18) from stock.

All shafts have a tolerance of h6 for running linear bearings on.

Please tell us the quantities and lengths you require for a quotation.

A Quick Guide to Choosing the Best Linear Motion Product

There is a vast range of linear motion products on the market and it can be difficult to know which product to select. This article discusses the various types of products available according to their rolling element and explores their advantages, disadvantages and limitations. Finally a selection chart clearly lists each product’s characteristics to help with specifying the best linear motion product.

Some of our linear motion products are shown in the table below:

Linear Bearings, Housings, Shafts & Supports Heavy Duty Rollers (NUTR, NUKR, NNTR) Vee Bearings Motion Guidance Systems (Standard & Aluminium)
Miniature Motion Guidance Track Guidance System Combined Roller Bearings Plain Sliding Linear Bearings

What are Linear Motion Products?

 The primary purpose of linear motion products is to move something from one place to another in one direction along a straight line. Usually this is achieved using a bearing with a rolling element. Traditionally this rolling element would be a ball or roller, but these days some linear motion bearings do not incorporate a rolling element and consequently are known as ‘plain’ bearings. These plain bearings are simply plastic or ceramic bushes and are sometimes lined with PTFE or oil impregnated plastic to help reduce the sliding friction. Continue reading