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:
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 →
Combined Roller Bearings were originally designed to be used in forklift truck masts. However, today they are used in a variety of applications (horizontally and vertically) and in a huge range of industries.
The smallest bearing is just 52.5mm in diameter and when used in conjunction with the corresponding steel profile, each bearing offers a load capacity of approximately 550kg. At the top end of the range the largest bearing is 390mm and has a capacity of over 30 tonnes.
The primary benefit of a Combined Roller Bearing over a standard track roller bearing is the integral side thrust roller bearing. This small roller is able to carry lateral loads and ensures free movement of the system.
To make a complete slide you simply need 2 rails and 4 bearings. The bearings can be welded directly to the structure or can be supplied pre-welded to a mounting plate and simply bolted into place. More complex, telescopic systems can be made by using additional rails and bearings to create further stages.
The application examples below show how versatile this sliding system is.
When the Landscape Director from N T Killingley contacted us about sliding a planter in and out of a glasshouse at RHS Chatsworth, our Technical Sales team listened to his specification and suggested various options. Their requirement was a system that was simple to install and robust enough to carry the weight of a laden planter, but most importantly would not cost a fortune as the display was temporary.
The end result was a system that was discreet and could be operated with very little effort. The display formed part of the “Garden for a Changing Climate” at RHS Chatsworth in June 2017 and featured on BBC’s Gardeners World.
The RHS video of the garden can be viewed here. And the BBC Gardeners World episode can be viewed here (approximately 41 minutes in).
If you need help to specify a linear sliding system, please contact us. We have a team of Engineers & Designers who can guide you through both selecting the most suitable product and specifying the correct size.
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.
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?
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.
Our Combined Roller Bearings consist of a radial bearing, an axial (face) bearing and a weldable hub. The main radial bearing can take very high loads and the axial roller takes side loads and prevents the bearing from crabbing in the channel. Used in conjunction with their mating steel channel it is possible to design and build a heavy duty linear sliding system, for either horizontal or vertical motion. More complicated systems can be built using the bearings and channel to create telescopic and cantilevered solutions. We can help you to select the correct size for your application. Our bearings range in size from an outer diameter of 52.5mm all the way up to 390mm (Jumbo CR range).
The hub of the bearing is weldable so that the bearing can either be welded directly to a structure or to a mounting plate. We keep the standard mounting plates on stock and we can supply the bearing welded to its plate. The standard mounting plates have both threaded holes and thru holes so that the plate can be fixed from the front or the back. We can fabricate bespoke mounting plates to your design.
We also offer a range of combined roller bearings that a have an eccentric adjustable face roller. The height of the face roller can be varied by removing the front face plate and rotating the shaft of the axial bearing, the ends of which are splined. More information on our website here: Eccentric Adjustable CR Bearings
If your application does not require the axial (face) roller then you could use our Radial Bearings which offer all the advantages of our Combined Roller Bearings and are designed to run in the same steel channels.