Guide circolari
I cuscinetti a sfera lineari – chiamati anche boccole con cuscinetti sferici o guide per alberi – servono a ridurre il più possibile l'attrito nei movimenti rettilinei di un elemento di una macchina lungo un albero cilindrico. A differenza dei cuscinetti sferici tradizionali, sono infatti dotati anche di un ricircolo di sfere assiale. I cuscinetti a sfere norelem sono conformi alla Serie 3 secondo la norma ISO 10285, che regola le principali dimensioni e le tolleranze dei cuscinetti a sfera lineari.
Overview
Round guides as connecting elements in machine construction
What is a round guide in machine construction?
How do linear ball bearings work?
What are the advantages of shaft guides?
An overview of the norelem range oflinear ball bearings
The linear ball bearing with round flange
The‘shaft support product category
Material quality: Steel round guides with plastic cages
What are the typical application sectors for round guides in machine construction?
The appropriate round guide from norelem
Round guides as connecting elements in machine construction
In machine construction, components used to perform longitudinal movements often need to be guided as straight as possible and with minimal friction. This is precisely where round guides come into play, guiding machine components along a cylindrical shaft without the need for lubrication. The following provides information on products and applications relevant to selecting the correct round guide.
What exactly is a round guide in machine construction?
In general a round guide – also known as a linear ball bearing, ball bush or shaft guide – is a robust machine component designed to enable straight linear and precise movements. Ideally, they are characterised by smooth running and low friction.
Unlike conventional ball bearings, round guides also feature an axial ball circulation system. The norelem ball bearings comply with Series 3 of ISO 10285, which specifies the key dimensions and tolerances for linear ball bearings.
How do linear ball bearings work?
The core components of round guides are, on the one hand the linear guide – which is primarily a precision-ground solid or hollow shaft – and, on the other hand the housing, which moves along it. This housing is also known as a linear ball bearing, plain bearing or ball bush. Shaft supports or shaft mounts are often used to stabilise the shaft to prevent bending over longer distances.
But how exactly does a linear ball bearing work?
For linear movements along a shaft or guide rail, rolling elements are guided in a recirculating ball system. This distributes the load and the balls circulate between the shaft and the bearing.
The ball-circulation mechanism is achieved through a precisely designed system of ball rows:
Load-bearing zone: The load is transmitted by the balls in the bearing as they rest directly on the guide shaft.
Recirculation: The unloaded balls are guided back to the starting point via internal channels in the bearing housing.
Endless cycle: The bearing can move back and forth along the shaft as far as required.
What are the advantages of shaft guidance?
Smooth running: By high-quality shaft guides, such as those from norelem, the rolling motion of the balls between the shaft and the bearing have very low frictional resistance
Compact integration: As they take up very little installation space, they are suitable even where space is limited.
Flexibility: norelem offers a wide range of round guides, ensuring that the matching type is available for a variety of applications.
An overview of the norelem range of linear ball bearings
The norelem range of round guides includes the following products:
The linear ball bearing with round flange
A popular product from norelem is the linear ball bearing with round flange, which complies with Series 3 of ISO 10285. The linear ball bearings are sealed both ends and have with a plastic cage. This makes for quiet running and outstanding run quality. The flange enables the product to be fitted directly to a housing. The specified load ratings apply with the use of hardened and ground shafts.
The shaft support product category
A shaft support is a component used to fixate and support round shafts and it absorbs rotational or linear forces and transfers them to the housing. With linear guides, they support the shafts along which the ball bearings move, ensuring that they do not bend or shift under heavy loads.
The shaft supports with mounting holes from norelem are ideal for the simple and secure clamping and fixating of guide shafts. There is a choice of different mounting holes and sizes. There is a diagram on the product page to help select the right size.
Material quality: Steel or aluminium round guides with a plastic cage
The norelem range includes a wide selection of round guides made from both steel and aluminium. Both materials are available in the highest quality, but they have different properties to suit different applications.
Steel round guides can withstand higher loads without deforming and therefore have a higher load capacity. They are also wear resistant and have a very hard surface. But they are also heavier, requiring more energy to move them at high speeds.
Aluminium, on the other hand is very light, which can be an advantage if frequent movement is required. Furthermore, it is naturally rust-resistant and is therefore also suitable for damp environments. However, it is not as rigid as steel and is so less able to withstand high loads than steel.
Linear ball bearings are often fitted with a plastic cage. This makes for quiet running and outstanding run quality. The flange enables direct mounting onto the housing. The load ratings stated on the product pages apply when hardened and ground shafts are used.
What are the typical applications of round guides in machine construction?
Round guides are used in machine construction wherever linear motion guidance is required. This is the case in e.g. automation, handling technology and in adjustment and positioning axis. Their robust construction and high repeatability make them suitable for both simple positioning tasks and for demanding industrial applications.
The matching round guide from norelem
Technical requirements and operating conditions should be taken into account when selecting a round guide. These include e.g. the type of shaft, the material and the load during operation. norelem offers the appropriate round guides for every application together with the necessary components for machine construction.
Ask for advice if you are unsure which norelem product to choose. Just send an email to technik@norelem.de or call our technical support team on 07145 206 60, and we will be happy to help.