The aluminum rail guide is a 2-row ball circulation guide with a carriage and profile rail made of aluminum with hardened and corrosion-resistant steel raceway inserts.

This composite construction results in a weight saving of over 60% compared to a conventional steel profile rail guide. Another advantage is the higher corrosion resistance and greater permissible parallelism and height deviations during assembly.

The floor ball roller is primarily designed for the easy movement of objects when installed with the ball facing downwards. In contrast to a swivel castor, it allows faster changes of direction with reduced reversing behaviour, thus enabling easier positioning.

Compared to a classic ball roller, it offers quieter running and, thanks to the large plastic ball, leads to lower floor loads.

In contrast to a conventional ball bushing, which runs on a smooth shaft and must therefore also be secured against twisting, e.g. by using a second guide shaft, a torque ball bushing runs on a profiled spline shaft with several guide tracks for the balls, a so-called torque shaft, and thus allows the construction of a torsion-resistant linear guide with only one shaft.

A common application is, for example, as a drive shaft in which the drive or output must be linearly displaced without play, or when a classic round guide with two shafts or a profile rail guide cannot be used due to space restrictions.

If a shaft-hub connection can transmit drive or torques in addition to axial forces, this is referred to as a positive torque transmission. If this shaft-hub connection is also axially (linearly) displaceable, toothed or splined shafts, for example, are used. However, if freedom from play and low displacement force under load are also required, torque shafts and bushings are recommended.

See also: Spline shaft

The dynamic load rating is a measure for calculating the service life of a linear guide as well as spherical plain bearings and rod ends. It defines a load whose direction of action and magnitude is constant and under which a nominal service life of 50 km or 100 km is achieved. The load limit of a machine element must always be considered in relation to the required service life.

The Eco rail guides are a cost-effective alternative to our premium rail guides from NSK. They comply with the ISO standard and are therefore compatible with most profile rails on the market in terms of connection dimensions.

The X-arrangement of the four rows of balls allows misalignments due to inaccuracies in the mounting surfaces to be better compensated, resulting in smooth, even running.

ECO rail guides are used in general mechanical engineering, fixture construction and assembly and handling applications.

In a spring-loaded ball roller, an integrated spring element ensures that the ball roller retracts from a certain load.

For use as guide shafts, the steel shafts must have a hardened surface. This guarantees that the balls of the ball bushings running on them do not wear in due to the small contact area. In order to still guarantee machinability, the steel shafts are inductively surface-hardened. This leaves the core soft and also offers high toughness to absorb dynamic loads.

Hardened steel shafts are available as solid shafts made of Cf53, chrome-plated or corrosion-resistant made of X90CrMoV18 (1.4112) or as hollow shafts made of C 60 or 100 Cr6.

In the case of rolled ball screw spindles, the particularly inexpensive version, the thread is manufactured without cutting by rolling. The material compaction results in a good surface of the ball raceways with an uninterrupted fibre flow of the structure. However, the disadvantages are the lower pitch accuracy and the associated play of the ball screw drive. In addition, there is an increased effort in end machining, as the outside diameter is not exactly defined by the material run-up during rolling.

See also: Whirled ball screw drives

Grinding the threaded spindle allows the highest precision to be achieved with regard to the pitch accuracy of the thread and concentricity of the spindle ends, which are usually already machined. Play-free ball screw drives can also be realised with ground spindles. However, grinding is the most cost-intensive solution.

A threaded spindle is a machine element in which a shaft is provided with an external thread. This can be a simple screw thread, a trapezoidal thread or a round thread, which is introduced by rolling, whirling or grinding. In combination with a nut with the same negative thread profile, this results in a threaded drive with which a rotary movement of the spindle is converted into a linear feed movement of the nut.

Threaded drives are a drive element that converts a rotary movement into a linear feed movement via a screw thread (threaded spindle).

A distinction is made here between slide-bearing trapezoidal threaded drives, rolling-bearing ball screw drives and roller screw drives.

During whirling, the thread is cut using a tool that rotates around the hardened and ground starting material. In this way, play-free threaded drives can be realised, as with ground spindles, and higher accuracies and better straightness can be achieved compared to rolled spindles. Thanks to the ground outer diameter, the end machining can be carried out with higher concentricity and less effort. This relativises the somewhat higher basic price of whirled spindles compared to rolled spindles.

A stroke-rotary module generates an arbitrarily combinable stroke and rotary movement of an output shaft via the rotary movement of two drives with simultaneous play-free guidance of the shaft.

Various types of connection are available for connecting two or more components. One of these is the non-positive connection. It represents the opposite of a positive (shaft-hub) connection. This can be, for example, a toothing or connection by means of a parallel key. In a non-positive connection, however, the torque or axial force to be transmitted is only transmitted via the friction of the parts to be connected. Therefore, a non-positive connection is always also a friction-locked connection. Common examples of this are a press composite, a clamping set or a tolerance sleeve connection.

In contrast to a profile rail guide, a crossed roller guide is a linear guide for limited travel distances. It consists of two ground pairs of rails, each with a V-shaped groove and intermediate cylindrical rollers as rolling elements, which are held in a crossed arrangement by a moving cage.

This type of linear guide offers the highest precision and load-bearing capacity with unsurpassed running performance. It is therefore generally used for measuring equipment, in optical instruments, in medical technology and in precision machining.

Ball bushings are rolling bearings for linear movements in which the balls are returned to the load zone in a constant cycle through closed circulation tracks. Therefore, unlimited travel distances are possible on a hardened guide shaft. Due to the point contact between the supporting balls and the shaft, precise, smooth movements can be performed with medium load capacities.

A ball bushing guide is a so-called round or shaft guide in which a linear guide is realised via usually two parallel shafts as a guide element and in which rolling-bearing linear ball bearings, so-called ball bushings, are used as guide sleeves instead of plain bushings.

A ball bushing guide is usually the simplest and cheapest type of rolling-bearing linear guide and is characterised by smooth running and low play.

The field of linear technology is a sub-discipline of drive technology that deals with the components or systems for performing linear movements.

See also: Track roller guide

Track roller guides are economical linear guides for lower loads and subordinate guide accuracy. The guidance is provided by four profiled track rollers that roll on steel shafts pressed into the aluminum guide rails. This principle of linear guidance allows a very high travel speed and is also ideally suited for harsh, dirty environmental conditions.

A ready-to-install linear system consists of a rigid base body (usually an aluminum or steel profile) that, in addition to a linear guide, also includes a drive, e.g. a threaded drive, toothed belt or pneumatic cylinder, and optional control elements such as limit switches etc. The connection to the drive motor is via standardised adapters, as is the combination to multi-axis systems.

A linear guide, also known as a linear guide, is a mechanical guide element. The linear guide enables the precise, linear (translational) displacement of a movable slide relative to a stationary component, e.g. the machine frame. A general distinction is made here between sliding guides, cage guides with a limited linear travel or guides with rolling element circulation for unlimited linear travel. Sliding guides include, for example, dovetail guides. Ball bushing guides, profile rail guides or track roller guides, on the other hand, represent guides with rolling element circulation.

The field of linear technology is a sub-discipline of drive technology that deals with the mechanical components or systems for performing linear movements. In addition to the linear guides, these components also include the mechanical drive elements for generating the linear movement. These include, for example, toothed belt drives, pneumatic or hydraulic cylinders, ball screw drives, trapezoidal screw drives or rack and pinion drives.

Linear systems are used in various technical systems, for example for infeed or feed movements as well as in handling systems. Linear systems include linear axes as a complete unit with integrated drive elements or also linear actuators or lifting drives.

Spline shafts are used in linear technology to transmit torques with simultaneous linear movement. They serve as a torsion-resistant linear guide or as a drive shaft with a linearly displaceable drive or output.

In the simplest case, it is a shaft with one or more rectangular longitudinal grooves and a sliding block. This engages with a negative contour in the grooves and thus ensures torque transmission.

For the play-free transmission of high torques with low displacement force, rolling-bearing systems are used. The spline or torque shaft has ground raceways in which the balls of the associated torque nut engage according to the ball circulation principle, resulting in a torsion-proof linear guide.

In simple terms, it is a profile rail guide in "round" with regard to the functional principle and performance data.

The positioning accuracy describes the deviation from the desired position, resulting, for example, from a calculated number of motor steps, and the actual position reached. This deviation results from the stiffnesses, any play in the drive/guide components, the pitch error of, for example, a threaded drive used and the deviation of the linear guide used from the ideal guide line.

See also: Non-positive connection

A roller circulation guide is a (profile) rail guide in which, in contrast to a ball circulation guide, rollers are used as rolling elements.

Due to the larger contact surface of a roller compared to the ball, even higher loads can be moved linearly. In addition, the deflection under load is lower, which makes the guide stiffer. For this reason, it can be used, for example, in high-performance machine tools for heavy machining.

In contrast to normal ball bushings, which only allow linear mounting of a guide shaft, a rotary movement of the shaft can also be mounted in a rotary ball bushing.

There are two different types: The rotary ball bushing, which, due to its design, allows an unlimited linear movement in addition to the rotation, and the short-stroke ball bushing, which, due to a moving cage, only allows a limited linear movement in addition to the rotation.

In linear technology, a linear guide with shafts as a guide element is also referred to as a round guide or shaft guide. The counterparts are slide-bearing guide bushings or rolling-bearing ball bushings for increased demands on precision and smooth running.

A slip or overload clutch slips from a certain torque and prevents damage to mechanical components such as gears, motors etc. due to overload.

This can be realised particularly compactly and inexpensively with a tolerance sleeve. However, it is essential to consult Dr. TRETTER, as the tolerance sleeve must be adapted to this application.

Rail guides are rolling-bearing linear guides based on the ball/roller circulation principle for unlimited linear movements. In contrast to a round guide with ball bushings and smooth guide shafts, a profiled guide rail with ground guide tracks for the rolling elements is used. This allows significantly higher loads to be transmitted and the guide can also transmit moments and is therefore torsion-resistant.

The static load rating Co is a measure of force or load that acts on machine elements. For a linear guide, the static load rating is defined as the static load that produces a remaining deformation (at the most heavily loaded contact point between the rolling element and the guideway). This must correspond to 0.0001 times the diameter of the rolling element. From this continuous load, a permanent damage to the guide is generally assumed.

Tolerance sleeves are slotted sleeves made of spring band material that have wave-like features. The operating principle of this elastic connection can be illustrated by many small compression springs distributed around the circumference. These are pre-tensioned when the clamping sleeve is pressed in, creating a friction-locked but detachable shaft-hub connection.

The tolerance sleeve is used in the form of non-positive connections in pumps, compressors, in electric motors or in conveyor technology.

The term tolerance ring can be used synonymously for the tolerance sleeve.

A transport roller describes a device for the occasional movement and transport of loads, usually in the form of a plate with 4 movable rollers.

In contrast, our Heavy-Mover transport aid is not equipped with swivel castors but with ball rollers. These enable easy changes of direction without the pivoting effect common with swivel castors and thus allow precise positioning of the load.

In addition, the low height of the ball rollers only requires a slight lifting of the load, which reduces the risk of the load tipping over.

In this cheapest form of threaded drive, the negative profile of the trapezoidal threaded spindle is cut into the nut, so the feed movement is transmitted via sliding friction. The advantage here is the self-locking at gradients of less than 4°, which is why trapezoidal threaded drives are used in lifting and clamping devices. However, the disadvantage is the greater play and higher friction.

An overload clutch protects mechanical systems from damage by interrupting or limiting the power transmission when a certain torque is exceeded. This allows components to be protected from overload or blockage.

A frequently used form is the tolerance sleeve. It functions as a slip clutch, in which two interconnected parts (e.g. shaft and hub) are coupled by friction. If the set torque is exceeded, the connection slips – the parts can move relative to each other. Thus, the tolerance sleeve acts as a mechanical overload protection.

In order to eliminate play and increase stiffness in a linear guide or ball screw, these can be preloaded. This is usually achieved through the use of larger rolling elements, which exerts a force on the rolling elements inside the guide. The amount of preload is defined as "negative play" in µm or, less frequently, as preload force in % of the load rating. As the preload increases, the displacement resistance increases and the service life of the component is reduced.

The term shaft-hub connection is used in mechanical engineering to describe the standardized connection of a rotationally symmetrical inner part with the receiving bore of an outer part. An inner part can be, for example, a shaft, a pin, a bearing outer ring or similar. Outer parts are usually pulleys, gears, bearing bores or similar.
The special feature of this connection is that torsional and bending moments as well as axial and transverse forces can be transmitted. Because of this, a tolerance sleeve can also be referred to as a shaft-hub connection.

In addition to the function of shaft guidance, hardened and ground shafts are also used in a wide variety of industrial applications as drive shafts, axles, rollers, pins or centering mandrels. Depending on the application, the shafts are machined according to customer drawings. Our machining spectrum of shaft machining includes the following turning and milling operations:

- Radial and face threaded holes

- Threaded pins

- Pins with fitting

- Grooves

- Flattening

- Widths across flats

- Keyways

- Deep hole drilling

See also: Ball bushing guide

The repeatability describes the deviation with which a certain position can be reached when approaching it repeatedly from the same direction. It is better than or equal to the positional accuracy, since e.g. spindle pitch errors or the guide deviation of the linear guide do not have an effect here.