Components for linear motion – key facts about drives, shafts, couplings, drives, guides and much more

Linear movement makes it possible to move loads in a straight line instead of rotating the loads around an axis. This is an important part of industrial automation. Read about linear motion complete solution in the first part of our linear motion guide.

This includes linear motors, linear actuators, linear axes, and other components that enable linear motion. Linear motors are specially designed motors that generate linear motion. They generate forces to move loads in a straight line.

Our most popular products include:

  • Linear guides
  • Linear motors
  • Linear actuators
  • Linear positioning systems
  • Linear couplings

What is a linear guide?

A linear guide is a mechanical component used to guide a moving part in a straight line.

The basic components of a linear guide are a guide profile and a linear bearing.

It can be used to move or hold a load in a straight line, for example to control a machine. Linear guides are used in many different industries, such as in the aerospace industry, 3D printing, robotics, medical technology and electronics. In general, linear guides are used in applications where precise and dependable movement is required. They are robust and durable and can achieve high precision.

Picture of a linear guide with guide profile
Linear guide with guide profile

Linear guide with ball chains

The ball track and ball chain form the core of the linear guide and ensure precise linear movement.

They consist of specially shaped and polished ball bearings which are inserted into the ball track. The ball chain is a chain of balls placed along the guide profile to enable linear movement. In addition to the balls used in the ball track and ball chain, linear guides also use running wheels that allow the components to slide over the guide profile as they move.

What is a single-axis actuator (LX)?

An actuator is a device that converts physical input (e.g. an electrical voltage) into a mechanical action, which then fulfils a specific purpose. Actuators are an important part of automation technology and can be used to drive a machine, create mechanical movements or control valves and dampers, for example. They can be controlled directly or indirectly and fulfil a variety of functions.

Servo motors, electromagnets, hydraulic cylinders, piezoelectrics and pneumatics are some of the most popular actuators.

A single-axis actuator can create a linear motion by applying a force to an object. This force can be generated using a motor or a liquid, for example. This causes a linear movement that takes place in the form of a straight line or circle. Single-axis actuators are commonly used in the design to move specific machines and equipment. The actuator can generate a variety of movements, including continuous or intermittent movements.

Picture of a single axis actuator
Single axis actuator

What must be taken into account when installing single-axle actuators?

Installing a single-axis actuator typically requires a rotary guide unit, spur gear, spindle, and electronics that control everything. A motor for direct drive control may also be required. In order to mount the actuator, mounting brackets and a frame must also be provided to enable the components to be fixed. If the actuator is mounted directly on a robot arm, a dedicated adapter part is required. A bearing set should also be available to align and protect the components.

  1. Make sure that all connections are correctly connected, mechanically and electrically.
  2. Check that the actuator size meets the system requirements.
  3. Make sure that the actuator mounting position offers sufficient space to operate the actuator.
  4. Check that the actuator is supplied with the correct voltage and frequency.
  5. Make sure that the actuator is fixed in place securely and cannot slip.
  6. Check that the actuator connections are suitable for operation in the system.
  7. Check the actuator cable connections regularly.

What is the difference between ball screws and lead screws?

Ball screws and lead screws differ in their specific properties and applications. Ball screws are typically used at high torques and speeds, while lead screws are used at low speeds and low torques.

Ball screws offer greater precision and a greater starting torque than lead screws. Ball screws are easy to install and maintain. lead screws enable greater load-bearing capacity and higher performance than ball screws. lead screws are also able to withstand higher loads, making them suitable for applications with higher torques.

There are significant differences in the maintenance and repair of ball screws and lead screws. One of the most obvious differences is that ball screws have a closed screw – with lead screws, the screw is open. This means that, if ball screws require maintenance or repair, more effort will be involved as the screw head needs to be removed.

With lead screws, the parts can be easily removed or replaced without removing the screw head. Another difference is that ball screws require greater precision during manufacturing, while lead screws usually have a lower precision. This means that ball screws must be set more precisely during maintenance and repair than lead screws. Finally, ball screws and lead screws also differ with regard to maintenance and repair costs. Ball screws can be more expensive due to their higher precision, while lead screws are usually more cost-effective.

  • The ball screw drive can be adjusted much more precisely, free from play, and therefore offers fewer batch errors than the lead spindle.
  • Ball screws also have a significantly lower frictional resistance, which has a positive impact on various aspects. The lower friction results in a lower break-away force, resulting in a lower stick-slip effect.
  • Ball screws enable a high feed rate of up to 250 m/min.
  • Ball screws require more installation space than lead screws.
  • The manufacturing process for lead screws is less complex.

Ball screws or belt driven actuators – which is the optimal solution?

Ball screws are an effective and reliable solution when it comes to actuator control. They offer a number of advantages over belt-driven actuators.

The first and probably most noticeable benefit is the higher efficiency. Ball screws transmit power with less friction and losses than belt drives, resulting in a higher overall efficiency. Another advantage is precision. Ball screws are able to produce precise movements with low positioning accuracy. This precision is essential for many applications, especially applications that require high accuracy.

Thirdly, ball screws offer long-lasting, reliable performance. The gear teeth are extremely wear resistant with very low play, which results in a longer service life. Ball screws are also less susceptible to vibration and interference.

The main difference between ball screws and belt-driven actuators is the type of drive effect. Ball screws use a ball screw to generate linear motion. Belt-driven actuators use a belt and wheel system to produce a rotatable motion.

Tips for lubricating ball screws

Ball screws are an extremely reliable, precise and durable drive system. Regular maintenance is required, however, to ensure that the system continues to operate correctly and efficiently.

It is advisable to carry out regular maintenance to maximise the service life of a ball screw. Typical maintenance tasks include oiling the balls, checking the balls for wear and checking the tightening torques or lubricants, depending on the application. It is recommended that the system is inspected at least once a year to ensure that the components are in good condition.

Ball screws require different lubrication cycles depending on the application. It is typically advisable to lubricate ball screws after installation and after each maintenance cycle. If the ball screws are used in a harsh or dirty environment, they must be lubricated more frequently to ensure optimal performance.

When servicing ball screws, a number of components should be checked to ensure that they are working correctly.

These include:

  • the balls
  • the thread
  • the bearing unit
  • the ball recirculation rings
  • the screws and the shafts

Quality control for tolerances and parts – how to achieve precise results

MISUMI carries out strict quality control to ensure the high quality of its products. This includes careful selection of materials, an extensive production process, a close-knit testing regime and a comprehensive final inspection. We also take several measures to ensure product quality, such as ensuring compliance with international regulations and standards, conducting regular quality checks and using high-quality components. Higher product quality is also achieved through the use of state-of-the-art production techniques.

MISUMI manufactures a wide range of linear motion systems made from high-quality components. The product catalogue includes a broad selection of drives and linear technologies suitable for a wide range of industrial applications.

MISUMI products are suitable for a wide range of applications, from automation to robotics applications. These include linear actuators, linear positioning systems, linear guides, linear motors, and other linear components. MISUMI offers a wide selection of accessories such as linear couplings, linear sensors and linear encoders.

MISUMI offers its customers extensive application support, such as technical advice, design and construction assistance and fast deliveries. With its high-quality products, professional services and comprehensive support services, MISUMI is a preferred partner for customers all over the world.

Configure your components

You can configure shafts and other components freely with the MISUMI configurator.

Select the component type and set the desired specifications and characteristics.

CAD library

Use our extensive CAD library to select the optimal part for your components and applications.

Find inspiration in our inCAD library and edit your designs with our SolidWorks add-on “inCADcomponents”.