Design principles of pneumatic components
Original article date: October 1997
The design principles of a new range of pneumatic components achieve fast pay back and productivity goals says Carl McGowan Sales Engineer with Parker Pneumatic
Increased productivity and fast pay-back times are the chief goals of design engineers when selecting and specifying automation equipment. In order to achieve these goals components should be modular self-contained rigid and capable of adjustment.
The latest automation components form Parker Pneumatic designed for use where constantly repeated movements are required to be performed for example in materials handling assembly lines loading and unloading machines and pick and place operations is the 3D range of linear actuator and carrier units base/wrist rotates grippers vacuum equipment and mounting kits.
To provide a cost effective method of modular automation components need to be easy to install with the minimum amount of design and engineering time. When a modification is required to piece of automation equipment – for example a different component being handled or assembled – the simple addition of another unit to perform a new function or positioning option assures maximum productivity from a single automation set up. Components in the 3 range are connected together by means of a simple dovetail or “T” slot a mounting system which ensures that all components in the range can either be attached together onto a machine surface or directly to a structural framework system by means of standard off-the-shelf accessories and mounting kits.
Automation components must be completely self-contained. If there is a requirement for sensing stroke adjustment speed control and cushioning such features should be in-built. Having to fit extra equipment to obtain these functions is time consuming and detracts from the overall appearance of the finished piece of equipment. Parker 3D linear and carrier units are therefore fitted with PNP or NPN sensors end of stroke adjustment blocks with in-built hydraulic shock absorbers speed control valves and electrical circuit boards for connection to the control device.
The anti-rotation qualities of components in the 3 series have been radically improved. Linear units work like a pneumatic cylinder in reverse with the piston rod remaining static while the barrel effects the linear motion. In previous designs the barrel or movement tube was circular and coupled to a guidance rail. The latest design incorporates a rectangular section aluminium extrusion that is both extremely strong and light. The section is fitted with two additional stainless steel rails which slide between linear bearings allowing torque loads of up to 25Nm to be applied to the largest size unit in the range. As a result the standard linear unit is sufficiently rigid to be used for vertical lift applications as well as linear movements.
The carrier system also incorporates the latest in guidance technology. Based upon the successful range of rodless cylinders recently introduced the cylinder incorporates a machine-hardened guidance rail in which slides the main carriage fitted with four double recirculating ball bearings. This enables the carrier system to be used for gantry type pick and place applications of up to 5 stroke lengths. The maximum torque load permitted on the size three carrier is 100Nm and the maximum transportable load is 50kg.
Stroke lengths of all units are variable by means of simple stroke adjustment blocks or an unique “mid-position stop” device. This precise positive stop allows up to four mid position stops to be fitted to a linear unit or multiple mid-position stops to be fitted to carrier units depending on stroke length. The stop is a pneumatic device with a fine adjustment of +/-2mm and positioned in a “T” slot within the unit. The mid-position stop is also fitted with a hydraulic shock absorber to ensure a smooth controlled accurate stop. In addition Numeric 3D units are available incorporating brushless servo motor control for unlimited numbers of precise stop positions. Also available are modular belt driven cylinders controlled by either pneumatic or electric motors offering multi-position options for greater flexibility.
- Parker Pneumatic
- Tel: 01543 456000
- Carl McGowan Sales Engineer
October 1997