Rexroth high reliability, low cost grippers
July 01st 2005

High reliability and low cost are two key benefits offered by Rexroth’s new GSP Series Grippers. Now, designers, manufacturers and end-users of factory automation systems have direct access to a gripper range engineered to provide competitively priced, technically competent and robust solutions for a wide range of industrial handling applications. In fact, Rexroth states that when compared with competitive products, its products’ superior gripping performance can allow the use of smaller units, thus adding further cost savings.

As practical examples, a size 40 GSP-R radial gripper offers 7.17Nm at 6bar, while the smaller size 32 unit can deliver 4.88Nm yet has a list price of just £331.52.

Angular models can offer up to 4.27Nm gripping force.

With industrial automation systems often operating in three-shift, seven-day manufacturing environments, gripper cost and reliability can have a dramatic effect on a system’s total cost-of-ownership. To this end, the European design team responsible for product development focused their engineering effort on the grippers’ bearing and fulcrum points to guarantee an extended operating life without increasing product cost.

Application areas for the grippers extend from food and packaging, to electronics and automotive. For example, in the food packaging sector the grippers are capable of stacking items as delicate as paper cups. Regarding electronics manufacturing, grippers are available to position individual components on printed circuit boards and then place a finished assembly, such as a mobile phone, into its packaging. Heavy duty applications can range from sorting bottled water into multi-packs, to placing valves into automotive engine cylinder heads.

To ensure the grippers can be quickly and easily integrated into new and existing automation systems they are engineered as drop-in replacements for existing designs, while also conforming to Rexroth’s Easy to Combine (E-to-C) modular format which eliminates the need for costly and awkward adapter plates.

On this point, the E-to-C format provides a common interface to products from Rexroth’s pneumatics and linear divisions, ensuring the benefits of easy integration apply to machines driven by either compressed air, electricity or both.

Combinations can include rodless cylinders, guided slide units, guided precision cylinders, mini slides, rotary tables and swivel units.

Continuing with the theme of integration, the grippers are supported by a portfolio of accessories providing the necessary interface components to link to other E-to-C products. Examples include reed/solid state sensors (flying lead or plug-in connection), plus a range of fittings and speed control devices.

Focussing on the product range, GSP series grippers are available in four distinct geometries: parallel, angular, radial and centric, handling work piece weights up to 5kg. Repetitive precision is quoted up to ±0.02mm (measured as end position deviation under constant operation during 100 consecutive strokes).

Design and application engineers will be pleased to hear that Rexroth bas backed up the introduction of this product range with comprehensive documentation and support. In addition to the data sheet (R499050121/2004- 05/EN) and website, Bosch Rexroth’s worldwide support infrastructure offers telephone helpdesks, in-house engineering departments, field application engineers and 2/3D CAD. The range is also being included on the next edition of the company’s CDROM.

For purchasing departments tasked with actually sourcing and buying the grippers, they are immediately available on a delivery timescale of three to five-days ex-stock from the company’s distribution centres. Depending on their company’s location, buyers can either purchase the grippers direct from Rexroth or via sales partners throughout the UK. If the grippers are integrated into automation systems destined for export, customers will be pleased to hear that they are available internationally via similar sales channels.

Rexroth’s Pneumatics Distribution Manager, Dennis Yeates, summarised the importance of this range to Rexroth and its customers: “Grippers are usually the last piece in the automated handling jigsaw, yet they are the devices that actually hold the customer’s product. As such, it is vital that they are correctly sized to provide sufficient holding force, while also offering long term accuracy and repeatability.

“This new GSP range allows Rexroth to offer grippers that fulfil all of these requirements at very competitive prices. Capable of generating high forces, we can often use a smaller unit than our competitors, thus offering a more compact solution. Add to this the benefits offered by Rexroth’s E-to-C system – direct combination of automation elements, simpler assembly, more compact designs and fewer components – and customer can save time, reduce cost and extend equipment life.”