Stretching Devices EDS, PDS, HDS for Felts and Drying Fabrics

Stretching devices EDS (Electric Drive Stretching), PDS (Pneumatic Drive Stretching), and HDS (Hydraulic Drive Stretching) are designed to stretch felts in the press part and drying fabrics in the drying part of paper machines. The stretching force can be applied pneumatically or electrically.

Design Features

General Structure:

• Comprises a motion screw with sidewalls, beddings, and gearbox on both the drive and service sides.
• Both sides are connected by a shaft between the gearboxes.
• The gearbox on the service side has a hand wheel for manual alignment of the beddings’ axis to be perpendicular to the PM axis.
• The drive side features an overhung geared electric motor that synchronously moves both motion screws.
• Guide rolls installed in the stretcher beddings allow for the stretching or relieving of the felt or drying fabric.
• End positions are protected by contactless inductive sensors, which stop the engine upon reaching an end position.

Control Devices:

• Basic models do not include fabric tension sensing.
• Can be upgraded with tension sensing systems, including tensometric sensors and automatic regulation of tension forces.

Pneumatic (PDS) and Hydraulic (HDS) Stretching Equipment:

• Consists of two beams (service and drive side) with guides and a rack bar.
• Carriages with bearing housings travel on the guides.
• Carriages are coupled with a connecting shaft and linked to pinions engaged in rack bars.
• Motion is provided by two pneumatic cylinders.
• Stretching value is proportional to air pressure in the pneumatic cylinders, eliminating the need for tensometric sensors or additional control elements.
• Air pressure is regulated by a reducing valve in the pneumatic circuit.

Main Parts

Type EDS:

1. Stretcher Body (1)
2. Connecting Shaft (2)
3. Stretcher Drive (Electric Gearbox) (3)
4. Bearing Housings (4)

Type PDS, HDS: 5. Beam with Support (5) 6. Pneumatic and Hydraulic Cylinder (6) and Pneumatic Circuit 7. Bearing Housings (7)

Material

• Stretching System: Made of common steel, with options for stainless steel for press part stretching based on customer requests.

Accessories

• Tensometric Sensors: With amplifier of output signal.
• Hydraulic Power Unit and Control System

Scope of Delivery

• Complete machine as per the main parts description.
• Optional accessories based on customer requirements.

Advantages

• Simple Operation: Easy to use and maintain.
• Reliable and Safe Operation: Ensures consistent performance and safety.
• Longer Service Life: Extends the lifespan of wires and felts.

These stretching devices ensure effective and reliable stretching of felts and drying fabrics, contributing to optimal operation and longevity of the paper machine components.