Gramac Quartz Powered Belt Curves: Design Advantages, Features and Benefits
Proven Track Record Across Industries
Gramac Quartz powered belt curves, also known as belt bends, have a proven track record of reliable operation and long service life in conveyor systems around the world. Designed for smooth changes in the direction of conveyed products, they are used in demanding industrial and materials handling environments.
Applications include airport baggage handling, post and parcel sorting, warehouse and distribution centres, refrigerated storage, printing and packaging, commercial laundries, cement and plaster products, building materials, horticultural products, fertilisers, compost and general manufacturing operations.
Robust and Durable Belt Curve Construction
Gramac Quartz belt curves feature a robust, patented design incorporating a strong, rigid frame fabricated from steel sections and plate. The frame is rolled and formed to achieve the required conveyor curve angle and radius.
A stiffened, smooth steel slide bed is mounted within the frame to support the conveyor belt and provide a consistent surface over which it travels.
Flexible Belt Curve Angles and Widths
The Gramac Quartz TSTR100 and TSTR150 powered belt curve ranges offer considerable flexibility in conveyor layout and design. In addition to the standard sizes shown elsewhere on this website, belt curves can be manufactured with subtended angles between 15° and 180° and belt widths from 300 mm to 1800 mm.
This flexibility is particularly useful when integrating conveyor systems into buildings with irregular layouts, limited available space or existing production equipment.
Special configurations are also possible. The photograph alongside shows a single spiral belt curve with a subtended angle of 270°, demonstrating how bespoke conveyor designs can accommodate complex changes in direction and elevation.
Tapered End Pulleys
Each Gramac Quartz belt curve incorporates tapered conical end pulleys manufactured from high-density polypropylene and mounted on steel shafts. The pulleys are supported by greased-for-life ball bearing units fitted to the curved conveyor frame.
Horizontal adjustment through the belt tensioning mechanisms allows the pulleys to be positioned to achieve the correct conveyor belt tension.
Efficient Friction Drive and Power Transmission
The drive pulley is coated with a non-slip, wear-resistant and heat-resistant lagging material that grips the underside of the conveyor belt.
Its tapered design allows contact across the full belt width, including during high-speed operation, helping to provide effective power transmission from the geared motor unit fitted to the drive pulley shaft.
This operating principle is known as friction drive and is a key feature of Gramac Quartz powered belt curves.
Long Belt Life, Low Noise and Minimal Maintenance
Some alternative powered belt curve designs use a positive mechanical drive system, where a roller chain is attached to the outer edge of the belt through punched holes. The chain is driven by a sprocket connected directly or indirectly to a geared motor unit.
Gramac Quartz belt curves instead use a friction-driven system, in which the drive pulley transmits power to the belt through friction. This design provides three important operating advantages:
- Longer Belt Life: Tensile stresses are distributed more evenly across the width of the conveyor belt, reducing localised stress concentrations that can contribute to tearing and premature belt wear.
- Lower Operating Noise: The absence of external drive chains and associated moving transmission components helps minimise operating noise. Gramac Quartz belt curves have a stated maximum running noise level of 65 dBA measured at a distance of 1000 mm.
- Minimum Maintenance: The friction-drive arrangement avoids the regular chain lubrication associated with positive mechanical drive systems. Pulley bearings are greased for life, helping to minimise routine lubrication requirements.
These features contribute to reliable conveyor operation, reduced maintenance requirements and a lower cost of ownership over the equipment's service life.
Positive Conveyor Belt Tracking
As a belt travels around a curved conveyor, it naturally tends to move towards the inside of the curve. Gramac Quartz belt bends use a positive belt tracking system to maintain the correct running position.
Polyurethane-tyred roller bearings are fitted to the reinforced outer edge of the conveyor belt. These bearings run along guide rails incorporated into the outer perimeter of the steel conveyor frame.
This arrangement provides controlled belt tracking throughout operation and helps maintain the belt's position around the curve.
Easy Belt Tensioning and Replacement
Gramac Quartz powered belt curves incorporate four easy-to-use belt tensioning mechanisms located at the pulley ends. These allow the pulley positions to be adjusted to achieve the correct belt alignment and even tension across the belt width.
Conveyor belts may stretch slightly during their initial period of operation. The adjustable tensioning system makes it straightforward to re-tension an existing belt or correctly tension a replacement belt following installation.
Maintenance Viewing Window for Easier Inspection
Regular inspection and maintenance are important for maintaining reliable belt curve performance, particularly in airport baggage handling and intralogistics systems operating around the clock.
Gramac Quartz belt curves incorporate a maintenance viewing window that allows guide roller bearings to be inspected for signs of wear without dismantling the conveyor.
If an individual bearing requires replacement, access through the window allows maintenance work to be carried out more quickly and with less dismantling than would otherwise be necessary.
Fully Guarded for Safe Operation
Gramac Quartz powered belt curves are supplied with safety guards designed to protect against access to moving components and potential trapping points, including the belt guide roller bearings.
The guards are lightweight to simplify removal during maintenance, and underside guarding is provided as standard.
Choice of Geared Motor Units
SEW Eurodrive SA47 geared motors are the standard drive option for Gramac Quartz belt curves. Alternative hollow-shaft geared motor units can also be accommodated to meet customer preferences and project requirements, including permanent magnet motor (PMM) types.
Powder-Coated and Galvanised Finishes
Gramac Quartz belt curve frames can be powder-coated in standard RAL or British Standard (BS) colours to suit the installation environment.
For humid or exposed operating conditions, a galvanised finish can also be specified to provide additional corrosion protection.
Frequently Asked Questions About Gramac Quartz Belt Curve Design and Benefits
Gramac Quartz powered belt curves combine robust steel frame construction, friction-driven belt operation, positive belt tracking and straightforward belt tensioning. These features are designed to provide reliable operation, long conveyor belt life, low running noise and reduced maintenance requirements across industrial and materials handling applications.
Gramac Quartz belt curves use friction between the drive pulley and the underside of the conveyor belt to transmit power. Unlike positive mechanical drive systems that use external chains, this arrangement distributes belt tension more evenly, avoids localised stresses caused by chain attachment points and eliminates the need for regular drive-chain lubrication. It also helps reduce operating noise, with a stated maximum running noise level of 65 dBA measured at 1000 mm.
Gramac Quartz TSTR100 and TSTR150 powered belt curves can be manufactured with subtended angles between 15° and 180° and belt widths from 300 mm to 1800 mm. Bespoke configurations are available for conveyor systems with unusual layouts or space restrictions. Special spiral belt curves can also be manufactured, including the 270° spiral conveyor illustrated on this page.
The positive belt tracking system uses polyurethane-tyred roller bearings attached to the reinforced outer edge of the conveyor belt. These bearings run along guide rails built into the outer perimeter of the steel frame, helping prevent the belt from moving towards the centre of the curve and maintaining its correct running position.
Gramac Quartz belt curves are designed to minimise routine maintenance. Their pulley bearings are greased for life, and the friction-drive system does not require regular drive-chain lubrication. Adjustable belt tensioning mechanisms simplify belt re-tensioning and replacement, while the maintenance viewing window allows guide roller bearings to be inspected and accessed without extensive dismantling. Lightweight safety guards also make maintenance access easier.
SEW Eurodrive SA47 geared motors are the standard drive option for Gramac Quartz belt curves. Alternative hollow-shaft geared motors, including permanent magnet motor (PMM) types, can be accommodated to meet project requirements. Belt curve frames can be powder-coated in standard RAL or British Standard colours, with galvanised finishes available for humid or exposed environments.