ConCar Variable Speed Belts 37x10 - 2240 Li

ConCar Variable Speed Belts 37x10 – 2,240 mm inner length – DIN 7719 / ISO 1604

This ConCar Variable Speed Belts with a 37x10 profile and an inner length of 2,240 mm, is a toothed variator belt conforming to DIN 7719 and ISO 1604. Variable Speed Belts are the mechanical alternative to frequency converters: they regulate the output speed purely through geometry, without electronics, harmonics, or an additional heat source in the control cabinet. In many woodworking, textile, and agricultural machines, this remains the more robust solution because it operates reliably even in dusty, humid, and vibration-prone environments.

This length in the drive

With an inner length of 2,240 mm, this belt is one of the longer versions of the 37x10 profile. For two equally sized pulleys with a 500 mm effective diameter, this corresponds to a center distance of approximately 355 mm. Long belts are less prone to bending stress; at 20 m/s, they rotate only about 8.8 times per second. However, they require more attention to tension: the slack side tends to flutter at large center distances, and the belt's own mass generates additional centrifugal force during operation, which reduces the contact pressure on the pulley.

For design and comparison with an existing belt, the three length specifications are important because manufacturers use different reference dimensions. The inner length (Li) is 2,240 mm; it is measured at the inner circumference of the belt and is the standard ordering dimension in Germany. The effective length (Ld) of 2,285 mm refers to the neutral axis and is the dimension used in many catalogs and drive calculations. The outer length (La) of 2,303 mm is measured at the back of the belt. With a profile height of 10 mm, the difference between the inner and outer lengths is 63 mm, which corresponds to twice the difference in circumference across the belt height. When replacing an old belt, always compare using the same reference dimension; otherwise, you can easily be off by several centimeters.

Dimensions and specifications

• Internal length (Li): 2,240 mm

• Effective length (Ld): 2,285 mm

• External length (La): 2,303 mm

• Profile: 37x10 according to DIN 7719 / ISO 1604

• Top width: 37 mm

• Height: 10 mm

• Flank angle: 28°

• Construction: open-sided, toothed

• Mixture: Chloroprene (CR)

• Tensioning material: Polyester cord

• Antistatic: yes, according to ISO 9563

• Temperature range: -30 °C to +80 °C

• Belt speed: up to 30 m/s

• Weight: 1.066 kg

• Article number: G437102240

• EAN: 4059213023210

• Manufacturer: ConCar

Structure and materials

The belt consists of a chloroprene rubber core with a longitudinally inserted polyester cord as a tensile member. The flanks are open, meaning they are not covered with fabric. This noticeably increases the coefficient of friction on the pulley and thus improves the transmissible torque, but in return requires clean, unworn pulley flanks. The compound is antistatically conductive according to ISO 9563, which allows the belt to be used in dusty areas and in ATEX-relevant environments.

The 28° flank angle is the crucial difference compared to a conventional V-belt, which operates at 34 to 40 degrees. The shallower angle generates less wedging effect per millimeter of radial travel, ensuring smooth belt operation across the entire pulley adjustment range and preventing binding at the end positions. Simultaneously, the large 37 mm upper width provides the necessary contact area to transmit torque solely through friction. The toothed underside reduces bending stiffness to such an extent that the belt can operate even on small effective diameters without the flanks overheating due to internal flexing.

Typical areas of application

Belts of this size cover the classic field of industrial variators: feed and grinding belt control in woodworking machines, demand-controlled piston and screw compressors, spinning and drawing units in textile machines, industrial mixers and kneaders with soft start, take-off and screw drives on plastic extruders, as well as boring mills and lathes with stepless control.

What these applications have in common is that the rotational speed must be adjusted during operation to suit the material, batch, or demand. A Variable Speed Belts solves this problem purely mechanically, without any electronics in the drive train. This is advantageous wherever dust, moisture, vibration, or temperature would damage a frequency converter, and it remains the only economical solution for existing machines because the variator is an integral part of the machine's design.

Assembly and tension

Before ordering, check the adjustment range of your drive. The belt must be able to be fitted without force, whether the pulleys are fully closed or open. After fitting, tension the belt to the tension specified by the machine manufacturer and check again after the break-in period. If several belts run in parallel in one drive, they must always be replaced as a complete set, as a new belt, in addition to worn ones, bears the entire load.

A typical wear pattern in the variator is glassy, ​​shiny edges. This is not a sign of aging, but rather slippage: the belt slips under load and polishes the edge. The cause is almost always insufficient tension or a worn pulley with an enlarged groove width. If only the belt is replaced and the pulley remains the same, the damage usually recurs within a few weeks.

Similar names for other brands

Variable Speed Belts are standardized according to DIN 7719 and ISO 1604. A belt with a 37x10 profile and an inner length of 2,240 mm is therefore dimensionally identical regardless of the manufacturer; no modification of the pulleys is required for replacement. This ConCar belt replaces, among others:

• OPTIBELT: VB 37x10 / VARIO POWER 37x10

• GATES: Multi-Speed ​​37x10 / Predator V Variable Speed

• CONTITECH: VARIO Speed ​​37x10 / CONTI-V VARISPEED

• MEGADYNE: VARISECT 37x10

• MITSUBOSHI: VARI-SPEED 37x10

• BANDO: Variable Speed ​​37x10

• PIX: Variable Speed ​​37x10

Delivery

The belt is supplied as a single, endless belt. Standard lengths and common profiles are available from stock; custom lengths and widths are available upon request. If you are unsure which length your drive requires, please send us the part number of your old belt or the dimensions of your pulleys, and we will check the compatibility.