ConCar Variable Speed Belts 47x10 – 1,120 mm inner length – DIN 7719 / ISO 1604
The ConCar Variable Speed Belts 47x10 with an inner length of 1,120 mm is a variator belt compliant with DIN 7719 and ISO 1604, designed for continuous operation in continuously variable speed drives (CVTs). Unlike a conventional V-belt, which runs on a fixed diameter, a Variable Speed Belts must maintain consistent friction across the entire adjustment range of the pulleys. To achieve this, it is significantly wider than it is tall and has a shallower flank angle, ensuring that the wedge effect remains uniform across the entire radial path and preventing the belt from binding or slipping at the end positions.
The inner length of 1,120 mm is a standard length in the mid-range for the 47x10 profile. For reference: With two pulleys of the same size and an effective diameter of 250 mm, the corresponding center distance is approximately 190 mm. At a belt speed of 20 m/s, the belt rotates around 17.2 times per second. This combination of moderate bending frequency and sufficient wrap is the reason why most standard drives operate within this length range.
For design purposes and comparison with an existing belt, the three length specifications are important because manufacturers use different reference dimensions. The inner length (Li) is 1,120 mm; it is measured at the inner circumference of the belt and is the standard ordering dimension in Germany. The effective length (Ld) of 1,165 mm refers to the neutral axis and is the dimension used in many catalogs and drive calculations. The outer length (La) of 1,183 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.
Internal length (Li): 1,120 mm
Effective length (Ld): 1,165 mm
External length (La): 1,183 mm
Profile: 47x10 according to DIN 7719 / ISO 1604
Top width: 47 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: 0.676 kg
Article number: G447101120
EAN: 4059213023715
Manufacturer: ConCar
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, allowing the belt to run smoothly across the entire adjustment range of the pulleys and preventing binding at the end positions. Simultaneously, the large upper width of 47 mm provides the necessary contact area to transmit torque solely through friction. The shaped 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.
Belts of this size are used in heavy-duty drives: threshing and drum drives on combine harvesters, intake and chopping units on forage harvesters, sawing and chipboard plants, large conveying and crushing plants, as well as compressor and blower drives where the speed must follow the demand without shifting a gearbox.
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.
Variable Speed Belts are supplied as continuous, single belts and cannot be shortened or joined. Before installation, the tapered pulleys must be fully opened so that the belt can be positioned at its smallest effective diameter. Tensioning is then achieved via the pulley's adjustment range or the motor rocker arm. Prying the belt open by the pulley edge is particularly damaging with Variable Speed Belts , as this can damage the exposed flanks and the tension member without any visible external damage.
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.
Variable Speed Belts are standardized according to DIN 7719 and ISO 1604. A belt with a 47x10 profile and an inner length of 1,120 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 47x10 / VARIO POWER 47x10
GATES: Multi-Speed 47x10 / Predator V Variable Speed
CONTITECH: VARIO Speed 47x10 / CONTI-V VARISPEED
MEGADYNE: VARISECT 47x10
MITSUBOSHI: VARI-SPEED 47x10
BANDO: Variable Speed 47x10
PIX: Variable Speed 47x10
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.