PU timing belt AT3 270 - Conti® Synchroflex

Conti Synchroflex AT3 270 – compact timing belt for precise motion transmission

Conti Synchroflex AT3 270 is an endless, cast polyurethane timing belt with 90 teeth, 3 mm tooth pitch and a pitch length of 270 mm. It is intended for synchronous power transmission, where the driving and driven shafts must follow a fixed tooth ratio without the slippage known from friction-based belt drives. The pitch length is the nominal length measurement in the belt's cord line and is therefore the measurement that must be compared with the existing belt, the machine's spare parts data and the installed timing belt pulleys. This is the standard version in the specified profile. It must not be confused with a possible GEN III version or a double-sided DL belt with the same pitch length.

The most important product data

• Pitch length: 270 mm
• Number of teeth: 90
• Tooth profile: AT3
• Tooth pitch: 3 mm
• Material: cast polyurethane with steel cord
• Brand: Conti Synchroflex

The list gathers the information normally used to identify a timing belt: nominal length, number of teeth, profile, material and make. It is important to read all the information together. Two belts can have the same pitch length but be incompatible if the tooth profile or tooth pitch is different. Conversely, a different width does not change the number of teeth as long as the profile and pitch length are the same.

What characterizes the AT3 profile?

The metric AT geometry has trapezoidal teeth with a larger tooth volume than the standard T profile. The purpose is to distribute the load advantageously in the tooth mesh and achieve higher tooth strength without making the drive unnecessarily large. The profile requires suitable AT timing belt pulleys with the same pitch; a visual similarity to other profiles is not evidence of compatibility.

Cast polyurethane and steel cord

Conti Synchroflex is manufactured by casting, where the polyurethane is precisely shaped to the tool's tooth geometry around the embedded steel cord tension elements. The casting process provides high pitch accuracy over the entire circumference of the belt and a strong connection between PU and cord. The finished timing belt is endless and therefore has no welded joints. The polyurethane provides a wear-resistant tooth and back surface, while the steel cord takes the longitudinal tensile load.

The specific product version

The product is the regular Conti Synchroflex standard version in the specified profile. Standard and GEN III may have the same pitch length and number of teeth, but they are different product series with different material construction and capacity data. The same applies to a DL belt, which has teeth on both sides. When reordering, the entire profile designation should therefore be checked, not just the length.

Typical applications and sizing

Continental cites small power drives, handling equipment, compact positioning axes and light synchronous drives as examples for this profile family. The examples describe the general application area of ​​the profile, but are not an approval for any specific installation. The final belt width and pretension must be selected based on the transmitted torque, starting and shock loads, operating time, pulley sizes, speed and the number of teeth in simultaneous engagement. For safety-critical or heavily loaded drives, an actual calculation should be made.

The belt width is selected on the product page

The basic price applies to 6 mm, and the other widths are calculated with the same percentage logic as the existing PU timing belts in the webshop. Integer widths from 6 to 50 mm can be selected on this product page. A width of twice the basic width therefore costs 100% more, while a width of one and a half times the basic width gives approximately 50% extra. This price rule is a webshop calculation; it does not replace a technical dimensioning of the belt's load-bearing capacity.

Selection of discs for the profile

The pulleys and belt should be considered as a single tooth engagement. Correct AT3 geometry ensures that the load is distributed over the tooth flanks rather than concentrated on tooth tips or edges. The drive ratio is selected by the number of teeth on the pulleys, while the belt's 90 teeth and 270 mm pitch length determine the required combination of pulleys and center distance. When changing the drive, the geometry should be calculated.

How to avoid unnecessary wear and tear

The timing belt pulleys must be parallel and in the same plane. Even minor misalignments can cause the belt to move towards a flange and cause edge or cord damage. The belt should be installed without being twisted, sharply bent or pressed over a flange with a tool. The center distance is adjusted to achieve the calculated preload. Too high a tension increases the bearing and cord load, while too low a tension can cause tooth jumps at load peaks.

How to identify the correct replacement belt

It is not enough to compare the total circumference of a belt. The correct replacement must have the same pitch, tooth profile and number of teeth as the existing drive. The width must match the pulleys and the required capacity, and a DL or GEN III version must be identified separately. If in doubt, pictures of the marking, tooth profile and pulleys can be used as a supplement, but a documented spare part designation is best.

Prevention of early belt damage

A properly running timing belt should move smoothly without continuous contact against one flange. Regularly check the teeth for deformation, the back for ctiming bars and the edges for frayed areas. Abnormal noise or heat can be an early sign of incorrect tension or pulley failure. A systematic check of pulleys and belt is more effective than trying to hide symptoms with lubricant.

Maintenance-free does not mean control-free

The standard material is specified for ambient temperatures from -30 °C to +80 °C. Applications close to the limits, especially below -10 °C or above +50 °C, may require special dimensioning. The timing belt operates without lubrication, and oil or grease should therefore not be added to dampen noise. The polyurethane is described as resistant to aging as well as simple oils, grease and petrol and to certain acids and bases. In the case of permanent contact, cleaning chemicals or unknown media, material compatibility should be specifically clarified.

Answers to typical questions

Conti Synchroflex AT3 270: can an old V-belt be directly replaced by this timing belt?

No. A timing belt requires timing belt pulleys with the correct profile and pitch, while a V-belt works by friction in V-grooves. A conversion therefore requires new pulleys and a dimensioning of the entire transmission. The product is intended as a timing belt, not as a universal replacement.

Conti Synchroflex AT3 270: can a wider belt always transmit twice as much?

Not necessarily. A larger width provides a more active belt cross-section and can increase the permissible load, but the drive capacity also depends on the profile, number of teeth in mesh, pulley size, speed, load factor and preload. The width should be selected by an overall calculation.

Conti Synchroflex AT3 270: are the standard widths the only possible widths?

The documented supplier widths for this size include 6, 8, 10, 12, 16, 20, 25, 32 and 50 mm. The product page may also show intermediate sizes as cut widths when they are within the allowed range. This does not change the tooth profile or length, but the price is calculated based on the base width.

Conti Synchroflex AT3 270: why can a timing belt make noise?

Noise can be caused by incorrect pretension, skewed pulleys, poor tooth profile compatibility, excessive speed, resonance or worn tooth grooves. Lubrication is not the solution. First check alignment, tension, pulley condition and whether the belt runs without abnormal side contact.

Conti Synchroflex AT3 270: can the belt be shortened or assembled to a different length?

No. This is a cast endless timing belt with a fixed pitch length. It can be cut to width within the available options, but the circumference and number of teeth cannot be changed. If the length needs to be changed, a different cast belt size is required.

Conti Synchroflex AT3 270: what does the steel cord mean for the function of the belt?

The steel cord tension members absorb the longitudinal tensile load and provide high longitudinal stiffness. This helps maintain pitch and position during operation. The cord must not be kinked, exposed or damaged during installation, as local damage can weaken the belt.

Conti Synchroflex AT3 270: can AT3 be used on a different tooth profile with the same pitch?

No, not without documented compatibility. The 3 mm tooth pitch describes the distance between the teeth, but the shape and clearance of the tooth flanks may differ. The belt must be used with pulleys manufactured for the AT3 profile. Visual similarity is not sufficient documentation.

Brief summary

Conti Synchroflex AT3 270 is the correct size when the drive requires AT3, 270 mm pitch length and 90 teeth. The belt is cast endless in PU with steel cord and must be used with timing belt pulleys that match the profile. Choose the width according to the technical load and always check the design, alignment and pretension before commissioning.