Conti Synchroflex AT3 GEN III 417

Conti Synchroflex AT3 GEN III 417 – precise PU timing belt for synchronous power transmission

Conti Synchroflex AT3 GEN III 417 combines a precise AT3 GEN III tooth geometry with a molded polyurethane body and longitudinally stable steel cord tension elements. The product has 139 teeth and a pitch length of 417 mm, which corresponds to a tooth pitch of 3 mm. The belt is used in synchronous drives where uniform movement and reproducible position are more important than the elasticity normally associated with a conventional V-belt or flat belt. The GEN III version is the reinforced high-performance construction with red high-performance polyurethane and a denser, two-filament steel cord structure. It should therefore be treated as a separate product series and not as the usual standard version.

Fixed specifications

• Pitch length: 417 mm
• Number of teeth: 139
• Tooth profile: AT3 GEN III
• Tooth pitch: 3 mm
• Material: cast polyurethane with steel cord
• Brand: Conti Synchroflex

The technical data below describes the part of the product that does not change when a different belt width is selected. Pitch length, tooth pitch and number of teeth remain identical for all width choices. However, the width affects the available belt cross-section width and the price calculated on the product page. Correct sizing must always take into account torque, speed, number of teeth in mesh, pulley diameters, service factor and any counter-bending.

Why the correct profile is crucial

In a synchronous belt drive, the movement is transmitted through the tooth flanks. The geometry of the AT profile is therefore crucial for both load distribution, noise level and position accuracy. A correct AT pulley supports the teeth according to the profile to which they are cast. If the pulley's tooth shape or pitch deviates, the load can be concentrated at a few pu and cause abnormal wear, even though the belt can apparently be mounted.

How the Conti Synchroflex belt is constructed

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 execution must be correctly identified

The red GEN III construction is not just a color variant. It is developed with higher cord density and a special steel cord construction that provides increased tensile strength, better grooveing and the ability to carry higher loads. The catalog also specifies a temperature range up to +100 °C. Standard and GEN III must therefore be created and selected as separate products, even when the length and profile are the same.

How the width variants work

The belt width is not written in the product name because the same pitch length is collected on one product page. The starting pu is 6 mm. Integer widths from 6 to 50 mm can be selected on this product page. The original supplier widths for this length are 6, 8, 10, 12, 16, 20, 25, 32 and 50 mm. Other intermediate sizes are offered as cut-to-size versions of the same type of timing belt sleeve when they are within the selection shown. The number of teeth, pitch length and profile do not change when the width is changed.

Which drives is the product compatible with?

The profile series is used in practice for tasks such as small power drives, handling equipment, compact positioning axes and light synchronous feeds. Common to these machines is the need for a fixed transmission ratio and controlled tooth meshing. A timing belt can transmit both force and position, but the capacity cannot be assessed based on length alone. Width, profile version, wrap angle and load cycle are among the data that must be included in the selection.

Profile and length must match

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.

Disc geometry and tooth engagement

The pulleys and belt should be considered as a single tooth engagement. Proper AT3 GEN III geometry ensures that the load is distributed across 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 139 teeth and 417 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.

Signs of improper operation

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.

Temperature, media and service

Continental specifies a temperature range of up to +100 °C for the GEN III series. When operating close to the temperature limits, the drive must still be dimensioned according to the specific load and environmental conditions. 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.

Technical questions about the product

Conti Synchroflex AT3 GEN III 417: what is the difference between tooth pitch and pitch length?

The tooth pitch is the distance from one tooth to the next and is 3 mm for this profile. The pitch length is the entire nominal circumference in the cord line and is 417 mm. When the pitch length is divided by the tooth pitch, the belt has 139 teeth.

Conti Synchroflex AT3 GEN III 417: does the number of teeth change when the belt width is changed?

No. All width choices on this product page have the same pitch length of 417 mm and the same number of teeth of 139. Only the width of the belt, and thus the price and possible load capacity, changes. The width must still match the pulleys and the technical dimensioning.

Conti Synchroflex AT3 GEN III 417: why is the number of teeth important for spare parts?

The number of teeth links the pitch of the profile to the nominal length of the belt. For this size, 139 teeth at 3 mm pitch gives a length of 417 mm. It is a simple check that often reveals faults that are not visible by a quick comparison of two loose belts.

Conti Synchroflex AT3 GEN III 417: what is the difference between AT3 GEN III and a GEN III belt?

This product is already GEN III. The reinforced version features high-performance PU and denser, two-filament steel cord construction and is a separate product line from the standard belt.

Conti Synchroflex AT3 GEN III 417: why is GEN III not merged with the standard version?

GEN III has a different material construction and capacity data than the standard belt. The higher cord density, two-filament construction and high-performance polyurethane make it a separate product line, even though the pitch length and tooth profile may be identical.

Conti Synchroflex AT3 GEN III 417: can the belt be installed by pressing it over the flange of the pulley?

This should be avoided. The belt should be installed by adjusting the center distance or following the correct installation procedure for the machine. Forcing it over a flange can damage the cord pullers, teeth or belt edge. After installation, the pulleys must be parallel and the pretension must be correct.

Is the Conti Synchroflex AT3 GEN III 417 welded?

No. The Conti Synchroflex series is manufactured as cast, endless timing belts. The belt therefore does not have a welded joint around the circumference. The cast process provides a uniform tooth pitch around the entire belt and a strong bond between the polyurethane and the cast steel cord tension elements.

The product in brief

Conti Synchroflex AT3 GEN III 417 is the correct size when the drive requires AT3 GEN III, 417 mm pitch length and 139 teeth. The belt is cast endless in PU with steel cord and must be used with timing belt pulleys that match the profile. Select the width according to the technical load and always check the design, alignment and pretension before commissioning.