Conti Synchroflex T5 390

Conti Synchroflex T5 390 – precise T-profile timing belt in cast polyurethane

With 78 teeth spread over a pitch length of 390 mm, the Conti Synchroflex T5 390 is designed for precise transmission of rotation, timing and position. The belt is cast endlessly in PU and has integrated steel cord tension elements that stabilize the length during normal operation. The nominal tooth pitch is 5 mm and the tooth profile must match the profile of the pulleys exactly. It is not sufficient for another belt to have approximately the same length or width. 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.

Dimensions, profile and number of teeth

• Pitch length: 390 mm
• Number of teeth: 78
• Tooth profile: T5
• Tooth pitch: 5 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.

Profile, tooth pitch and engagement

The trapezoidal T-geometry is a standardized solution for synchronous transmission. The teeth mesh with corresponding grooves in the timing belt pulley, so that the speed ratio is maintained without slipping. The correct pitch is crucial: a T5 belt, for example, will not fit in an AT5 pulley simply because the tooth pitch is 5 mm in both places. The shape and clearance of the tooth flanks are different.

Belt construction

With the cast manufacturing method, the finished belt becomes an exact copy of a precision-machined shape. This is a major reason for the uniform tooth pitch and reproducible length. The steel cord is integrated into the polyurethane and contributes to position and angular precision. The design is suitable for synchronous drives, where a conventional elastic friction belt does not provide the desired repeatability.

The construction behind this variant

This item is a single-sided standard design. The teeth are located on the inside of the belt, while the back is smooth. It should not be confused with a double-sided DL version or the red GEN III series. If the machine is originally dimensioned for a specific variant, a change should only be made after a technical assessment of load, pulleys and preload.

From basic width to desired width

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.

Where is this profile used?

Continental cites office machines, household appliances, positioning drives and control drives as examples for this profile family. The examples describe the general area of ​​application of the profile, but do not constitute 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.

Profile and length must match

When replacing a spare part, the marking on the existing belt should be compared with the product name. Check the profile designation, pitch length, number of teeth, design and width. If the text on the belt has worn away, the number of teeth can be counted and the pitch can be assessed by measuring over several teeth. A single external length measurement is less reliable because the nominal length of the timing belt is indicated in the pitch line.

Selection of discs for the profile

The number of teeth on the pulleys affects both the gear ratio, deflection and how many belt teeth carry the load. A small pulley may be necessary in a compact drive, but it should not be selected without considering the minimum profile requirements and any counter deflection. Use timing belt pulleys with 5 mm pitch and the correct T5 tooth shape, and check that the flanges do not damage the belt edge.

Correct splice in the timing belt tensioner

When installing, the cord pullers must be protected against kinks and local pressure damage. The belt must not be pinched with pliers or a screwdriver, and it should not be folded sharply. Check that the pulleys have the same pitch and profile as the belt and that they are not worn out. A stable drive is achieved through the right combination of alignment, wrapping and calculated pretension.

Wear patterns and troubleshooting

Troubleshooting should start with pu location of the damage. Edge wear is typically associated with grooveing and alignment, while tooth skipping can be associated with too low tension, load peaks or too few teeth in mesh. Ctiming bars on the back can be caused by too small rollers, back bending or environmental influences. Do not simply replace the belt without also finding the mechanical cause.

Operating environment and maintenance

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.

Technical questions about the product

Conti Synchroflex T5 390: what happens if the discs are not aligned?

Misalignment can cause the belt to wander towards a flange, causing edge pressure, heat and wear damage. It can also affect tooth engagement and reduce service life. Check both the parallelism of the shafts and the alignment of the pulleys.

Conti Synchroflex T5 390: 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, 78 teeth at 5 mm pitch gives a length of 390 mm. It is a simple check that often reveals faults that are not visible by a quick comparison of two loose belts.

Conti Synchroflex T5 390: can the belt be turned upside down on the pulleys?

The standard version is single-sided with teeth on the inside and a smooth back. It must run with the teeth in the corresponding tooth grooves; the back is not an alternative tooth side.

Conti Synchroflex T5 390: 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 T5 390: 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 390 mm and the same number of teeth of 78. 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 T5 390: 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 T5 390: when should the timing belt pulleys be replaced?

Pulleys should be evaluated if the tooth grooves are worn, sharp, crooked or damaged. A new belt on worn pulleys may have poor load distribution and short life. Also check flanges for bars and side contact and the grooves for foreign objects.

Conti Synchroflex T5 390: 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.

Conclusion

In summary, this is a Conti Synchroflex PU timing belt with a fixed geometry of 5 mm pitch, 78 teeth and 390 mm pitch length. The width is selected separately, but does not change the length or number of teeth. A safe replacement requires that the entire designation and the specific version match the machine documentation.