Timing Belt Stress Analysis
The HTD and STD timing belt tooth profiles are analyzed in the below pictures and videos for their individual performance in various timing belt pulley tooth profiles. Stress analysis tests were performed with matching timing belt tooth profiles and dissimilar (non-matching) timing belt tooth profiles. The stress analysis performed on the dissimilar timing belt and timing belt pulley profiles reflects real world circumstances where mismatched replacement of timing belts often happens.
Pfeifer Industries will be the first one to tell you that “yes various timing belt tooth profiles with the same pitches will fit into one another.” However, there are strong reasons why you should only use matching timing belt tooth profiles together and not interchange them.
Problems commonly seen by mixing timing belt tooth profiles include:
- Safety
- Significantly shortened timing belt life (identified in the below pictures)
- Loss of precision registration
- Increased noise
- Harsh vibration
- Timing belt tooth ratcheting
- Timing belt tooth delamination
- Increase of operating temperatures within the drive system
The stress analysis identified on the below pictures is broken down into RED being extremely severe and BLUE being within operating specifications.
HTD Timing Belt Tooth Profile Stress Analysis
HTD timing belt tooth profile operating in various timing belt pulley profile configurations.
HTD Timing Belt in a HTD Timing Belt Pulley Stress Analysis
Considerations:
- HTD timing belt tooth profile depth is greater than the STD timing belt tooth profile allowing for higher horsepower ratings.
The stress analysis identified on the below picture is broken down into RED being extremely severe and BLUE being within operating specifications.
HTD Timing Belt in a PowerGrip GT2 Timing Belt Pulley Stress Analysis
Considerations:
- HTD timing belt tooth profile fits snuggly in the PowerGrip GT2 timing belt tooth profile pulley. Clearance values between the timing belt and the timing belt pulley are tight resulting in stresses on the tensile cords.
The stress analysis identified on the below picture is broken down into RED being extremely severe and BLUE being within operating specifications.
HTD Timing Belt in a PolyChain GT Timing Belt Pulley Stress Analysis
Considerations:
- HTD timing belt tooth profile is too large for the PolyChain GT timing belt tooth profile. Resulting in poor engagement and disengagement of the meshing teeth causing high interference and associated loss of efficiency due to friction. Precision registration is also severely affected.
The stress analysis identified on the below picture is broken down into RED being extremely severe and BLUE being within operating specifications.
STD Timing Belt Tooth Profile Stress Analysis
STD timing belt tooth profile operating in various timing belt pulley configurations.
STD Timing Belt in a STD Timing Belt Pulley Stress Analysis
Considerations:
- STD timing belt tooth profile runs noticeably quieter than the HTD timing belt tooth profile (depending on RPM’s the difference can be up to 10 dB). Design of the STD timing belt tooth profile allows for air between the timing belt and timing belt pulley teeth to exit easier.
The stress analysis identified on the below picture is broken down into RED being extremely severe and BLUE being within operating specifications.
STD Timing Belt in a HTD Timing Belt Pulley Stress Analysis
Considerations:
- STD timing belt tooth profile is too small for the HTD timing belt pulley tooth profile. Resulting in poor registration and increased belt stresses.
The stress analysis identified on the below picture is broken down into RED being extremely severe and BLUE being within operating specifications.
STD Timing Belt in a PowerGrip GT2 Timing Belt Pulley Stress Analysis
Considerations:
- STD profile is too small for the PowerGrip GT2 tooth profile. Resulting in poor registration and increased belt stresses.
The stress analysis identified on the below picture is broken down into RED being extremely severe and BLUE being within operating specifications.
STD Timing Belt in a PolyChain GT Timing Belt Pulley Stress Analysis
Considerations:
- STD timing belt tooth profile is not deep enough to contact the PolyChain GT timing belt pulley tooth profile bottom. Resulting in increased belt stresses.
The stress analysis identified on the below picture is broken down into RED being extremely severe and BLUE being within operating specifications.
