In last month’s blog, we looked at the different types of torque limiters available to prevent expensive mechanical breakdown, and the benefits of fitting torque limiters to your equipment.
Made exclusively by Howdon Power Transmission since 1977, our trademarked Wedgepin torque limiter is a simple fix for the disadvantages of traditional shearpin design. Since then, it’s been used by businesses around the world to protect complex and costly equipment, and limit the associated downtime and expense of repair.
This month, we look at the advantages of the Wedgepin over the traditional shearpin.
The problem with traditional shearpins
Power transmission drives –
A shearpin is a replaceable pin that’s fitted to the equipment couplings to form the weakest link in the drive train. When the coupling hits a power overload, the shearpin breaks –
The technical bit
Shearpins usually include a centrally located annular groove that defines the point at which the pin should fail. For this to happen, the shearpin must fit within the coupling elements it connects with no clearance ・called an interference fit.
As it’s hard to achieve an interference fit with a traditional shearpin, shearpins are typically assembled with some clearance. The resultant bending that occurs mean the shearpins need to be replaced regularly as a precaution –
A failed or broken shearpin can be hard to remove from the machinery it’s intended to protect, as even the smallest twist in the coupling elements can offset the axes of the respective bores. Stepped shearpins –
Advantages of the Wedgepin
The Wedgepin is a wedge-
- Its wedge construction provides maximum strength with no backlash, making it ideal for use in indexing or reversing drives, where conventional shearpins can’t be used.
- Clever design prevents wearing of the shearpin hole, and the resultant fretting and fatigue that lead to premature breaking.
- The Wedgepin’s radial position removes load sharing uncertainty and stops the shear neck becoming skewed.
- Its design prevents the fitting of unknown shearpins such as nails or screws, which leads to improved operator safety.
The accuracy of shearpins traditionally falls within the +/-
To find out more about the Wedgepin and other Howdon engineering solutions, call our sales team on 01453 750814, email firstname.lastname@example.org, or visit www.howdon.co.uk.