Techdrives precision universal joints are designed to connect machine parts with high misalignment and shaft sizes from 6 to 50mm. Single, double and telescopic versions are available. Universal joints for low speed running use plain bearings, whilst for higher speeds needle bearings are recommended.
The slower the speed, the better suited are types with plain bearings, ie. types G,GD & GA. These are better able to withstand torque peaks and reversals. Above 1000 r/min select models with needle roller bearings, types H, HD & HA.
For arduous applications below 1000r/min consider the types S and SA which have rubbing parts with matched hardness. Details are in the catalogue.
2. Do output speeds match input speeds?
A single joint running at an angle will give an output speed fluctuation 4 times per revolution. Sometimes this is not important, for example hand winding. To achieve a smooth output speed you need a second joint installed so that the running angle of each joint is equal. Alternatively use a double joint.
3. WHAT ABOUT LUBRICATION?
Universal joints with plain bearings will need lubrication (unless intermittent running at low speeds). This is normally achieved by adding grease filled rubber gaiters. Joints with needle roller bearings do not need lubrication or gaiters.
4. HOW ARE UNIVERSAL JOINTS INSTALLED?
If two single joints are used, it is important to align the knuckles of the joints. Also to achieve a smooth output speed, the running angles of both joints should be equal.
5. HOW DO I FIX UNIVERSAL JOINTS TO THE SHAFTS?
Pinning is the most common and economic method as it accepts both torque and axial loads. Keyways are possible, but additional axial fixing is needed. A number of special options are available on request, for example square or splined bores, quick release hubs.
6. WHAT ARE THE ADVANTAGES OF TELESCOPIC UNIVERSAL JOINTS?
Telescopic universal joints are not suitable for cases where the centre distance moves during running - they are inclined to lock due to torque and friction. Instead they suit machines where horizontal or vertical adjustment is needed between sections and the adjustment is made when not running.
7. WHICH STANDARDS APPLY TO UNIVERSAL JOINTS?
The most common standard is DIN808 which defines the external dimensions in metric units. There is an older standard with imperial dimensions from the UK. DIN808/7551. This results in joints that typically have a smaller outside diameter and are longer. Models are available on request.