What does self-locking lead screw technology mean? How do I install a flange lead screw nut? What is the maximum load a polymer lead screw nut can take? Can the bearing clearance of my application be reduced or even eliminated? And do I have to lubricate my lead screw drives?
Question after question - and we provide the answers! Here you will find a summary of all questions about lead screw technology, sorted by topic and answered in detail. Immerse yourself in the world of lead screw technology and let us convince you of the advantages of our dryspin technology.
► What does the dryspin high helix thread product range offer?
It offers a wide range of different lead screw nuts and lead screw models in various dimensions. The range of dryspin® high helix threads includes diameters from 4 to 20mm and pitches from 2.4 to 100mm. Due to the diversity of the product range, the dryspin thread geometry is conceivable in almost all applications.
► Can drylin sliding lead screw drives replace conventional ball screw drives?
Basically, yes. It is necessary to adhere to the application parameters (axial load, rotation speed, etc.) and reach the required positioning accuracy. Our lead screw drive expert offers optimal help for choosing the perfect lead screw system for every application.
► What are the advantages of dryspin technology compared to conventional lead screw drives?
Low-noise and low-vibration operation
Longer service life due to asymmetry
► How much can I save with my dryspin lead screw drives?
Our drylin lead screw nuts are up to 50.9% more cost-effective than metal lead screw nuts.
► What does self-locking lead screw technology mean?
Self-locking means that lead screw nuts and lead screws cannot be moved without the application of external force. It has to do with the pitch and coefficient of friction.
► In what temperature ranges can dryspin lead screw drives be used?
Lead screw nuts that are made of tribologically optimised iglidur® materials can be used in temperature ranges between -20°C and +150°C.
► Which lead screw support does igus offer for the dryspin lead screw technology?
Our lead screw support blocks are available in thread sizes of 6-24mm. Choice of mounting: plain bearings or, with higher dynamics, ball bearings (BB). All lead screw support blocks, like the matching lead screw clamp rings, are supplied in hard anodised aluminium.
► How do I prevent unwanted bearing clearance?
In addition to the correct choice of material for the lead screw nut, a preload mechanism against unwanted bearing clearance has proven to be an effective measure in practice. For trapezoidal threads and dryspin® high helix threads, anti backlash, zero backlash & low clearance versions with preload of the thread nut are available.
► Should igus lead screw drives be lubricated?
It is not necessary to provide external lubrication for the lead screw drives. All of the materials we use have been tribologically optimised and designed for dry running. If you should want to lubricate, however, you can do so in combination with a silicon-free lubricant.
► How much load can a plain lead screw nut withstand?
The special type of the JGRM threaded nut, in combination with a stainless steel plate, allows the accommodation of static loads of up to 6 MPa.
► What do I have to consider when installing a flange lead screw nut?
The most important thing to remember when installing a polymer flange lead screw nut is not to exceed the maximum tightening torque of 2.5Nm. It is also recommended to secure the fastening screws with a third medium, e.g. a semi permanent thread locking glue.
► What is the difference between single and multi-start threads?
Single-start lead screws consist of only one thread. This means that the distance between the flanks, marked by pitch, is also the linear travel (lead) in millimetres per revolution of the lead screw.
If another thread is added, the lead screw reaches twice the stroke (2x pitch) with one revolution. The calculation for the linear travel always remains the same depending on the number of threads, only the pitch of a single thread differs. This procedure can also be applied to our multi-start dryspin® high helix lead screws.
► What materials are dryspin lead screw nuts available in?
Our lead screw nuts are available in 6 different materials: iglidur J, iglidur 350, iglidur R, iglidur A180, iglidur J200 and iglidur E7. The differences and advantages of the individual materials can be found here:
► Surface pressure
|iglidur® J||4 MPa|
|iglidur® W300||5 MPa|
|iglidur® A180||3,5 MPa|
|iglidur® J350||2 MPa|
|iglidur® E7||0,5 MPa|
|iglidur® J200||2 MPa|
► What is the manufacturing tolerance?
Apart from the pitch accuracy of 0.1 to 300mm, customer-specific tolerances are implemented in the end machining of the lead screws and the machining of nuts.
► Required effective support surface:
Ae = Faxial / ppermitted [mm2]
pv = preal x v
► Surface speed
v = nxd1xπ/60,000[m/s]
n = vx1,000x60/πxd1 [1/min]
► Feed rate:
► Drive torque:
Mta= Faxial x p/2000 x π x η
Mte= Faxial x p x η/2000 x π
► How do I calculate the load capacity of a trapezoidal thread?
The load capacity of trapezoidal lead screw nuts made of high-performance polymers depends on the surface pressure, the sliding speed and the resulting temperature. The temperature behaviour is also influenced by the operating time and the selected lead screw material and its specific thermal conductivity.
Surface speeds of the iglidur® materials in m/s:
► Max. permissible pv value
With the pv value and the percentage contact area stated in the dimensions tables, the permissible sliding speed and from it the feed speed for each thread size can be determined.
Standard values when using drylin® polymer nuts without lubrication (with 500mm stroke). A correction factor must be reckoned for very short or long strokes.
|Operating time ED||pv-valuemax.[MPaxm/s]|
|Ppermitted||Max. permitted surface pressure 5N/mm2|
|preal||Actually occurring surface pressure|
for the selected size
|Ae real||Effective support surface of the selected|
trapezoidal lead screw nut
|Mta||Drive torque [Nm] when converting a rotation -|
into a longitudinal movement
|Mte||Drive torque [Nm] when converting a longitudinal movement |
into a rotary movement
|v||Surface speed [m/s]|
|Øs||Feed rate [m/s]|
► Selection of the desired thread size and determination of the actual surface pressure:
preal = Faxial / Ae real [MPa]
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