Please choose your delivery location

The selection of the country/region page can influence various factors such as price, shipping options and product availability.
Inquiry / Contact
igus® Canada

180 Bass Pro Mills Drive

Concord

Ontario L4K 0G9

+1 (800) 965-2496
+1 905 760-8688
CA(EN)

iglide® plastic bushings - p x v value and lubrication


Table 1.3: Heat conductivity values of shaft or housing materials

Material Thermal Conductivity [W/m x k]
Steel 46
Aluminum 204
Cast iron 58
V2A 16
Ceramic 1,4
Plastic 0,24


plastic bushing correction factor Figure 1.9: Correction factor for the p x v value
Plastic bushing research Picture 1.9: Testing the properties of plastic bushings

Table 1.4: Adjustment of the permitted p x v value through lubrication

Lubrication Correction factor
Dry operation 1
In the installation 1.3
Persistent, fat 2
Persistent, water 4
Persistent, oil 5

p x v value

For plastic bushings, the product is given a new value depending on the specific load (p) and the surface speed (v). The p x v value can be considered a measure of the frictional heat and can be used as an analytical tool to answer questions concerning the proper application of a plastic bushing. For this purpose, the actual p x v value is a function of the shaft material of the ambient temperature and the operating time.

Permitted p x v value

Permitted p x v value
Present is
K1, K2 Constant for heat dissipation
  (K1 = 0.5, K2 = 0.042)
s Plastic bushing wall thickness (inch)
b1 Plastic bushing length (inch)
μ Coefficient of friction
λs Heat conductivity of the shaft
λk Heat conductivity of the plastic bushing
ΔT (Ta - T u)
Tu Ambient temperature
Ta Max. ambient temperature

Correction factor

The tolerated p x v value can be increased in intermittent operation if the plastic bushing temperature never reaches its maximum limit because of the short operating times. Tests have shown that this is true for operating times below 10 minutes. An important qualifier here is the ratio of the operating time and pause intervals. Long pauses make a greater contribution to re-cooling.
The different curves in Figure 1.9 represent different ratios ("3 times" means that the pause lasts 3 times longer than the operating time).

Lubrication

Although iglide® plastic bushings are designed to run dry, they are compatible with standard lubricants. A single lubrication during installation improves the start-up behavior and coefficient of friction, thus reducing the frictional heat. The permissible loads for plastic bushings can also be increased by using lubrication. Table 1.4 shows the correction factors for the p x v value when using lubrication.


Next chapter



The terms "igus", "Apiro", "chainflex", "CFRIP", "conprotect", "CTD", "drylin", "dry-tech", "dryspin", "easy chain", "e-chain", "e-chain systems", "e-ketten", "e-kettensysteme", "e-skin", "e-spool", "flizz", "ibow", "igear", "iglidur", "igubal", "kineKIT", "manus", "motion plastics", "pikchain", "plastics for longer life", "readychain", "readycable", "ReBeL", "speedigus", "triflex", "robolink", "xirodur", and "xiros" are legally protected trademarks of the igus® GmbH/ Cologne in the Federal Republic of Germany and where applicable in some foreign countries.

igus® GmbH points out that it does not sell any products of the companies Allen Bradley, B&R, Baumüller, Beckhoff, Lahr, Control Techniques, Danaher Motion, ELAU, FAGOR, FANUC, Festo, Heidenhain, Jetter, Lenze, LinMot, LTi DRiVES, Mitsibushi, NUM,Parker, Bosch Rexroth, SEW, Siemens, Stöber and all other drive manufacturers mention in this website. The products offered by igus® are those of igus® GmbH