Engineering Data of All plastic Polymer Rod Ends

Special properties of LDK all plastic Rod End Bearings

• Body and ball made of special plastic polymer (Patent ZL 2009 2 0031919.1)

• Maintenance free,self lubricating

• High  strength  under  impact  loads.

• High  tensile  strength  for  varying  loads.

• Compensation  for  alignment  errors.

• Resistant to dirt and dust.

• Resistant  to  corrosion  of  chemicals.

• High  vibration  dampening  capacity.

• Suitable for rotating,oscillating and linear movements.

• Very low weight.

Application Temperatures

LDK bearing elements can be used in temperatures from -30℃ to+80℃. Table1 shows the effect of temperature on the loading capacity of the LDK bearing elements.

Table 1: Applications temperatures

Chemical Resistance

The moisture absorption of LDK is appro- ximately 1.3% of weight  standard  atmos- phere.The saturation limit in water is 6.5%. This must betaken into account for these types   of   applications.LDK   all   plastic polymer are  resistant  to weak  alkalines, weak acids and fuels,as well as all types of lubricants.

Table 2: Chemical resistance

UV Resistance

The corrosion resistance of the LDK bearings give them special value for outside applications

LDK  bearing  elements  are  permanently resistant to UV radiation.A small change in colour (dark coloration)of the spherical ball due to UV radiation does not effect the mechanical,electrical or thermal properties.

Loads

The load capacity of the maintenance free LDK bearing elements is very high at normal ambient  temperatures.LDK bearing elements absorb high forces and weigh only a fifth of traditional, metal bearing housings. The excellent dampening properties are based on the fact that the polymer material of the two part bearing can absorb vibrations differently than steel.

Table 3:Effect of the speed of load application on the maximum tensile strength of LDK rod end bearings

However, plastic specific properties, such as dependence on temperature and behaviour under long term stress, must betaken into consideration when using LDK bearings. The load capacity of the rod end bearing should therefore be checked in a performance test, particularly if they are to be used under continuous high loads and at elevated temperatures.

Table 4: Effect of the temperature on the maximum tensile strength of LDK rod end bearings

Coefficients of Sliding Friction and Speed

One important advantage of LDK spherical bearings is that rapid, rotary movements of a  mounted shaft take place directly in the spherical  portion, made of special  plastic polymer. In metallic rod ends, rotary motion takes place between the race and the spherical bearing. High speeds can be achieved with LDK bearings.

LDK bearings area used in such a way that the angular movements of the spherical bearings takes place at the outer diameter in contrast, rotations of the shaft are supported directly in the I.D. of the spherical portion. The advantage,therefore,lies in the  polymer vs.steel relationship. Polymer produces lower friction and permits high speeds, even when running dry.

Table 5: Thread pitches of the LDK rod end bearings

Structure for Part Numbers for LDK Rod End Bearings

The part numbers of LDK rod  end  bearings are designed according to the following system:

The example given is the number for a rod end bearing of the dimensional series PK with metric female right hand thread.The inner diameter of the spherical ball is 10mm.