Composite Dry Sliding Bearings
The composite dry sliding sleeve is a dry sliding (journal) plain bearing for bearing with
radial load, requiring only a small radial space. Such bushings allow reciporating or ratational
movement. Suitable for maintenance-free applications or where lubricant deficiencies may occur.
There are two standard designs for composite bushings, except for the components of the sliding layer: composite B/E bushings and composite M-bushings.
B material has a layer of copper-plated steel backing (bearing wall thickness of 2 mm
(inclusive)), above the sintered 0.2 to 0.4 mm thick tin bronze porous layer. Bearing wall thicker
bearings, the backing is not copper. The mixture of PTFE (polytetrafluoroethylene) and other
additives capable of reducing the friction is filled into the pores on the sintered layer by a
pressing process. This layer of sintered copper is covered with a 5 to 30 mm thick, abrasive layer
made of the same mixture. The bearings made with B/E material provide the best combination of
the mechanical properties of sintered copper with the excellent sliding and lubricating
properties of the PTFE mixture. This combination ensures good dimensional stabllity and thermal
M material also has steel backing (wall thickness of 2 mm (inclusive) bearing copper
plating) and 0.2 to 0.4 mm thick sintered tin bronze layer. Tha main feature of this tyoe of
bearing is that its acetal resin (POM) coating is relatively thick (0.3 mm), tightly fixed on the
sintered copper layer. The cover layer has a roller groove for lubricating grease. As the cover
is thick, even if there is a certain degree of misalignment and not related to the edge of the
load, the bearing is not vulnerable.
The composite dry slide sleeve is rolled so that the butt joint extends beyond the width of
the entire sleeve. The roller sleeve made of M material is designed with a roller groove for
grease. All free surfaces of the backing plate are electrolytic tinned.
Made of M material composite dry sliding sleeve, where the diameter of 10 mm (inclusive), the
width of not less than 12 mm standard products, are equipped with a lubrication hole. The hole
is centrally located at 45.5 degrees from the butt joint.
The dimensions of metric composite dry sliding sleeves with diameters ranging from 4 to 160
mm are included in ISO 3547-1976 and 1983 DIN 1494 part 1, with a dew exceptions. The size of the
imperial hsaft has not yet been standardized.
The outer diameter tolerance of the metric composite dry sliding sleeveis in accordance with
the provisions of DIN 1494 Part of 1983. When checking the values, the steps specified in the DIN
version of DIN 1494, Part 2 should be used.
Allowable operating temperature range:
B/E composite bushings can be used at temperatures between -200 ℃ and +250 ℃. M composite
bushings range from -40 degree centigrade to +110 degrees Celsius, although they can work briefly
at +130 degrees Celsius.
During the brief run-in period, some of the material on the cover (PTFE) of the B/E composite
bushing will be transferred to the opposite sliding surface. After the transfer occurs, you can
get low friction and wear characteristics.
The sleeve made of M material has an insulating effect because it is an acetal resin. In
order to avoid static accumulation, there are dangerous parts of electrostatic accumulation
should be grounded.