JDB Solid lubricating bearingsProduct description
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EPT Plastic bearings
Universal strongest plastic bearings, to meet the operating temperature of 80 or less most of the workplace.
1: continuous use temperature: -40 ℃ ~ + 80 ℃;
2: Universal strong for use in low-load situations most;
3: Suitable for dry running, maintenance-free, corrosion-resistant;
4: minimize the damage to the shaft;
5: Very low coefficient of sliding friction.
Material Properties Table
| Material Properties Table | |||
| Common Capability | Unit | EPT | Testing Method |
| Density | g/cm³ | 1.46 | |
| Color | Black gray | ||
| Max.water absorption,23℃/ 50% | [%weight] | 0.2 | DIN 53495 |
| Max.water absorption | [%weight] | ＜1.2 | |
| Dynamic friction /steel | μ | 0.05-0.15 | |
| Max.PV（dry） | MPa•m/s | 0.4 | |
| Mechanical behavior | |||
| E-module | MPa | 2,300 | DIN 53457 |
| Tensile strength,20℃ | MPa | 80 | DIN 53452 |
| Compressive strength | MPa | 65 | |
| Max.static pressure of the surface,20℃ | MPa | 35 | |
| Shore D hardness | 70 | DIN 53505 | |
| Physical and thermal properties | |||
| Continuous work tempreature | ℃ | +80 | |
| short-time work tempreature | ℃ | +120 | |
| Minimum operating temperature | ℃ | -40 | |
| Thermal conductivity | W/m•K | 0.2 | ASTM C 177Lin |
| Thermal expansion,23℃ | K | 7 | DIN 53752 |
| Conductive propertiesK-1•10-5 | |||
| Volume resisticity | Ωcm | ＞1012 | DIN IEC 93 |
| Surface resisticity | Ω | ＞1015 | DIN 53482 |
PV Value of Bearings
The max PV value of the EPT series bearing is 0.4N/mm2*m/s which detemines the load capacity of bearing is inversely proportional to the speed. Please refer to the chare for more detailed information (Graph EPT-1).
The Relation of Load,Speed and Temperature
EPT allows the max static load of 35Mpa, The max compressive deformation rate under the max load is listed in Graph EPT-2; The actual load capaxity of bearing is slightly less than 35Mpa, The bearing load is variable against the speed and temperature, Fast speed( Vmax: 1.0m/s) results into higher temperture(Tmax: 80℃) which decreases the load capacity of the bearing. Please refer to the Graph EPT-3 for such variation.
Friction Factor
EPT friction factor is not sensitive to the operation speed and bearing loading(see Graph EPT-4 and Graph EPT-5). The above features are the most common considerations for the bearing material selection.The friction of EPT could be maintained at a relatively lower lebel so that the good wearing features are guaranteed.From the Graph EPT-6, we could see that the friction factor is variable against the changing of shaft roughness. The recommended shaft roughness is Ra0.3~0.5.
| EPT | Dry | Grease | Oil | Water |
| Friction coefficient μ | 0.05~0.15 | 0.09 | 0.04 | 0.04 |
Wearing and shaft material
The shaft material is an important media for the bearing wearing but EPT is suitable for almost all kinds of shaft materials. Graph EPT-7 and Graph EPT-8 show that the wearing feature of EPT is excellent when the shaft material are hardened chrome steel or hardened steel or hardened Aluminum.
Chemical Resistance
EPT is good at chemical resistance against mild base, weak acidic medium and various kinds of lubricants.
Water Absorbability
The water absorb rate of EPT is 0.2% under the atmospheric pressure while it is 1.2% when the material is immerged into water. With its low water absorbability, the material is suitable for humid environment applications.
UV Resistance
EPT can maintain its color unchanged when it is exposed into the UV ray. The hardness, Compressive strength and wear resistance of the material is also stable under such condition.
Bearing Installation
EPT series bearings with the tolerance
| d mm² | Tolerance after fit E10 | Fit Housing H7 | Fit Shaft h9 |
| ＞0~3 | +0.014~+0.054 | 0~+0.010 | 0~-0.025 |
| ＞3~6 | +0.020~+0.068 | 0~+0.012 | 0~-0.030 |
| ＞6~10 | +0.025~+0.083 | 0~+0.015 | 0~-0.036 |
| ＞10~18 | +0.032~+0.102 | 0~+0.018 | 0~-0.043 |
| ＞18~30 | +0.040~+0.124 | 0~+0.021 | 0~-0.052 |
| ＞30~50 | +0.050~+0.150 | 0~+0.025 | 0~-0.062 |
| ＞50~80 | +0.060~+0.180 | 0~+0.030 | 0~-0.074 |
| ＞80~120 | +0.072~+0.212 | 0~+0.035 | 0~-0.087 |
| ＞120~180 | +0.085~+0.245 | 0~+0.040 | 0~-0.100 |
