As the core component of mechanical transmission system, bushing bearing plays a key role in the fields of automobile, aerospace, industrial equipment, etc. Its name is diversified due to differences in application scenarios, material properties and structural design, which often confuses buyers and engineers. Based on industry standards, patent analysis and international certification system, this article systematically sorts out the 7 major professional terms of bushing bearings, reveals its technical essence and market trends, and provides decision-making references for participants in the industrial chain.
Table of Contents
1. Industry Background and Naming Standards
2. Analysis of 7 Professional Terms of Bushing Bearings
2.1 Sleeve Bushing
2.2 Plain Bearing
2.3 Liner Bearing
2.4 Oil-Free Bearing
2.5 Sintered Bearing
2.6 Composite Bearing
2.7 Spherical Bushing
3. Technical Roots of Naming Differences
4. Industry Pain Points and Future Trends
1. Industry Background and Naming Standards
Bushing bearings achieve rotation or reciprocating motion support through sliding friction. The global market size is expected to reach US$38 billion in 2025, with a compound annual growth rate of 6.8%. Its naming system is affected by the following factors:
Material properties: different terms for metal-based, polymer-based, and ceramic-based materials
Lubrication method: oil-containing, solid lubrication, and self-lubricating classification
Structural design: integral, split, flanged, and other form differences
Application scenarios: customized needs of automobiles, ships, and medical machinery
International standard ISO 12300 classifies them as "sliding bearings", but there are still diverse naming habits in industry practice. For example, in automobile engines, bushing bearings are often called "bearings", while "sleeves" or "liner bearings" are mostly used in industrial equipment.
2. Analysis of 7 professional terms for bushing bearings
1. Sleeve Bushing
Technical definition: a cylindrical hollow part that is sleeved on a shaft to reduce friction.
Material type:
Metal: copper alloy (Rongchang BZP), aluminum alloy (7075-T6)
Non-metal: PTFE (polytetrafluoroethylene), UHMWPE (ultra-high molecular weight polyethylene)
Application scenarios:
Automobile wiper drive shaft (load ≤ 50MPa)
Industrial robot joint (lifespan > 100,000 hours)
Naming controversy: easily confused with "bearing", the latter specifically refers to the split structure.
2. Plain Bearing
Technical definition: friction pair without rolling elements, including bushings, bearings, thrust pads, etc.
Classification standard:
By lubrication method: fluid lubrication (dynamic pressure/static pressure), boundary lubrication
By load direction: radial bearing, thrust bearing
Typical products:
Main bearing of marine diesel engine (load>200MPa)
Gearbox bearing of wind turbine (temperature resistance -40℃~+120℃)
Standard basis: ISO 12300-2015 "Terms, definitions and classification of sliding bearings"
3. Liner Bearing
Technical definition: anti-friction layer embedded in the shell, thickness is usually <3mm.
Core technology:
Bimetallic composite process: steel back + copper-lead alloy layer (ASTM B297 standard)
Surface treatment: lead plating, molybdenum spraying to improve anti-seizure performance
Application areas:
Internal combustion engine cylinder liner (wear resistance up to 1000 hours)
Hydraulic cylinder seal (pressure resistance>35MPa)
Performance limitations: metal-to-metal adhesive wear is prone to occur at high temperatures.
4. Oil-Free Bearing
Technical definition: No external oil supply system is required, and it relies on self-lubricating materials to operate.
Material system:
Solid lubricant: molybdenum disulfide (MoS₂), graphite
Oil-containing bearing: sintered bronze (oil content 15-25%)
Certification standard:
ISO 13715 "Sliding bearings Metal bearing materials Composition and performance"
JIS K6250 "Sintered metal materials for self-lubricating bearings"
Typical cases:
Food machinery conveyor belt bearings (FDA certified)
Bearings for vacuum environments (gas outflow rate <1×10⁻⁹ Pa・m³/s)
5. Sintered Bearing
Technical definition: Porous oil-containing bearings manufactured by powder metallurgy process.
Process parameters:
Sintering temperature: 850-900℃ for copper-based materials, 1100-1150℃ for iron-based materials
Porosity control: 18-30% (affects oil storage capacity)
Performance advantages:
Low cost (40% lower than the price of machined bearings)
Long self-lubricating cycle (5000 hours of operation after first refueling)
Application limitations: Not suitable for high impact load scenarios.
6. Composite Bearing
Technical definition: Multilayer structural bearing composed of two or more materials.
Typical structure:
Steel back - sintered copper layer - PTFE / fiber reinforcement layer (such as GGB BC series)
Aluminum alloy - graphene coating (thermal conductivity increased by 3 times)
Performance breakthrough:
Load capacity: ＞800MPa (2 times higher than traditional materials)
Friction coefficient: 0.03-0.05 (dry friction state)
Technical challenge: Insufficient interface bonding strength leads to delamination failure.
7. Spherical Bushing
Technical definition: Spherical sliding bearing that allows angular displacement between two axes.
Structural design:
Inner ring convex spherical surface + outer ring concave spherical surface (clearance control 0.01-0.05mm)
Self-aligning range: ±15°
Material selection:
Hardened steel (HRC58-62)
Engineering plastics (POM, PA66)
Application scenarios:
Building machinery crane arm (swing frequency > 10Hz)
Medical device joints (high biocompatibility requirements)
3.Technical roots of naming differences
Material innovation drive:
Carbon-ceramic composite materials (C/C-SiC) give birth to the new term "high-temperature bearing"
Bio-based materials (PLA) promote the popularization of the concept of "environmentally friendly bearings"
Process technology iteration:
3D printing technology realizes "porous structure bearings"
Laser surface alloying technology derives "reinforced bearings"
Application scenario segmentation:
"Precision bushings" are used in the aerospace field
The automotive industry adopts "Engine bearing"
4.Industry pain points and future trends
Existing problems:
Inconsistent standards: Domestic companies are very arbitrary in naming, which increases the communication cost of the supply chain
Lack of testing methods: There is a lack of life assessment standards for composite bearings
Environmental pressure: Traditional oil-containing bearings have high energy consumption in production (sintering process consumes 300kWh/ton)
Technology trends:
Intelligent: integrated sensors monitor temperature and wear status (such as SKF's Explorer series)
Lightweight: Carbon fiber reinforced polymer (CFRP) reduces weight by 60%
Green manufacturing: Water-based sintering technology reduces energy consumption by 40%
5.Summary and purchase recommendations
The diverse naming of bushing bearings reflects the rapid evolution of industry technology. Things to pay attention to when purchasing:
Performance parameters: load capacity (>300MPa), operating temperature (-40℃~+400℃)
Certification qualifications: ISO 13715 (material standard), AS9100D (aerospace certification)
Environmental indicators: carbon footprint (recommended <1.5kg CO₂/piece), recyclability
In the future, with the advancement of localization of new energy vehicles and high-end equipment, bushing bearings will develop in the direction of "high load, long life, and intelligence". It is recommended that enterprises in the industrial chain strengthen cross-industry collaboration, promote naming standardization and unified testing methods, so as to enhance China's voice in the global supply chain.