During the operation of construction machinery, hydraulic cylinder assemblies, automated transplant swing mechanisms and agricultural machinery hinge points, hinge parts continuously bear combined radial loads. Meanwhile, angular deflection and micro swing are required to compensate coaxial errors caused by assembly. Conventional rolling bearings cannot adapt to large-amplitude swing and angular offset conditions, which easily lead to jamming and damage from stress concentration. Ordinary metal sliding bearings need continuous grease replenishment. Lubrication maintenance becomes difficult under outdoor open-air working conditions, and dust, mud and water easily invade friction surfaces and cause rapid wear. Hydraulic transmission and construction machinery industries are in urgent demand for high-performance radial spherical plain bearings with self-aligning capacity and optional maintenance-free solutions.

A large number of outdoor equipment operates long-term under harsh environments mixed with dust, moisture and mud. Hinge support points of equipment swing back and forth frequently at low speed while bearing prominent impact loads. Without self-aligning capability, coaxial deviation generated by frame machining and assembly will continuously create local high pressure, resulting in surface scratch wear within a short period. Frequent shutdown for lubrication will reduce operation efficiency of construction equipment, and regular maintenance is hard to implement in many field construction scenarios. Basic spherical plain bearings available on the market feature limited wear resistance and lack reliable self-lubricating liner structures, failing to meet the demand of long-duration continuous operation. Various construction machinery and hydraulic systems urgently require high-quality radial spherical plain bearings.

NMT Radial Spherical Plain Bearings consist of an inner ring with convex spherical surface and an outer ring with concave spherical surface. The inner ring can tilt and swing at multiple angles relative to the outer ring with excellent self-aligning performance, effectively compensating coaxial errors induced by assembly deviation and force deformation. Inner and outer spherical surfaces are precisely machined for stable precision of matching friction surfaces. Self-lubricating versions are embedded with wear-resistant polymer liners, enabling maintenance-free operation without continuous oil supply. The bearings feature strong load capacity and can steadily withstand combined radial and axial impact loads, adapting to low-speed swing and reciprocating deflection conditions. Multiple structural versions including open type and closed type are available. Closed types can effectively prevent dust, mud and water from invading friction pairs with enhanced protection performance. Overall dimensions comply with universal industrial standards for convenient replacement during renovation of new and old construction machinery and hydraulic assemblies, supporting two operation modes: dry friction self-lubrication and grease lubrication.

Inner and outer rings are manufactured from high-strength alloy steel. Precision forging optimizes internal metallographic structure and improves compression resistance and impact resistance of spherical surfaces. All metal components are strengthened via heat treatment with uniform surface hardness to resist surface indentation damage caused by impact loads. Fine grinding is carried out on spherical friction surfaces to lower initial operating friction resistance. Self-lubricating liners adopt high-wear-resistant composite materials with strong adhesion to avoid falling off and maintain low-friction operation persistently. Optimized sealing design and dust barriers are equipped on closed products to adapt to open-air work environments with pollutants.

The bearings cover comprehensive specifications with favorable interchangeability. Widely used in hinge points of excavators and loaders, trunnion connections of hydraulic cylinders, swing modules of automation equipment, connecting rod mechanisms of agricultural machinery, suspension hinges of special vehicles and swing support points of metallurgical fixtures, meeting demands of self-aligning swing and heavy-load support for all kinds of hinge structures.

Core Product Advantages

Spherical matching structure enables wide-range self-aligning capacity to compensate assembly error and force deformation and prevent bearing jamming;

Heavy-load design withstands combined radial and axial loads and tolerates instantaneous impact loads during operation;

Optional self-lubricating liners eliminate regular refueling maintenance and greatly cut daily maintenance workload of outdoor equipment;

Open and closed structures are available. Closed types block dust and mud and adapt to harsh field working environments;

Precisely ground spherical friction surfaces deliver stable starting friction and avoid creeping jamming during low-speed reciprocating swing;

High-strength forged steel inner and outer rings resist extrusion and impact, preventing surface indentation under long-term alternating loads;

Mature matching of friction pair materials ensures lasting wear resistance and reduces replacement frequency of hinge components;

Standardized overall dimensions with good general interchangeability. No rework on mounting seats is required for renovation of hydraulic cylinders and construction machinery.

Typical Application Scenarios

Connecting rod hinge points of excavators, loaders and other construction machinery; ear ring and piston rod hinge parts of all types of hydraulic cylinders; transplant swing mechanisms and turnover fixtures of automated production lines; transmission connecting rods of harvesters, tractors and other agricultural machinery; suspension and steering hinge points of special engineering vehicles; fixture and turnover workbench swing support points of metallurgical equipment; hinge assemblies of sanitation machinery and aerial work platforms.

Quality Assurance

NMT Radial Spherical Plain Bearings are produced with premium alloy structural steel raw materials. Incoming materials complete composition inspection and metallographic sampling to strictly control steel purity. Inner and outer ring blanks are formed via precision hot forging to optimize metal flow distribution and enhance comprehensive mechanical performance of spherical load-bearing areas. Stress relief annealing is implemented after rough machining to eliminate internal stress generated by forging and cutting and guarantee long-term dimensional stability of workpieces. Multi-stage precision grinding is adopted on spherical matching surfaces to strictly control spherical roundness and surface finish and reduce operation wear.

All components pass flaw detection screening to remove workpieces with cracks and collision defects. High-temperature pressing process is applied to self-lubricating liners to ensure tight bonding with outer rings and prevent displacement and falling during operation. Components are cleaned and dried before assembly. Finished products complete swing durability tests, ultimate pressure tests and dust-proof simulation tests. All unqualified products are eliminated thoroughly to guarantee consistent quality of bulk goods and supply stable self-aligning sliding support solutions for all kinds of hinge transmission structures.

Product Range

Open radial spherical plain bearings, closed self-lubricating radial spherical plain bearings. Selection depends on operating environment, lubrication conditions and load types.

Brand Strength

NMT specializes in R&D and manufacturing of hinged sliding bearings. Targeting common industry pain points of construction machinery and hydraulic systems including harsh outdoor operating environments, complicated swing loads at hinge positions and difficult maintenance, NMT continuously optimizes precision spherical machining technology and composite material formula of self-lubricating liners. The bearings effectively solve typical problems of traditional hinge bearings such as surface scratch, frequent maintenance requirement and insufficient impact resistance, extend replacement cycles of components for construction machinery and hydraulic equipment and lower operation and maintenance costs of outdoor machinery.