Views: 0 Author: Site Editor Publish Time: 2025-03-28 Origin: Site
In the machinery world, bearings might not be the flashiest components, but they’re the unsung heroes that keep equipment moving smoothly. These bearings can guide rotating or back-and-forth motion while reducing friction. Based on the load direction they carry, the bearings sort themselves into three main types: radial bearings, thrust bearings, and composite load bearings. Let’s break it down simply. Radial bearings (such as deep groove ball bearings, etc.) specialize in withstanding radial force perpendicular to the axis. However, their axial load-carrying capacity is weak. That’s where thrust bearings come in. Thrust bearings (just like thrust ball bearings, etc.) are designed to withstand axial force parallel to the axis. Then the composite load bearings juggle radial forces, axial forces, and overturning forces. As modern machinery evolves to be both more powerful and compact, bearings are also being asked to improve performance. The bearing design requires comprehensive consideration of load direction, operating speed, and working conditions, etc. As per accurate matching between bearing performance and working conditions, the mechanical device's operation efficiency and reliability can be guaranteed under the state of cost control.
Radial bearing is one of the most common types of bearings, referring to the type of bearings that are specially designed to withstand loads perpendicular to the axial direction (i.e. radial loads). The structure of radial bearings usually includes the inner ring, outer ring, rolling bodies (balls or rollers), cage, and other major components, through the rolling bodies in the inner and outer ring raceways between the multiple points of contact, the radial load is evenly dispersed, reducing friction and wear, thereby improving the efficiency and service life of mechanical equipment. The main characteristic of radial bearing is that it can only bear radial load, axial bearing capacity is limited, if bear too large axial force may lead to raceway edge wear or even stalling.
Common types of radial bearings are as follows:
(1) Deep groove ball bearing: Simple structure, deep groove raceway, low friction, and high-speed performance.
(2) Thin-section bearing: Cross-section dimensions are smaller, light in weight, suitable for space constraints and lightweight applications.
(3) Self-aligning ball bearing: Its outer ring raceway is spherical, allowing shaft offset (self-aligning function), which can automatically compensate for mounting error or shaft bending.
(4) Spherical mounted bearing: The spherical outer ring, along with the bearing seat, has a centering effect, easy to install and adjust.
(5) Cylindrical roller bearing: Cylindrical roller as rolling elements, the roller and raceway line contact, high radial load carrying capacity, can bear impact load.
(6) Needle roller bearing: Rolling body for the slender needle, with very low radial cross-section height, with high load-carrying capacity, and sensitive to mounting errors.
(7) Spherical roller bearing: Double rows of roller + outer ring spherical structure, both having high radial load capacity and centering capability with good impact resistance.
Radial bearings are engineered to handle loads perpendicular to the shaft axis (radial loads), making them ideal for high-speed operations and heavy-duty applications. Their versatility shines across industries – here’s where you’ll commonly find them in action:
(1) Motors & Generators: Such as deep groove ball bearings and cylindrical roller bearings, etc. can offer smooth rotation and robust load capacity.
(2) Gearboxes & Drivetrain Systems: For instance, spherical roller bearings, needle roller bearings, and so on have great performance in these fields.
(3) Automotive Wheel Hubs: Deep groove ball bearings strike the perfect balance between durability and compact packaging for modern wheel hubs.
(4) Material Handling Systems: Self-aligning ball bearings, spherical mounted bearings, etc. keep conveyor lines running smoothly.
(5) Appliance Industry: Thin-section bearings, deep groove ball bearings an so on, can maximize the working efficiency in domestic electric appliance such as dishwashers, washing machines, fans, etc.
(6) Textile Machinery: Deep groove ball bearings, self-aligning ball bearing, cylindrical roller bearings, etc. play an importand roles in textile machines.
(7) Agricultural Equipment: From combine harvesters to irrigation systems, the spherical mounted bearings, needle roller bearings, and so on weather harsh and high load environments.
Thrust bearings, also known as axial bearings, are specially designed to withstand axial loads (along the axis of the direction of the force) of a class of bearings. Thrust bearings are generally composed of two or more thrust shims and a number of rolling bodies (balls or rollers), and thrust shims are generally divided into shaft and seat parts.Thrust bearings disperse the axial force evenly through the contact between the plane raceway and the rolling bodies, and are widely used in the equipment that needs to support the axial force of rotating or reciprocating motion, and its unique design can effectively reduce the friction, and improve the equipment's load carrying capacity and running stability. Thrust bearings require strict mounting accuracy, if the shaft ring and seat ring are tilted or misaligned, it will easily lead to partial load failure.
Common types of thrust bearings are as follows:
(1) Thrust ball bearing: Which composed of washers with raceways and balls, with simple structure and low cost.
(2) Thrust cylindrical roller bearing: Using cylindrical rollers, rollers and raceways for line contact, high axial load carrying capacity.
(3) Thrust tapered roller bearing: Roller for the truncated cone, can withstand axial and certain radial load.
(4) Thrust spherical roller bearing: Roller for the spherical roller, axial load carrying capacity, with automatic self-aligning ability, can compensate for installation errors and shaft deflection.
(5) Thrust needle roller bearing: Needle rollers are used as rolling bodies, high axial load carrying capacity, compact structure, and small radial volume, saving installation space.
(6) Automobile clutch main pin bearing: Usually thrust ball bearing or sliding bearing structure, mainly bearing axial force, compact design.
Thrust bearings are mainly used to carry axial load (thrust), in all kinds of mechanical equipment to reduce friction, improve efficiency, etc. The following are the main application areas of thrust bearings:
(1) Automobile transmission and clutch: Such as thrust ball bearings, automobile clutch main pin bearings, etc.
(2) Turbine engines: Such as thrust ball bearings, thrust cylindrical roller bearings, etc.
(3) Machine tool spindles: Such as thrust tapered roller bearings, thrust angular contact ball bearings, etc.
(4) Wind turbines and hydroelectric generators: Such as thrust ball bearings, thrust spherical roller bearings, etc.
(5) Ship propellers: Such as thrust spherical roller bearings, etc.
(6) Hydraulic and pump equipment: Such as thrust ball bearings, thrust needle roller bearings, etc.
(7) Textile machinery: Such as thrust needle roller bearings, etc.
Composite load bearing is a kind of bearing that can simultaneously withstand radial load (force perpendicular to the axis), axial load (force along the direction of the axis), tilting moment, and other loads. Composite load bearing through the rolling body and raceway geometry matching, the composite load will be decomposed into the bearing components that can withstand the force, so as to realize the multi-dimensional force of the synergistic bearing, taking into account the high stiffness and high reliability, suitable for complex force situation, so that the equipment operation is more stable and reliable.
General types of composite load bearings are as follows:
(1) Angular contact ball bearing: Inner and outer ring raceways of the bearings incline in relation to each other and form some contact angle (usually 15°, 25°, or 40°). The greater the contact angle, the greater the axial load that the bearing will support, usually has to be employed in pairs.
(2) Tapered roller bearing: The contact surface between the tapered rollers and the raceways is tapered, and is able to bear heavy radial and axial loads, axial load capacity is dependent on the cone angle, the larger the angle, the greater the axial load capacity, usually fitted in pairs.
(3) Thrust angular contact ball bearing: Angular contact ball bearing configuration, 60 ° ~ 90 ° contact angle, but employed particularly to withstand high axial load, at the same time have a certain radial load carrying capacity.
(4) Crossed roller bearing: Internal 90 ° cross configuration of the bearings' roller structure, between isolation block or roller spacing cage, to avoid the mutual friction roller, improve the rotational accuracy, compact structure, can bear large radial, axial, and tilting moment load simultaneously.
(5) Slewing ring bearing: Also referred to as turntable bearing, which is a type of large bearing, with inner gears or outer gears or mounting holes, structure of varied shape, can support axial load, but also can support radial load and tilting moment.
Composite load bearings are widely used in various industrial and mechanical equipment because they can simultaneously withstand radial load, axial load, and tilting moment. The following are its main application areas:
(1) Machine tool spindle: Such as angular contact ball bearings, thrust angular contact ball bearings, etc.
(2) CNC rotary tables: Such as crossed roller bearings, etc.
(3) Automobile wheel units and gearboxes: Angular contact ball bearings, tapered roller bearings, etc.
(4) Excavators and tower cranes: Such as turntable bearings, etc.
(5) Robots: Such as angular contact ball bearings, crossed roller bearings, etc.
(6) Wind turbine yaw and pitch system: Angular contact ball bearings, turntable bearings, etc.
| Item | Radial bearing | Thrust bearing |
| Direction of load | Withstand radial load (force perpendicular to the axis) | Withstand axial load (force along the direction of the axis) |
| Structural design | Inner ring, outer ring, rolling element, cage, etc. | Shaft ring, seat ring and rolling element, etc. |
| Common types | Deep groove ball bearings, cylindrical roller bearings, etc. | Thrust ball bearings, thrust roller bearings, etc. |
| Common applications | Electric motors, automobiles, pumps, gearboxes and transmissions, etc. | Ship propeller thrust supports, high-pressure pumps, turbines, centrifugal pumps and automobile differentials, etc. |
| Installation and Maintenance | Radial clearance needs to be ensured and lubrication focuses on reducing radial friction. | Precise axial positioning is required, and maintenance is concerned with axial clearance and lubricant compression resistance. |
Myth 1: Radial bearings can only withstand radial loads, and thrust bearings can only withstand axial loads.
Truth: Although radial bearings and thrust bearings are designed to give priority to a certain load direction, many bearings can withstand a certain axial load (for radial bearings) or a certain radial load (for thrust bearings). For example, some radial bearings (such as deep groove ball bearings) can support minor axial loads, while thrust bearings have been designed to handle small radial loads.
Myth 2: Composite load bearings are simply a combination of radial and thrust bearings.
Truth: Composite load bearings are not simply radial and thrust bearings stacked together, but their design is more complex, involving the arrangement of rolling elements, contact angles and other factors in order to efficiently withstand radial loads, axial loads and tilting moments at the same time.
Myth 3: Radial bearings are widely used because they are more durable than thrust bearings.
Truth: Bearing usage lifespan depends on many factors such as load, lubrication, and mounting accuracy, not bearing type. If an axial bearing is used in the right conditions, it will not be less durable than a radial bearing.
Myth 4: Thrust bearings can only be used in low-speed rotating equipment.
Truth: While conventional thrust bearings typically have low rotational speeds, certain thrust ball bearings (such as angular contact thrust ball bearings) can be used in high-speed operating environments. And modern designs (such as high-speed thrust ball bearings) have been able to accommodate higher speeds by optimizing materials and structure, although high-speed performance is still usually lower than that of radial bearings.
Myth 5: Composite bearings can completely replace radial or thrust bearings.
Truth: Composite bearings are multifunctional, but the cost is high. If only a single direction load is required, it is more economical and efficient to use radial bearings or thrust bearings directly.
(1) Can thrust bearings replace radial bearings?
No, they cannot. Thrust bearings are designed to support axial loads and their structure cannot effectively support radial loads. Forced substitution may result in abnormal wear of the rolling elements and rails, or even cause equipment failure.
(2) Can composite load bearings completely replace the combination of radial bearings and thrust bearings?
No. They cannot be completely replaced. Although composite load bearings (such as angular contact ball bearings) can bear radial and axial loads at the same time, their load carrying capacity and accuracy are limited by design. In high load or high precision scenarios, still need to optimize the performance through the combination of bearings.
(3) Are the rolling elements of thrust bearings and radial bearings interchangeable?
No, they are not. The rolling bodies of thrust bearings (such as thrust balls, thrust rollers) are specially designed for transmitting axial forces, and their shapes, sizes and contact methods are significantly different from those of radial bearings (such as balls and cylindrical rollers), and forcibly interchanging them will lead to bearing failure.
(4) Composite load bearing for which working conditions?
Composite load bearing can withstand both radial and axial load and tilting moment, etc., suitable for high-speed, high-precision or complex conditions, such as machine tool spindles and automobile transmissions, etc.
(5) Do radial bearings require axial fixation?
In some applications (such as drive shafts), radial bearings still need to be fixed axially (such as retaining ring, housing limit) to prevent axial runout, to avoid affecting the normal operation of the equipment, although its main function is to bear radial load.
(6) Composite load bearing lifespan is necessarily longer than the use of radial bearings and thrust bearings alone?
Not necessarily. Bearing life depends on load size, speed, lubrication and maintenance and other factors. Composite load bearing if used within the design range, life may be comparable with the combination of bearings; but if overload or improper maintenance, life may be shorter.
(7) How to choose the right type of bearing?
Comprehensive consideration needs to be given to the direction of load, speed, operating environment, life requirements and installation space, to ensure that the selection of suitable bearing types and specifications.
