How to Distinguish Ball Bearings and Roller Bearings
The crossed roller slewing bearing is a high-precision and high-rigidity slewing bearing. Its rolling elements are cylindrical rollers, which are arranged vertically and crosswise in the raceway.
Feature of Ball Bearings
Primarily composed of balls, inner rings, outer rings, and retainers. Generally, for industrial ball bearings, the balls and rings are made of high-chromium steel, while the retainers are less hard compared to the balls and rings, and can be made of metal or non-metal materials.
Advantages of Ball Bearings
– Low friction resistance: Compared to other types of bearings, ball bearings have lower rotational friction resistance, resulting in lower temperatures generated by friction at the same speed.
– Ability to withstand combined loads: Can handle both radial and axial loads simultaneously, though the load capacity is relatively lower compared to roller bearings.
– Less sensitive to lubrication interruption: Short-term lubrication interruptions have relatively less impact on their performance.
– No self-excited instability: Operates more stably, less prone to self-excited instability.
– Easy to start at low temperatures: Easier to start in low-temperature environments, quickly reaching normal operating conditions.
Classification of Ball Bearings
– Deep groove ball bearings: Simple structure, easy to use, mass-produced, widely used, mainly for radial loads, can also handle some axial loads.
– Angular contact ball bearings: The contact points between the balls and the inner and outer rings are angular, capable of withstanding higher axial and radial loads, with high rigidity and precision, suitable for high-speed machinery.
– Self-aligning ball bearings: Have two rows of steel balls, inner rings with two raceways, outer ring raceways are spherical, with self-aligning properties, can automatically compensate for coaxiality errors caused by shaft deflection and housing deformation.
– Thrust ball bearings: A separable bearing, the shaft washer, housing washer can be separated from the cage and ball assembly, can only withstand axial loads, single-direction thrust ball bearings can only withstand axial loads in one direction, double-direction thrust ball bearings can withstand axial loads in both directions.
The feature of Roller Bearing
Roller bearings are a type of rolling bearing that uses rollers as rolling elements, relying on rolling contact between main components to support rotating parts, widely used in modern machinery. The following is a detailed introduction:
Structural Composition
– Radial roller bearings: Composed of inner rings, outer rings, rollers, and retainers. Rollers are arranged between the outer diameter surface of the inner ring and the inner diameter surface of the outer ring, the retainer evenly distributes the rollers, preventing mutual contact friction.
– Thrust roller bearings: Rollers and retainers are sandwiched between two washers, the structure can be integral or split, determined by assembly convenience.
Rolling Element Shapes
– Cylindrical roller bearings: Rollers are cylindrical, radial type only withstands radial loads, thrust type only withstands thrust loads.
– Needle roller bearings: Rollers are slender like needles, with the smallest outer diameter for the same inner diameter, suitable for places with small radial space.
– Tapered roller bearings: Rolling elements are conical, can withstand loads perpendicular to the shaft and axial loads in a fixed direction.
– Spherical roller bearings: Rolling elements are barrel-shaped, can withstand loads perpendicular to the axis and axial loads in both directions, with good self-aligning properties.
Advantages of Roller bearing
– High load capacity: Rolling elements and raceways are in line contact, high load capacity, small deformation after loading.
– High rotational accuracy: Ensures precise positioning of rotating components, making equipment operation smoother.
– Low starting torque: Requires less torque to start, saving energy, improving equipment efficiency.
Ball bearings and roller bearings can be distinguished in the following aspects:
Observing Rolling Element Shapes
– Ball bearings: Rolling elements are spherical, usually steel balls, but can also be ceramic balls.
– Roller bearings: Rolling elements are cylindrical, conical, or barrel-shaped rollers.
Comparing Load Capacity
– Ball bearings: Rolling elements and raceways are in point contact, small contact area, relatively lower radial and axial load capacity, but more balanced performance under combined loads.
– Roller bearings: Rolling elements and raceways are in line or surface contact, large contact area, can disperse loads, significantly higher radial load capacity than ball bearings, axial load capacity depends on roller type.
Comparing Speed Performance
– Ball bearings: Rolling element shape suitable for high-speed operation, low friction resistance, low heat generation, high limiting speed.
– Roller bearings: Large contact area, high friction resistance, prone to heat generation, suitable for medium and low-speed equipment, relatively lower limiting speed.
Feeling Vibration and Noise Levels
– Ball bearings: Spherical rolling element design, smoother operation, generally lower vibration and noise levels.
– Roller bearings: Due to rolling element shape and contact method, may produce more vibration and noise in certain applications.
Considering Installation and Maintenance Difficulty
– Ball bearings: Simple structure, generally easier to install and maintain.
– Roller bearings: Complex manufacturing process, higher installation precision requirements, relatively higher maintenance cost and time.
Viewing Application Scenarios
– Ball bearings: Suitable for high-speed, precision equipment, such as motors, machine tools, bicycles, etc.
– Roller bearings: Used for high-load, long-life applications, such as heavy machinery, automobiles, railway vehicles, etc.
Regarding the Price of Roller Bearings and Ball Bearings
Different types of roller bearings or ball bearings have different prices due to structural and manufacturing process differences. For example, thrust roller bearings are relatively complex in structure, generally more expensive than ordinary cylindrical roller bearings; high-precision angular contact ball bearings are difficult to manufacture, more expensive than ordinary deep groove ball bearings. Common materials include chromium steel, stainless steel, bearing steel, etc. If special materials such as ceramics are used, the cost will significantly increase, and the price will also be higher. Bearings made of special materials have high temperature resistance, corrosion resistance, etc., suitable for special working conditions.
Of course, LDB-Bearing company will provide you with the best production assembly and the most favorable prices. If you want to know more, you can contact us.