The following are the characteristics and applicable scenarios of different types of needle roller bearings:

Drawn Cup Needle Roller Bearings

Characteristics: The outer ring is precisely formed by thin steel plate stamping. It has a small structural space and a relatively large load capacity. There are two types: perforated and sealed. The sealed type has one end closed, which is suitable for shaft ends and can withstand small axial floating forces. Some sealed drawn cup needle roller bearings are equipped with sealing rings to protect the bearings from debris intrusion and grease leakage within a certain temperature range.

Applicable Scenarios: They are suitable for occasions where the installation space is limited and the housing bore is not suitable to be used as a raceway, such as in the gearboxes of machine tools, automobiles, motorcycles, or textile machinery. Drawn cup needle roller bearings with a cage are suitable for high-speed and heavy-load applications. Drawn cup needle roller bearings without a cage, filled with needle rollers, are applicable to swinging working conditions under heavy loads, such as the shaft ends of aircraft frames and the main wings of missiles.

Solid Ring Needle Roller Bearings

Characteristics: They have a small volume and high load-carrying capacity, which can meet the requirements of light weight, small space occupation, and large power transmission. Depending on the application scenarios, bearings with or without an inner ring can be used. The double ribbed outer ring (or double retaining ring) needle roller bearings with a cage, types NA and NKI, can have the inner ring and outer ring installed separately, have relatively high allowable rotational speeds, and are available in single-row and double-row versions. Single-sided or double-sided sealed needle roller bearings can effectively prevent dirt from entering, and the inner ring has lubricating oil holes for supplementary lubrication according to configuration needs.

Applicable Scenarios: They are mostly used in machine tools, automobile gearboxes, etc. Their advantage lies in their small radial cross-sectional size and large radial load-carrying capacity. Standard solid ring needle roller bearings all have cages, so they can rotate at relatively high speeds and can meet the requirements of machine tools and automobile gearboxes.

Needle Roller Bearings with Wheels

Characteristics: The structure is relatively simple, mainly composed of wheels and needle rollers. They can withstand certain radial and axial loads and have good wear resistance and impact resistance.

Applicable Scenarios: They are suitable for printing machinery, forage machinery, agricultural machinery, guide wheels for CNC equipment rails, conveyor lines, etc., and can play roles in supporting, guiding, and transmitting loads in these devices.

Needle Roller and Cage Assemblies

Characteristics: They are actually needle roller bearings without rings. They have high load-carrying capacity and high rigidity design. Each needle roller is accurately guided and held by the cage, and their high-speed motion performance is excellent. Cages made of different materials can be used according to needs. For example, glass fiber reinforced nylon 66 cages can work for a long time at a temperature of 120 °C.

Applicable Scenarios: They are mostly used in parts such as the large and small ends of connecting rods in automobiles and motorcycles. Since the temperature inside the cylinder rises, the bearings need to be able to withstand high temperatures. They are also suitable for components where the shaft and housing bore can be directly used as raceways and the radial size is limited.

Combined Needle Roller Bearings

Characteristics: They are composite bearing units composed of radial needle roller bearings and thrust bearings or angular contact ball bearings. They have a compact structure, a small size, can withstand relatively high radial loads and a certain amount of axial loads at the same time, and have multiple structural forms with a wide range of applications and are easy to install. The diameter difference between needle rollers is within 2 μm, the precision grade is G2, and the dimensional tolerance and geometric accuracy are implemented according to JB/T8877.

Applicable Scenarios: They are widely used in various mechanical equipment, such as machine tools, metallurgical machinery, textile machinery, and printing machinery, which can make the overall design of mechanical systems more compact and flexible.

One-way Needle Roller Bearings

Characteristics: They are mainly used in occasions where rolling is only allowed in one direction. Both the inner and outer rings are equipped with oil grooves and sealing devices to prevent lubricating oil leakage.

Applicable Scenarios: For example, in the crankshafts of automobile engines, they can play a role in these parts that rotate in one direction and require good lubrication and sealing.

Double-direction Thrust Needle Roller Bearings

Characteristics: They have the ability to bear loads in both positive and negative directions. Both the inner and outer rings are equipped with oil grooves and sealing devices to ensure the lubrication effect.

Applicable Scenarios: They are widely used in fields that require withstanding bidirectional axial loads, such as industrial robots and medical equipment.

Oil-free Needle Roller Bearings

Characteristics: They can work normally without the need to add lubricating oil. Both the inner and outer rings are made of plastic, which can avoid chemical reactions with lubricating oil.

Applicable Scenarios: They are suitable for some special occasions, such as food processing machinery and other equipment with high hygiene requirements where lubricating oil cannot be used.