Single Row Cylindrical Roller Bearings Without Inner Ring
Single row cylindrical roller bearings without an inner ring are designed for applications where the shaft serves as the raceway. These bearings are ideal for compact designs requiring high radial load capacity. Common uses include automotive systems, gearboxes, and industrial machinery.
The Special Structure of "No Inner Ring"
As the name suggests, the bearing without an inner ring abandons the traditional independent inner ring, with the shaft itself directly serving as the inner ring. The core components of this bearing only include rollers, cages, and an outer ring.
This structure makes the bearing and the shaft more compact and enables the bearing to move freely along the axial direction, only being restricted by the effective width of the raceway on the shaft. At the same time, the structure without an inner ring also means that a larger diameter shaft can be used under the same external dimensions. A larger shaft diameter usually implies higher shaft strength and rigidity, which is crucial for applications that bear high loads, high speeds, or require high precision.
The Optimization and Challenges Brought by the Absence of an Inner Ring
This structure without an inner ring represents a fundamental innovation in the field of bearings, as it alters the traditional physical structure.
The inner ring, as a key component of a bearing, is omitted, and the shaft takes on the function of the inner ring. This means that the shaft must fulfil the role of the inner ring: in terms of material selection, heat treatment process, surface grinding accuracy, and geometric tolerance, all must meet the extremely high standards equivalent to those of the bearing raceway. This implies that the shaft and the bearing have achieved deep integration in a new way.
Outstanding Adaptability Under Specific Working Conditions
Cylindrical roller bearings without inner rings have a wide range of applications, mainly covering multiple industrial fields with strict performance requirements:
- Machine Tool Spindles: Pursuing high rigidity and high precision.
- Planetary Gearboxes: The internal space of the planet gears is extremely limited.
- Automotive/Motorcycle Transmissions: Compact design and high load requirements.
- Printing Machinery Rollers: Needing highly rigid support shafts.
- Connecting Rod Big Ends: Such as compressors, etc.
- Rolling Mill Support Rollers: Withstanding huge radial impact loads.
FREQUENTLY ASKED QUESTIONS
What should I do if the hardness of my shaft is not sufficient?
It must never be used. The raceway of the shaft will wear out rapidly and develop pits, causing the bearing clearance to increase, vibration to intensify, and ultimately fail within an extremely short period of time. This is the most common failure mode. If necessary, you can consider using our other series of bearings. You can contact us for purchasing advice.
What parameters do I need to refer to in order to determine the type of bearing I need?
The main parameters you need to provide are: the diameter of your shaft, the diameter of the bearing housing bore (the outer diameter of the bearing), the installation width, as well as your load, speed and operating temperature. You can check our product detail page or contact us at any time, and we will provide you with professional selection support.
What model is generally used to represent cylindrical roller bearings without an inner ring?
Cylindrical roller bearings without inner rings are generally indicated by the model prefix "RNU".
For instance, "RNU306" represents a NU306 bearing without an inner ring. Here, "NU" indicates cylindrical roller bearings with no flanges on the inner ring, and the addition of "R" indicates the structure without an inner ring.
How long will it take to ship after the payment?
We have sufficient inventory. Most orders will be shipped within 10 days or less. After the order is dispatched, you can track the logistics information at any time until the goods are signed for.