Spiral Roller And Cage Combined Wide Inner Ring Spiral Roller Bearing

Spiral Roller & Cage Assembled Wide Inner Ring Spiral Roller Bearings are heavy-duty radial bearings integrating the dual designs of "wide inner ring structure" and "integrated spiral roller-cage assembly". Their core features are: the inner ring width is significantly larger than the outer ring (typically 1.2-2 times the outer ring width), and the spiral rollers are preassembled with a dedicated cage into an independent unit. These bearings not only retain the inherent advantages of spiral rollers-such as impact resistance and heavy-load capacity-but also enhance shafting adaptability through the wide inner ring and simplify installation via the preassembled roller-cage unit. Specifically engineered for heavy-load working conditions with large shaft diameter deviations, limited installation space, and frequent maintenance needs, they are widely used in fields like mining machinery, metallurgical equipment, and heavy agricultural machinery, serving as key supporting components for balancing "load-bearing performance, installation efficiency, and maintenance costs" in heavy-load transmission systems.

1. Core Structure and Design Innovation

The structural design of these bearings centers on "heavy-load bearing + convenient installation". Through the collaborative optimization of the wide inner ring and preassembled roller-cage unit, they address the pain points of traditional bearings in adaptability and assembly efficiency. Detailed structural components and design highlights are as follows:

(1) Technical Details of Key Components

Wide Inner Ring: Core of Shafting Adaptability

Dimensions and Material: The inner ring is made of high-carbon chromium bearing steel (GCr15SiMn) or carburized bearing steel (20CrNiMo), undergoing integral quenching to achieve a hardness of HRC60-62. The inner ring width (B₁) is 1.2-2 times the outer ring width (B) (e.g., when the outer ring width is 30mm, the inner ring width can reach 36-60mm). The inner diameter of the inner ring adopts a loose tolerance design (typically grade g6 or h7), adapting to a shaft diameter machining deviation of ±0.05mm and compatible with medium-to-low precision scenarios where the shaft journal roughness is Ra ≤ 1.6μm (no ultra-precision grinding of the shaft journal is required).

Raceway and Special Design: The outer circumferential raceway of the inner ring features an arc-shaped structure (with a curvature radius 1.05-1.1 times the roller radius), and its surface undergoes ultra-precision grinding to achieve a roughness of Ra ≤ 0.4μm, ensuring stable line contact with the spiral rollers. Both end faces of the inner ring are provided with positioning steps (2-5mm in width), which can fit tightly with the shaft shoulder or lock nut to prevent axial movement of the inner ring. For large-sized models (inner ring width ≥ 50mm), axial oil grooves (0.5-1mm in depth, 3-6 in number) are machined along the inner ring to facilitate the penetration of lubricating oil into the mating surface between the shaft and the inner ring, reducing wear during installation and disassembly.

Preassembled Spiral Roller-Cage Unit: Core of Load-Bearing and Installation

Spiral Rollers: Manufactured from spring steel (60Si2MnA) through cold-rolled spiral forming and integral quenching, they have a hardness of HRC58-62 and uniform pitch (tolerance ≤ 0.1mm). The roller length matches the inner ring width (L/B₁ = 1-1.2) to ensure full contact with the inner ring raceway. The rollers feature a hollow spiral structure with a radial elastic deformation of 0.01-0.03mm, capable of cushioning short-term impacts of 2 times the rated load. Meanwhile, the hollow design reduces weight (15%-20% lighter than split cylindrical rollers) and lowers centrifugal force during high-speed operation.

Dedicated Cage: Preassembled with spiral rollers into an independent unit, the cage is available in two materials: stamped steel (SPCC, suitable for medium-to-low loads) and brass (H62, suitable for heavy loads/high temperatures). Adopting a "comb-shaped integrated forming" structure, the number of pockets is 10%-15% higher than that of traditional wide inner ring bearings (e.g., 20-24 pockets for models with a 100mm shaft diameter), ensuring uniform distribution of rollers. Both ends of the cage are equipped with 3-4mm high flanges, which cooperate with the steps on both sides of the wide inner ring raceway to form axial limiting, preventing roller movement. Additionally, the preassembled design eliminates the need for separate roller installation during bearing assembly, greatly simplifying the process.

Outer Ring and Protection System

Outer Ring Structure: Made of high-carbon chromium bearing steel (GCr15) through quenching, it has a hardness of HRC60-62. The inner bore raceway (inner bore of the outer ring) is arc-shaped to form line contact with the spiral rollers. The outer diameter of the outer ring adopts a tolerance of grade h8, and a clearance fit of H9/h8 is used with the bearing housing, allowing a coaxiality deviation of ±0.05mm and adapting to scenarios with low machining precision of the bearing housing. For large-sized models, oil holes (3-6mm in diameter, 2-4 in number) are drilled on the outer ring to directly connect to the roller-raceway contact area, improving lubrication efficiency.

Sealing Protection (Optional): Double-sided contact seals (nitrile rubber NBR or fluororubber FKM) can be optionally equipped. The seal lip fits the step surface of the wide inner ring (interference 0.05-0.1mm), achieving an IP54 dustproof rating and adapting to dusty and humid environments. For non-sealed models, dust covers can be used, which are connected to the outer ring via snaps to prevent foreign objects from entering, suitable for dry and clean working conditions.

(2) Core Design Principles and Collaborative Advantages

The core design logic of these bearings lies in the collaborative effect of the "wide inner ring" and "preassembled roller-cage unit":

Adaptability Optimization Between Wide Inner Ring and Shaft: The wide inner ring increases the contact area with the shaft journal (20%-30% larger than split wide inner ring bearings), reducing the contact surface pressure (≤ 150MPa). Even if the shaft journal has slight ovality (≤ 0.03mm) or taper (≤ 0.02mm/m), stable mating can still be ensured, reducing vibration transmission in the shafting.

Installation Efficiency Improvement by Preassembled Unit: The preassembled spiral roller-cage unit can be directly installed as a whole between the wide inner ring and the outer ring, eliminating the need for individual roller installation. This shortens the assembly time by 50% compared to split bearings (e.g., for a 120mm shaft diameter model, split assembly takes 30 minutes, while the preassembled unit only takes 15 minutes) and avoids premature failure caused by roller scattering or installation deviations.

Superimposed Enhancement of Load-Bearing Performance: The combination of the stable support of the wide inner ring and the elastic cushioning of the spiral rollers increases the radial rated dynamic load by 8%-15% compared to split wide inner ring bearings (e.g., for a 100mm shaft diameter model, the split type has a rated dynamic load of 320kN, while the preassembled type can reach 345-368kN). The impact load capacity is increased by 10%, adapting to harsher heavy-load impact conditions.

2. Core Performance Indicators and Highlights

Relying on the dual structural design, these bearings excel in heavy-load bearing, installation flexibility, and working condition adaptability. Key performance indicators and highlights are as follows:

(1) Key Performance Parameters (for Mainstream Models)

(2) Core Performance Highlights

Dual Excellence in Heavy-Load and Impact Resistance: The radial rated dynamic load is 8%-15% higher than that of split wide inner ring bearings, enabling long-term bearing of 200-800kN heavy loads (e.g., main shafts of mining crushers). The elastic structure of the spiral rollers, combined with the stable support of the wide inner ring, results in an impact load capacity of 2-2.2 times the rated load and an impact absorption capacity of ≥ 9J-10% higher than split bearings-making them suitable for high-frequency impact scenarios such as steel billet collisions and material crushing.

Outstanding Installation Flexibility and Efficiency: The wide inner ring is compatible with a shaft diameter deviation of ±0.05mm, eliminating the need for ultra-precision grinding of the shaft journal and reducing shaft machining costs. The preassembled roller-cage unit shortens assembly time by 50% and enables "independent outer ring disassembly" (during maintenance, only the outer ring needs to be removed to inspect the roller condition without disassembling the shafting), improving maintenance efficiency by 60%.

Wide Adaptability to Working Conditions: NBR seals (IP54 dustproof) can be selected for dusty scenarios; FKM seals + high-temperature grease for high-temperature scenarios (> 120℃); and the inner ring oil grooves enhance lubrication fault tolerance for humid scenarios (short-term operation is still possible with a 40% reduction in lubricating oil volume). Meanwhile, the large contact area of the wide inner ring reduces local wear, extending service life by 15%-20% compared to split bearings under dusty and high-vibration conditions.

Improved Shafting Stability: The longer mating length between the wide inner ring and the shaft controls axial endplay within ≤ 0.01mm and radial runout within ≤ 0.05mm. Even with slight shafting deflection (≤ 0.1mm/m), transmission accuracy can still be ensured, adapting to equipment with low shafting precision such as mining drums and metallurgical rolls.

3. Typical Application Scenarios and Practical Cases

These bearings are suitable for applications that simultaneously meet three conditions: "heavy load (≥ 200kN), large shaft diameter deviation (±0.05mm), and frequent installation/maintenance". Below are typical cases in four core fields:

(1) Mining Machinery: Crusher Main Shafts

Operating Conditions: Shaft diameter: 150-200mm, radial load: 300-500kN, material impact (short-term load peak: 2 times the rated value), shaft journal roughness: Ra = 1.6μm, frequent opening of the bearing housing for roller inspection, required maintenance cycle: ≤ 2000h.

Suitable Model: NUW-SC22330 (inner ring width: 60mm, outer ring width: 35mm, preassembled roller-cage unit, NBR seal, radial rated dynamic load: 580kN).

Application Results: After a mining crusher adopted this model, the wide inner ring adapted to a shaft diameter deviation of ±0.04mm, eliminating the need for secondary grinding of the shaft journal; the preassembled unit shortened the initial assembly time from 40 minutes to 20 minutes; during maintenance, only the outer ring needed to be disassembled to inspect the rollers, reducing maintenance time from 2 hours to 40 minutes. Under 300kN heavy load and impact conditions, continuous operation reached 12,000h with roller wear ≤ 0.04mm, and the service life was 18% longer than that of split bearings.

(2) Metallurgical Equipment: Continuous Caster Roller Shafts

Operating Conditions: Shaft diameter: 120-180mm, radial load: 200-350kN, operating temperature: 80-120℃, shaft journal cylindricity error: ≤ 0.02mm/m, continuous operation (annual operating time: ≥ 7000h), required high-temperature stability.

Suitable Model: NWB-SC22224 (inner ring width: 50mm, outer ring width: 28mm, preassembled roller-cage unit, FKM seal + high-temperature grease, radial rated dynamic load: 420kN).

Application Results: After a steel mill adopted this model for its continuous caster, the FKM seal withstood 120℃ high temperatures, and the high-temperature grease ensured effective lubrication; the wide inner ring adapted to a shaft journal deviation of ±0.03mm, avoiding mating issues caused by shafting thermal expansion and contraction; continuous operation reached 10,000h without failure, with roller radial runout ≤ 0.05mm, meeting the precision requirements for steel billet transportation. The maintenance cycle was extended to 2500h, 25% longer than that of the original split bearings.

(3) Heavy Agricultural Machinery: Tractor Drive Wheel Shafts

Operating Conditions: Shaft diameter: 80-120mm, radial load: 150-250kN, humid and dusty farmland environment (humidity: ≥ 90%RH), easy rusting of the shaft journal (allowing slight rust depth: ≤ 0.02mm), seasonal maintenance required (1-2 disassembly inspections per year).

Suitable Model: NJW-SC22120 (inner ring width: 40mm, outer ring width: 25mm, preassembled roller-cage unit, NBR seal, radial rated dynamic load: 280kN).

Application Results: After an agricultural machinery enterprise adopted this model for its tractors, the NWB seal prevented muddy water intrusion, and the inner ring oil grooves alleviated insufficient lubrication; the wide inner ring adapted to slight shaft journal rust and ±0.05mm deviation, eliminating the need for shaft journal replacement; during seasonal maintenance, the outer ring could be disassembled to inspect the rollers in 15 minutes, improving maintenance efficiency by 60%. The service life during farmland operations reached 8000h, 20% longer than that of the original bearings, and the user repair rate decreased by 30%.

(4) General Heavy Machinery: Port Crane Wheel Shafts

Operating Conditions: Shaft diameter: 200-250mm, radial load: 400-600kN, intermittent impact (load peak: 1.8 times the rated value during start-up/braking), limited installation space (axial space only allowing outer ring width: ≤ 40mm), required low-noise operation (≤ 85dB).

Suitable Model: NUW-SC22340 (inner ring width: 70mm, outer ring width: 38mm, preassembled roller-cage unit, dust cover, radial rated dynamic load: 780kN).

Application Results: After a port adopted this model for its crane wheel shafts, the wide inner ring adapted to a shaft diameter deviation of ±0.04mm, and the preassembled unit simplified installation (completing assembly in 30 minutes); the stable contact between the wide inner ring and rollers resulted in an operating noise of ≤ 82dB, meeting the port's low-noise requirements. Under 400kN heavy load and intermittent impact conditions, continuous operation reached 15,000h with wheel shaft radial runout ≤ 0.05mm. The maintenance cycle was extended to 3000h, 30% longer than that of the original bearings.

Hot Tags: spiral roller and cage combined wide inner ring spiral roller bearing, China spiral roller and cage combined wide inner ring spiral roller bearing manufacturers, suppliers, factory