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RTB ABS - Combined axial-radial roller bearings with integrated inductive encoder

RTB ABS - Combined axial-radial roller bearings with integrated inductive encoder

Product catalog summary

Overview: The document provides comprehensive technical specifications and guidelines for precision bearings used in machine tools, focusing on combined axial-radial roller bearings and needle roller bearings. It includes sections on technical specifications, dimensional tables, and special configurations.

RTB Series: This section discusses combined axial-radial roller bearings for indexing tables, emphasizing their high axial stiffness and capacity to bear high tilting moments. Key features include high stiffness, considerable load rating, and high rotational accuracy. The bearings are available in both ungreased and pre-lubricated versions.

Technical Specifications: Detailed information is provided on the general description, stiffness, assembly instructions, preload concept, friction, operating speed, and lubrication for RTB bearings. The document highlights the importance of precise and rigid movement facilitated by high-quality materials and specific heat treatments.

SRB Series: This section covers combined needle and roller bearings for ball screw support, including technical specifications for various configurations like SRB-L, SRB-T, SRB-F, and SRB-FL. It emphasizes the importance of precise assembly for optimal performance.

Special Configurations and Designations: Information on special configurations for both RTB and SRB bearings is provided, along with their respective designations. The document also covers precision locknuts and customized crossed roller bearings, providing examples of customized applications.

Tolerances and Standards: Tolerance tables for RTB bearings are included, detailing specifications for inner and outer rings, shaft washers, and housing washers. The document adheres to UNI ISO 76 and UNI ISO 281 standards, ensuring high-quality and reliable performance.

Company Information: Mondial and UNITEC are highlighted as leading companies in the design, manufacturing, and distribution of precision bearings, with certifications in ISO 9001 and ISO 14001. They offer comprehensive technical and logistic support to meet unique application requirements.

Technical Specifications and Stiffness Calculation: The document discusses the stiffness calculation of RTB bearings using finite element models, noting that published stiffness values are indicative and may vary based on design, materials, and assembly tolerances. RTB bearings are noted for their high axial stiffness and ability to withstand high tilting moments, making them suitable for rotary tables and positioning systems.

Mounting Instructions: Specific tolerances are recommended for assembly to ensure precision and limit friction torque. Different recommendations are provided for rotating inner and outer rings, emphasizing the importance of press fits and clearances.

Preload Concept: Preloading bearings increases stiffness and rotational accuracy by eliminating clearance due to elastic yielding. Preloaded systems have higher axial stiffness and reduced axial deflection compared to non-preloaded systems.

Friction Considerations: Friction in bearings is influenced by preload, lubricant viscosity, applied load, bearing size, and rotational speed. Guidelines for minimizing friction include using specific grease types and ensuring proper assembly conditions.

Data and Charts: Tables and charts detailing stiffness values and friction torque for various RTB bearing models are included, emphasizing the importance of proper assembly and lubrication for optimal performance.

Technical Specifications Overview: Detailed technical specifications for RTB bearings are provided, focusing on friction torque, rolling torque, operating speeds, lubrication, and dimensional data. Guidelines for assembly, lubrication, and preload management are included to ensure optimal performance.

Friction and Rolling Torque: The friction torque chart outlines maximum values for different RTB models, indicating the resistance moment in Nm. The rolling torque table specifies torque values for various bore sizes, essential for understanding mechanical load capacity.

Operating Speeds: Operating speeds are categorized for grease and oil lubrication, with specific RPM limits for continuous and intermittent operations. The document emphasizes maintaining appropriate lubricant viscosity as per UNI ISO 281 standards.

Lubrication Guidelines: Lubrication is critical, with specific grease types and quantities recommended for relubrication intervals. Lithium soap grease with a viscosity of 150 cSt at 40°C is advised, with a relubrication interval of approximately 3000 hours under optimal conditions.

Dimensional Specifications: The dimensional table provides detailed measurements for various RTB models, including bore, diameter, and axial/radial runout tolerances, crucial for ensuring proper fit and function in mechanical assemblies.

RTB HS Bearings: Designed for high-speed applications, RTB HS bearings feature modifications in axial rollers, radial filling, and preload. They are available in ungreased and greased versions, with specific assembly instructions to minimize interference and maximize speed.

Stiffness and Preload Management: Stiffness values are provided for radial, axial, and tilting conditions, considering the deformation of all bearing components. Proper preload and temperature management are essential to prevent excessive rolling torque and ensure bearing longevity.

Assembly and Mounting Recommendations: For optimal performance, minimal interference fits and appropriate clearances are advised to accommodate thermal expansion, maintaining bearing precision and reducing friction-related issues.

Specifications: The document discusses the RTB HS series of bearings, emphasizing the importance of maintaining temperature differences between rotating and fixed components within a few degrees Celsius to prevent bearing damage. High-speed applications require careful temperature monitoring and control to avoid excessive preload or clearance generation.

Procedures and Recommendations: For high-speed applications, it is crucial to ensure that adjacent components can dissipate heat effectively, and an adequate cooling system may be necessary. Customers are advised to consult technical services for new applications involving RTB-HS bearings.

Dimensional Table: A detailed dimensional table for various RTB HS models is provided, including specifications such as axial and radial runout, suitable table diameter, and load ratings according to ISO standards.

RTB AMS and RTB ABS Bearings: These bearings are designed for rotary tables and spindle heads in machine tools, featuring integrated inductive encoders for precise angle measurement. The RTB AMS version includes an incremental measuring system, while the RTB ABS version features an absolute measuring system. These bearings offer high load capacity, stiffness, and low resistant torque, making them suitable for direct drive installations.

Inductive Measuring System: A new generation of inductive measuring systems is described, providing high precision and resilience to environmental influences. The system does not contain magnetic parts, making it insensitive to electromagnetic interference, and offers high dynamic performance suitable for direct torque drives.

Technical Specifications: The inductive measuring system features scales with pitches of 500 µm and 1000 µm, precision classes of ±3 µm and ±5 µm, and options for one or two sensor heads. The system provides sinusoidal output signals and various interpolation factors to achieve the desired resolution.

Conclusion: The document provides comprehensive technical details on the RTB HS, RTB AMS, and RTB ABS bearings, emphasizing the importance of temperature control, heat dissipation, and precision measurement in high-speed applications.

Technical Specifications: The document outlines the technical specifications of the RTB AMS and RTB ABS systems, focusing on their modularity and adaptability to customer requirements. It highlights the availability of various interpolation factors and the importance of contacting the technical department for correct system configuration.

STU-20 Tool: The STU-20 is an optional advanced electronic tool designed to enhance the setting procedure of the RTBxxxAMS measuring system. It allows for verification of system functionality before or during operation and is particularly useful for multiple installations.

Advantages of the System: Several advantages of the RTB AMS system are listed, including its non-magnetic inductive measuring principle, real-time output signals ideal for direct drives, high rotation speed, high measuring resolution, compact solution, insensitivity to external agents, simple installation, quick setting, no need for setting software, and stable and reliable function.

Dimensional Tables: Detailed measurements for various RTB AMS sizes are provided, noting differences in flange thickness and recommendations for sensor head tightening post-bearing installation.

RTB ABS System Features: The RTB ABS system is described as a new generation system with different precision and resolution levels. It features a standardized solution with high dynamic performance and easy installation design. The system includes absolute measuring system features with various communication protocols and a self-centering measuring head.

Available Configurations: Available configurations based on a single reading head with integrated electronics are detailed, highlighting the influence of precision class and signal resolution on system accuracy.

Technical Specifications: Detailed specifications for SRB bearings and SH seal carriers are provided, including dimensional tolerances, load ratings, and radial and axial clearances according to ISO standards. The document specifies the use of tolerance classes P6 and P4 for geometrical and rotational accuracy.

Seal Carriers: SH seal carriers are designed for SRB F/FL bearings, offering a cost-effective solution for sealing in grease lubrication applications. They come with a rotary shaft seal, mounting screws, and a gasket.

Special Configurations: Special configurations of SRB bearings include high thrust load configurations, reduced envelope designs, and integrated seal carriers for specific machinery like flexo printing.

Precision Locknuts: MONDIAL precision locknuts are designed to address precision and durability issues in recirculating ball screws. They are manufactured with high precision to meet demanding requirements. Different locking mechanisms are available, including side, axial, radial, and spring locking, each with specific material and hardness specifications.

Tightening Torque: Guidelines for determining the tightening torque necessary to achieve an axial preload equivalent to 5% of the dynamic load-carrying capacity of the bearing are provided.

Crossed Roller Bearings: UNITEC XRB series crossed roller bearings are highlighted for their compact design and ability to handle high axial loads in both directions, combined with radial loads and high tilting moments. They are suitable for applications with limited space or where a lower center of gravity is needed.

Catalog excerpts

RTB ABS - Combined axial-radial roller bearings with integrated inductive encoder-1

PRECISION BEARINGS FOR MACHINE TOOLS CUSCINETTI DI PRECISIONE PER MACCHINE UTENSILI

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RTB ABS - Combined axial-radial roller bearings with integrated inductive encoder-3

Specifiche tecniche Combined needle and roller bearings Indicazione per esecuzione parti adiacenti SRB Radial needle roller combined bearings with axial cylindrical roller Cuscinetti radiali a rullini combinati con assiali a rulli cilindrici Cuscinetti customizzati a rulli cilindrici incrociati TOLERANCES TABLES TABELLE TOLLERANZE n

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RTB ABS - Combined axial-radial roller bearings with integrated inductive encoder-4

MONDIAL UNITEC Mondial is a leading company in the import and distribution of power transmission components. Mondial always provides its customers with highly qualified products matched with an excellent logistic and technical support. Mondial is an ISO 9001 certified Company. Mondial, Azienda leader nell’importazione e commercializzazione di componenti meccanici innovativi e di elevata qualità, offre un servizio costantemente adeguato alle esigenze del mercato. Un servizio che integra dinamicamente l’organizzazione commerciale con quella tecnica e logistica, proponendo una completa gamma di...

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RTB ABS - Combined axial-radial roller bearings with integrated inductive encoder-5

UNITEC, leading company in the design and manufacturing of spec jl precision cylindrical roller bearin 3s for machine tools and general industry, delivers high quality service and support to customers worldwide. Engineering partnership, technical and logistic services and our commercial network, supplied by different distribution channels, allows us to fulfil unique application requirements on the marketplace. UNITEC is a certified ISO 301 and ISO 14001 company, be. >ng ,ig to Mondial S.p.A. Group. Advanced technology to meet your customers requirements. Our engineers will assist you in selecting the...

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RTB ABS - Combined axial-radial roller bearings with integrated inductive encoder-6

2. STIFFNESS High stiffness, considerable load rating, high rotational accuracy are the essential features of the combined UNITEC RTB bearings. The axial cages with a high number of rolling elements with linear contact as well as a very high precision of the machining permit a precise and rigid movement. The size of the axial and radial rollers as well as of the inner and outer rings are carefully measured in order to obtain. The requested preloads by tightening the cap screws. The tolerances of the preload value are particularly restricted, so that a constant and uniform quality of supplies...

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RTB ABS - Combined axial-radial roller bearings with integrated inductive encoder-7

2. RIGIDEZZA Elevata rigidezza, grande capacità di carico, elevata precisione di rotazione, sono i requisiti fondamentali dei cuscinetti assiali – radiali UNITEC serie RTB. L’impiego di gabbie assiali ad elevato numero di corpi volventi con contatto lineare, oltre all’elevatissima precisione delle lavorazioni meccaniche, contribuisce ad ottenere un movimento preciso e rigido. Le dimensioni dei rulli, sia assiali che radiali, e degli anelli interno ed esterno sono calibrate in modo tale che al serraggio delle viti di fissaggio si ottengano i precarichi previsti.Le tolleranze, del valore del precarico...

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RTB ABS - Combined axial-radial roller bearings with integrated inductive encoder-8

RTB TECHNICAL SPECIFICATIONS SPECIFICHE TECNICHE Bearing assembled in housing and model for FEM analysis Schema di montaggio del cuscinetto e modello analisi FEM MOUNTING WITH THRUST WASHER (VSP) - MONTAGGIO CON RALLA DI SUPPORTO (VSP) In case a thrust washer is used in the assembly of the RTB bearing, the correct axial setting have to be evaluated. In this case, for any needed support, please contact our technical department. Nel caso di utilizzo della ralla di supporto, il cuscinetto RTB viene configurato a richiesta, valutando il corretto valore di registrazione assiale. Per ogni necessaria...

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RTB ABS - Combined axial-radial roller bearings with integrated inductive encoder-9

Stiffness values of rolling lements in preloaded con tions Rigidezze relative ai soli elementi volventi in condizioni di precarico teorico Stiffness values of a complete assembled bearing (°) Rigidezze relative al cuscinetto completo in condizioni di installazione di 'ferimento (°) (°) A.m. stiffness values consider the deformation of all components of the bearing and of the parts assembled with cap screws. Deviations from the actual values are possible according to the approximation of the model with respect to the real system. (1) The axial stiffness is calculated with the load applied top...

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RTB ABS - Combined axial-radial roller bearings with integrated inductive encoder-10

RTB TECHNICAL SPECIFICATIONS SPECIFICHE TECNICHE 3. ASSEMBLY INSTRUCTIONS As for assembly, we recommend to follow specifications indicated in figure 3.1. Usually, tolerances can lead to different mounting situations such as deflection or misalignments according to bore/outer diameter of bearings. WITH ROTATING INNER RING Rotating shaft We recommend a press fit of max 0,005 mm to impro ve accuracy and to limit friction torque. Housing We recommend to keep a small mounting clearance, except for applications demanding high precision in bearing adjustments. WITH ROTATING OUTER RING 3. INDICAZIONI...

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RTB ABS - Combined axial-radial roller bearings with integrated inductive encoder-11

Fig. 3.1 RTB assembly instructions Indicazioni di montaggio per RTB

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RTB ABS - Combined axial-radial roller bearings with integrated inductive encoder-12

RTB TECHNICAL SPECIFICATIONS SPECIFICHE TECNICHE The preload of the bearings increases the stiffness and the rotational accuracy. In presence of a load from the outside, the preload of the bearing eliminates or avoids the clearance corresponding to the elastic yielding due to the load itself. In this case, for a given range of loads, the elastic deformations caused by the load are smaller rather than in a non-preloaded bearing. Assuming approximately the stiffness is linear (rollers in contact with tracks) at the same axial load, the axial deflection is smaller in a preloaded bearings system...

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RTB ABS - Combined axial-radial roller bearings with integrated inductive encoder-13

δ with preload δ con precarico δ without preload δ senza precarico Fig. 4.1 (1) System without preload - sistema senza precarico (2) Preload diagram - sistema con precarico Fo Fx = System with preload Fo - forza assiale esterna δ = Axial deflection - spostamento assiale

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RTB ABS - Combined axial-radial roller bearings with integrated inductive encoder-14

TECHNICAL SPECIFICATIONS SPECIFICHE TECNICHE5. FRICTION ■ As for the bearings, the friction depends on many factors, the most important of which are: ■ preload ■ viscosity and amount of the lubricant ■ applied load ■ bearing size ■ rotational speed i.e.: ■ A bigger preload turns out in a bigger rolling friction torque ■ Tightening values affect considerably riotion values. As for RTB bearings the fixing of the inner ring screws reduces to zero the dimensional c r inner axial clearance as well as the elastic comp1' ssion of the inner ring. In general we recommend to use bolt class 10.9 and recommend...

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