XRB Customized crossed roller bearings
XRB Customized crossed roller bearings
This 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 covers design, assembly, operational characteristics, and applications in indexing tables and high-speed rotations.
The RTB series features combined axial-radial roller bearings for high-precision applications like indexing tables and spindle heads. Key characteristics include high axial stiffness and the ability to bear high tilting moments. The document details stiffness, assembly instructions, preload concepts, friction, operating speed, and lubrication requirements.
General Description: RTB bearings consist of an L-shaped inner ring, an outer ring, two roller thrust bearings, and a cylindrical roller bearing. They are available in ungreased and pre-lubricated versions.
Stiffness: Achieved through precise machining and high-quality materials, with methods for calculating stiffness provided.
The SRB series includes combined needle and roller bearings for ball screw support, designed for high radial and axial load capacities.
Guidance on selecting appropriate bearings for specific applications is provided, along with special configurations and designations for RTB and SRB bearings.
Sections discuss precision locknuts and customized crossed roller bearings, highlighting selection criteria and examples of customized applications.
Tolerance tables for RTB bearings are included, detailing specifications for inner and outer rings, shaft washers, and housing washers. Products adhere to ISO 9001 and ISO 14001 standards.
Stiffness calculation of RTB bearings using finite element models is discussed, noting that published stiffness values may vary. RTB bearings are noted for high axial stiffness and ability to withstand high tilting moments.
Specific tolerances are recommended for assembly to ensure precision and limit friction.
Preloading increases stiffness and rotational accuracy by eliminating clearance due to elastic yielding under load.
Friction is influenced by preload, lubricant viscosity, applied load, bearing size, and rotational speed. Proper lubrication and assembly are recommended to minimize friction.
Tables and charts illustrate stiffness values and friction torque for various RTB bearing models.
Detailed technical specifications for RTB bearings focus on friction torque, rolling torque, operating speeds, lubrication, and dimensional data.
Charts outline maximum friction torque values for different RTB models.
Operating speeds are categorized for grease and oil lubrication, with specific RPM limits.
Specific grease types and quantities are recommended for relubrication intervals.
Dimensional tables provide measurements for various RTB models.
RTB HS bearings are designed for high-speed applications, with specific assembly instructions to minimize interference.
Stiffness values for radial, axial, and tilting conditions are provided, highlighting the importance of preload and temperature management.
Maintain minimal fitting tolerance, ensure proper lubrication, and monitor temperature variations closely for optimal performance.
RTB HS series bearings use lithium soap grease and emphasize temperature management to prevent bearing damage.
Consulting technical service is recommended for new applications with RTB-HS bearings.
An adequate cooling system is necessary for high-speed applications to dissipate heat.
RTB AMS and RTB ABS series bearings integrate an inductive angle measuring system, noted for precision and high load capacity.
The AMO inductive measuring system is highly accurate and resilient to environmental influences.
Custom configurations with different precision and resolution levels are available.
Tables detail periods per revolution, flange runout, and system accuracy for different RTB AMS models.
RTB AMS system highlights modularity and ability to be tailored to customer requirements.
The STU-20 tool enhances the setting procedure of the RTBxxxAMS measuring system.
- Inductive measuring system resistant to electromagnetic interference.
- Real-time output signals ideal for direct drives.
- High rotation speed and measuring resolution.
- Compact solution simplifying design and manufacturing.
- Insensitive to external agents.
- Simple installation and quick setting.
- Stable and reliable function.
Dimensional tables for various RTB AMS models are provided.
The RTB ABS system offers different precision and resolution levels with a standardized solution.
Configurations are based on a single reading head with integrated electronics.
Advanced generation ABS systems with encoder scales mounted directly on the inner ring of the bearing are discussed.
Pitch accuracy of the measurement scale is ±3 µm.
Available configurations include integrated head and electronics with a 1000 µm pitch.
Available interpolation factors and communication protocols are detailed.
Connector types include 17pin M23, 8 pin M12, 20pin FANUC, and 15pin Sub-D.
Dimensional tables for various RTB ABS models are provided.
Special configurations include RTB without washer and RTB with measured B-H values.
SRB bearings are needle roller bearings designed for radial/axial support of precision ball screws.
The document provides detailed technical specifications, configurations, and guidelines for advanced ABS systems and SRB bearings.
Specifications for SRB bearings and SH seal carriers are provided.
Dimensional tolerances for SRB bearings are outlined.
MONDIAL precision locknuts are highlighted for their precision and durability.
Guidelines for determining tightening torque are provided.
Special configurations for SRB bearings are mentioned.
UNITEC crossed roller bearings are recommended for applications requiring compact design and high load capacity.
UNITEC XRB series of crossed roller bearings are characterized by compact design and high load capacity.
Main applications include rotary tables, positioning tables, and spindles of robots.
UNITEC XRB bearings are designed and produced exclusively upon customer request.
Three basic configurations are available with optional fixing holes and different types of seals.
Detailed tables of tolerances for various precision classes are included.
The catalogue is produced with care, but no liability is assumed for incorrect or incomplete data.
Catalog excerpts
PRECISION BEARINGS FOR MACHINE TOOLS CUSCINETTI DI PRECISIONE PER MACCHINE UTENSILI
Open the catalog to page 1
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
Open the catalog to page 3
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...
Open the catalog to page 4
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...
Open the catalog to page 5
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...
Open the catalog to page 6
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...
Open the catalog to page 7
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...
Open the catalog to page 8
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...
Open the catalog to page 9
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...
Open the catalog to page 10
Fig. 3.1 RTB assembly instructions Indicazioni di montaggio per RTB
Open the catalog to page 11
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...
Open the catalog to page 12
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
Open the catalog to page 13
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...
Open the catalog to page 14All UNITEC catalogs and technical brochures
Product Range16 Pages
Archived catalogs
Gamma Prodotti - Product Range16 Pages