The SX011840 crossed roller bearing provides a large 200 mm through-bore within a compact 250 mm outside diameter and 24 mm width. It is designed for hollow-axis torque motors, CNC rotary axes, gear-testing equipment and large optical positioning platforms.
Alternately crossed cylindrical rollers enable the SX011840 to support radial, axial and tilting-moment loads in one bearing position. Its dynamic axial rating is 106 kN, its static axial rating is 425 kN, and its approximate mass is 3.1 kg.
LYDL can supply SX011840 bearings in P5, P4, P2 or customized accuracy classes. Internal clearance or preload can be selected according to system rigidity, rotational accuracy, motor torque and operating temperature.
For replacement orders, please provide the complete original designation and suffix. Dimensional compatibility does not automatically confirm equivalent preload, clearance, coating, running torque or accuracy.
SX011840 Crossed Roller Bearing Overview
The SX011840 crossed roller bearing is a large-bore precision bearing with dimensions of 200 × 250 × 24 mm. It provides a 200 mm central passage while retaining a relatively compact 250 mm housing diameter.
The bearing has an integrated inner ring and a circumferentially split outer ring. Cylindrical rollers are arranged alternately at 90 degrees, allowing one bearing position to support radial loads, axial loads and overturning moments.
Its compact 24 mm width can reduce the axial length of a rotary assembly. This is particularly useful when a torque motor, encoder, slip ring, optical path or service connections must be integrated around the rotating axis.
For other bore sizes and load capacities, view the complete LYDL SX crossed roller bearing series. Use a clear product photograph showing the thin section, integrated inner ring and split outer-ring structure. The product marking should display LYDL SX011840.
The listed ratings are catalogue reference values, not direct maximum operating loads. Final selection must consider radial load, axial load, tilting moment, duty cycle, speed, lubricant, temperature and required service life.
Load ratings from different manufacturers should not be mixed in one calculation. Differences in internal geometry, roller number, materials and calculation methods may result in different published values for dimensionally similar bearings.
For an explanation of crossed roller bearing structures, load directions and selection principles, refer to the LYDL crossed roller bearing selection guide.
Why Choose the SX011840?
Large 200 mm Central Passage
The 200 mm bore can accommodate a hollow shaft, torque-motor rotor, encoder, slip ring, cable group, optical path or process connections.
This allows drive and service components to be integrated through the center of the rotary assembly without substantially increasing the outside diameter.
Combined-Load Capability
The crossed roller arrangement supports radial, axial and moment loads simultaneously. In suitable applications, one SX011840 can replace a more complex arrangement using two separated bearing positions.
Compact 24 mm Width
The bearing’s low axial height helps shorten the spindle or rotary-table structure. A shorter structure can reduce overhang and improve the rigidity of the complete assembly.
High Static Load Capacity
The SX011840 provides a static axial rating of 425 kN and a static radial rating of 208 kN. This makes it suitable for slow-indexing equipment and stationary fixtures carrying meaningful offset loads.
Precision Options
P5 is appropriate for many industrial rotary systems. P4 or P2 can be supplied for applications with more demanding runout and positioning requirements.
The final accuracy grade should be selected using the complete system-error budget rather than choosing the highest grade automatically.
Main Applications
Hollow-Shaft Torque-Motor Axes
SX011840 can support direct-drive axes requiring a 200 mm hollow passage. The central opening can accommodate the motor rotor, encoder components, cables or rotary connections.
Motor heat, rotor imbalance and electromagnetic forces should be evaluated together with bearing preload and housing expansion.
CNC B-Axes and Rotary Tables
The bearing can be used in machine-tool B-axes, indexing tables and precision workholding platforms. Its compact width helps reduce the distance between cutting forces and the bearing center.
Workpiece weight alone is not sufficient for selection. Cutting forces, chuck overhang, fixture eccentricity and emergency-stop loads must also be considered.
Gear and Transmission Test Systems
SX011840 can support combined forces created during gear, reducer or transmission testing. Its large center opening provides space for shafts, torque sensors and test connections.
Test-load fluctuations, reversing torque and misalignment should be included in the engineering review.
Optical and Scanning Platforms
The 200 mm central aperture can accommodate lenses, scanners, sensors or optical paths. Controlled rotational torque and low runout are important for repeatable scanning.
P4 or P2 accuracy may be selected when the complete platform, mounting components and encoder can support the same precision level.
SX011840 is appropriate when a 200 mm central passage is required and its 425 kN static axial rating provides sufficient load margin.
SX011836 can reduce housing size and rotating mass when a 180 mm bore is sufficient. SX011848 provides a 240 mm bore and substantially higher capacity but requires a larger 300 mm outside diameter.
If the application requires an alternative inner-ring and outer-ring configuration, compare the LYDL RB series crossed roller bearings.
Accuracy and System-Level Performance
LYDL can supply P5, P4, P2 or customized rotational accuracy. Bearing accuracy is only one part of the complete rotary system.
Final system performance can be affected by:
Shaft-seat roundness
Housing-seat geometry
Mounting-face flatness
Flange parallelism
Clamping deformation
Drive eccentricity
Encoder installation
Worktable deformation
Thermal expansion
Assembly cleanliness
A P2 bearing installed in an inaccurate or flexible housing will not automatically produce P2 system-level rotation.
For CNC or optical equipment, define permissible radial runout, axial runout, angular error and repeatability before selecting the accuracy class.
Internal Clearance and Preload
An internal-clearance configuration generally provides lower friction torque and greater tolerance of mounting or thermal variation. It may be suitable for rotary support applications without demanding angular-rigidity requirements.
Controlled preload can improve rigidity, reversal accuracy and settling behavior. It is commonly considered for direct-drive axes, CNC rotary tables and precision inspection systems.
Excessive preload may increase starting torque, heat generation and sensitivity to mounting deformation. The required preload should be evaluated together with motor capacity, lubricant resistance and operating temperature.
For torque-motor applications, specify both the permissible starting torque and continuous operating temperature when requesting a preloaded bearing.
Suffix and Designation Explanation
Suffixes may identify internal clearance, preload, coating, accuracy or design generation. Their meanings are manufacturer-specific.
In Schaeffler technical documentation, examples may include:
RL0: reduced internal clearance
VSP: defined preload
RR: Corrotect-coated version
A: may identify a particular design generation
An SX011840-A-VSP should not automatically be replaced by a standard SX011840. The original suffix, drawing and operating requirements must be reviewed before replacement approval.
Do not remove any suffix from the RFQ, even when the external dimensions appear identical.
Replacement and Interchangeability
SX011840 and LRC 20024 may be used as dimensional interchange references. Functional interchangeability requires more than matching the 200 × 250 × 24 mm dimensions.
Confirm:
Complete original designation and suffix
Bore, outside diameter and width
Dimensional tolerances
Accuracy class and runout
Internal clearance or preload
Starting and running torque
Load-rating basis
Material and heat treatment
Lubricant
Coating or corrosion protection
Inspection and traceability documents
LYDL can review the original label, catalogue page, product drawing or inspection report before confirming interchangeability.
Third-party brand names are used only for technical identification and comparison. Their use does not imply authorization, affiliation or original-brand manufacture.
Mounting Recommendations
The split outer ring must be retained uniformly by a rigid housing cover or clamping flange. Uneven clamping can distort the raceways and create torque variation.
A reference mounting arrangement may use 24 × M10 flange screws. The final screw diameter, quantity, strength class and tightening torque must be calculated according to the actual housing and external loads.
Both mounting faces should be flat, parallel, clean and free from burrs. Local high points, uneven coatings and insufficient flange thickness can affect running accuracy.
Tighten the flange screws gradually in a diagonal sequence. Rotate the bearing during tightening and investigate any sudden increase in starting or running torque.
Gears, pulleys and heavy fixtures should be positioned close to the bearing where possible. Increasing the distance between the applied force and bearing center increases the tilting moment.
Thermal Considerations
Torque motors and nearby drive components may transfer heat into the inner ring. A temperature difference between the inner and outer rings can alter the bearing’s internal operating condition.
Aluminum housings expand more than bearing steel. This difference can change mounting fits and effective preload as the equipment temperature increases.
The thermal review should include:
Motor heat generation
Housing material
Shaft material
Continuous operating time
Cooling method
Ambient temperature
Expected inner-to-outer-ring temperature difference
A room-temperature assembly result may not represent the bearing condition after the machine reaches thermal equilibrium.
Lubrication and External Sealing
The standard SX011840 is open and does not include integral seals. External protection is required in environments containing chips, dust, coolant or moisture.
Select lubricant according to speed, load, oscillation, temperature and required service life. Grease resistance should be included when calculating torque-motor capacity.
Avoid excessive grease filling because it can increase drag and operating temperature. Grease quantity and distribution should be controlled during assembly.
For optical, cleanroom or semiconductor equipment, specify cleanliness, lubricant compatibility and packaging requirements before ordering.
LYDL Manufacturing and Quality Control
LYDL can manufacture SX011840 using GCr15 or GCr15SiMn bearing steel. Accuracy, internal clearance, preload and lubrication can be configured according to the application.
Manufacturing and inspection may include:
Raw-material verification
Precision turning
Heat treatment and cryogenic stabilization
Raceway grinding
Raceway superfinishing
Roller manufacturing and optical sorting
Precision dimensional measurement
Deep cleaning and demagnetization
Controlled preload assembly
Starting and running-torque testing
Radial and axial runout inspection
Final visual inspection
Laser marking
Rust prevention
Inspection requirements and acceptance limits should be agreed before production.
Inspection Documents and Packaging
Available documentation may include:
Material certificate
Hardness report
Dimensional inspection report
Radial and axial runout report
Starting or running-torque record
Clearance or preload record
Product traceability information
Packaging photographs
The bearing can be individually protected with anti-rust treatment, protective wrapping, shock-resistant foam and an individual carton.
Reinforced export wooden cases can be supplied for international transport. Additional moisture protection should be specified for sea freight or long-term storage. Use a real inspection and packaging photograph. The product label, individual box and export-case information should consistently display SX011840.
These sources provide general technical and comparison information. Final SX011840 selection should be based on the confirmed LYDL specification, customer operating conditions and approved drawing.
Information Required for an Accurate Quotation
Please provide:
Required quantity
Complete bearing designation and suffix
Accuracy class
Clearance or preload requirement
Radial and axial loads
Tilting moment or load offset
Maximum and continuous speed
Operating cycle
Operating temperature
Housing and shaft materials
Lubrication and sealing requirements
Inspection-document requirements
Delivery destination and required date
Frequently Asked Questions
1. What is the main design advantage of the 200 mm bore?
The large bore allows a torque-motor rotor, encoder, slip ring, optical path or service connections to pass through the center while keeping the outside diameter at 250 mm.
2. Can SX011840 be used for continuous torque-motor rotation?
Potentially, but a universal speed limit should not be assumed. Preload, lubricant, motor heat, housing accuracy and operating temperature must be evaluated.
3. When should SX011848 be selected instead of SX011840?
SX011848 should be considered when a 240 mm bore or substantially higher load capacity is required. SX011840 remains more compact and has lower rotating mass.
4. How do gears or pulleys affect bearing selection?
Gear and belt forces create radial loads. If the force is offset from the bearing center, it also creates a tilting moment that must be included in the calculation.
5. Will a P2 SX011840 guarantee P2 machine accuracy?
No. System accuracy also depends on the shaft, housing, flange, encoder, drive components, worktable and assembly process.
6. Why can running torque increase after the motor becomes warm?
Thermal expansion may change the shaft fit, housing fit or effective preload. Excessive grease and external seal friction can also increase torque.
7. Can SX011840-VSP be replaced by a standard SX011840?
Not automatically. VSP may indicate a defined preload condition that affects rigidity, torque and positioning performance.
8. What inspection should be requested for a CNC B-axis?
Typical requirements include critical dimensions, radial runout, axial runout, rotational torque, preload verification and individual traceability.
Request an SX011840 Quotation
Send LYDL your complete SX011840 designation, quantity, accuracy class, preload or clearance and operating conditions.
You can contact LYDL for SX011840 pricing and technical support to request drawings, inspection documents, customization information and export delivery options.
Use a real inspection and packaging photograph. The product label, individual box and export-case information should consistently display SX011840.