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SHF / SHG Cross Roller Bearings — Hollow-Shaft Selection Guide

SHF / SHG cross roller bearings provide output support for compatible harmonic reducer assemblies. Compare the bearing interfaces together with the central passage required by your complete mechanism.

Published LYDL reference sizes are 14, 17, 20, 25, 32, 40 and 50. Separate envelope and interface tables help check bore steps, axial dimensions and mounting circles.

Review cable or shaft clearance, flange attachment, external loads and mounted accuracy. Additional sizes and component load ratings require a model-specific drawing review.

Provide the reducer identification, assembly section, quantity and operating requirements to request a LYDL specification review and quotation.

Need this model? Request a SHF / SHG Cross Roller Bearings — Hollow-Shaft Selection Guide quotation and drawing or email us directly — LYDL replies within one working day.

SHF / SHG Cross Roller Bearings for Hollow-Shaft Assemblies

SHF / SHG cross roller bearings provide output support for compatible harmonic reducer mechanisms, including assemblies needing a central service passage. Compare reference sizes, read the section drawing and define the interface review. Start with the complete reducer configuration and available passage, then assess mounting, loading and accuracy requirements.

LYDL SHF and SHG hollow-shaft harmonic reducer output bearing product view
SHF / SHG family product view. Confirm the selected model on its drawing.

The SHF / SHG product directory groups the available family references. A bearing’s central opening is only one part of a hollow-shaft system: surrounding flanges, shafts, seals and internal parts also determine the usable passage. Plan the complete service route before choosing a candidate.

SHF and SHG Unit References

Harmonic Drive identifies SHF-2UH and SHG-2UH as hollow-shaft gear units with cross roller output support and a flange for attaching the load. SHG is the high-torque gear-unit alternative. Standard and lightweight configurations require their own interface checks; a gearbox designation does not specify every replacement bearing detail. [1, 2]

The flange support bearing reacts loads from the driven equipment. The wave-generator flexible bearing is a separate component in the strain-wave transmission. Confirm the component’s location when requesting a replacement. For another output-support layout, compare the CSG / CSF selection page using the actual drawings.

Read the Cross-Section and Mounting Layout

The series illustration shows the central opening, section details and mounting circles. d and D identify the bore and outside diameter; H, C, B and B1 locate axial dimensions. dm and dn mark mounting pitch circles, while d1, d2 and d3 identify additional diameter references. Values must be taken from the corresponding model drawing rather than estimated from image proportions.

SHF and SHG cross roller bearing cross-section and hollow-shaft mounting layout with dimension symbols
SHF / SHG structure reference; model-specific drawings define dimensions, holes and tolerances.

In particular, d and d3 locate different features. Check their mating components and axial positions before assigning either value to a cable or shaft clearance. The plan view illustrates a mounting pattern; it does not prescribe the illustrated hole count for every size. Inner pitch-circle data and hole specifications need a separate drawing check.

SHF / SHG Size Comparison and Product Navigation

The tables below retain the existing LYDL reference dimensions in millimetres and separate the main envelope from secondary interfaces. Published entries cover sizes 14–50. A size reference is not the bore diameter: for example, SHF/SHG-25 has a listed d value of 67 mm. Confirm additional sizes through a drawing review.

LYDL dimensional references — bore, outside diameter and axial details (mm)
Model referencedDHCBB1Drawing
SHF/SHG-14387015.214.213.75Drawing
SHF/SHG-174780171616.46.5Drawing
SHF/SHG-20549018.517.517.57Drawing
SHF/SHG-256711020.718.719.77.5Drawing
SHF/SHG-328814224.423.423.48Drawing
SHF/SHG-40108170302928.59.5Drawing
SHF/SHG-50135214363434.511Drawing
LYDL dimensional references — secondary diameters and outer PCD (mm)
Model referenced3d1d2dmDrawing
SHF/SHG-1436575364Drawing
SHF/SHG-1744.268.16474Drawing
SHF/SHG-2051.37872.684Drawing
SHF/SHG-2564.294.890102Drawing
SHF/SHG-3284123117.6132Drawing
SHF/SHG-40106148142.6158Drawing
SHF/SHG-50129188182.6200Drawing

For size 20, the reference envelope includes d = 54 mm, D = 90 mm and H = 18.5 mm; d3 is 51.3 mm. These dimensions help screen candidates. The ring interfaces, thread details, hole depths, seals and tolerances still require verification against the intended assembly.

Check the Usable Central Passage

List what passes through the axis: electrical cables, pneumatic lines, a shaft, optical components or a rotary union. Include connector dimensions and assembly access; installation may need more space than the cable occupies in service.

Review clearance throughout the planned travel, allowing for relative movement, bends and adjacent parts. Define how hoses and cables are restrained and whether their motion requires a separate routing device. The bearing supports the mechanical output; it does not itself solve service twisting or establish the full gearbox’s through-bore capacity.

Match the Housing and Output Flange

Use two interface checks: one for the stationary support and another for the driven flange. Compare locating diameters, shoulder contact, axial offsets and the complete fastening pattern. Record mounting pitch circles, hole quantity, thread size, engagement depth and any countersinks or spotfaces.

Keep those details together on one controlled drawing revision. A nominally similar flange can have incompatible registers or bolt access. Confirm that installed fasteners clear internal moving parts and that the supporting faces are flat and clean. Apply the specified tightening sequence and torque, then inspect running behaviour after clamping.

Evaluate Force, Moment and Motion

Describe the loading at the bearing location, rather than supplying payload mass alone. Include force direction, centre-of-gravity position, tooling offsets, acceleration, stopping events and any process force. An overhung load can create a significant overturning moment even when its mass appears modest.

For an illustrative single-force case, 200 N acting perpendicularly at a 0.15 m lever arm produces 30 Nm. This is a geometry example, not a permissible load for a listed model. Review radial and axial loading, moment capacity, required life and the assembly’s stiffness together. Variable cycles also need the time spent at each loading and output-speed condition.

The current LYDL dimensional table does not provide confirmed SHF / SHG bearing ratings. Request C, C0 and applicable moment data for the supplied configuration. C denotes basic dynamic load rating; C0 denotes basic static load rating. Original gear-unit torque, output-bearing specifications and complete-unit mass remain reference data for their stated assembly and cannot be assigned directly to a LYDL component.

Define Precision and Environmental Requirements

Describe the required rotation at the driven flange: radial runout, axial runout, allowable tilt and running torque. Specify where measurements are taken and whether acceptance is before or after mounting. Clearance or preload must be assessed alongside supporting stiffness; a catalogue accuracy label alone does not define the finished mechanism’s performance.

Identify temperature, contamination, lubrication access and sealing needs. For short reversing movements, discuss the motion profile and lubrication requirements explicitly. Semiconductor and medical equipment may impose additional material, cleanliness or qualification conditions. Compare alternative constructions in the LYDL cross roller bearing catalogue.

Typical Equipment and Installation Positions

These representative applications explain the mechanical role of output support. They do not confirm fit in a particular machine or establish regulatory suitability. Harmonic Drive’s application examples cover the wider equipment fields. [3]

  • Industrial robotics: support rotary joints with internal service routing. Check arm inertia, tool offsets and cable clearance through the assembled joint.
  • Machine tool positioning: carry the driven flange of compact orienting axes where a suitable reducer is used. Keep process loads and mounting deflection in the calculation.
  • Semiconductor handling: support articulated transfer or positioning axes with coordinated motion. Verify environmental requirements and the routing of vacuum or electrical services.
  • Medical robotics: support controlled articulation or instrument positioning. Validate the complete device’s mechanical and application requirements independently.
Harmonic reducer applications in robot joints, machine tool positioning, semiconductor handling and medical robotics
Application illustrations: industrial robotics, machine tool positioning, semiconductor handling and medical robotics.

Inspection Records and Shipment Protection

Define acceptance characteristics before placing the order. For this family, bore steps, seating faces and hole interfaces should be checked alongside specified runout and running characteristics. Request records tied to the part identification and approved drawing. LYDL’s manufacturing information explains the available inspection approach.

Agree anti-corrosion protection, individual wrapping, ring restraint and outer packing for the transport route. Keep machined surfaces protected until installation, and follow the supplied handling instructions when removing protective materials.

Cross roller bearing inspection and export packing with protected bearings and individual cartons
Representative inspection and export packing. Acceptance and transport protection follow the order specification.

SHF / SHG Engineering Questions

Is d the usable through-bore of the complete reducer?

It is a bearing reference dimension in this drawing. The assembled passage can be restricted by shafts, flanges, seals or internal components. Check the full axis section and connector access before confirming routing space.

Why are both d and d3 listed?

They describe different diameters at the indicated section features. Determine which component mates with each surface and where it sits axially. Treating them as interchangeable dimensions can lead to a clearance or locating error.

Can I order size 65 from this selection table?

The published LYDL entries cover sizes 14–50. Send the complete size-65 requirement and drawing for availability and interface review; dimensions from another unit configuration should not be used to fill the missing row.

Does changing from SHF to SHG guarantee greater bearing capacity?

SHG identifies a high-torque gear-unit family. Compare the actual output-bearing specification and mounting arrangement to establish support capacity. The gearbox family label alone does not certify a replacement bearing’s load rating.

What should be checked before fitting a rotary union through the centre?

Review the union’s envelope, supports, mounting access and service connections throughout travel. Include any forces transferred to the bearing and verify clearance against the complete assembly drawing, not only the nominal bore.

Send Your SHF / SHG Selection Requirements

Request an SHF / SHG drawing review from LYDL. Provide the reducer identification, required quantity, assembly section, mounting dimensions and working load profile. Include your passage requirement, accuracy targets, inspection records and delivery destination. Clear interface information helps establish an appropriate component specification before quotation and production.

Reference Sources and Specification Scope

  1. Harmonic Drive SHF-2UH gear unit information.
  2. Harmonic Drive SHG-2UH gear unit information.
  3. Harmonic Drive application examples.

LYDL is the supplier of its own bearing products. Referenced brand and series names identify comparison families. Confirm supplied dimensions, performance and inspection criteria in the agreed LYDL drawing and order specification.