Planetary and hollow strain-wave drives

WANSHSIN: compare the motion duty before the headline torque

WANSHSIN supplies gearboxes, gearmotors and related drive equipment from its Hunan headquarters. Two precision ranges in this directory solve different packaging problems: WVRB planetary units connect to a motor shaft, while WSHD hollow strain-wave units offer a flat coaxial layout. Their torque and precision figures use different definitions.

Prepare your enquiry Manufacturer website ↗

WVRB090: changing the ratio changes the rating

For the single-stage WVRB090, the official performance table gives the following rated output torques. The size remains the same; the rating does not.

Single-stage ratio	WVRB090 rated output torque	Selection implication
3 : 1	130 Nm	Use this row for a ratio-3 selection.
5 : 1	160 Nm	This is higher than the ratio-3 and ratio-10 rows.
8 : 1	100 Nm	Do not carry the ratio-5 rating across.
10 : 1	90 Nm	Higher reduction does not establish higher allowable torque.

The same table gives WVRB090 rated input speed 4,000 rpm and maximum input speed 8,000 rpm. A speed maximum is not permission to run continuously at that speed and rated torque together; request the selected duty calculation.

WSHD20: four torque limits describe four different duties

The WSHD table explicitly states rated torque at 2,000 rpm input. Here is one frame at two ratios, with the columns kept separate.

WSHD20 ratio	Rated at 2,000 rpm input	Starting / stopping allowance	Average-load allowance	Momentary allowance
50 : 1	16 Nm	37 Nm	23 Nm	66 Nm
100 : 1	28 Nm	54 Nm	32 Nm	90 Nm

A momentary limit cannot replace a continuous operating rating. For frequent reversals, supply the complete cycle, loads and stopping conditions rather than selecting from the last column.

Keep angular units and precision grades attached to the assembly

Planetary precision grade

For WVRB090, the official single-stage P0 limit is ≤1.5 arcmin; the two-stage P0 limit is ≤3 arcmin. Include stage count and grade in the enquiry. A family-level precision headline does not identify the supplied configuration.

Hollow strain-wave layout

WSHD is presented as a flat hollow coaxial assembly. Its table uses 15 arcseconds for backlash: 0.25 arcmin after unit conversion. This is an angular allowance, not a guaranteed positioning error for an entire robot axis. Ask for stiffness and load-dependent performance for the chosen frame.

External load and installation

For a pinion, pulley or hollow-axis arrangement, provide forces, offsets and the supporting structure. Include cable or shaft clearance through the hollow axis, the mounting fit, bolt pattern and accessible assembly sequence in the drawing review.

Continue with the model-specific records

WVRB Precision Planetary GearboxSpecifications

WSHD Hollow Strain Wave GearboxSpecifications

WRA Precision RV ReducerSpecifications

The additional WRA record is a separate reducer family. Its figures should not be used to extend the WVRB or WSHD tables above.

Describe the actual motion cycle

A useful quotation should identify the frame, ratio, precision grade and load calculation for one complete assembly.

Prepare sourcing request

Save this manufacturer first to include it in your sourcing request.

Axis type and required layout: motor-shaft planetary or flat hollow strain-wave, including available dimensions.
Output speed and continuous torque, acceleration events, reversal frequency, dwell periods and emergency stop conditions.
Motor model and input speed; WVRB grade and stage count, or WSHD frame and ratio.
Radial/axial loads, their offsets, mounting drawings and hollow-axis clearance if applicable.
Required accuracy under load, test and acceptance conditions, quantity and a request for the applicable model-specific table.

Sources & review

Numeric entries are manufacturer-published table values for the stated frame and configuration. Unit conversion and procurement comments are editorial analysis. The exhibition entry does not establish measured product performance.

Reviewed 8 October 2026.

WANSHSIN · Official company history ↗Company scope, Dongguan origin and Changsha headquarters history.
WANSHSIN · WVRB official performance table ↗WVRB090 single-stage torque rows, input-speed entries and stage-specific P0 backlash.
WANSHSIN · WSHD official performance table ↗WSHD20 ratio-50 and ratio-100 torque definitions, 2,000 rpm rated condition and angular unit.
Agroprodmash · 2023 official exhibitor catalog ↗Historical WANSHSIN company listing; not a current certification or independent product test.