HCS Standard Cup-Type Harmonic Reducer

The flexspline adopts a cup-type standard cylindrical structure with compact size; the input shaft mates directly with the wave generator bore and connects via a flat key, typically with the circular spline fixed and the flexspline as output. Highly meshed and lightweight. The HCS harmonic reducer features high transmission accuracy, low noise, fast response and excellent reliability. Because multiple teeth engage simultaneously at two symmetric 180° positions, pitch and cumulative pitch errors average out, yielding very high positional and rotational accuracy.

Model Range:Frame 14 / 17 / 20 / 25 / 32 / 40
Structure: Standard cup
Mounting Holes: 6 / 8 / 10 / 16 hole groups
Reduction Ratio: 50 : 1 – 160 : 1 (custom)

6 model codes · frame 14 / 17 / 20 / 25 / 32 / 40 · See the model matrix ↓

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Specifications

Typical reference parameters. Final specifications are subject to our technical confirmation.

Parameter	Value
Reduction Ratio	50 : 1 – 160 : 1 (custom)
Rated Torque @2000 rpm (N·m)	3.5 – 686
Peak Torque (N·m)	up to 1,180
Backlash	≤ 20 arc-sec (≤ 10 optional)
Rated Input Speed	2000 – 3000 rpm
Design Life	≥ 7,000 h
Operating Temp.	-10 °C ~ +50 °C
Mounting Holes	6 / 8 / 10 / 16 groups

Model Matrix

WHS-HCS Model Matrix

6 orderable codes across frame sizes 14 / 17 / 20 / 25 / 32 / 40 — pick the frame first, then the structure code.

Frame	U-I · Standard cup	Mounting Holes
14	WHS-HCS-14-XX-U-I	6 groups
17	WHS-HCS-17-XX-U-I	6 groups
20	WHS-HCS-20-XX-U-I	6 groups
25	WHS-HCS-25-XX-U-I	8 groups
32	WHS-HCS-32-XX-U-I	10 groups
40	WHS-HCS-40-XX-U-I	16 groups

Frame size = outside diameter of the circular spline (mm). "—" marks a combination that is not offered. Mounting-hole groups increase with frame size. All frames use the standard cup structure; reduction ratio is confirmed when the order is placed.

All five series · 53 codes → Request a Quote

Technical Detail

Structure & Working Principle

The HCS series uses a cup-shaped flexspline as the elastic element. The input shaft mates directly with the wave-generator bore through a key connection, the rigid circular spline is normally fixed, and the cup end provides the output. This classic cup structure is compact and light, with high meshing contact for smooth, precise transmission.

Key Features

Cup-shaped flexspline, compact and lightweight
Direct key connection between input shaft and wave generator
High meshing ratio for smooth, low-noise running
High positional and rotational accuracy
Easy to seal and integrate into compact axes

Selection Guide

Choose HCS when you need a proven, general-purpose precision reducer for robot joints, rotary tables and servo axes where a cup output and compact body are preferred. Available across the standard reduction-ratio range; confirm torque and mounting dimensions against your load case.

Products

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The HSD series is an ultra-short hat-type product developed from the HST platform. Its flexspline uses a hollow-flange structure; the unit is shorter axially and more compact, with an internal support bearing and fully sealed construction for easy installation. The HSD harmonic reducer offers high precision, high rigidity and light weight — ideal for axial space-constrained, weight-sensitive applications.

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