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Our Strengths

A treasure store of technologies and skills creating high-precision products

For more than 40 years, ever since our founding occasioned by our fateful encounter with strain wave gearing, the HDS Group has pursued the endlessly expanding potential of speed reducers. The irreplaceable assets of the HDS Group are the development technologies, production technologies, processing and assembly skills, and production systems that we have built up over this time, and these are also our greatest and unrivaled strength.

The HarmonicDrive® has evolved continuously since its birth. Between the time of the R Series (left) marketed in 1981 and today's mainstay CSF Series (center), thickness has been reduced to 3/5 and rotation accuracy and transmitted torque have been doubled. Moreover, the ultra-flat CSD Series (right), by applying the latest technology and skills, succeeds in achieving high rotation accuracy and torque while reducing thickness to 1/3 that of the R Series. In such ways The
HarmonicDrive® continues its non-stop advance toward a more compact shape that is able to transmit a larger force with greater accuracy.

A product lineup providing compact size, light weight, and high accuracy

Semiconductor wafer transport robot provided to Daihen Corporation

The mechatronics products and speed reducers made and sold by HDS group are winning high praise from customers who require advanced levels of motion control and more compact, lightweight equipment.
Among these products,the HarmonicDrive®, with its compact size, light weight, and high precision, has won a high worldwide market share as a speed reducer embedded in the joints of industrial robots, which are used in manufacturing processes of automobiles, digital equipment, semiconductor wafers, and flat panel display. Moreover, in wide-ranging applications from humanoid robots and measuring and test equipment to space satellites and oil drilling equipment, it is providing distinctive added value that would be difficult to achieve with another mechanism.

Technology enabling the provision of total motion control

AC servo actuator
Hollow, flat type SHA-25

In addition to speed reducers, the HDS Group has built up technology and skills through R&D and production of motors, sensors, drivers, controllers and other system elements. The resulting tangible and intangible technologies and skills are essential for providing the advanced motion control our customers demand, and are the source of the competitive advantage of the HDS Group.

The HDS Group is especially proud, for example, of having the original reducer, bearing, motor, and sensor technologies that go into our thin and hollow actuators, along with the capability of merging these components in a high-level way.

(Sensor) Encoder (Motor) AC motor (Bearing) Cross roller bearing (Speed reducer) HarmonicDrive® Mechatronics Controller, driver Actuator Unit Components Speed Reducer

Business operations integrating marketing, production, and development

In order to reflect customer needs in our product development and manufacturing, the HDS Group administers business operations in a way that ensures close relations among the marketing, production, engineering, and development divisions.
For example, these main functions are concentrated in our Hotaka Plant in Nagano Prefecture; and an efficient workflow is implemented from the initial contacts with customers to technical studies, prototyping, order-taking, manufacturing, and shipment.
A strength of our organization is our ability to quickly reflect customer needs and the ideas of engineers in production, for timely provision of new motion control.

Marketing Provide optimal solutions Cultivate new markets and uses Development Solve technology problems Shorten development lead time Quickly bring new products to market Manufacturing Improve skills and production technology Shorten manufacturing lead time Stably provide high-quality products

Strengths of the HarmonicDrive®

What is the HarmonicDrive®?

The HarmonicDrive® is a gear mechanism for transmitting motive power. It is used when the speed and direction of motive power need to be changed.The HarmonicDrive® is used mostly for lowering (reducing) speed, so here we will talk about its strengths as a speed reducer.

1. What is a speed reducer?

Besides gears, there are many different kinds of speed reducers such as pulley and belt combinations or sprocket and chain arrangements. In each case the function is to lower the rotating speed of the driving force so as to output torque (force) in proportion to the reduction ratio. In other words, by lowering the speed, a small force is converted into a larger force. When transporting a heavy load, for example, a speed reducer makes it easier to carry; or when riding a bicycle up a steep slope, a speed reducer lets you climb easily. In such ways a speed reducer is an essential mechanism for obtaining the desired motion and force.

Example of a bicycle

Example of a bicycle Per one pedaling cycle   Go forward 3m Can travel fast on flat terrain Cannot climb steep slope without strong legs Using a speed reducer to climb slopes... Per one pedaling cycle   Go forward 1m Speed becomes slower, but... Can climb slopes without strong force

2. The strain wave gearing mechanism of the HarmonicDrive®

The HarmonicDrive® made by HDS group is a speed reducer making use of a gear mechanism. There are many different kinds of gears, but the gear mechanism used in the HarmonicDrive® is one kind of planetary gear called a strain wave gear.

Main types of gears

Spur gear  Helical gear  Bevel gear  Rack and pinion  Strain wave gear

  • *When the HarmonicDrive® was originally invented in the United States by C. W. Musser, it was announced at the time with the name "strain wave gearing," and that is the name under which it was patented. Later Harmonic Drive Systems Inc. succeeded in making practical application of the technology in Japan.
    The academic and generic name of the HarmonicDrive® is "strain wave gearing." HarmonicDrive® is a registered trademark that can be used only with products manufactured and sold by Harmonic Drive Systems Inc.

Strengths of the HarmonicDrive®

  1. Compact and light

    The biggest feature of the HarmonicDrive® is its small size and light weight made possible by a simple structure of just three components.

    Its unique principle applying the flexibility of metal makes it possible to create a HarmonicDrive® having a much higher reduction ratio (1/30 to 1/320) than standard reducers of the same volume and weight. For example, in order to obtain a high reduction rate of 1/320 with a spur gear, a large number of teeth would be needed, resulting in a heavy weight and occupying a very large space. The HarmonicDrive® with its compact size and light weight is used widely in the aviation and space fields where size and weight are severely limited, and in small industrial robots.

    The smallest HarmonicDrive®
    The smallest HarmonicDrive® is just 13mm in diameter, smaller than a Japanese one yen coin (20 mm in diameter), and has teeth that are 0.042mm in size, around half the average thickness of a human hair. The strength of our company is having the technology and skills for machine processing of such tiny teeth, measuring them, and assuring quality.
  2. Non-backlash

    The HarmonicDrive® is a non-backlash speed reducer, meaning no motion is lost due to clearance between mated gear teeth. Ordinary gear mechanisms, which reduce speed by meshing many turning gears, require a certain amount of clearance, and therefore backlash, since without that clearance the gears would jam or otherwise not rotate smoothly. Backlash of a mere 0.5 degrees at the center of gear rotation, however, would result in error of 8.7mm after one meter of movement. For semiconductor manufacturing equipment or industrial robots that require precise positioning, the existence of backlash would be a fatal problem.

    An ordinary gear mechanism

    The HarmonicDrive®, on the other hand, in principle requires no backlash at all. At a distance of 1m or even 10m, the amount of error caused by gear teeth clearance is essentially zero; moreover, the number of teeth engaged at one time is large, enabling highly accurate positioning.
    In fact, nearly all HDS group products are used in applications such as industrial robots, semiconductor manufacturing equipment, and flat panel display manufacturing equipment that require highly accurate positioning.

    The HarmonicDrive®

  3. High efficiency

    The mating portion of each tooth is subjected to very little slide motion. Motion loss due to friction is therefore reduced substantially, so that high efficiency is maintained even at high reduction ratios and driving motors can be made smaller.

  4. High torque capacity

    he flex spline is made of special steel highly resistant to fatigue. Unlike an ordinary mechanism for transmitting motive power, approximately 30% of the total number of gear teeth are engaged at one time, and the contact is made between surfaces; moreover, the amount of force on one tooth is very small. As a result, high torque capacity is achieved

  5. Easy mounting and assembly

    Despite the high reduction ratio achieved, the HarmonicDrive® is made of just three basic parts. Since they share the same centerline, assembly is easy and simple design is possible.

  6. Quiet, smooth operation

    Quiet operation with very little vibration is the result of the low circumferential speed of tooth engagement and the well-balanced force across the mechanism.