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Zero Backlash Gearboxes

A zero-backlash gearbox gearbox is a type of mechanical transmission system designed to eliminate backlash, which is the play or loose movement between meshing gear teeth when the direction of load is reversed. Strain wave gearboxes (also known as harmonic gearboxes) and cycloidal gearboxes are two common types of zero-backlash precision gearboxes.

Zero Backlash Cycloidal Gearboxes

Fine Cyclo

Fine Cyclo® cycloidal gearboxes feature zero-backlash and high-precision mechanisms. With their compact design, long life, and optimal integration into your application, these single-stage and double-stage cycloidal drives can provide a high level of performance.

Their high torque, coupled with their low moments of inertia, makes them ideal solutions for highly dynamic tasks.

Available Input & Outputs

  • Hollow Shaft
  • Keyed
  • Coupling
  • Clamp Ring

Gearbox Product Specifications

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Torque

Nominal: Up to 12,000 N•m (106,209 lb•in) / Acceleration: Up to 30,000 N•m (265,522 lb•in)

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Diameter

Up to 138 mm (Hollow Bore)

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Ratio Range

29:1 to 283:1

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Input Speed

Up to 10,260 RPM


Fine Cyclo Options

A Series
Single-stage gearbox option, all featuring high acceleration torque and bearing capacity for high-precision point-to-point movement.
C Series
Fully sealed single-stage gearbox with a large hollow shaft for high-precision point-to-point movement.
DA Series
Fully sealed single-stage gearbox with high acceleration torque and stiffness. (featured above)
T Series
Spur gear two-stage high-precision cycloidal gearbox. This gearbox comes pre-staged and has three eccentrics.
UA Series
Double-stage gearbox with a planetary 1st stage and cycloidal 2nd that offers highly efficient traverse movement.
W Series
High-load precision one-stage cycloidal gearbox with extremely large hollow shaft and integrated pre-stage.

Zero Backlash Strain Wave/Harmonic Gearboxes

Elastic Cyclo (ECY)

Our Elastic Cyclo gearbox blends strain wave reduction and cycloidal engagement technologies to provide zero-backlash performance. Its torsional stiffness is approximately double that of its general strain wave gear competitors. 

In order to provide zero-backlash performance, we designed this harmonic/strain wave precision gearbox with trochoid teeth similar to our Cyclo®.

The ECY features a highly compact design to achieve excellent torque density.

Available Input & Outputs

  • Hollow Shaft

E-Cyclo Product Specifications

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Torque

Nominal: Up to 67 N•m (6.8 kgf•m) / Acceleration: Up to 284 N•m (29.0 kgf•m)

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Diameter

Up to 25.5 mm (Hollow Bore)

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Ratio Range

29:1 to 283:1

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Input Speed

Up to 8,500 RPM


Discover Precision Engineering with Our Motion Control Products Brochure

Designed for precision and durability, our gearboxes offer zero backlash, high torque capacities, and exceptional performance. 

View the range of capabilities and features of our motion control solutions in our detailed brochure.

The brochure provides information on our cycloidal gearboxes, strain wave gearboxes, and servo gearboxes.

Benefits of Zero-Backlash Gearboxes from Sumitomo

Increased Accuracy
They provide extremely precise positioning and movement control, which is crucial for applications like robotics, CNC machines, and aerospace equipment.
High Repeatability
With zero play between the gear teeth, these gearboxes ensure consistent performance, critical for quality and reliability in automated processes.
Smooth Operation
Eliminating backlash reduces vibrations and noise during operation, leading to smoother and quieter gearbox performance.

Comparing Cycloidal vs Strain Wave Gearboxes: Key Features and Applications Explained

Feature Cycloidal Gearboxes Strain Wave/Harmonic Gearboxes
Mechanism Uses cycloidal discs and pin-tooth engagement Utilizes a flexible spline and circular spline
Backlash Near-zero to very low backlash Zero backlash
Torque Capacity High torque capacity due to robust design High torque capacity but generally lower than cycloidal due to thinner, more flexible elements
Efficiency Generally lower efficiency due to sliding contact High efficiency due to rolling contact
Size and Weight Bulkier and heavier for equivalent torque Compact and lightweight for equivalent torque
Load Distribution Good load distribution due to multiple contacts Concentrated load points due to flex spline deformation
Speed Lower input speeds compared to harmonic Suitable for high-speed applications
Precision High precision, slightly less than harmonic Extremely high precision
Application Ideal for heavy load and industrial applications Often used in robotics, aerospace, and where compactness and precision are paramount
Durability Very durable due to robust construction Less durable, requires careful handling due to flexible elements
What Is the Difference Between Strain Wave & Cycloidal drives

Questions About Our Zero-Backlash Precision Gearboxes?

Send us a message, and we'll contact you as soon as we can. You can also email us at [email protected].

Frequently Asked Questions (FAQs)

Dive into our comprehensive FAQ section to understand the nuances of zero backlash gearboxes. Learn about their principles, materials, thermal management, and applications. Perfect for engineers and industry professionals seeking to enhance precision in high-performance systems.

What is the difference between zero backlash gearboxes, anti-backlash gearboxes, and low backlash gearboxes?

What is the difference between zero backlash gearboxes, anti-backlash gearboxes, and low backlash gearboxes?

Zero backlash, anti-backlash, and low backlash gearboxes are all designed to minimize the gap between gear teeth, enhancing precision and reducing play in mechanical systems. However, they differ in their design intent, backlash elimination level, and application suitability.

Zero Backlash Gearboxes

These are engineered to completely eliminate backlash. They use precise mechanisms, like spring-loaded or dual gear trains, to maintain constant engagement between gear teeth, ensuring no play or gap. Ideal for high-precision applications such as robotics, aerospace, and high-speed automation, where even minimal backlash could affect performance.

Anti-Backlash Gearboxes

These gearboxes significantly reduce, but may not entirely eliminate, backlash. They often employ mechanisms like adjustable gears or spring-loaded components to compensate for gear play. Anti-backlash gearboxes are used in scenarios where high precision is necessary but not to the extent required by zero backlash systems, like in some CNC machines or printing equipment.

Low Backlash Gearboxes

Designed with tighter manufacturing tolerances than standard gearboxes, low-backlash gearboxes have reduced backlash, but it is not as minimized as in anti-backlash or zero-backlash gearboxes. Low-backlash gearboxes are suitable for applications where improved precision is beneficial but extreme accuracy is not critical, such as in various industrial machines and conveyance systems.

What is the principle of operation for zero backlash gearboxes?

Zero backlash gearboxes operate by ensuring that there is no play or loose movement between the gear teeth. This is achieved through mechanisms like preloaded spring systems, split gears, or dual gear trains that compensate for any potential slack, allowing for precise control and high repeatability in motion transfer.

Can you explain the role of preloaded springs in maintaining zero backlash?

Preloaded springs in zero backlash gearboxes exert a continuous force on the gear assembly, ensuring constant engagement of the gear teeth without any gap. This mechanism compensates for wear and tear and thermal expansion, maintaining zero backlash throughout the operational lifespan of the gearbox.

What are the common materials used in the construction of zero backlash gears, and why?

What are the common materials used in the construction of zero backlash gears, and why?

Zero backlash gears are typically made from high-grade alloy steels, engineered polymers, or aluminum. These materials are chosen for their strength, wear resistance, and ability to maintain precise dimensions under load and temperature variations, ensuring reliable operation and longevity of the gear system.

How does the design of a zero backlash gearbox mitigate harmonic distortion and torsional rigidity?

How does the design of a zero backlash gearbox mitigate harmonic distortion and torsional rigidity?

The design of a zero backlash gearbox often incorporates features like optimized tooth profiles, high-precision machining, and stiff housing materials to reduce harmonic distortion and enhance torsional rigidity. These design choices minimize vibrations and ensure stable torque transmission, critical for high-precision applications.

In terms of load distribution, how do zero backlash gearboxes compare to traditional gear systems?

Zero backlash gearboxes are designed for more uniform load distribution across the gear teeth, reducing peak stresses and wear. This is achieved through precise gear alignment, specialized tooth geometry, and sometimes flexible elements that distribute forces evenly, enhancing durability and operational life.

How do servo-mechanisms benefit from the use of zero backlash gearboxes?

How do servo-mechanisms benefit from the use of zero backlash gearboxes?

Servo-mechanisms benefit from zero backlash gearboxes through improved accuracy, faster response times, and higher precision in position control. The elimination of backlash reduces positional errors and allows for smoother motion profiles, essential in robotics, CNC machines, and other high-precision applications.

What defines a precision gear box, and how is it different from standard gear boxes?

What defines a precision gear box, and how is it different from standard gear boxes?

A precision gearbox is defined by its high manufacturing tolerances, superior materials, and design features that allow for minimal backlash, high torque density, and exceptional accuracy in controlling motion and power transmission.

How do precision gear boxes differ from standard gear boxes?

Precision gearboxes differ from standard gearboxes in terms of their backlash, efficiency, and durability. They are designed to provide more accurate and reliable performance, often with less than 1 arc-min of backlash, higher efficiency, and longer service life, making them suitable for applications requiring exact motion control.

What are the typical applications of precision gearboxes?

What are the typical applications of precision gearboxes?

Precision gearboxes are commonly used in robotics, aerospace, medical devices, machine tools, and other high-precision applications. They are essential in applications where precise control of motion and positioning is critical for the success of the operation.

What types of precision gearboxes are there?

What types of precision gearboxes are there?

There are several types of precision gearboxes, including planetary, strain wave/harmonic, and cycloidal gearboxes, each with unique advantages in terms of load capacity, size, efficiency, and the specific types of applications they are best suited for.

What are the signs of a failing precision gearbox?

What are the signs of a failing precision gearbox?

Signs of a failing precision gearbox include increased noise, vibration, temperature, and leakage, as well as a decrease in performance accuracy. Any of these symptoms should prompt an immediate inspection to prevent further damage and costly downtime.

What is the minimum backlash of a gear?

The minimum backlash of a gear depends on its application, size, and design specifics, but generally, it is in the range of 0.05 to 0.20 mm for industrial gears. Precision applications, like in watches or high-speed machinery, may have even tighter tolerances, necessitating minimal backlash to ensure accuracy and performance. However, it's important to note that some backlash is always required to prevent gear tooth interference and allow for thermal expansion and lubrication.

What should be the backlash of a gearbox?

What should be the backlash of a gearbox?

The optimal backlash of a gearbox varies depending on its design, the application's load and speed conditions, and the precision required. For standard industrial gearboxes, backlash is typically between 0.05 to 0.20 mm, but for high-precision gearboxes, such as those used in robotics or aerospace, backlash may be reduced to as low as 0.01 mm or even less. The specific requirements should be determined based on the manufacturer's specifications and the operational demands of the application to balance between efficiency, longevity, and performance.

What is backlash?

What is backlash?

Backlash is the clearance or play between mating gear teeth in a mechanical gearbox, defined as the amount of space between the teeth when in a meshed position. It's a crucial parameter in gear design, allowing for lubrication, thermal expansion, and accommodating manufacturing imperfections. Backlash ensures that gears can operate smoothly without interference, prevents teeth from binding, and helps in distributing wear evenly across the gear teeth.

What factors should be considered when selecting a zero backlash gearbox?

When selecting a zero backlash gearbox, factors to consider include the required torque and speed, the precision level, the operational environment (temperature, contamination, etc.), size and weight constraints, and the overall cost, including maintenance and potential downtime.

Can zero backlash gearboxes handle high torque?

Yes, zero backlash gearboxes can handle high torque levels. They are designed with robust gearing mechanisms that distribute loads efficiently, allowing them to transmit high power while maintaining precision.

Why are zero backlash gearboxes important in precision applications?

Zero backlash gearboxes are crucial in precision applications because they provide highly accurate motion control, minimize positional errors, and ensure smooth operation, which is essential in sectors like robotics, aerospace, and high-speed automation.

How does Sumitomo ensure the quality of its zero backlash gearboxes?

Sumitomo ensures the quality of its zero backlash gearboxes through rigorous testing and quality control procedures, including precision manufacturing processes, material selection, and extensive performance testing to meet stringent industry standards and customer requirements.

Can Sumitomo zero backlash gearboxes be customized for specific applications?

Yes, Sumitomo Drive Technologies specializes in customizing gearboxes, including zero backlash models, to meet the specific requirements of different applications. Customization can include gear ratios, mounting configurations, shaft options, and other specifications to fit the needs of the application.

What industries commonly use Sumitomo's zero backlash gearboxes?

Industries such as robotics, aerospace, medical equipment, semiconductor manufacturing, and precision machining commonly use Sumitomo's zero backlash gearboxes due to their high accuracy, reliability, and performance in demanding applications.

How does Sumitomo’s cycloidal design contribute to zero backlash performance?

Sumitomo’s cycloidal design in gearboxes like the Fine Cyclo® series contributes to zero backlash performance by using a combination of cycloidal and eccentric gears that ensure continuous tooth contact, eliminating the gap and thereby achieving near-zero backlash for high precision and load capacity.

What support and services does Sumitomo offer for their zero backlash gearboxes?

Sumitomo Drive Technologies offers comprehensive support and services for their zero backlash gearboxes, including installation assistance, maintenance and repair services, technical support, and access to a wide network of service centers and engineers to ensure optimal performance and longevity of their products.