Precision Fasteners & Couplings | Zero-Play Links

The precision fasteners & couplings play an essential role in maintaining correct joining of components within robotic structures. These are high-tolerance bolts, screws, nuts, dowel pins to ensure precise alignment, and press-fit elements to guarantee structural soundness during motion. These fasteners, secure, withstanding in time, safeguard the ultimate functioning and precision of robotic systems. The couplings have to be backlash-free in linking shaft motors to loads to reduce any play and misalignment. Flexible diaphragm and positive locking types are most often preferred in robotics for their responsiveness and stability. Norck Robotics also offered engineered solutions customized to robotic applications, including fasteners and quick-release mechanisms.

Fasteners or connecting hardware (bolts, screws, nuts, pins) are fundamental components for robotic assembly for all of the following reasons.

Fasteners or connecting hardware (bolts, screws, nuts, pins) are fundamental components for robotic assembly for all of the following reasons,

• Precision Fasteners & Couplings are important because they allow for secure and accurate robotic assembly. Fasteners such as bolts, screws, nuts, and pins - dowel pins in particular - are used for high-tolerance alignment and can provide long-term structural integrity. Fasteners ensure structural rigidity under load and prevent unwanted movement.
• Properly tightened and precise fasteners are highly important in the area of robotics because they can have significant effects on the overall accuracy, repeatability, and longevity of a robot. If fasteners are misaligned, deteriorated, or placed incorrectly, there will be variations in the assembly, among other issues such as premature wear, vibration, and lower reliability of the robot system.
• Backlash-free couplings are the method to connect motor shafts to mechanical loads without slack or slip. Most common types are flexible diaphragm couplings and positive-locking couplings; both primarily maintain smooth transfer of torque and controlled motion; two very important factors in robotics.
• Precision fasteners & couplings can be advantageous in their modularity, maintenance capabilities, and flexibility in custom configurations. In some higher performance and mission critical robotic systems, Norck specializes in providing industry standards such as custom fasteners, quick release fasteners, and application specific couplings, meant for particularly harsh conditions or specific mechanical requirements.

In robotic assemblies, there are specific alignment features intended to promote accuracy and repeatability in the position of components. The following are the major ones:

1. Dowel Pins

Dowel pins are hardened steel or stainless steel cylindrical pins that are designed to precisely go into reamed holes. They are used to ensure that two or more components are aligned at the precise location to ensure correct positioning and to minimize misalignment during operation and assembly.

2. Locating Pins

Locating pins designed to locate common components in fixtures, jigs, and the locating pins are able to provide quick and repeatable alignments. Locating pins can be utilized in modular robotics or custom rigs, which allow users to simply disassemble components and then have the option of reconfiguring components without compromising the alignments.

3. Precision Bushings

These bushings are used more in conjunction with other devices to guide and support motion while holding an alignment. Additionally, they are often recognized as valuable components in joints and rotating components that want minimal play.

4. Press Fit Sleeve or Collar

Press fit sleeves, collars, or limiting devices are intended to be installed into holes to guide shafts or pins into place to help maintain what are otherwise tight tolerances between moving parts.

5. Alignment Key or Keyways

These features, such as alignment keys, are important in rotating assemblies were established design requirements can depend on aligning the motor shaft of a drive system with associated couplings and gears, or to eliminate slippage in systems transmitting torque that permit backlash.

Fasteners with high tolerances are important to preserving the overall precision of a robotic system. Here is why:

• Maintain structural alignment:

High tolerance fasteners, e.g., dowel pins and tightly spec’d bolts, keep parts in the orientation requested at assembly. It is critical to prevent the accumulation of errors across robotic joints and link arms and frames to ensure the proper positioning and repeatability of the system.

• Minimize loosening and activity:

The common scenario in dynamic systems is that vibration and motion can lead to loosening of fasteners with low tolerances. High tolerance fasteners fit tightly enough that they do not drift and that consistent joint position and structural rigidity is maintained during periods of repeated operation.

• Enhance load distribution:

Precision fasteners should limit force distribution across a connected component to only its likely intended use. Precision fasteners reduce the potential for mechanical stress concentration that can result in deformation, preferably, and, at the very worst, backlash and inaccuracy of the robotic system.

• Limit system tolerances within a system:

Many robotic subsystems utilize tolerances under a micrometer, especially either with backlash free couplings or precision assemblies. High tolerance fasteners securely maintain tolerances if needed, especially seen during realistic operational use.

• High-tolerance fit: Precision fasteners and couplings made to tight tolerances for no-play assembly, possible.
• Universal application: Used and trusted in robotics, and commercial industries like aerospace, medical devices, and industrial machinery.
• Material independence: Fasteners and couplings can be provided in stainless steel, titanium, and specialty alloys to suit many environments.
• Low-maintenance operation: Caution is taken in product specification, design, and manufacture to minimize need for servicing of parts to achieve a long life, which includes minimal maintenance in high-duty cycle systems.
• In-house machining & testing: Each part produced by Norck Robotics, and each part tested for quality is followed in Norck Robots controlled processes.
• Custom precision couplings: Couplings designed utilizing analysis of the stresses/torque/stiffness/alignment requirements of the assembly.

Couplings are mechanical devices attached to two rotating shafts - that is, essentially between the motor shaft and the load (for example, the gearbox or actuator) - to assist them in transmitting torque and rotary motion from one to the other. In robotics, they need to be coordinated to ensure smooth, reliable, and precise motion between parts.

Here are some reasons why these couplings should be backlash-free in robotic systems:

• Eliminates the Play or Slop in Motion

Backlash-free couplings (flexible diaphragm or positive-locking types) must be able to never allow even the slightest delay or oddly-shaped looseness to exist between shaft rotations. This is particularly important for accurate control in applications like robotic arms, grippers, and CNC.

• Maintain Positional Accuracy

In robotic systems where a millimeter or sub-millimeter movement is significant, such as in medical robots or pick-and-place machines, backlash can result in very serious positional errors. Hence, zero-backlash couplings ensure that the corresponding motion will be transmitted accurately.

• Improves Response and Repeatability

Backlash delays the robotic system, affecting response time and repeatability. Backlash-free coupling provides constant performance even under variable loads and motion profiles.

• Reduce Mechanical Wear

With the removal of internal play, these couplings minimize shock loads and vibrations, thereby increasing the life expectancy of components and smoothing operation.

All in all, backlash-free couplings are an integral part of high-performance robotic setups which demand precision, consistency, and durability.

Norck specializes in a wide range of custom solutions relating to precision fasteners and couplings that address the unique mechanical and structural criteria of today's advanced robotic systems. Below is what Norck can provide:

• Custom Fasteners for Unique Assemblies

Custom fasteners, such as bolts, screws, and dowel pins, can be designed and fabricated by Norck. The fasteners can be made to the exact specifications of the user, including dimensions, material grades, and surface finishes that are tailored to your specific mechanical loads, thermal conditions, or assembly constraints.

• Application Specific Quick-Release Mechanisms

Two-for-one. Some systems will involve quick reconfiguration or maintenance (i.e., research rigs or modular robots). GrenSmart custom fasteners quick-release fasteners that provide security as well as rapid change-outs and adjustment of individual parts.

• Backlash-Free Couplings

Norck custom backlash-free couplings can be manufactured for different torque ratings, shaft sizes, and misalignment characteristics. These coupling types are used when ultra-smooth motion with a highly precise positional tolerance is required of a robotic system.

• Customized Materials and Coatings

Norck will match materials and coatings to applications requiring special and demanding conditions like aerospace, underwater robotics, or cleanroom specified products. Light-weight aluminum alloys to high-strength titanium or corrosion resistance stainless steel fasteners can be customized to fit the demanding requirements of those applications.

• Custom Fastener-Coupling Systems

Norck can develop custom integrated mounting and transmission systems that incorporate fastening with torque transmission, directly coupling the functions to maximize space in an assembly.