Quality Gearing Keeps Mission-Critical Systems Rotating for Combat

September 1, 2024

Power transmission and gear components must meet extreme performance and reliability demands in order to prove effective on the battlefield. That’s because they are the heart of rotating mechanisms used to rapidly detect threats, home in on targets and fire projectiles quickly aboard combat vehicles and ships. In these situations, lives and mission success often depend on their ability to support heavy payloads and deliver fast, precise motion reliably, often under punishing conditions.

The U.S. Army recently received its first M10 Booker Vehicle from General Dynamic Land Systems, and it provides an example of the type of modern armored vehicle designs and configurations that gear technology and rotating military equipment must support. The Booker vehicle employs a four-person crew and features an enhanced thermal viewer, a large-caliber cannon, a lightweight hull and turret, and a modern diesel engine, transmission and suspension system, according to General Dynamic’s description of the M10.

Over the next two years, the Army will put the M10 Booker through a battery of testing to ensure it meets the rigorous standards required to provide Soldiers with world class capability, according to an April 2024 U.S. Army press release about the M10. This testing will include firing thousands of rounds of ammunition and driving thousands of miles to understand the reliability and maintainability for the program.

“We will also put the vehicle through production qualification and testing in desert, arctic, temperate and tropical conditions, challenging it with obstacles like gaps and walls to scale, and engaging it with real word threats to ensure its survivability,” said Maj. Gen. Glenn Dean, Program Executive Officer for Ground Combat Systems.

When equipping rotating military equipment with gear technology, keep in mind that not all gear products are up to the challenges of the battlefield. For mission-critical applications, you need the highest-quality gear design and construction. Here are some examples of rotating equipment aboard combat vehicles and ships that incorporate gear technology, along with the lofty performance needs and harsh environment considerations they present to system designers:

Tank Turret Systems

A typical tank turret system can use one of several drive systems available such as chain, belt or a ring gear with slew bearing mounted to the tank hull. To determine which drive system works best, engineers must consider the turret’s weight, rotation speed, position accuracies, various shock loads and mounting configuration. For example, using an integrated ring gear with slew bearings reduces the mounting space. Typically, the ring gear is mounted to the turret and the pinion and motor are stationary.

Today’s massive tank turrets can weigh tons and support cannons designed to fire shells up to 120 millimeters in diameter or more which can weigh as much as 50 pounds. That means ring gears must handle high loads with high speed and accuracy so the cannon can quickly acquire the target position. Military vehicles are also expected to withstand vibrations and high shock loads from recoil, travel through rough terrain, resist dust and dirt, and endure extreme weather. Even with good sealing, dust and dirt may still enter the turret, so durability is critical.

Automated Mortar Systems

Recently a globally recognized defense system contractor turned to Redex high-performance planetary gearboxes for one of its newest vehicle-mounted automated mortar systems. The latest mortar systems are compact in size and can rapidly fire 81-millimeter or larger shells. Computer-controlled, they operate with greater accuracy, longer range and less recoil. Given these advances, infantry units can “shoot and scoot” before an enemy is able to return fire.

Like a more nimble tank turret, these systems can be raised, lowered and rotate a full 360 degrees. In order to build a mobile mortar system with these capabilities, manufacturers incorporate a rotating ring gear below the gun along with a high-performance gearbox. The gearbox must offer exceptional precision, rigidity and durability and work with motors with up to 2 kilowatts of power output or more. Using Redex gearboxes, the vehicle-mounted automated mortar system can determine a target, position the gun with accuracy of 2 meters or less and destroy the target in mere seconds.

Rotating Radar Systems

When the antenna rotates, it sweeps the airspace with a narrow radio wave over a full 360 degrees. The parabolic antenna can transmit and receive linear and circular signals, and it can operate from masts, truck roofs and other portable structures. Some systems are required to reach speeds ranging from 15 to 44 rpm or higher. With these challenging requirements, antenna accuracy can suffer without gearboxes that can minimize or eliminate backlash – lost motion that occurs when gears alternate during acceleration and deceleration, such as when a radar antenna or turret turns.

Redex planetary gearboxes are well suited to demanding rotating radar and other military applications. For example, our versatile SRP family features exceptional output torsional stiffness, ultrahigh output radial stiffness and tilting moment, high input speeds, low inertia, minimal gear frequency noise, excellent acceleration and torque density, and a minimal backlash of one to three arc minutes. The SRP Series is available in seven different sizes with nine different reduction ratios from 5 to 91:1.

Another family — the KRP Series ring gear for rack and pinion applications — also offers minimal backlash of one to three arc minutes as a single unit, plus maximum stiffness on the ring gear. Each unit can also integrate with a DualDRIVE or TwinDRIVE Kit as a mechanical or electrically preloaded, respectively, zero-backlash system. Low-or zero-backlash ensures smooth, play-free motion that is especially desirable for accurate radar tracking. KRP rack and pinion drives come in five sizes with reduction ratios from 5 to 91:1.

When selecting gear systems for demanding rotating radar installations aboard ships and land-based vehicles, it pays to work with a manufacturer that can offer quality products and service.

Here’s how Redex motion components help your rotating mechanisms perform with precision and reliability on the battlefield under demanding requirements:

• High load capacity. Gearing components with helical teeth typically offer higher load capacity than those with straight teeth.

• High precision. Gearboxes must have minimal or zero backlash to deliver the highest accuracy. Redex gearboxes mitigate and even eliminate backlash thanks to their robust mechanical designs and electrical preload systems.

• Stiffness and high torque density. Components with induction-hardened helical gear teeth offer maximum stiffness and deformation resistance.

• Ability to withstand impacts and shock loads. We offer induction-hardened gear teeth that can resist deformations, and our engineers can help you select a gearbox size that accounts for the additional loading that comes from wind at sea.

• Reliability in harsh environments. Redex gearboxes are constructed from hardened steel for durability in hot, dry, mountainous or icy environments as well as to withstand shock loading from mortar firing and vehicle operation. Corrosion-resistant coatings are also available.

• Conformity with military specifications. We offer factory accessible testing (FAT) to ensure our components meet relevant MIL specifications and certificate of performance requirements.

For many applications, it often makes sense to choose a special solution. Redex engineers can design gearboxes, ring gears and bearings to the application to meet both the requirements and space limitations of your rotating system. For high-loads in turret installations, for example, we can create a two-pinion, two-gearbox system — in one housing — that can be driven by just one motor. This arrangement provides two points of contact, thereby doubling the load capacity while also allowing easy setup.

This article was written by Thomas Osygus, Vice President, Sales and Marketing, Redex USA (Ocean Township, NJ) For more information, visit here  .

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