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Zero-Max – Shaft Couplings, Keyless Bushings, Adjustable Speed Drives

Zero-Max Brand LogoISC Companies and Adams-ISC can supply the Zero-Max products on this page and many others found on the Zero-Max website. For more information or for a product quote, please contact us by phone 763-559-0033, by email [email protected], or by filling out our online contact form.

Zero-Max is a leading provider of motion control solutions and one of the industry’s most trusted coupling manufacturers. Products include composite disc couplings, servo couplings, offset couplings, torque limiters, right angle gear drives, linear actuators, and mechanical variable speed drives. Zero-Max products are known throughout the world for their innovative designs, high quality, high performance, and durability.

Zero-Max Trademarks/Names: ServoClass, Roh’lix, Control-Flex, OHLA, Posi-Lok, Crown, Phas-Lok, ETP (ETP-CLASSIC, ETP-EXPRESS, ETP-TECHNO, ETP-POWER, ETP-HYLOC, ETP-HYDROPRESS)

Flexible Shaft Couplings

Composite Couplings

Composite Disc shaft couplings deliver high performance with zero backlash and are designed to withstand the punishment and stress of demanding servomotor applications. These high speed flexible shaft couplings are ideal for cyclic applications where speed and repeatable accuracy are critical. Other brands may have high torsional stiffness; but are too brittle to withstand the punishment of high speed, reversing applications.

The working parts of these disc couplings are made of high precision composite material. This unique design has high torsional stiffness, yet allows for misalignment in high stress applications. They have excellent chemical and moisture resistance and can operate without maintenance in hostile environments.

Single-Flex Configuration Composite Couplings

Single Clamp Type Aluminum A1C HubsSingle Clamp Aluminum A1C Hubs

Single Clamp Type Steel HubsSingle Clamp Steel Hubs

Single Set Screw Type Steel HubsSingle Set Screw Steel Hubs

Single Clamp Type Aluminum HubsSingle Clamp Aluminum Hubs

Single QD Bushing Type HubsSingle QD Bushing Hubs

Single Clamp Type Stainless Steel HubsSingle Clamp Stainless Steel Hubs

Single Set Screw Type Stainless Steel HubsSingle Set Screw Stainless Steel Hubs

Double-Flex Configuration Composite Couplings

Double Clamp Type Aluminum A1C HubsDouble Clamp Aluminum A1C Hubs

Double QD Bushing Type HubsDouble QD Bushing Hubs

Double Clamp Type Aluminum HubsDouble Clamp Aluminum Hubs

Double Set Screw Type Steel HubsDouble Set Screw Steel Hubs

Double Clamp Type Steel HubsDouble Clamp Steel Hubs

Floating Shaft Configuration Composite Couplings

Floating shaft couplings, or spacer couplings, are three-part assemblies consisting of a floating tubular shaft with an integrated flexible coupling attached to both ends. Floating shaft couplings are designed to transmit torque and accommodate misalignment in applications where drive and load components are spaced far apart.

Clamp Type HubsClamp Type Hubs

Setscrew Type HubsSetscrew Type Hubs

ServoClass Flexible Couplings

ServoClass couplings provide the optimal blend of performance, durability, and price. They are manufactured from high quality materials using state-of-the-art CNC manufacturing equipment. ServoClass shaft couplings are ideal for servomotor actuators.

ServoClass Single FlexServoClass Single Flex

ServoClass Double FlexServoClass Double Flex

Control-Flex Flexible Shaft Couplings

Control Flex shaft couplings are specially designed  for use with feedback devices such as encoders. They are engineered for zero backlash operation to ensure encoder accuracy. Additional features include clamp hubs for vibration-resistant shaft engagement and flex elements which provide low bearing reaction loads.

Bolted Style Control Flex CouplingsBolted Style Control Flex Couplings

Clamp Style Control Flex CouplingsClamp Style Control Flex Couplings

Schmidt Flexible Couplings

Schmidt shaft couplings are uniquely designed to handle applications with challenging or extreme misalignments, including models for offset and inline shaft applications.

Schmidt 5-D CouplingsSchmidt 5-D Couplings

Schmidt Offset Shaft CouplingsSchmidt Offset Shaft Couplings

Schmidt Flexible CouplingsSchmidt Flexible Couplings

Schmidt Inline CouplingsSchmidt Inline Couplings

Wind Turbine Products

Zero-Max has developed an advanced, all-in-one disc coupling solution for wind turbine drivetrains with capacities up to 5MW.

Zero-Max’s torque limiters protect wind turbines against peak loads, reverse torques, and grid shorts. Shaft-mounted to the generator shaft, our wind turbine torque limiters are factory-set to slip at specific torque settings, ranging from 4,000 to 50,000Nm.

Zero-Max Wind Turbine Composite CouplingsWind Turbine Composite Disc Couplings

Zero-Max Wind Turbine Torque LimitersWind Turbine Torque Limiters

Overhung Load Adapters

Overhung load adapters are hydraulic system components that protect shaft seals and prevent breakdown by absorbing internal and external stress from the motor and pump. They also provide a seal to protect motor components and prevent contamination of hydraulic fluid. SAE overhung load adapters prevent costly damage to shaft seals and are used for fan drives, recycling equipment, mixer units, industrial conveyor drives, and various other hydraulic motor applications.

Non-SAE Mount Overhung Load AdaptersNon-SAE Mount

SAE C Mount Overhung Load AdaptersSAE C Mount

SAE F Mount Overhung Load AdaptersSAE F Mount

SAE A Mount Overhung Load AdaptersSAE A Mount

SAE D Mount Overhung Load AdaptersSAE D Mount

Zero-Max Double Male OHLADouble Male OHLA

SAE B Mount Overhung Load AdaptersSAE B Mount

SAE E Mount Overhung Load AdaptersSAE E Mount

Zero-Max Custom OHLACustom OHLA

Roh’Lix Linear Actuators

Roh’Lix linear actuators are threadless, mechanical, screw-type devices designed to convert rotary motion into precise linear motion and thrust using rolling element ball bearings. These adjustable automatic overload protectors will slip when overloaded, providing linear clutching without any additional clutch mechanisms.

The Roh’Lix is intended for horizontal or vertical axial loading applications. Sideloads and twisting loads should be avoided whenever possible, as they cause uneven bearing loading and can shorten lifetime.

Inch Model Linear ActuatorsInch Model

Metric Model Linear ActuatorsMetric Model

Phase Adjusting Hubs

The Phas-Lok Adjusting Hub is an economical, yet precision device that provides an easy way to change the phase relationship of a drive component and shaft. It is ideal for fine-tuning timing adjustments, adjusting for chain elongation, and sprocket tooth wear.

Phas-Lok for BushingsPhas-Lok for Browning Bushings

Phas-Lok for BushingsPhas-Lok for QD Bushings

Phas-Lok for BushingsPhase Adjusting Hubs

Adjustable Speed Drives

Adjustable speed drive speed adjustments are easily made by moving a lever control through an arc or turning the hand-wheel of a screw type control. In either case, easy and precise speed control settings are possible with Zero-Max adjustable speed drives – also referred to as variable speed drives.


Unidirectional DrivesUnidirectional Drives

Reversible DrivesReversible Drives

Drive AccessoriesDrive Accessories

Crown Gear Right Angle Gearbox

Crown Gear is a brand of right-angle gear drive boxes designed for dependable, economical transfer of speed or power. These high-performance gears are mounted to input and output shafts positioned at 90-degree angles, allowing the gearbox to intersect with a plane or cross on two parallel planes. Both series are available in 1:1 and 2:1 speed ratio with two-way (one output shaft) or three-way (two output shafts) versions.

Crown Gear gearboxes are available in two versions;

  • Standard, black anodized aluminum housing, stainless steel shafts
  • IP65-Rated, nickel-plated aluminum housing, stainless steel shafts, shaft seals, food-grade grease

Counter-Rotating GearboxCounter-Rotating Gearbox

Zero-Max IP65 Counter Rotating Gearbox IP65-Rated Counter Rotating Gearbox

Three-Way Right Angle GearboxThree-Way Right Angle Gearbox

Zero-Max IP65 Three Way GearboxIP65-Rated Three Way Gearbox

Two-Way Right Angle GearboxTwo-Way Right Angle Gearbox

Zero-Max IP65 Two Way GearboxIP65-Rated Two Way Gearbox

Overload Safety Devices

Torq-Tender overload safety devices incorporate torque limiters for dependable overload protection. When a jam-up or excessive loading occurs, the built-in torque limiter will reliably and quickly release to prevent system damage. Torque value is controlled by the part number that is ordered; that value determines what spring is used during assembly of the torque limiter.

End of Shaft Mount - Type JEnd of Shaft Mount – Type J

Zero-Max H-TLCH-TLC Torque Limiters

End of Shaft Mount - Type JFEnd of Shaft Mount – Type JF

Shaft-to-Shaft Mount - Type CShaft-to-Shaft Mount – Type C

End of Shaft Mount - Type SEnd of Shaft Mount – Type S

Through Shaft Mount - Type BThrough Shaft Mount – Type B

Keyless Shaft Bushings

Keyless shaft bushings provide solid connections between the shaft and hub, without stress or wear to mounted components. Using hydraulic pressure to maintain their position, they eliminate keyways, tapers, and tapped holes, which can cause component stress and wear due to fretting, corrosion, and backlash.

Keyless shaft bushings enable fast, precision mounting of shaft components, providing solutions in the following situations:

  • Where frequent readjustment is required, either rotationally or axially, such as during machine changeover
  • In systems where balance and runout are inherent problems
  • When repeated fastening, adjusting, and holding of shaft components is required
  • Where downtime is critical and costly
  • Where precise mounting location is critical
ETP Keyless Bushings

ETP keyless locking devices are designed to solve specific application requirements, such as phasing and timing to synchronize machine components. They feature double-walled sleeves and tightening mechanisms that form solid, continuous connections between shafts and hubs when tightened.

ETP Classic Keyless Shaft BushingsETP-CLASSIC

ETP Express Stainless Steel Keyless Shaft BushingsETP-EXPRESS Stainless Steel


Zero-Max ETP Keyless BushingsETP-CLASSIC Stainless Steel


ETP Techno Keyless Shaft BushingsETP-TECHNO

ETP Express Keyless Shaft BushingsETP-EXPRESS


Posi-Lok BushingsPosi-Lok Bushings

Posi-Lok Keyless Bushings

Posi-Lok (PSL) keyless shaft bushings are locking devices that provide a secure shaft-to-hub connection. Most models feature socket-head cap screws for easy tightening and distribution of pressure over the full length of the connection to reduce fretting, corrosion, and backlash. They are ideal for positioning and locking shaft components, and eliminate the need for keyways, tapers, and tapped holes, which can weaken or cause excess wear to shaft couplings.

Posi-Lok keyless shaft bushings utilize tapers that form a mechanical locking wedge as the actuation screws are tightened, pressing the inner sleeve against the shaft and outer sleeve against the hub. The resulting connection transmits high levels of torque and resists axial forces.

Zero-Max PSL-G Posi-LokPSL-G Posi-Lok

Zero-Max PSL-D-C Nickel Plated Posi-LokPSL-D-C Nickel Plated Posi-Lok

Zero-Max PSL-K-C Nickel Plated Posi-LokPSL-K-C Nickel Plated Posi-Lok

Zero-Max PSL-G-C Nickel Plated Posi-LokPSL-G-C Nickel Plated Posi-Lok

Zero-Max PSL-K Posi-LokPSL-K Posi-Lok

Zero-Max PSL-K-F Stainless Steel Posi-LokPSL-K-F Stainless Steel Posi-Lok

Zero-Max PSL-D Posi-LokPSL-D Posi-Lok

Zero-Max PSL-K-B Hex Head Posi-Lok PSL-K-B Hex Head Posi-Lok

Zero-Max PSL-M Posi-LokPSL-M Posi-Lok

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ISC Companies and affiliate Adams-ISC are industrial distributors of bearings and mechanical power transmission parts. We have many different models and brands in stock for fast delivery. Our sales professionals are happy to assist you in the selection process to ensure the correct part is specified for your application. Get a quote by clicking below on “Request Pricing” and filling out the contact form or give us a call at 1-800-627-9434.

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