SERVOFLEX – Miki Pulley

Rigorous analysis using finite element method, metal disc-spring method for ultra-high torsional stiffness

These metal disc-spring couplings with ultra-high torsional stiffness were developed for servo motor applications. The disc-spring method provides excellent properties: firmness in the torsional direction but flexibility in the bending, step-difference, and axial directions. The disc spring that serves as the element has an unbeatable theoretically derived shape that is the result of rigorous analysis with the latest finite element method. These couplings are available in a full line-up for many different applications. Compact and lightweight SFC models use high-strength aluminum alloy for the hub material. SFS models, which use carbon steel for the body material, come in many different variations. And the SFM and SFF models were developed for main and feed shafts of machine tools.

List of Products

Printing Presses

Customization

FAQ

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	SFC Models These are disc-spring couplings that use a lightweight, high-strength aluminum alloy for the clamp hub to enable high torsional stiffness and high response. Both single-element types with high torsional stiffness and flexible double-element types that separate double elements with a spacer are available. Both lower the moment of inertia by linking the outer diameter of the hub to the shaft diameter. Basic Specifications Max. rated torque : 250 N･m Bore ranges : 3 mm to 45 mm Backlash : Zero
	SFS Models These couplings have disc springs that use steel for the body. They are the basic type of SERVO FLEX. Single-element types with high torsional stiffness, flexible double-element types that separate double elements with a spacer, and floating shaft types that combine double elements with intermediate flanges are available. Basic Specifications Max. rated torque : 800 N･m Standard Bore ranges : 8 mm to 60 mm Backlash : Zero
	SFF Models These couplings have disc springs that use steel for the body. This makes them optimal for ordinary feed shafts that have high torsional stiffness, have accurate shaft rotation, and are capable of ultra-precise control. Both single-element types with high torsional stiffness and flexible double-element types that separate double elements with a spacer are available. Basic Specifications Max. rated torque : 800 N･m Standard Bore ranges : 8 mm to 60 mm Backlash : Zero
	SFM Models These models were developed to be compatible with spindle applications on machine tools. They are disc spring couplings capable of high precision and high speed. To enable high-precision mounting, both the flange unit and the pressurization flanges are equipped with centering mechanisms. They are also shaped so that the flange covers the periphery of the disc spring with few raised or lowered surfaces to minimize whistling during high speed rotation. Both single-element types with ultra-high torsional stiffness and flexible double-element types that separate double elements with a spacer are available. Basic Specifications Max. rated torque : 800 N･m Standard Bore ranges : 12 mm to 80 mm Backlash : Zero
	SFH Models The maximum size with disc spring couplings for high-output applications is an outer flange diameter of 262 mm and rated torque of 8000 N・m. Single-element types with high torsional stiffness and flexible double-element floating-shaft types that connect double elements with an intermediate floating shaft are available. The floating shaft is particularly able to handle the setting of lengths according to customer requirements. Basic Specifications Max. rated torque : 8000 N･m Standard Bore ranges : 12 mm to 115 mm Backlash : Zero

Printing Presses

Product Models Used : SFC + ETP

ETP bushings are used to secure the feed roll in place. The roll and shaft can be secured in place easily and accurately, allowing the length along the direction of the shaft to be reduced.

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Medical Equipment

Product Models Used : BXW + SFC

SFC model metal disc couplings and BXW model spring-actuated brakes with sound-absorbing springs are used to transmit power and maintain positions in diagnostic imaging systems. They contribute to improving quietness.

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SFC Models End-face Tap Specifications

Bores can be drilled into the tap on the end face of the hub to use for attaching a slit plate or other part for the position detection sensor

SFC Models Slit Plate Specifications

These specifications can be used for position detection sensors such as encoders and photo sensors with attachment of a slit plate between hubs.

SFC Models Long Spacer Specifications

These specifications are used for applications with wider distances between mounting shafts. They can also be used in synchronization of gantry mechanisms and other applications.

SFC Models Assembly Specifications

These models are special made-to-order parts assembled using an SFC model, a POSI-LOCK (shaft-lock) PSL-K model, a timing pulley, and a shaft.

Q : What are the durability and aging deterioration of the SERVOFLEX?

A : We conduct a torsional durability test by applying a load larger than the rated torque. SERVOFLEX passed the test by withstanding the metal fatigue limit of 10 million cycles of repeated load. SErvoflex is all made of metal materials so the deterioration is extremely slow, and it is able to transmit torque with high precision for a long period of time.

Q : When a coupling is mounted, the driven shaft runs out. What is the cause?

A : The runout of a driven shaft caused by a coupling is mainly attributed to the counterforce of the shaft caused by insufficient centering. All of the SERVOFLEX series are assembled using high-precision special jigs to ensure high concentricity of the bores on the left and right. The counterforce of the shaft is extremely small so the runout of the driven shaft can be minimized.

Q : Noise and vibrations occurred during use of a metal disc coupling. Please tell me how to prevent them.

A : For a servo motor, noise and vibrations can be suppressed by setting the machine resonance suppression filter to its natural frequency in the control system. For a stepper motor, vibrations can be absorbed and suppressed by changing the rotation speed or using a STEPFLEX coupling with high damping ability.

Q : Can enough torque be transmitted using the clamping method for connection to the shaft?

A : Our torque transmission test uses a sufficient safety factor, so slip of the connection caused by the connection method will not occur when using the rated torque in the catalog. A keyway can be milled into the clamping hub. If you are interested, please refer to P.041 Keyway Milling Option.

Rigorous analysis using finite element method, metal disc-spring method for ultra-high torsional stiffness

SFC Models

SFS Models

SFF Models

SFM Models

SFH Models