Overview

This document details the technical specifications, configurations, service factors, mechanical ratings, dimensional data, and installation guidelines for the Fluid & Power Series K3 gear units. It covers triple reduction servo and reducer units across sizes K03 to K08, focusing on proper selection, sizing, and integration for reliable industrial power transmission.

1. Unit Designations and Configurations

The Series K3 gear units are triple reduction units with multiple mounting and output shaft options, including feet mounting, output flange on the left, torque brackets, and servo adapters. Unit codes systematically represent series, size, reduction stages, revision, nominal ratio, unit version, output shaft type, input adapter, mounting position, motor mounting, and additional features, facilitating precise ordering and configuration.

2. Output Bore and Shaft Options

Output bore sizes are specified in both imperial and metric units, with detailed thread sizes and lengths for each unit size (K03 to K08). Shaft options include single and double extensions, extended shafts for flange-mounted units, and hollow shafts. These options support diverse mechanical integration needs and are clearly identified for ordering.

3. Mounting Positions and Motor Mounting Codes

Mounting positions cover base and flange-mounted units with six standard orientations. Motor mounting codes vary by unit size and motor shaft diameter, with precise flange and shaft dimensions, bolt circle diameters, and pilot diameters provided to ensure accurate motor coupling and alignment.

4. Mechanical Service Factor Calculation

Mechanical service factors (SFm) adjust catalog torque ratings to real application conditions by considering load inertia, motor inertia, load classification, service duration, and start frequency. The calculation involves:

• Summing external and motor inertias.
• Determining mass acceleration factor.
• Using tables to find load classification factor (Fm) and start/stop factor (Fs).
• Calculating SFm = Fm × Fs.
• Computing equivalent mechanical torque = application torque × SFm.
• Classifying the application as continuous or cyclic based on shaft rotation and dwell times.

5. Thermal Service Factor Calculation

For continuous applications, thermal service factors (SFth) account for ambient temperature, air velocity, and motor speed:

• Ambient temperature adjustment factor (Ft) from temperature tables.
• Air velocity correction factor (Fv) based on environment (confined, indoor, sheltered outdoor, outdoor).
• Speed correction factor (Fsp) based on motor RPM.
• SFth = Ft × Fv × Fsp.
• Equivalent thermal torque = application torque × SFth.
• The greater of equivalent mechanical or thermal torque is compared to published mechanical ratings to verify suitability.

6. Mechanical Output Torque Ratings

Torque ratings at 2000 rpm input speed are tabulated for gear ratios from 8:1 up to 125:1 across unit sizes K03 to K08. Values are given in lb.in and Nm, with maximum torque reaching approximately 23,700 lb.in (2678 Nm) for the largest units. These ratings guide gear unit selection based on calculated equivalent torques.

7. Overhung and Axial Load Limits

Maximum permissible radial and axial loads on input and output shafts are specified per unit size, with shaft extension dimensions (A and B) provided. A formula calculates equivalent overhung load (P) considering power, shaft speed, pitch diameter, and load factor (K) depending on mounted element type (chain sprocket, spur gear, belt pulley, etc.).

Best practices include positioning mounted elements close to the gear unit to minimize bearing and shaft stresses. If loads exceed limits, options include using separate shafts with flexible couplings or selecting larger gear units.

8. Shaft and Coupling Dimensions

Detailed tables specify output shaft diameters, lengths, key sizes, and mounting hole patterns for each size. Motor plate and coupling dimensions are designed for servo motor compatibility. Information on hollow output bores, set screws, retaining rings, nuts, and tapered bushings supports secure assembly.

9. Shrink Disc Locking Device

The gear units employ a shrink disc locking mechanism on hollow output shafts, providing a keyless, positive friction fit between gear unit and driven shaft. The device includes a locking collar, tapered inner ring, and screws that clamp to create radial forces securing the shafts. Lubricated taper surfaces prevent seizing and allow easy removal. This method ensures hermetic sealing, prevents fretting corrosion, and offers high torque transmission capacity.

10. Assembly and Disassembly Procedures

Instructions cover assembly onto customer shafts and disassembly methods, emphasizing the need for customer-supplied parts, adherence to specified shaft diameters, lengths, and tolerances. Use of tapped holes and extended output shafts for flange units is standard. Maximum component dimensions during disassembly are provided to ensure safe removal.

11. Installation and Mounting Recommendations

• Verify key strength and length when supplied or when using thick wall bushings.
• Torque arms require stirrup-type anchoring to resist reaction forces.
• Mounting flange dimensions (B5/D flange) and extended output shaft details are standardized.
• Consult application engineers for non-standard load conditions or opposite handing requirements.

12. Operational Parameters and Limitations

• Maximum radial and axial loads per size prevent mechanical failure.
• Maximum input speed is 3000 rpm; continuous operation recommended at 2000 rpm.
• Recommended lubrication is EP 320 gear oil.
• Operating temperature limit is 100 °C (212 °F).

13. Industry Applications

Series K3 gear units are suitable for diverse industries including agriculture, automotive, cement, chemical, construction, defence, energy, food & beverage, forestry, marine, metals, mining, pulp & paper, quarrying, rubber & plastics, textiles, transportation, and water treatment.

Critical Parameters and Best Practices

• Ensure overhung loads do not exceed tabulated maximums; use provided formulas and factors.
• Position mounted elements close to gear units to reduce stresses.
• Use shrink disc locking for secure, keyless shaft connections with easy removal.
• Verify key dimensions and shaft strength during installation.
• Adhere to lubrication, speed, and temperature limits for durability.

Summary

This comprehensive technical reference enables correct selection, sizing, installation, and operation of Fluid & Power Series K3 gear units. It integrates mechanical and thermal service factor calculations, detailed dimensional data, torque ratings, and assembly guidelines to ensure reliable, efficient performance across varied industrial applications.