Description

F Series Parallel Shaft Helical Gearbox & Gearmotor Manufacturer

Compact High-Torque Parallel-Shaft Drives for Conveyors, Material Handling and Industrial Machinery

KB Transmission Star F Series parallel shaft helical gearboxes and gearmotors provide compact, high-efficiency power transmission for industrial applications where installation space is limited and the input and output shafts need to remain parallel.

Available from F27 to F157, the complete product family covers motor combinations from 0.12 to 200 kW, with maximum output torque from 130 to 18,000 Nm. Solid-shaft, hollow-shaft, shrink-disc, foot-mounted and flange-mounted configurations are available for conveyors, material handling equipment, mixers, packaging machinery and other industrial drive systems.

F27–F157 | 0.12–200 kW | Up to 18,000 Nm | Parallel-Shaft Design | Multiple Mounting Options

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F Series Parallel Shaft Helical Gearbox at a Glance

*The maximum catalog ratio includes extended and combined gearbox configurations. It should not be interpreted as the available ratio range of every individual F Series gearbox size.

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What Is an F Series Parallel Shaft Helical Gearbox?

An F Series parallel shaft helical gearbox is an industrial speed reducer in which the input and output shafts are arranged parallel to each other.

Precision helical gears reduce motor speed and increase usable output torque while allowing the drive to maintain a compact, narrow installation profile.

Compared with an inline R Series gearbox, the F Series uses an offset parallel-shaft arrangement. Compared with a K Series helical-bevel gearbox, it does not turn the drive through 90 degrees.

This makes the F Series particularly suitable for conveyors, material handling systems and industrial machinery where a compact shaft-mounted or parallel-shaft drive arrangement is required.

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Why Choose an F Series Parallel Shaft Helical Gearbox?

Compact Parallel-Shaft Design

The parallel-shaft architecture allows high torque capacity within a relatively narrow gearbox profile, making the F Series particularly useful where axial installation space is restricted.

High Transmission Efficiency

The catalog provides approximate gear transmission efficiencies of:

1-stage: 98%
2-stage: 96%
3-stage: 94%

Actual efficiency therefore depends on the number of gear stages and the selected configuration rather than one universal efficiency value.

High Torque Capacity

The F Series product family covers maximum gearbox torque ratings from 130 Nm to 18,000 Nm, supporting applications ranging from compact conveyors to heavy industrial material-handling systems.

Hollow-Shaft Installation

Hollow-shaft configurations allow the gearbox to be mounted directly onto the driven machine shaft, helping reduce the need for additional couplings and drive components.

Flexible Mounting Options

Foot-mounted, B5 flange, B14 flange, hollow-shaft and shrink-disc configurations provide flexibility for OEM machinery and replacement applications.

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F Series Gearbox Configurations

F Series gearboxes can therefore be configured according to both the machine mounting arrangement and the required output-shaft connection.

Not every configuration is available with every gearbox size and ratio. Final availability should be confirmed during engineering selection.

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F27–F157 Technical Selection Overview

Website Model	TF2015 Model	Solid Output Shaft Ø	Solid Shaft Extension	Hollow Shaft Bore Ø	Gear Unit Width	Gear Unit Height
F27	TF28	25 mm	50 mm	25 mm	150 mm	222 mm
F37	TF38	25 mm	50 mm	30 mm	165 mm	252 mm
F47	TF48	30 mm	60 mm	35 mm	180 mm	269 mm
F57	TF58	35 mm	70 mm	40 mm	200 mm	317 mm
F67	TF68	40 mm	80 mm	40 mm	212 mm	343 mm
F77	TF78	50 mm	100 mm	50 mm	270 mm	425 mm
F87	TF88	60 mm	120 mm	60 mm	330 mm	531 mm
F97	TF98	70 mm	140 mm	70 mm	400 mm	623 mm
F107	TF108	90 mm	170 mm	90 mm	450 mm	717 mm
F127	TF128	110 mm	210 mm	100 mm	530 mm	856 mm
F157	TF158	120 mm	210 mm	120 mm	660 mm	1,021 mm

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Important Technical Selection Note

Motor power, ratio and maximum torque must not be selected independently.

The complete F Series catalog covers 0.12–200 kW and an overall ratio range of 3.77–31,434, but these are family-level catalog envelopes. The highest ratios include extended or combined gearbox configurations and are not available on every individual F Series size.

Final selection must be verified according to:

• Motor power
• Input speed
• Required output speed
• Required gear ratio
• Required output torque
• Service factor
• Daily operating hours
• Starting frequency
• Radial and axial loads
• Output-shaft arrangement
• Mounting position

For an exact F27–F157 motor/ratio combination, send us your operating data for engineering verification.

CHECK MY APPLICATION

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F Series Gearmotor and Motor Options

F Series gearboxes can be supplied as complete parallel-shaft helical gearmotors or configured for connection to an appropriate electric motor.

The Performance Parameter section of the supplied catalog provides motor/gearbox combinations beginning at 0.12 kW and continuing through progressively larger industrial motor ratings across the F Series range.

Available drive arrangements can include:

• Complete helical gearmotor
• IEC motor adapter
• Three-phase asynchronous motor
• Brake motor
• Application-specific motor matching

The final motor frame should be selected together with the gearbox ratio and permissible torque rather than independently.

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How to Select an F Series Parallel Shaft Helical Gearbox

Correct gearbox selection requires more than matching the motor power or choosing a reduction ratio.

A reliable F Series selection should consider the complete drive system.

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1. Determine Motor Power

Identify the rated input power:

P₁ = Motor Power (kW)

Motor power defines the available input power but does not independently determine the required gearbox size.

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2. Determine Input and Required Output Speed

Identify:

n₁ = Input Speed (rpm)

n₂ = Required Output Speed (rpm)

These values determine the required reduction ratio.

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3. Calculate the Required Gear Ratio

Use:

i = n₁ / n₂

Example

Motor speed:

1,400 rpm

Required output speed:

70 rpm

Therefore:

i = 1400 ÷ 70 = 20:1

An F Series gearbox with a suitable available ratio near 20:1 can then be evaluated.

Ratio alone, however, does not determine the correct gearbox.

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Calculate Required Output Torque

The catalog uses the relationship:

M₂ = 9550 × P₁ × η / n₂

Where:

M₂ = Output torque (Nm)
P₁ = Input power (kW)
η = Transmission efficiency
n₂ = Output speed (rpm)

The appropriate efficiency should be selected according to the number of gear stages:

η ≈ 0.98 — 1-stage

η ≈ 0.96 — 2-stage

η ≈ 0.94 — 3-stage

The calculated operating torque must then be checked against the permissible gearbox torque and required service factor.

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Check the Service Factor

Service factor is a critical part of industrial gearbox selection.

The supplied catalog considers factors including:

• Operating hours per day
• Starting frequency
• Load classification
• Mass acceleration
• Machine operating characteristics

The catalog provides different load classifications and service-factor guidance according to the severity of the application.

A useful engineering check is:

Required Permissible Gearbox Torque ≥ Operating Torque × Required Service Factor

A gearbox operating continuously for long hours or under frequent starting and shock loading may therefore require a larger size than a gearbox carrying the same nominal running torque under light-duty conditions.

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Check Radial and Axial Loads

External drive components such as:

• Chain sprockets
• Pulleys
• Belt drives
• External gears

can generate additional radial or axial loads on the gearbox output shaft.

These loads must be checked against the permissible shaft-load capacity of the selected gearbox.

For conveyor applications, provide:

Sprocket or pulley diameter

Output shaft configuration

Load application point

Required output torque

Radial load if known

This allows a more reliable gearbox selection.

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Select the Correct Output-Shaft Configuration

Solid Shaft

Suitable where the gearbox output is connected to the driven machine using a coupling, sprocket, pulley or other external transmission element.

Hollow Shaft

Allows the gearbox to be mounted directly onto the machine shaft, making it particularly useful for conveyor and material-handling applications.

Hollow Shaft with Shrink Disc

Provides a keyless clamping connection between the gearbox and driven shaft for applications requiring secure torque transmission and simplified shaft-mounted installation.

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Select the Correct Mounting Configuration

F Series gearboxes are available in multiple mounting arrangements, including:

Foot Mounted

B5 Flange

B14 Flange

Shaft Mounted

The supplied catalog also provides M1–M6 mounting positions, allowing lubrication and installation requirements to be determined according to gearbox orientation.

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F Series Gearbox Selection Example

Example: Conveyor Drive

Assume the following preliminary application data:

Motor Power: 5.5 kW
Input Speed: 1,400 rpm
Required Output Speed: 70 rpm
Operating Time: 16 hours/day
Application: Belt Conveyor

Step 1 — Calculate Ratio

i = 1400 ÷ 70

i = 20:1

Step 2 — Calculate Preliminary Output Torque

Assuming a two-stage configuration with approximately 96% gear efficiency:

M₂ = 9550 × 5.5 × 0.96 ÷ 70

M₂ ≈ 720 Nm

Step 3 — Apply Service Factor

The required permissible gearbox torque must then be checked against the appropriate service factor for:

• Belt conveyor load characteristics
• 16-hour daily operation
• Starting frequency
• Starting torque
• External radial load

Therefore, selecting the gearbox solely because its nominal torque exceeds approximately 720 Nm would not be sufficient.

Final gearbox size should be determined only after the required service factor and shaft loads have been verified.

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F Series Gearbox Mounting Positions

F Series parallel shaft helical gearboxes can be installed in multiple mounting positions to suit machine layout requirements.

The catalog provides mounting arrangements from:

M1 to M6

Correct mounting-position identification is important because gearbox orientation can affect:

• Lubricant quantity
• Oil level
• Breather position
• Drain position
• Bearing lubrication
• Thermal behavior

Always specify the required mounting position when ordering.

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Typical F Series Gearbox Applications

Belt Conveyors

The compact parallel-shaft arrangement and hollow-shaft mounting options make F Series gearboxes particularly suitable for industrial belt conveyors.

Chain Conveyors

High torque capacity and shaft-mounted configurations make the F Series suitable for chain conveyor drives used in material-handling systems.

Pallet Conveyors

F Series gearmotors can provide compact drive arrangements for pallet transportation, warehouse automation and production logistics.

Bucket Elevators

High-torque parallel-shaft configurations can be evaluated for bucket elevators and vertical material-handling equipment according to torque, service factor and safety requirements.

Mixers and Agitators

F Series gearboxes can be used for industrial mixers and agitators where the parallel-shaft arrangement fits the machine layout and shaft loads are properly evaluated.

Packaging Machinery

Compact gearbox dimensions and multiple mounting arrangements allow integration into conveyors and packaging production lines.

Food Processing Equipment

Parallel-shaft gearmotors can be integrated into conveying and processing machinery where the required material, sealing and environmental specifications are appropriately selected.

OEM Industrial Machinery

Multiple gearbox sizes, output-shaft arrangements and motor configurations make the F Series suitable for custom machine builders and industrial OEM applications.

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F Series vs R Series Gearbox

F Series or R Series?

Choose an F Series gearbox when the application requires a compact parallel-shaft or shaft-mounted drive.

Choose an R Series gearbox when the motor and driven shaft need to remain inline or coaxial.

EXPLORE R SERIES HELICAL GEARBOXES

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F Series vs K Series Gearbox

F Series or K Series?

Choose an F Series gearbox when the input and output shafts should remain parallel.

Choose a K Series gearbox when the application requires approximately 90-degree power transmission.

EXPLORE K SERIES HELICAL BEVEL GEARBOXES

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F Series Parallel Shaft Gearbox vs Worm Gearbox

An F Series parallel shaft helical gearbox is generally preferred when the machine requires an efficient parallel-shaft or shaft-mounted drive for continuous industrial operation.

A worm gearbox is more appropriate where the application specifically requires a compact right-angle arrangement or a high reduction ratio in a compact package.

Self-locking characteristics of worm gearboxes depend on ratio, lead angle, lubrication and operating conditions and should not be used as a substitute for a dedicated safety brake.

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Looking for a More Efficient Industrial Gearbox?

For applications currently using a worm gearbox, the correct alternative depends on the machine shaft arrangement.

Choose:

F Series — for parallel-shaft applications

K Series — for right-angle helical-bevel applications

R Series — for inline/coaxial applications

Our engineers can evaluate the existing motor power, ratio, output speed, torque, shaft arrangement and mounting dimensions before recommending an alternative.

SEND YOUR EXISTING GEARBOX DETAILS

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SEW F Series Gearbox Equivalent & Replacement Support

Looking for an SEW F Series Gearbox Equivalent?

KB Transmission Star F Series parallel shaft helical gearboxes can be evaluated for selected applications currently using an F Series parallel-shaft gearbox from another manufacturer.

A replacement should not be selected from the model number or gear ratio alone.

For replacement engineering, we compare:

• Existing gearbox brand and model
• Motor power
• Motor speed
• Gear ratio
• Output speed
• Required output torque
• Solid or hollow shaft
• Hollow-shaft diameter
• Output shaft diameter
• Flange dimensions
• Mounting dimensions
• Mounting position
• Shrink-disc arrangement
• Radial and axial loads
• Service factor

Send us the existing gearbox nameplate, dimensional drawing and installation photos for cross-reference.

CHECK MY EXISTING GEARBOX

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F Series Dimensions & Replacement Data

The supplied F Series catalog includes detailed dimensional drawings for different gearbox sizes and configurations.

Available engineering information includes:

• Overall dimensions
• Solid output-shaft dimensions
• Hollow-shaft dimensions
• Shrink-disc dimensions
• Foot mounting dimensions
• B5 flange dimensions
• B14 flange dimensions
• Motor adapter dimensions
• Mounting positions

Because dimensions vary according to gearbox size and configuration, replacement compatibility should be verified using the complete gearbox designation rather than the frame size alone.

REQUEST F SERIES DIMENSION DRAWING

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F Series Gearbox Manufacturing & Quality Control

Precision Gear Manufacturing

Helical gears are manufactured for stable tooth contact, smooth meshing and reliable industrial torque transmission.

CNC Housing Machining

Bearing bores, mounting surfaces and shaft positions are machined to maintain alignment and dimensional consistency.

Shaft and Bearing Inspection

Critical shaft dimensions, bearing fits and gearbox interfaces are inspected before assembly.

Controlled Gearbox Assembly

Gears, shafts, bearings, seals and housings are assembled according to defined production procedures.

Running Inspection

Completed gearboxes are checked for smooth operation, abnormal noise, leakage and general running condition.

Dimensional Verification

Shaft arrangement, mounting configuration, flange interface and customer specifications are checked before shipment.

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Why Choose KB Transmission Star F Series Gearboxes?

Engineering-Based Selection

We evaluate ratio, torque, service factor, operating time, shaft load and mounting arrangement instead of selecting a gearbox from motor power alone.

F27–F157 Product Range

The product family provides gearbox sizes for compact conveyor applications through high-torque industrial machinery.

Multiple Output Configurations

Solid-shaft, hollow-shaft and shrink-disc configurations are available according to gearbox size and application.

Flexible Mounting

Foot, B5 flange, B14 flange and shaft-mounted arrangements provide flexibility for OEM machine design.

OEM Manufacturing Support

Engineering selection, motor matching, dimensional drawings and OEM branding support are available for industrial customers and distributors.

Replacement Engineering

Existing gearbox nameplates, dimensional drawings and installation information can be reviewed before a replacement recommendation is made.

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F Series Parallel Shaft Helical Gearbox FAQ

What is an F Series parallel shaft helical gearbox?

An F Series gearbox is an industrial helical gear reducer in which the input and output shafts are arranged parallel to each other. It provides speed reduction and torque multiplication in a compact offset-shaft configuration.

What F Series gearbox sizes are available?

The website product family covers:

F27, F37, F47, F57, F67, F77, F87, F97, F107, F127 and F157.

What is the maximum torque of an F Series gearbox?

The supplied catalog covers maximum gearbox torque ratings from approximately 130 Nm to 18,000 Nm, depending on gearbox size.

What is the motor power range?

The complete F Series catalog covers motor combinations from approximately 0.12 to 200 kW. Actual permissible motor power depends on gearbox size, ratio and operating conditions.

What is the gear ratio range?

The complete catalog specifies an overall ratio range of approximately 3.77 to 31,434, including extended and combined gearbox configurations. Individual F Series sizes have more limited available ratio ranges.

What is the efficiency of an F Series gearbox?

The supplied catalog gives approximate gear efficiencies of 98% for single-stage, 96% for two-stage and 94% for three-stage configurations.

What is the difference between F Series and R Series gearboxes?

F Series gearboxes use a parallel, offset shaft arrangement. R Series helical gearboxes use an inline or coaxial arrangement.

What is the difference between F Series and K Series gearboxes?

F Series gearboxes use parallel input/output shaft geometry, while K Series helical-bevel gearboxes provide approximately 90-degree right-angle power transmission.

Is the F Series suitable for conveyors?

Yes. The compact parallel-shaft design and hollow-shaft mounting options make the F Series particularly suitable for belt conveyors, chain conveyors and material-handling systems.

Are hollow-shaft F Series gearboxes available?

Yes. Hollow-shaft configurations are available, including configurations with shrink-disc connections depending on gearbox size.

What mounting configurations are available?

Depending on gearbox size and version, F Series units can be supplied in foot-mounted, flange-mounted and shaft-mounted configurations, with M1–M6 installation positions.

How do I select the correct F Series gearbox?

Selection should consider motor power, input speed, required output speed, gear ratio, required torque, service factor, radial and axial loads, output-shaft arrangement and mounting position.

Can your F Series replace an existing SEW F Series gearbox?

Selected applications can be cross-referenced, but compatibility should not be assumed from the model number alone. Ratio, torque, shaft dimensions, mounting dimensions, motor interface and operating conditions must be verified.

What information is required for an F Series quotation?

Please provide motor power, input speed, required output speed or ratio, required torque, application, operating hours, load type, output-shaft configuration, mounting position, quantity and existing gearbox details where applicable.

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Get an F Series Engineering Selection

Send us your application data and our engineering team will evaluate a suitable F Series gearbox and gearmotor configuration.

Application

Motor Power (kW)

Motor Speed (rpm)

Required Output Speed (rpm)

Required Gear Ratio

Required Output Torque (Nm)

Operating Hours per Day

Starting Frequency

Load Type

Solid Shaft / Hollow Shaft / Shrink Disc

Mounting Type

Mounting Position

Existing Gearbox Brand & Model

Quantity

Country

Email

Upload Nameplate / Drawing / Installation Photo

GET ENGINEERING SELECTION

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F Series Parallel Shaft Helical Gearbox Manufacturer

KB Transmission Star supplies F Series parallel shaft helical gearboxes and gearmotors for industrial OEMs, distributors, machine builders and end users.

From compact F27 gearboxes to high-torque F157 units, our engineering team can support new drive selection, motor matching, mounting configuration, dimensional verification and replacement projects.

F27–F157 | 0.12–200 kW | Up to 18,000 Nm | High-Efficiency Parallel-Shaft Drive

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