Knowledge Center

Split Shaft PTO gearboxes are essential components in applications where multiple systems or equipment need to be powered simultaneously from a single engine. They provide efficiency, versatility, and reliability, making them a preferred choice for heavy-duty industries requiring reliable power distribution and operational flexibility.

What is Split Shaft PTO?

A Split Shaft PTO gearbox is a mechanical device that transfers power from an engine to various auxiliary equipment or systems. These gearboxes are commonly used in heavy-duty applications such as trucks, emergency vehicles, industrial machinery, and mobile equipment. They allow for the simultaneous operation of multiple equipment or systems without compromising power or efficiency.

Key Features & Benefits of Split Shaft PTO gearboxes:

• 1. Power Distribution: Split Shaft PTO gearboxes enable the distribution of power from a single source to multiple systems or vice versa. Usually, a single power source is used to distribute power to systems such as hydraulic pumps, generators, compressors, winches, or other auxiliary devices.
  
  
• 2. Simultaneous Operation: The split shaft design allows different output shafts to operate independently or simultaneously while engaging various equipment without affecting each other's performance. This enhances productivity and flexibility in applications where multiple systems need to be powered concurrently.
  
  
• 3. High Torque Capacity: Split Shaft PTO gearboxes are designed to handle high torque loads and heavy-duty applications. They are built with robust materials and precision-engineered gears to withstand demanding conditions and ensure reliable power transmission.
  
  
• 4. Versatility: These gearboxes can be customized and adapted to suit specific application requirements. Different gear ratios, input/output configurations, and PTO shaft sizes can be accommodated to match the needs of various industries, including construction, utility, emergency services, and more.
  
  
• 5. Integration: Split Shaft PTO gearboxes can be integrated into existing drivetrain systems, making them compatible with a wide range of vehicles and equipment. They can be mounted between the engine and the transmission or between the transmission and the rear axle, depending on the vehicle's configuration.
  
  
• 6. Enhanced Efficiency: By efficiently distributing power to multiple systems, Split Shaft PTO gearboxes help optimize fuel consumption and reduce engine wear and tear. They minimize the need for additional engines or motors, resulting in improved overall system efficiency.

PTO Selection by Torque

Any rotating shaft (axle, propeller, engine shaft, gearbox shaft) must sustain the torque transmitted by it, which is being produced by the power source.

Power = Constant * Torque * Rotating Speed

By changing speed from a given power, torque can increase or decrease at a given time. Thus, a PTO gearbox should be selected for maximum possible torque of chassis of any other power source to avoid any damage to the main drive or the PTO gearbox.

Calculating Chassis Torque:

For a typical chassis, to calculate the maximum torque at input of split shaft PTO we need its Engine maximum torque and its maximum gear ratio (usually First Gear Ratio of main gearbox or Crawler Gear ratio if chassis has a crawler gear).
Torque = Max. Engine Torque * Max. Gear Ratio (1st or Crawler, whichever is higher)
Say for example,
Engine’s Max. Torque : 550 Nm
Max. Gear Ratio – 8.28 : 1
Chassis Max. Torque = 550 * 8.28 = 4,554 Nm
Safety Factor of 20-30% should be usually added to the above calculated Torque for design robustness.
Final Torque = Chassis Max. Torque + 30 %
Final Torque = 4554 * 1.3 = 5920 Nm

Calculating our PTO Gearbox Torque:

We are using Alloy Steel material (Cr/Mn/Ni/Mo) which is case hardened and grinded. The same material is being used by reputed OEMs. Further, we are using Forged material for shafts and gears which gives higher strength due to better grain distribution.
To consider safe stress we consider Impact loading conditions as well as heavy duty application conditions for safety factor. Safe Tensile Strength (STS) for our standard gearbox shafts is 33 Kg-mm^2.
Our shafts usually have a spline end for connection which has Major Dia and Minor Dia which we are denoting as OD and ID.
Strength at Spline Size = (pi/16) * ((OD^3+ID^3)/2) * S.T.S
Say for example,
Our model V3+ has Driveline Bearing Bore Of 50 mm however, the weakest point is the Coupling Splines having sizes of 50 mm x 44 mm x 8 Nos. (Std. VAS V3+ Splines)
Strength at Spline Size = (3.14/16)*((50^3+44^3)/2)*33 Kgmm ~ 6660.9 Nm
So for Chassis with required torque of 5,920 Nm, our model V3+ will be suitable with 6,660 Nm Driveline Design Torque.