Model of SHANNXI Fast Transmission Power Take-offs (PTOs) Report

 Model of SHANNXI Fast Transmission Power Take-offs (PTOs) Report

1. Project Background and Research Objectives

With the rapid development of the special-purpose vehicle industry, the Power Take-off (PTO), as a key component connecting the transmission and working devices, directly affects the operational efficiency and reliability of the entire vehicle. Fast, a leading domestic manufacturer of automotive transmission systems, is renowned for its PTO products with high reliability and wide applicability, which are widely used in various special-purpose vehicles. This report aims to comprehensively sort out the model system, technical parameters, application scenarios, and selection key points of Fast transmission PTOs, providing systematic references for relevant designers, purchasers, and users.

Research shows that Fast has a rich product line of PTOs, covering various installation methods such as front-mounted, rear-mounted, and side-mounted PTOs, with torque ranging from 200Nm to 700Nm. These PTOs can meet the needs of special-purpose vehicles of different tonnages and uses. Against the backdrop of the full implementation of the National VI emission standards, Fast has continuously launched PTO products that comply with the new regulations. For example, the F3E560 system launched in 2025 has been mass-produced and put on the market, providing power support for new energy mining trucks.

2. Overview and Working Principle of PTOs

2.1 Definition and Functions of PTOs

A Power Take-off (PTO) is a power output device that transmits engine power to the working devices of special-purpose vehicles, usually installed on the transmission. By connecting with the transmission gear system, Fast PTOs can transmit part or all of the engine power to working devices such as hydraulic pumps and air compressors, realizing the special operation functions of the vehicle.

The core functions of Fast PTOs include:

• Realizing the power splitting of the engine, enabling the vehicle to perform special operations while driving.

• Providing stable power output to meet the torque and speed requirements of different working devices.

• Supporting multiple installation methods to adapt to the layout requirements of different vehicle models and working devices.

• Equipped with a reliable control system to ensure safe and stable PTO engagement and disengagement.

2.2 Working Principle and Classification

The working principle of Fast PTOs is based on the transmission gear system. Through pneumatic or electronic control systems, the engagement and disengagement between the PTO gears and transmission gears are realized, thereby controlling the output and cut-off of power. According to different classification standards, Fast PTOs are mainly divided into the following categories:

1. Classification by Installation Position:

◦ Front-mounted PTO: Installed between the transmission and the clutch, such as the QF60 series.

◦ Rear-mounted PTO: Installed at the rear of the transmission, such as the QH70 series.

◦ Side-mounted PTO: Installed on the side of the transmission, such as the QC40A and QC20B series.

◦ Side (bottom)-mounted PTO: Installed on the side or bottom of the transmission, such as the QD50J series.

1. Classification by Power Take-off Method:

◦ Stationary PTO: The PTO works when the vehicle is stationary, requiring an intermediate position cylinder.

◦ Mobile PTO: The PTO works when the vehicle is moving, and special attention should be paid to operating specifications.

◦ Full-power PTO: Can transmit all the engine power to meet the needs of high-load operations.

1. Classification by Control Method:

◦ Pneumatic control: Controls the engagement and disengagement of the PTO through air pressure, featuring simple structure and fast response.

◦ Electronic control: Realizes precise control through an electronic control system, enabling more flexible operation.

◦ Hydraulic control: Uses a hydraulic system for control, which can provide a large acting force.

2.3 Key Technical Parameters

The key technical parameters of Fast PTOs include:

1. Rated Output Torque: The maximum torque that the PTO can continuously and stably output, which is a core parameter for PTO selection, ranging from 200Nm to 700Nm.

2. Speed Ratio: The speed ratio between the PTO input shaft and output shaft, which affects the speed and torque output of the working device.

◦ Calculation formula: Speed ratio = Input shaft speed ÷ Output shaft speed = Number of teeth on the output shaft ÷ Number of teeth on the input shaft.

◦ Common speed ratio range: 0.94 to 1.28, with different speed ratios for different PTO models.

1. Rated Input Speed: The maximum input speed at which the PTO can work normally, usually 2600rpm.

2. Output Shaft Rotation Direction: The rotation direction of the PTO output shaft, which is the same as or opposite to that of the engine, and needs to match the requirements of the working device.

3. Weight: The net weight of the PTO, which affects the weight distribution of the entire vehicle, ranging from 10kg to 115kg.

4. Lubrication Method:

◦ Sharing lubricating oil with the transmission: For PTOs installed at the bottom or side of the transmission.

◦ Independent lubrication system: For PTOs installed at the front or rear cover of the transmission, requiring separate lubricating oil filling.

3. Main Models and Technical Parameters of Fast PTOs

3.1 Front-mounted PTO Series

Front-mounted PTOs are installed between the transmission and the clutch, taking power directly from the engine without being affected by the clutch. They can be used when the vehicle is moving or stationary.

QF60 Series Front-mounted PTOs

The QF60 series is a main front-mounted PTO model of Fast, with the following technical parameters:

The QF60 series PTOs are suitable for various special-purpose vehicles equipped with Fast double countershaft and 9JS180 series transmissions, including cement mixers, truck cranes, oil tankers, dump trucks, fire trucks, and sprinklers. This series of PTOs adopts a three-shaft structure, with the output flange rotating in the same direction as the engine. They do not require separate oil filling, as their inner cavity is connected to the transmission.

3.2 Rear-mounted PTO Series

Rear-mounted PTOs are installed at the rear of the transmission, taking power from the auxiliary box countershaft. They are one of the most widely used types of PTOs in Fast's product line.

QH50 Series Rear-mounted PTOs

The QH50 series is one of the main rear-mounted PTO models of Fast, with the following main technical parameters:

The QH50 series PTOs are suitable for various special-purpose vehicles and special vehicles equipped with double countershaft series transmissions, such as dump trucks, truck cranes, and fire trucks. This series of PTOs takes power from the auxiliary box countershaft of Fast double countershaft series transmissions and adopts bidirectional pneumatic control for engagement.

QH70 Series Rear-mounted PTOs

The QH70 series is another main rear-mounted PTO model of Fast, with the following performance parameters:

The QH70 series PTOs are suitable for various special-purpose vehicles and special vehicles equipped with double countershaft series transmissions, such as dump trucks, truck cranes, and fire trucks. This series of PTOs takes power from the auxiliary box countershaft of Fast double countershaft series transmissions, and the total output speed ratio can be changed according to the transmission gear.

QH55F/QH70P PTO Assemblies

The QH55F/QH70P are rear-mounted PTO assemblies specially designed by Fast for crane operations, adaptable to the 8JS125T (G5777) transmission. Their main features are as follows:

• Manufactured using original factory supporting processes, perfectly matching the transmission.

• Made of high-strength alloy steel casting, with internal gear sets undergoing precision heat treatment.

• Adjustable output speed, adaptable to various crane models.

• Low operating noise, quieter than non-genuine products.

• Easy to install, no additional adjustments required.

3.3 Side-mounted PTO Series

Side-mounted PTOs are installed on the side of the transmission, taking power from the countershaft gear. They have a compact structure and are the most diverse type of PTOs in Fast's product line.

QC20B Series Side-mounted PTOs

The QC20B is a representative model of Fast's small-sized side-mounted PTOs, with the following technical parameters:

The QC20B series PTOs feature a compact structure and light weight, making them suitable for vehicle models with limited space. This series of PTOs adopts one-way pneumatic control for easy operation. They do not require separate oil filling, as their inner cavity is connected to the transmission.

QC40A Series Side-mounted PTOs

The QC40A series is a side-mounted PTO specially designed by Fast for double countershaft series transmissions, with the following technical parameters:

The QC40A series PTOs take power from the right countershaft power take-off gear of the Fast double countershaft series transmission main box. They are suitable for various special-purpose vehicles and special vehicles equipped with non-synchronizer double countershaft series transmissions, such as dump trucks, truck cranes, and fire trucks. This series of PTOs adopts bidirectional pneumatic control for engagement. Before use, the operation manual should be carefully read and operating regulations should be followed.

QC45 Series Side-mounted PTOs

The QC45 series is another side-mounted PTO model of Fast, with the following technical parameters:

The QC45 series PTOs take power from the countershaft gear of the F6J95T and 6J90T series transmissions. They have a small center distance, compact overall structure, and light weight, and adopt one-way pneumatic control for easy operation. This series of PTOs is suitable for various special-purpose vehicles and special vehicles equipped with the F6J95T and 6J90T series transmissions.

QC35 Series Side-mounted PTOs

The QC35 series is a side-mounted PTO designed by Fast for low-torque requirements, with the following main technical parameters:

The QC35 series PTOs are adaptable to the Fast 6DS60T transmission and are mainly used in light-duty special-purpose vehicles with low torque requirements. This series of PTOs adopts a one-way pneumatic control design for easy operation.

3.4 Side (Bottom)-mounted PTO Series

Side (bottom)-mounted PTOs are installed on the side or bottom of the transmission, combining the characteristics of side-mounted and bottom-mounted PTOs, and offering more flexible installation methods.

QD50J Series Side (Bottom)-mounted PTOs

The QD50J is a main side (bottom)-mounted PTO model of Fast, with the following technical parameters:

The QD50J series PTOs are suitable for various vehicle models and working scenarios, with flexible installation positions that can be selected according to the vehicle structure and working requirements. This series of PTOs adopts bidirectional pneumatic control for easy operation and can meet the power take-off requirements under different working conditions.

QD40 Series Side (Bottom)-mounted PTOs

The QD40 series is another type of side (bottom)-mounted PTO of Fast, including multiple models such as QD40A, QD40B, QD40I, QD40L, and QD40M. Their main technical parameters are as follows:

The QD40 series is the most diverse type of PTOs in Fast's product line, capable of meeting the needs of different vehicle models and working conditions. This series of PTOs is mainly used in specific Dongfeng vehicle models and transmission configurations, and is also suitable for Fast small 8-speed series transmissions.

3.5 Other PTO Series

In addition to the above main series, Fast also provides a variety of PTO products for special purposes.

QQ90 Series Front-mounted PTOs

The QQ90 series is a large-sized front-mounted PTO of Fast, with the following technical parameters:

The QQ90 series PTOs are the front-mounted PTOs with the largest output torque of Fast, suitable for heavy-duty special-purpose vehicles with high torque requirements. This series of PTOs adopts a three-shaft structure, with the output flange rotating in the same direction as the engine. They require separate oil filling until the oil overflows from the oil hole.

F3E560A New Energy Pure Electric PTOs

The F3E560A is a PTO specially designed by Fast for new energy pure electric vehicles, with the following technical parameters:

FAST 17G0A9-22 ,9JS135T-B,8JS118TA-B,9JS119TA,10JS Two Types of PTOs (Power Take-Offs) with Gear Ratios of 0.78 and 0.94: Modification Applications

In modification scenarios, the core function of PTOs (Power Take-Offs) with gear ratios of 0.78 and 0.94 is to adjust the matching relationship between the output speed and torque of power, so as to meet the working conditions of different modified equipment. Essentially, they utilize the "inverse proportional characteristic of speed and torque" (the smaller the gear ratio, the higher the output speed and the smaller the torque; the larger the gear ratio, the lower the output speed and the larger the torque) to solve the problems of "speed mismatch and insufficient/excessive torque" between the original vehicle power and the modified equipment.

1. Core Concept: The Essential Impact of Gear Ratio

The gear ratio of a PTO = Input speed of the PTO (usually from the engine or transmission) ÷ Output speed of the PTO. The core differences between the two gear ratios are as follows:

2. PTO with 0.78 Gear Ratio: Modified Scenarios Focusing on "High-Speed Operation"

With the characteristic of "overdrive output", the PTO with a 0.78 gear ratio is suitable for modified equipment that has high speed requirements and relatively light load. Its core advantage is to improve the working speed of the equipment to enhance operating efficiency. Common applications include:

1.1 High-Speed Fluid Conveyance Modification

Modification Scenarios: On-board pumps for oil tankers/chemical liquid transport vehicles, high-pressure spray pumps for sprinkler trucks, and high-pressure water pumps for cleaning vehicles (e.g., road cleaning, pipeline dredging).

Adaptation Reason: Pumps of this type (such as centrifugal water pumps and gear pumps) require high speeds to achieve large flow and high-pressure output (e.g., sprinkler trucks need high-speed pumps to ensure the spray coverage range, and cleaning vehicles need high-pressure pumps to achieve strong decontamination). The overdrive output of the 0.78 gear ratio allows the pump to reach the rated working speed when the engine is running at medium to low speeds, avoiding high-load operation of the engine while improving conveyance efficiency.

1.2 High-Speed Mechanical Transmission Modification

Modification Scenarios: Slewing mechanisms of small truck-mounted cranes (below 3 tons), high-speed rolling shutters (e.g., automatic tarpaulin shutters for special vehicles), and light material conveyor belts (e.g., horizontal conveyor belts for bulk feed trucks).

Adaptation Reason: The slewing mechanism of small cranes needs to quickly adjust the operating angle (no need for ultra-large torque), and high-speed rolling shutters need to quickly retract and release the tarpaulin. The high-speed output of the 0.78 gear ratio can shorten the operation time and improve operational flexibility.

1.3 Auxiliary Equipment Drive (Low Load)

Modification Scenarios: On-board generators for large trucks (supplying power to air conditioners and tools) and auxiliary refrigeration compressors for refrigerated trucks (supplementing the original refrigeration capacity of the vehicle).

Adaptation Reason: Such equipment only requires a stable speed (no need for high torque). The 0.78 gear ratio allows the generator/compressor to reach the rated speed when the engine is idling or running at medium speed, ensuring power supply/refrigeration efficiency while reducing the additional load on the engine.

3. PTO with 0.94 Gear Ratio: Balanced Modification Scenarios Focusing on "Medium Torque + Medium Speed"

With an output speed close to the input speed and a slight increase in torque, the PTO with a 0.94 gear ratio is suitable for modified equipment that has certain torque requirements and no need for excessively high speed. Its core advantage is to "balance load capacity and operating efficiency". Common applications include:

3.1 Medium-Load Material Handling Modification

Modification Scenarios: Hoisting/luffing mechanisms of medium-sized truck-mounted cranes (3-8 tons), forklifts (modified into off-road forklifts, with PTO driving the hydraulic system), and hydraulic lifting pumps for dump trucks (heavy dump trucks with large carriage weight).

Adaptation Reason: Medium-sized cranes need sufficient torque to prevent stalling when lifting heavy objects (e.g., 5-ton goods), and dump trucks need hydraulic pumps to provide high pressure (relying on torque) to lift heavy carriages (e.g., muck, ore). The torque increase of the 0.94 gear ratio ensures stable operation of the equipment under load, while the speed will not be too low to reduce operating efficiency.

3.2 Medium-Pressure Fluid Operation Modification

Modification Scenarios: Vacuum pumps for sewage suction trucks/manure suction trucks (extracting viscous sewage), medium-pressure fire pumps for fire trucks (lift: 50-100 meters), and auxiliary mixing mechanisms for concrete mixers (supplementing the original mixing power of the vehicle).

Adaptation Reason: The vacuum pump of a sewage suction truck needs to overcome the resistance of viscous sewage (requiring medium-high torque), and the medium-pressure fire pump needs stable pressure output (excessively high speed may cause pressure fluctuations). The "medium torque + medium speed" of the 0.94 gear ratio can balance "suction/pressure" and "operational stability", preventing the equipment from jamming due to insufficient torque or being damaged due to excessively high speed.

3.3 Special Operation Equipment Drive (Medium Load)

Modification Scenarios: Milling mechanisms of road maintenance vehicles (small milling machines for processing asphalt pavement), hydraulic systems for compression push plates of garbage compression trucks, and hydraulic outriggers of truck-mounted cranes (stabilizing the vehicle body, requiring sufficient thrust).

Adaptation Reason: The milling mechanism needs to cut the pavement (requiring torque to overcome friction), the garbage compression truck needs the push plate to squeeze garbage (requiring hydraulic torque), and the hydraulic outriggers need to lift the vehicle body (to avoid sinking). The torque reserve of the 0.94 gear ratio ensures the reliability of these medium-load operations, while the medium speed will not cause excessive wear of the equipment.

4. Key Notes for Modification

Matching the Original Vehicle Power Parameters: It is necessary to confirm the rated speed and torque of the PTO input end (engine/transmission) to avoid improper gear ratio selection leading to "a small horse pulling a big cart" (e.g., using a 0.78 gear ratio to drive a heavy crane, resulting in insufficient torque and burning the PTO) or "a big horse pulling a small cart" (e.g., using a 0.94 gear ratio to drive a high-speed pump, resulting in insufficient speed and low efficiency).

Adapting to the Rated Working Conditions of the Equipment: Select the gear ratio according to the "rated speed and rated torque" of the modified equipment (e.g., if the rated speed of the equipment is 2000 rpm, and the original vehicle PTO input speed is 2500 rpm, a 0.8 gear ratio can be used to approach the rated value, and the 0.78 gear ratio is more suitable).

Installing Protection Devices: For high-load modifications (e.g., cranes, sewage suction trucks), torque limiters and overload protection valves should be equipped to prevent the PTO from being damaged due to instantaneous overload; for high-speed modifications (e.g., cleaning trucks, generators), speed sensors should be installed to prevent equipment failure caused by excessively high speed.

In summary, the PTO with a 0.78 gear ratio is a "efficiency-first" choice, suitable for high-speed and low-load equipment; the 0.94 gear ratio is a "balance-first" choice, suitable for medium-load equipment that requires torque reserve. During modification, the selection must be based on the dual factors of "original vehicle power + equipment working conditions".

  FAST GEARBOX Power Take-off PTO  Express weight list:

Dong Runze Special Vehicle