What is a torque converter? What is its structural principle and scope of application?

Torque converter. Composed. Pump wheels.

Turbines, guide wheels.

Compose. Installed between the engine and transmission to:

Hydraulic fluids. ATF).

Working medium. It plays the role of transmitting torque, torque change, speed change and clutch.

Added: Torque converter.

fluidtorque

converter

A non-rigid torque that uses a liquid as the working medium.

Inverter. Be.

Hydraulic transmission. one of the types. The picture shows the torque converter, which has a closed working chamber, and the liquid circulates and flows in the cavity, in which the pump wheel, turbine and guide wheel are respectively connected with the input shaft

Output shaft. and the shell.

Power machine. When the input shaft is rotated by an internal combustion engine or electric motor, the liquid flows out of the centrifugal pump in turn, passes through the turbine, the guide wheel and then returns to the pump wheel, and circulates repeatedly. The pump wheel will be entered into the shaft.

Mechanical energy. Pass to liquids. The high-speed liquid pushes the turbine to rotate, transferring energy to the output shaft. Torque converters are generated by the interaction of the liquid with the blades.

Angular momentum. to transmit torque. Torque converters are different from hydraulics.

Coupler. The main feature is that it has fixed guide wheels. The diversion effect of the guide wheel on the liquid makes the output torque of the torque converter higher or lower than the input torque, so it is called a torque converter. The ratio of the output torque to the input torque is weighed.

Torque conversion factor. When the output speed is zero.

Zero-speed torque conversion factor.

Usually about 2 6. The torque conversion coefficient decreases as the output speed increases. The input shaft and the output shaft of the torque converter are connected by liquid, and there is no rigid connection between the working components. Torque converters are characterized by the elimination of shocks and vibrations, and overload protection.

performance and. Starting performance.

Good; The speed of the output shaft can be greater or less than the speed of the input shaft, and the speed difference between the two shafts varies with the size of the transmitted torque; There are good ones.

Automatic transmission. performance, when the load increases, the output speed will automatically decrease, and vice versa; Ensure that the power machine has a stable working area, and the transient change of load will not be reflected on the power machine. The torque converter is in.

Rated operating condition. The efficiency is higher in the vicinity, with a maximum efficiency of 85 92. The impeller is the heart of the torque converter.

Its type and placement as well as the shape of the blades determine the performance of the torque converter. Some torque converters have more than two turbines, guide wheels or pump wheels to achieve different properties. The most common are:

Forward rotation. The output shaft and input shaft are steered consistently), and a single-stage (only one turbine) torque converter. It is called both torque converter and coupler performance characteristics.

Integrated torque converter.

For example, a torque converter can be fixed with a guide wheel or rotate with a pump wheel. In order for the torque converter to work properly, avoid generation.

Cavitation. And to ensure heat dissipation, it needs to be assisted by a certain oil supply pressure.

Oil supply system. And.

Cooling system.

The internal structure of the torque converter is the actual object.

When the torque converter works, the shell is filled with hydraulic oil, the engine drives the shell to rotate, the shell drives the pump wheel to rotate, and the hydraulic oil between the pump wheel blades flows from the inner edge to the outer edge under the action of centrifugal force. When the speed of the pump wheel is greater than the speed of the turbine, the hydraulic pressure of the outer edge of the pump wheel blade is greater than the hydraulic pressure of the outer edge of the turbine, and the oil flows to the turbine by the pump wheel in turn under the effect of the above-mentioned pressure difference while making a circular motion around the axis of the pump wheel. The pump wheel rotates clockwise, and the oil will drive the turbine to rotate in the same clockwise direction.

If the turbine is stationary or the speed of the turbine is much smaller than that of the pump wheel, the kinetic energy transferred by the liquid to the turbine is very small, and most of the energy is lost during the return of the oil from the turbine to the pump wheel, i.e., the circumferential velocity and kinetic energy of the oil gradually decrease as it flows from the outer edge of the turbine blade to the inner edge. When the oil returns to the pump wheel, the pump wheel does work on the oil, so that the kinetic energy and circumferential velocity gradually increase during the flow from the inner edge of the pump wheel blade to the outer edge, and then flow to the turbine.

1.Torque amplification characteristics.

2.Coupling operating characteristics.

When the turbine speed increases to 90% of the pump wheel speed, the liquid flow from the turbine just rushes the guide wheel along the direction of the guide wheel outlet, because the direction of the liquid flow through the guide wheel is unchanged, so the guide wheel torque MD is zero, that is, the turbine torque is equal to the pump wheel torque, MW=MB, and is in the coupling working state.

The common one-way clutch has two structural forms: wedge type and roller type.

3.Stall characteristics.

The stall state of the torque converter refers to the phenomenon that the turbine stops rotating due to excessive load, but the pump wheel still keeps rotating, at this time, the torque converter only has power input and no output, and all the input energy is converted into heat energy, so the oil temperature in the torque converter rises sharply, which will cause serious harm to the torque converter. The stall speed refers to the input speed of the torque converter when the turbine stops rotating, and the magnitude of the speed depends on the engine torque, the size of the torque converter and the blade angle of the guide wheel and turbine.

4.Locking characteristics.

Torque converter with lock-up clutch can improve transmission efficiency and economy; It can realize two working conditions: hydraulic torque converter transmission and mechanical direct transmission, and combine the advantages of the two into one.

The loader has an instantaneous thrust of up to 50 tons, and in addition to the powerful engine, it is also a key part.

The structure of the torque converter is generally composed of 4 elements, and this torque converter is commonly used in modern cars. As shown in Figures 1 and 2, the torque converter consists of a pump wheel, a turbine, a guide wheel, and a torsional damper (turbine torsional damper or dual damper system). The pump wheel is directly connected to the engine, while the turbine is connected to the input shaft of the automatic transmission.

The torque converter output shaft is a splined connection between the turbine and the transmission input shaft. The guide wheel is connected to the oil pump shaft by a spline in the one-way clutch and is able to fix the guide wheel in one direction. Figure 3 shows the actual working wheel and lock-up clutch structure.

A lock-up clutch consists of components such as a lock-up piston, torsion damper, and turbine rotor. After connecting the locking piston and torsional damper, it can move back and forth, and the shock absorber and turbo drive plate are connected by a buffer spring to attenuate the torsional oscillator and the first action when the locking clutch is connected. The turbine rotor is riveted to the front end of the turbine, and friction plates are attached to the front face of the torque converter housing (or the front face of the locking piston).

Torque converters serve a variety of purposes: power transmission, increased deceleration torque, cushioning vibrations, functioning as an automatic clutch, driving the oil pump of the transmission, and acting as a flywheel. Under different working conditions, the engine power can be transmitted to the transmission hydraulically or mechanically, and when the turboshaft speed is lower, the engine output torque can be increased, the transmission output speed can be reduced, the vehicle can be convenient to start, and the torsional vibration of the engine and the vibration transmitted from the vehicle transmission system to the engine can be reduced.

In the state of engine rotation and the old shift gear of the transmission meshed, the vehicle can be stationary. The hydraulic pressure generated by the oil pump of the torque converter is the power source for the action of the hydraulic system inside the automatic transmission and the shift drive, and the oil pump is driven by the torque converter. The torque converter can increase the moment of inertia of the engine flywheel, play the same role as the flywheel, and make the engine run smoothly.

The hydraulic torque converter is composed of three basic elements: pump wheel, turbine and guide wheel, as well as a torsion converter housing. Torque converters are usually only found in conventional automatic transmission vehicles.

Working principle of torque converter:

The pump wheel of the torque converter is connected with the flywheel at the output end of the engine crankshaft, the turbine is connected with the input shaft of the transmission, the guide wheel is between the pump wheel and the turbine, and the guide wheel is also fixed in the transmission housing through the guide wheel fixing sleeve. The engine operation drives the pump wheel to rotate, and the rotation of the pump wheel agitates the hydraulic oil in the torque converter, and the turbine that is agitated by the hydraulic oil rotates and transmits power to the transmission. The role of the guide wheel is to enhance the output torque of the turbine.

The role of the torque converter:

The function of connecting or disconnecting the engine from the transmission. The manual transmission is connected to the engine through a clutch, which realizes the connection or disconnection of the transmission and engine power. The role of the torque converter is similar to that of the clutch, and the flexible connection between the transmission and the engine is realized, and the powertrain work is smoother.

Hydraulic torque converter is a type of coupler, which can also be called hydraulic coupler, and the medium of coupling is hydraulic oil. The disassembly and assembly of the hydraulic coupling is first separated from the power unit and the transmission device, the hydraulic oil inside the hydraulic coupling is released, and the pump wheel, guide wheel and turbine can be disassembled by loosening the flange. The picture below shows the disassembly and assembly of the fluid coupling**.

It is installed between the engine and the transmission, and uses hydraulic oil as the working medium to transmit torque, torque conversion, speed transmission and clutch. 2. The working principle of the torque converter is: the pump wheel is driven by the engine to rotate and push the liquid to rotate around its axis with the pump wheel to obtain a certain speed and pressure.

3. The characteristics of the hydraulic torque converter are: (1) According to the driving resistance or working resistance of the machine, the torque converter can automatically and steplessly change the speed and torque within a certain range. (2) Extend the service life of the machine.