KR100774349B1 - Planetary- geared turbocharger - Google Patents

Abstract

A planetary geared turbocharger is provided to easily obtain high low-end torque by controlling motor speed even when flow amount of a turbine is less, and to obtain rapid response speed by using speed control of an electric motor. A planetary-geared turbocharger comprises a planetary gear(8), a turbine(4), a compressor(6), a waist gate(10), a controller(18) and a hall sensor(22). The planetary gear controls rotation speed of the turbine and the compressor. The turbine is supplied with energy from exhaust gas of an engine and rotated. The compressor receives speed and torque provided from the planetary gear and turbocharges inflow air to have a desired target value. The waist gate discharges some of extra exhaust gas to downstream of the engine. The controller is connected to the planetary gear and controls an electric motor for varying speed of the compressor according to turbine speed and engine demand conditions. The hall sensor measures turbine wheel speed.

Description

Variable Speed Compression Supercharging System Using Planetary Gears {PLANETARY- GEARED TURBOCHARGER}

1 is a view showing a variable speed compression supercharging system using planetary gear according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

2: Variable speed compression supercharging system

4: turbine

6: Compressor

8: Planetary Gear

10: wastegate

12: electric motor

14: Electronic control device

18: control unit

20: turbine wheel speed sensor

22: Hall sensor

The present invention relates to a variable speed compression supercharging system using planetary gears. More particularly, the turbocharger used in an internal combustion engine is improved, and a planetary gearbox and an electric motor are continuously used for the engine load and the required supercharge amount. The present invention relates to a variable speed compression supercharging system using a planetary gear that is supercharged by adjusting the compressor rotation speed.

Explaining generally known supercharging systems,

WGT (WasteGate Turbocharger):

Classic turbocharger. Since there are no vanes in the compressor and turbine, it is not possible to arbitrarily adjust the supercharge at a given engine condition. To increase efficiency at full load, the wastegate valve opens to bypass part of the exhaust gas when the turbine inlet pressure is increased above the threshold. The advantage is that it is durable and inexpensive, and the disadvantage is that the vane is fixed, so there is a limit on the maximum output and there is a problem in that it is impossible to adjust the supercharge amount.

VGT (Variable Geometry Turbocharger):

The vane of the turbine is variable by pneumatic or step motor to adjust the compressor wheel rotation speed to meet the desired supercharge. The advantage is that the desired supercharge can be adjusted by adjusting the vane.

The disadvantage is that the capacity is increased to meet the engine's maximum power, so the inertia increases, so the supercharge response is low at low flow rate (energy) at low speed, and low-end torque at low speed is also achieved. There is a limit to surging due to surging. In addition, the operation mechanism of the vanes occupy a lot of costs, there was a problem that the durability is less than the conventional turbocharger.

VGC (Variable Geometry Compressor):

Vane has been added to the compressor compared to VGT. The vane of the compressor can also be changed by pneumatic or motor. The advantage is that the vanes are variable enough to close at low speeds, allowing maximum supercharging even at low speeds (low flow rates), resulting in high low-end-torque and avoiding surging as much as possible.

However, the disadvantage is that the vanes run on both the turbine and the compressor, so the cost is higher than the VGT, the durability is lower, and the degree of freedom (vane) increases, which makes it difficult to control. There was a problem that the compressor occupies a larger volume than the existing VGT for adjusting the vanes.

2-Stage Turbocharger:

With two turbochargers connected in series, low-capacity HP (high pressure) turbochargers are mainly used at low speeds, and high-capacity low-pressure turbochargers (LP) are used for supercharging at high speeds. The advantage between HP and LP Stage is that the turbine and compressor are both vane-free and durable. In addition, the proper combination of LP and HP Stage enables simultaneous high low-end-torque and high peak power, and HP's low inertia provides excellent response at low speeds.

However, the disadvantage is that once the volume is much larger than the existing turbocharger, it is a problem in layout design when the vehicle is mounted, the exhaust gas flow path design is very complicated, there is a problem that it is difficult to control because at least three valves are required.

The object of the present invention is to solve the problems of the prior art made as described above. It is to provide a variable speed compression supercharging system using a planetary gear which is supercharged by continuously adjusting the compressor rotation speed.

Other objects and advantages of the invention will be described below and will be appreciated by the embodiments of the invention. Furthermore, the objects and advantages of the present invention can be realized by means and combinations indicated in the claims.

In order to achieve these technical challenges,

Planetary gears installed to artificially adjust rotational speeds of the turbine and the compressor;

A turbine installed to rotate by receiving energy from exhaust gas of the engine;

A compressor configured to supercharge the inflow air to a desired target value by receiving the speed and torque from the planetary gear;

A waste gate for discharging a portion of excess exhaust gas to the downstream of the engine as required;

An electric motor connected to the planetary gear and configured to arbitrarily vary the speed of the compressor according to the turbine speed and engine requirements, and a control unit including a circuit unit and an electronic control circuit unit to drive the motor; It provides a variable speed compression supercharging system using a planetary gear characterized in that it consists of a Hall sensor for measuring the turbine wheel speed sensor.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention.

Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

1 is a view showing a variable speed compression supercharging system using planetary gears according to an embodiment of the present invention.

Referring to the drawings, the variable speed compression supercharging system 2 using the planetary gears includes a planetary gear 8 installed to artificially adjust the rotational speeds of the turbine 4 and the compressor 6; A turbine 4 which is rotated by receiving energy from exhaust gas of the engine; A compressor (6) which receives the speed and torque from the planetary gear (8) to supercharge the inlet air to a desired target value; A waste gate 10 for discharging a portion of excess exhaust gas to the downstream of the engine as required; The turbocharger adjusting device 14 and the electronic control connected to the planetary gear 8 to drive the electric motor 12 and the motor 12 to arbitrarily vary the speed of the compressor 6 according to the turbine speed and engine requirements. A control unit 18 comprising an apparatus 16; It consists of the hall sensor 22 measuring the turbine wheel speed sensor 20.

The planetary gear includes a sun gear S connected to a compressor shaft, a carrier C engaged with the sun gear S and connected to the turbine shaft, and a sun shaft S engaged with the sun gear S. It is composed of a ring gear (R) that is connected to (24).

 Fresh air introduced through the intake system from the outside is a pressure at atmospheric pressure, and is pressurized to a desired level by the rotation of the compressor 6.

In addition, the hot-high pressure exhaust gas discharged from the combustion chamber inside the engine via the exhaust manifold causes the turbine 4 with the desired torque and rotational energy, and is discharged to the exhaust pipe at a low temperature and low pressure.

In addition, when too much exhaust gas enters the turbine 4, the efficiency decreases due to the increase in back pressure. Thus, the wastegate valve 10 is opened in the high speed region mainly in accordance with the supercharge situation required by the engine, thereby exhausting the exhaust gas into the turbine 4. Bypass to the exhaust pipe without going through.

Like the existing turbocharger, there is an input / output of lubrication / cooling to handle the internal lubrication and cooling of the turbocharger.

Referring to the operation of the present invention made as described above, similar to the existing turbocharger system, but the motor and planetary gear is introduced is the core part of the present invention.

The shaft 24 of the motor 12 is connected to the shaft 4 of the turbine 4 and the compressor 6 through the planetary gear 8 to transfer the kinetic energy generated from the turbine 4 to the compressor shaft 26. To pass.

At this time, by controlling the speed of the motor 12 by the speed ratio according to the gear ratio of the planetary gear 8, the rotation speed of the compressor 6 required by the engine is generated according to the current engine state.

The rotational speed of the wheel of the turbine 4 is measured through the turbine wheel speed sensor 20 and enters the electronic controller 16. The speed control of the motor is handled by a motor control circuit called a turbocharger control unit (14) circuit, and this circuit controls the desired motor rotational speed in communication with the electronic control device (16).

The electronic controller 16 is configured with the desired boost pressure from the input data such as the currently generated boost pressure and motor rotation speed, turbine wheel rotation speed, engine rotation speed, engine injection fuel amount, atmospheric pressure, air amount, and the like. The speed required is detected, and the turbocharger 14 is commanded to receive feedback (feedback).

In addition, the ECU restricts the amount of momentum of the turbine 4 by modifying the pneumatic valve that moves the wastegate 10 when bypass of exhaust gas is required according to the state (speed and load) of the engine. .

The equation for the planetary gear with the motor, turbine, and compressor engaged is:

: 모터의 회전속도

: 컴프레서의 회전속도

: Speed of motor

: Speed of compressor

: 터빈의 회전속도

: 모터측 링기어의 기어치수

: Speed of turbine

: Gear dimension of ring gear on motor side

: 컴프레서측 선기어의 기어치수

: Gear dimension of compressor side sun gear

는 결정된다. Assuming that the wastegate is properly controlled, the turbine speed depends on the engine speed and load

Is determined.

역시 결정되므로 위의 식을 이용하여 모터의 회전속도

를 결정지을 수 있다.At this time, the compressor rotation speed depends on the supercharge required by the engine.

Since it is also determined, the rotation speed of the motor using the above equation

Can be determined.

에 맞도록 모터를 제어해주면 된다. 이는 곧, 주어진 터빈속도에 대해 모터의 속도를 알맞게 제어함으로 컴프레서의 속도를 원하는 대로 제어할수 있음을 의미한다.The motor speed determined

You can control the motor to fit. This means that the speed of the compressor can be controlled as desired by appropriately controlling the speed of the motor for a given turbine speed.

Overcome the shortcomings of turbochargers (2-Stage Turbochager and Variable Geometry Compressor) and realize the Planetary-Geared Turbocharger (PGT), a variable-speed compression supercharging system that can more efficiently reach the target supercharge based on engine condition and driver demand. can do.

As mentioned above, although this invention was demonstrated by the limited embodiment and drawing, this invention is not limited by this and is given by the person of ordinary skill in the art to the following, Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

The present invention overcomes the shortcomings of the state-of-the-art turbocharger (2-Stage Turbochager and Variable Geometry Compressor) and is a variable speed compression supercharging system that can more efficiently reach the target supercharge according to the engine condition and the driver's demand. Geared Turbocharger) is effective.

In a conventional turbocharger system such as WGT, VGC, VGT, 2-Stage, the turbine and the compressor wheel are directly connected to each other so that the rotational speed is always the same between the two wheels, thereby limiting the supercharge performance according to the engine condition.

Turbine flow is insufficient when the engine is at low speed, so the conventional turbocharger has a limitation in turbine rotational speed.Therefore, there is a limit to sufficient supercharging on the compressor side (VGT, WGT). Maximize the charging efficiency (VGC), or low-capacity turbocharger mainly used at low speed (2-Stage) is possible to effect.

In addition, the turbocharger of the present invention can increase the rotational speed of the compressor sufficiently by controlling the speed of the motor even when the turbine flow rate is low, thereby making it possible to easily secure high low-end-torque.

In addition, in the case of the existing VGT and VGC, since the mechanical vane system has a limit on the response speed than when a sudden change such as rapid acceleration is required, the present invention uses the speed control of the electric motor, so it uses a large volume like a 2-stage turbocharger. Even if you do not use it has the effect of ensuring a fast response speed.

In addition, high speed compressor speed and supercharge amount can be realized by low flow rate turbine energy in low speed area, and it is possible to secure extra EGR amount by returning the extra exhaust flow rate to EGR system. NOx) has a more advantageous effect on the reduction.

In addition, since the compressor rotational speed can be used as desired even in the high speed range while maintaining the above advantages, it has an advantage over the 2-stage turbocharger in terms of small volume and simpler control.

Therefore, the present invention has the advantages of low speed supercharge, excellent transient characteristics, high speed supercharge equivalent or more, concise and relatively small volume system, and increased exhaust gas reduction potential. There is an advantage to supplement.

Claims (4)

 Planetary gears installed to artificially adjust rotational speeds of the turbine and the compressor; A turbine installed to rotate by receiving energy from exhaust gas of the engine; A compressor configured to supercharge the inflow air to a desired target value by receiving the speed and torque from the planetary gear; A waste gate for discharging a portion of excess exhaust gas to the downstream of the engine as required; A controller connected to the planetary gear and controlling the electric motor and the motor to arbitrarily vary the speed of the compressor according to the turbine speed and engine requirements; Variable speed compression supercharging system using planetary gears, characterized in that consisting of a Hall sensor for measuring the turbine wheel speed sensor. The method according to claim 1, The planetary gear includes a sun gear S connected to a compressor shaft, a carrier C engaged with the sun gear S and connected to the turbine shaft, and a sun shaft S engaged with the sun gear S. Variable speed compression supercharging system using planetary gears, characterized in that consisting of ring gear (R) is connected to the installation (24). The method according to claim 1, The turbine wheel speed sensor is a variable speed compression supercharge system using a planetary gear, characterized in that for transmitting a signal to the electronic control device by detecting the hall sensor formed in the turbine. The method according to claim 1, The wastegate valve is a variable speed compression supercharging system using a planetary gearbox, characterized in that the engine is opened in a high speed region and bypasses the exhaust gas to the exhaust pipe without passing through the turbine according to the supercharge situation required by the engine.

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