JPH0245475Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a supercharging device, and more specifically, a dynamic pressure air bearing supercharger driven by the exhaust gas of an engine, and a supercharger driven by the engine. It is used as a supercharging device for vehicle supercharged engines, etc., in combination with a mechanically driven supercharger.

Conventional technology Lubricated oil bearings have traditionally been used for turbocharger bearings, but the use of foil-type hydrodynamic air bearings has a simpler structure and does not require oil, which reduces the impact on the engine. It has the advantages of being able to be mounted vertically and horizontally, there are no problems associated with oil, high mechanical efficiency, and good heat resistance, so it is hoped that it will be put into practical use, but so far this has not been achieved. .
The reason for this is that since a dynamic pressure type air bearing is used in a vehicle supercharger that is frequently started and stopped, an air film is not sufficiently formed during startup. In other words, since air has extremely low viscosity compared to oil, a certain speed or higher is required to form an air film, but vehicle superchargers are often used at low speeds. It is.

Problems that the invention aims to solve As mentioned above, the load capacity of hydrodynamic air bearings at low speeds is small, and therefore the lack of thrust load capacity is a major problem in this type of rotating machinery with large thrust loads. It is a point. In other words, while foil-type journal bearings can withstand repeated starting and stopping on their own, foil-type hydrodynamic thrust bearings use flotation air (jumping air) to form some kind of air film on the bearing surface during startup. ), that is, it is necessary to feed compressed air, and therefore there is a problem as to what means should be used to feed the air. The present invention attempts to solve the above problems. In other words, the present invention compensates for the disadvantages of the hydrodynamic air bearing supercharger with a supercharging system, and also fully utilizes the advantages of the mechanically driven supercharger, which has a large supercharging effect in the low speed range. Another object of the present invention is to provide a supercharging device that can take advantage of the advantages of a hydrodynamic air bearing, such as heat resistance and low mechanical loss, at high speeds.

Measures to solve the problem: A hydrodynamic air bearing supercharger is combined with a mechanically driven supercharger, and a portion of the air discharged from the mechanically driven supercharger is used to float the hydrodynamic air bearing during startup and low speed. Now it can be sent for use (for jack-up). That is,
The present invention provides a supercharged engine having a combination of a dynamic pressure air bearing supercharger driven by engine exhaust gas and a mechanically driven supercharger driven by the engine. A clutch is provided between the mechanically driven supercharger and is automatically engaged and disengaged, and the clutch is engaged when the engine is started and at low speeds by detecting the operating state of the engine, and the mechanically driven supercharger is engaged. a controller for operating the mechanically driven supercharger and disengaging the clutch to stop the mechanically driven supercharger at medium and high speeds of the engine; The compressed air discharged from the mechanically driven supercharger during operation is sent to the engine as supercharging air, and at the same time, a portion of the compressed air is used as flotation air for the hydrodynamic air bearing of the hydrodynamic air bearing supercharger. It is characterized by having air piping that feeds into the air bearing.

Operation When the engine is started and at low speed, the controller engages the automatically engaging/disengaging clutch to operate the mechanically driven supercharger, and the compressed air discharged from the mechanically driven supercharger is mainly used for supplying air. This air is sent to the engine as air, but a portion of it is sent to the dynamic air bearing of the hydrodynamic air bearing supercharger as levitation air (air for jacking up). Also, at medium and high engine speeds, the controller disengages the self-engaging and disengaging clutch to shut down the mechanically driven supercharger, allowing air to be supplied to the engine only from the dynamic air bearing supercharger. by.

Embodiment FIG. 1 shows an embodiment of the present invention. 1st
In the figure, 1 is an engine, 2 is a dynamic pressure air bearing supercharger driven by the exhaust gas of the engine 1, and 3 is a mechanically driven supercharger such as a screw type or Roots type that is driven by the engine 1. A feeder, 4, is an automatically engaging/disengaging clutch provided between the engine 1 and the mechanically driven supercharger 3, and 5 is a clutch that is sent to the engine 1 and detects the boost pressure or amount of air to be fed. a controller for engaging and disengaging the clutch 4;
is the turbine of the hydrodynamic air bearing supercharger 2, 7 is the same compressor, 8 is the same hydrodynamic air bearing, 9 and 10 are exhaust gas pipes, 11 and 12 are atmospheric suction pipes, 13, 14, 15, and 16. 17 is a compressed air pipe, and 18, 19, and 20 are check valves. Note that the controller 5 may detect the rotational speed of the engine 1 and engage/disengage the clutch 4 of an automatic engagement/disengagement type.

In the supercharging device configured as shown in FIG. 1, the controller 5 detects the operating state of the engine 1, that is, when the engine 1 is started and at low speed, the boost pressure or the amount of air intake is kept at a constant value. At medium speeds and high speeds, it exceeds a certain value, so it is detected, and when the engine 1 is started and at low speeds, the clutch 4 is engaged and the mechanically driven supercharger 3 is operated. At medium and high speeds of the engine 1, the clutch 4 is disengaged to stop the mechanically driven supercharger 3.

That is, since the mechanically driven supercharger 3 operates when the engine 1 is started and at low speed, the compressed air discharged from the mechanically driven supercharger 3 mainly flows through the compressed air pipe 1 at the time of starting and at low speed.
3 → 14 → 15 and is sent to the engine 1 as supply air, but a part of it passes through the compressed air pipe 17 and is sent to the dynamic pressure air bearing 8 of the dynamic pressure air bearing supercharger 2 for flotation air (air for jack up) sent as. In other words, when the engine 1 is running at low speed, the amount of exhaust gas is small, so the dynamic pressure air bearing supercharger 2
The output of the turbine 6 is also small, and therefore the discharge pressure and discharge amount of the compressor 7 are both small, so at low speeds, supercharging is mainly performed by the discharge air of the mechanically driven supercharger 3. So, the mechanically driven supercharger 3 has two roles.

Moreover, as the check valves 18, 19, and 20, simple ones for instrumentation air piping are used. As a result, even if there is an imbalance between the discharge pressures of the dynamic pressure type air bearing supercharger 2 and the mechanically driven supercharger 3, reverse flow will not occur. Note that the check valve 20 of the compressed air pipe 16 of the hydrodynamic air bearing supercharger 2 is set to such an extent that the compressor 9 does not surge.

FIG. 2 shows an example of the structure of the dynamic pressure air bearing supercharger 2 shown in FIG. Turbine 6, compressor 7, foil thrust dynamic air bearing 21,
The arrangement of the wheel-type journal dynamic pressure air bearing 22 is almost the same as that of a normal metal bearing supercharger.
The compressed air discharged by the mechanically driven supercharger 3 explained in FIG. 21
and the thrust collar 23 as flotation air, and some of it is also supplied to the journal dynamic air bearing 22 and the labyrinth seal part 2.
It is also distributed as 5, 26 seal air. Note that 28 in FIG. 2 is a cooling water inlet, and 29 is a cooling water outlet. That is, although FIG. 2 shows a water-cooled bearing chamber 27, it may be air-cooled.

Effects of the invention The present invention combines a dynamic pressure type air bearing supercharger driven by engine exhaust gas and a mechanically driven supercharger driven by the engine, and the mechanical drive is controlled by a controller when starting the engine and at low speeds. The mechanically driven supercharger is controlled to operate, and the mechanically driven supercharger is controlled to stop at medium and high speeds, and a part of the air discharged from the mechanically driven supercharger is controlled to Since the air is fed to the dynamic pressure air bearing of the pressure type air bearing supercharger, the mechanically driven supercharger can exert a supercharging effect when the engine is started and at low speeds, and is similar to a turbocharger. There are no delays. Also, at startup and at low speeds,
Compressed air is sent to the thrust foil surface of a dynamic pressure air bearing supercharger to improve thrust load capacity.
To improve the starting performance of hydrodynamic air bearings. Furthermore, at medium and high speeds, instead of the mechanically driven supercharger, a dynamic pressure air bearing supercharger is used for supercharging, which has the advantages of a dynamic pressure air bearing, that is, heat resistance and low mechanical You can take advantage of losses.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention, and FIG. 2 is a detailed sectional side view of the dynamic pressure type air bearing supercharger shown in FIG. DESCRIPTION OF SYMBOLS 1... Engine, 2... Dynamic pressure type air bearing supercharger, 3... Mechanically driven supercharger, 4... Automatic engagement/disengagement type clutch, 5... Controller, 6... Turbine, 7
... Compressor, 8 ... Dynamic pressure type air bearing, 9,
10... Exhaust gas piping, 11, 12... Atmospheric suction piping, 13, 14, 15, 16, 17... Compressed air piping, 18, 19, 20... Check valve, 21...
Thrust dynamic pressure type air bearing, 22...Journal dynamic pressure type air bearing.

Claims (1)

[Scope of utility model registration request] In a supercharged engine having a combination of a dynamic pressure air bearing supercharger driven by engine exhaust gas and a mechanically driven supercharger driven by the engine, the engine and the mechanically driven supercharger has a self-engaging and disengaging clutch provided between the two, and
The operating state of the engine is detected, and the clutch is engaged to operate the mechanically driven supercharger when the engine is started and at low speed, and the clutch is disengaged when the engine is at medium speed and high speed. It has a controller that stops the mechanically driven supercharger, and sends compressed air discharged from the mechanically driven supercharger to the engine as supercharged air when the mechanically driven supercharger is activated. At the same time,
A supercharging device comprising an air pipe that sends a portion of the air to the hydrodynamic air bearing of the hydrodynamic air bearing supercharger as flotation air for the hydrodynamic air bearing.