JPH08312362A - Oil feeder of mechanical turbosupercharger - Google Patents

Abstract

PURPOSE: To enable lubricating oil to be fed to a bearing simultaneously with the start of an engine by installing a pressure accumulating passage, forcibly feeding this lubricating oil, in the bearing supporting a turbine shaft in a parallel manner, and interconnecting an oil feeding passage and this pressure accumulating passage both to the bearing side after being switched. CONSTITUTION: During normal operation, a solenoid selector valve 22 is operated into a state that an oil feeding passage 13 is interconnected to an oil filler port 8 and a gearcase 16 by dint of a return spring 23. In brief, lubricating oil out of the oil feeding passage 13 is forcibly fed to the oil filler port 8 and the gearcase 16, and thereby all sliding parts of each bearing or the like. In addition, the lubricating oil forcibly fed to the oil feeding passage 13 is guided to an accumulator 26 by way of a check valve 25 and accumulated in terms of pressure. On the other hand, in time of the start of an engine, the solenoid selector valve 22 is transferred to a state that a pressure accumulating passage 21 is interconnected to the oil filler port 8 and the gear case 16 simultaneously with the operation of a starter switch, and simultaneously with engine starting, the lubricating oil stored in the accumulator 26 is forcibly fed to the oil filler port 8 and the gearcase 16, lubricating the sliding parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil supply device for a turbine shaft in a mechanical turbocharger in which a rotary shaft of an engine and a turbine shaft are mechanically directly connected.

[0002]

2. Description of the Related Art A mechanical turbocharger in which a crankshaft of an engine and a turbine shaft of a supercharger are mechanically directly connected by a gear train is known. This mechanical turbocharger is suitable for use in scavenging a two-cycle engine, for example, because the turbine shaft is accelerated and rotated via a gear train at the same time when the engine is started. In the mechanical turbocharger, the turbine shaft is rotated at a high speed at the same time when the engine is started, and supercharging is performed by the compressor wheel, and the capacity of the supercharger is maximized when the engine is started. Lubricating oil is pumped to the bearing of the turbine shaft by an oil pump driven by the rotation of the engine, and the lubricating oil is supplied to the bearing of the turbine shaft when the engine is started.

[0003]

In the conventional mechanical turbocharger, the lubricating oil pumped by the oil pump is supplied to the bearing of the turbine shaft which is rotated at high speed at the same time when the engine is started. Therefore, the supply of the lubricating oil to the bearing is surely performed by starting the engine. However, since it takes some time for the pressure of the lubricating oil to rise immediately after the engine is started, a time delay may occur in the oil supply to the bearings of the turbine shaft at the time of starting. Since the turbine shaft rotates at high speed at the same time as the engine starts, if there is a time delay in the oil supply to the bearing, the turbine shaft will rotate at high speed without lubricating oil being supplied, which will adversely affect the bearing. Could lead to burnout.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an oil supply device for a mechanical turbocharger capable of supplying lubricating oil to a bearing of a turbine shaft at the same time when the engine is started. To do.

[0005]

In order to achieve the above object, the structure of the present invention is to connect a rotating shaft of an engine and a turbine shaft of a supercharger via a gear train, and supply oil to a bearing that supports the turbine shaft. In a lubrication device for a mechanical turbocharger that pumps lubricating oil through a passage, a pressure accumulation passage is provided in parallel in the oil passage, a pressure accumulation means is provided in the pressure accumulation passage, and the oil passage and the pressure accumulation passage are switched. A switching valve that communicates with the bearing side is provided, and switching means that switches the switching valve to a state in which the pressure accumulation passage communicates with the bearing side when the engine is started.

Further, the pressure accumulating means in the above structure is
A check valve that allows the flow of the lubricating oil to the switching valve side, and an accumulator provided between the check valve and the switching valve, the switching valve and the switching means, the starter of the engine. It is characterized in that it is an electromagnetic switching valve that is operated in association with a switch so that the pressure accumulation passage communicates with the bearing side.

[0007]

In normal operation, the switching valve is operated so that the oil supply passage communicates with the bearing side, the lubricating oil is pressure-fed to the bearing, and the lubricating oil is accumulated in the pressure accumulating means of the pressure accumulating passage. When the engine is started, the switching means switches the switching valve to a state where the pressure accumulation passage communicates with the bearing side, and the lubricating oil accumulated in the pressure accumulation means is supplied to the bearing of the turbine shaft at the same time when the engine is started.

During normal operation, the electromagnetic switching valve is operated so that the oil supply passage communicates with the bearing side, the lubricating oil is pumped to the bearing, and the lubricating oil is accumulated in the accumulator through the check valve. When the engine is started, the electromagnetic switching valve is operated in conjunction with the starter switch to connect the accumulator and the bearing side, and the lubricating oil accumulated in the accumulator is supplied to the bearing at the same time when the engine is started.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a hydraulic circuit for lubricating oil of an oil supply device for a mechanical turbocharger according to an embodiment of the present invention, and FIG. 2 shows a schematic configuration of the mechanical turbocharger.

The mechanical turbocharger 1 will be described with reference to FIG. A turbine shaft 2 connected to a crank shaft of an engine (not shown) via a gear train is rotatably supported by a housing 4 via a pair of journal bearings 3 as bearings. A turbine rotor 5 is attached to the turbine shaft 2.
Also, a compressor wheel 6 is provided, and the turbine shaft 2 is accelerated and rotated at the same time when the engine is started so that the compressor wheel 6 performs supercharging. After starting the engine, the turbine rotor 5 is also rotated by the exhaust gas and supercharging is performed. An oil supply passage 7 is formed in the housing 4, and lubricating oil is supplied to the oil supply passage 7 from an oil supply port 8. Reference numeral 9 in the drawing is a thrust bearing, and the lubricating oil is also supplied to the thrust bearing 9 from the oil supply passage 7.

The oil supply device will be described with reference to FIG. The oil pump 11 is driven by the rotation of an engine (not shown), and the oil tank 12 is driven by the oil pump 11.
Lubricating oil therein is pressure-fed to the mechanical turbocharger 1 through the oil supply passage 13. An oil filter 14 and a pressure accumulator 15 are provided in the oil supply passage 13, and the lubricating oil is pressure-fed to the oil supply port 8 and the gear case 16 of the mechanical turbocharger 1 by the pressure accumulator 15. Reference numeral 17 in the drawing is a strainer provided at the suction port of the oil pump 11.

The pressure accumulator 15 will be described. A pressure accumulation passage 21 is provided in parallel to the oil supply passage 13, and the oil supply passage 13 and the pressure accumulation passage 21 are selectively communicated with the oil supply port 8 and the gear case 16 by an electromagnetic switching valve 22 as a switching valve. Normally, as shown in the figure, the return spring 23 allows the oil supply passage 13 to communicate with the oil supply port 8 and the gear case 16. The coil 24 of the electromagnetic switching valve 22 is excited in cooperation with the starter switch, and the pressure accumulation passage 21 communicates with the fuel filler port 8 and the gear case 16 when the starter switch is operated. The pressure accumulation passage 21 is provided with a check valve 25 which allows the lubricating oil to flow to the electromagnetic switching valve 22 side, and an accumulator 26 is provided between the check valve 25 and the electromagnetic switching valve 22. That is, the check valve 25 and the accumulator 26 constitute pressure accumulating means.
It is also possible to use a back pressure valve that maintains a predetermined back pressure as the pressure accumulating means, and to store the lubricating oil in the pressure accumulating passage 21 at a predetermined pressure by the back pressure valve.

Next, the operation of the oil supply device of the mechanical turbocharger 1 having the above structure will be described. Solenoid switching valve 2 during normal operation
The second coil 24 is not excited and the electromagnetic switching valve 22 is operated by the return spring 23 so that the oil supply passage 13 communicates with the oil supply port 8 and the gear case 16. In this state, the lubricating oil from the oil supply passage 13 is pumped to the oil supply port 8 and the gear case 16, and the lubricating oil is supplied to the journal bearing 3, the thrust bearing 9 and the gear case 16. At the same time, the lubricating oil pressure-fed through the oil supply passage 13 is accumulated in the accumulator 26 through the check valve 25.

When the starter switch is operated when the engine is started, the coil 24 of the electromagnetic switching valve 22 is excited at the same time when the starter switch is operated, and the pressure accumulating passage 21 is connected to the oil supply port 8.
The electromagnetic switching valve 22 operates so as to communicate with the gear case 16. As a result, the lubricating oil accumulated in the accumulator 26 is pumped to the oil supply port 8 and the gear case 16 at the same time when the engine is started, and the lubricating oil is supplied to the journal bearing 3, the thrust bearing 9 and the gear case 16. After the engine is started, the coil 24 is in the non-excited state, and the electromagnetic switching valve 22 is operated by the return spring 23.
Thus, the oil supply passage 13 is operated in a state of communicating with the oil supply port 8 and the gear case 16, and the lubricating oil from the oil supply passage 13 is pressure-fed to the oil supply port 8 and the gear case 16.

Therefore, according to the lubrication device of the mechanical turbocharger 1 described above, the lubrication accumulated in the accumulator 26 is applied to the journal bearing 3 and the thrust bearing 9 of the turbine shaft 2 which are rotated at high speed at the same time when the engine is started. Since the oil is supplied in association with the operation of the starter switch, the turbine shaft 2 can be lubricated at the same time when the engine is started. Therefore, the turbine shaft 2 can be lubricated until the engine is started and the oil pressure is raised by the oil pump 11, and the turbine shaft 2 does not rotate at a high speed in a state where the lubricating oil is not supplied.

[0016]

According to the oil supply device of the mechanical turbocharger of the present invention, the pressure accumulation passage is provided in parallel in the oil passage and the pressure accumulation means is provided in the pressure accumulation passage, and the oil passage and the pressure accumulation passage are switched to communicate with the bearing side. A switching valve is provided to switch the switching valve to a state in which the pressure accumulation passage communicates with the bearing side when the engine is started.Therefore, when the engine is started, the pressure accumulation passage is communicated with the bearing side by the switching means. By switching the switching valve, it becomes possible to supply the lubricating oil accumulated in the pressure accumulating means to the bearing of the turbine shaft at the same time when the engine is started. As a result, the turbine shaft can be lubricated at the same time as the engine is started, and the lubricating oil is supplied to the bearing of the turbine shaft at the same time as the rotation is started, so that there is no possibility that the bearing will be burnt or the like.
Further, the lubricating oil accumulated in the accumulator is supplied to the bearing of the turbine shaft in synchronism with the operation of the starter switch, so that it is possible to reliably lubricate the turbine shaft at the same time as starting the engine with a simple configuration. Become.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram of an oil supply device for a mechanical turbocharger according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a mechanical turbocharger.

[Explanation of symbols]

 1 Mechanical turbocharger 2 Turbine shaft 3 Journal bearing 4 Housing 5 Turbine rotor 7 Oil supply passage 8 Oil supply opening 9 Thrust bearing 11 Oil pump 12 Oil tank 13 Oil supply passage 14 Oil filter 15 Pressure accumulator 16 Gear case 17 Strainer 21 Accumulation passage 22 Electromagnetic switching valve 23 Return spring 24 Coil 25 Check valve 26 Accumulator

Claims (2)

[Claims] 1. A mechanical turbocharger in which a rotating shaft of an engine and a turbine shaft of a supercharger are connected via a gear train, and lubricating oil is pressure-fed to a bearing supporting the turbine shaft via an oil supply passage. In the oil supply device, a pressure accumulation passage is provided in parallel in the oil supply passage, a pressure accumulation means is provided in the pressure accumulation passage, a switching valve that switches between the oil passage and the pressure accumulation passage and communicates with the bearing side is provided, and the engine is started. An oil supply device for a mechanical turbocharger, characterized by further comprising switching means for switching the switching valve so that the pressure accumulation passage communicates with the bearing side. 2. The pressure accumulating means includes a check valve that allows the flow of lubricating oil to the switching valve side, and an accumulator provided between the check valve and the switching valve. And the switching means is an electromagnetic switching valve that is operated in a state in which the pressure accumulation passage communicates with the bearing side in conjunction with a starter switch of the engine.
A lubrication device for a mechanical turbocharger according to.