JP2009287513A - Supercharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a supercharger preventing damage to a bearing due to shortage of lubricating oil, in a supercharger with a supercharger rotor rotated at low speed when performing an overhaul. <P>SOLUTION: In this supercharger 1, a supercharger turbine and the shaft portion 4 of a compressor respectively stored in a housing 5 are coupled to each other, the bearing 7 arranged on a bearing stand 6 in the housing 5 rotatably supports the shaft portion 4, and the compressor driven by the supercharger turbine compresses combustion air for an internal combustion engine and supplies the compressed combustion air to a combustion chamber. The supercharger 1 includes: a main lubricating oil system coupled to a main lubricating oil pump and supplying lubricating oil to the bearing 7; an oil sump 12 formed at the bottom of the bearing stand 6 and accumulating the lubricating oil dropping after lubricating the bearing 7 by a predetermined amount; and an auxiliary lubricating oil system coupled to an auxiliary lubricating oil pump 20 operated when the main lubricating oil pump is stopped and supplying the lubricating oil accumulated in the oil sump 12 to the bearing 7. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a supercharger applied to a marine or power generation large diesel engine or the like.

2. Description of the Related Art Conventionally, a supercharger that compresses combustion air of an internal combustion engine and forcibly sends high-density air into a combustion chamber is known. For example, it is widely used in large diesel engines for ships and power generation. In such a turbocharger, a compressor for compressing combustion air and a turbocharger turbine serving as a drive source for the compressor are coaxial, housed in a housing, and rotate integrally. Note that the turbocharger turbine is driven by the energy held by the exhaust gas of the internal combustion engine.
In a turbocharger in which the compressor and the turbocharger turbine are coaxial, a technology is provided in which an impact sensor is provided in the housing, and the oil supply control means is operated by outputting an abnormal signal when an impact exceeding the reference value is detected. Is disclosed. The oil supply control means in this case is an electromagnetic valve for suppressing or stopping the supply of lubricating oil from the oil pump to the bearing of the rotary shaft. (For example, see Patent Document 1)
Japanese Patent Laid-Open No. 5-321687

By the way, in a large-sized diesel engine for marine use or power generation, when opening the diesel engine itself and / or the supercharger, air in the engine room enters the engine and is discharged from the chimney through the supercharger turbine. Normally, since the outside air is sent into the engine room by a ventilation fan, the amount of air described above increases when the ventilation fan is operated.
Further, the upward air flow of the air due to the heat in the chimney promotes the air flow described above. Such a flow of air energizes the turbine as it passes through the turbocharger turbine, so that the turbocharger rotor (coaxially connected turbocharger turbine and compressor rotor) rotates at a low speed. Will be.

Even when the supercharger rotor rotates in this way, no problem occurs when lubricating oil is supplied to the supercharger.
However, when the diesel engine is opened, it is necessary to stop the main lubricating oil pump and carry out the operation, so that the supply of lubricating oil to the supercharger is also stopped. Therefore, when the turbocharger rotor rotates due to the above-described factors, the bearing that cannot receive the supply of lubricating oil may be damaged even at a low speed. That is, in a supercharger in which the supercharger rotor rotates at a low speed when performing release maintenance, there is a concern about bearing damage due to lack of lubricating oil.
The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent bearing damage due to lack of lubricating oil in a supercharger in which a supercharger rotor rotates at a low speed when performing release maintenance. It is to provide a supercharger that is prevented.

In order to solve the above problems, the present invention employs the following means.
The turbocharger according to the present invention is connected to a shaft portion of a turbocharger turbine and a compressor housed in a housing, and a bearing installed on a bearing stand in the housing rotatably supports the shaft portion, In the supercharger in which the compressor driven by the supercharger turbine compresses combustion air of an internal combustion engine and supplies the compressed air to the combustion chamber, a main lubricant pump is connected to a main lubricating oil pump and supplies lubricating oil to the bearing. A lubricating oil system, an oil sump provided at a bottom portion of the bearing base and retaining a predetermined amount of lubricating oil falling after lubricating the bearing, and an auxiliary lubricating oil pump operated when the main lubricating oil pump is stopped And an auxiliary lubricating oil system that supplies the bearing with the lubricating oil that is connected and stays in the oil reservoir.

According to such a supercharger, the main lubricating oil system that is connected to the main lubricating oil pump and supplies the lubricating oil to the bearing, and the lubricating oil that is provided at the bottom of the bearing stand and falls after lubricating the bearing are provided. Because it has an oil reservoir that retains only a fixed amount, and an auxiliary lubricating oil system that is connected to an auxiliary lubricating oil pump that is operated when the main lubricating oil pump is stopped and supplies lubricating oil remaining in the oil reservoir to the bearing. Even when the main lubricating oil pump is stopped, the lubricating oil can be supplied to the bearing by the auxiliary lubricating oil pump.
In such an auxiliary lubricating oil system, the auxiliary lubricating oil pump sucks the lubricating oil from the oil reservoir in the supercharger and supplies it to the bearing, and the lubricating oil after lubricating the bearing falls into the oil reservoir. The accumulated lubricating oil circulates in the turbocharger and completes.

  In the above invention, since the auxiliary lubricating oil pump is automatically started when the pressure of the lubricating oil flowing in the main lubricating oil system falls below a predetermined value, the auxiliary lubricating oil pump is stopped when the main lubricating oil pump is stopped. The lubricating oil can be supplied to the bearing by reliably starting.

According to the present invention described above, for example, when it is necessary to stop the main lubricating oil pump and perform work when the diesel engine is opened, the supply of lubricating oil from the main lubricating oil system to the supercharger is stopped. Also, the lubricating oil can be supplied from the auxiliary lubricating oil system to the bearing of the turbocharger. Therefore, even if the turbocharger rotor rotates at a low speed due to air inflow or the like in the engine room, the lubricating oil can be supplied from the auxiliary lubricating oil system to the bearing. Occurrence can be prevented or suppressed.
That is, when the diesel engine itself and / or the turbocharger is released and maintained, the turbocharger in which the turbocharger rotor rotates at a low speed can reliably prevent or suppress the occurrence of bearing damage due to lack of lubricating oil. .

Hereinafter, an embodiment of a supercharger according to the present invention will be described with reference to the drawings.
A supercharger 1 shown in FIG. 1 is installed in an intake system of an internal combustion engine, compresses combustion air, and sucks and explodes an air-fuel mixture that exceeds the original intake amount of the internal combustion engine, thereby exceeding the apparent exhaust amount. A device for obtaining output.
The turbocharger 1 is connected to a turbocharger turbine 2 and a shaft portion 4 of a compressor 3, and is connected to a turbocharger rotor (coaxially connected supercharger turbine 2 and compressor) housed in a housing 5 described later. 3 rotating body) rotate together. The supercharger turbine 2 introduces exhaust gas discharged from the internal combustion engine, and rotates at high speed using the energy (temperature and pressure) of the exhaust gas. The supercharger turbine 2 serves as a drive source for rotating the coaxial compressor 3.

  The compressor 3 rotates using the turbocharger turbine 2 as a drive source, and sucks and compresses combustion air of the internal combustion engine. The combustion air compressed by the compressor 3 is supplied to the combustion chamber through the intake system of the internal combustion engine.

FIG. 1 is a configuration diagram showing an outline of the supercharger 1, and shows a cross section of a shaft portion 4 that connects the supercharger turbine 2 and the compressor 3 in FIG. 2.
In the illustrated supercharger 1, a shaft portion 4 is accommodated in a bearing stand 6 provided in a housing 5 and is disposed horizontally. The shaft portion 4 is rotatably supported by a bearing 7 installed on a bearing base 6 of the housing 5. That is, a bearing base 6 is provided at an intermediate portion between the supercharger turbine 2 and the compressor 3, and a bearing 7 installed on the bearing base 6 supports the shaft portion 4 in a freely rotatable manner.

A head tank 8 is provided above the bearing base 6 as a space for storing lubricating oil to be supplied to the bearing 7. The head tank 8 is connected to a main lubricating oil pipe 9 that is connected to a main lubricating oil pump (not shown) to form a main lubricating oil system. In the head tank 8, lubricating oil passages 10 and 11 for guiding the lubricating oil in the head tank 8 to the bearing 7 are formed. That is, when the supercharger 1 is operated, the main lubricating oil pump is also operated, so that the head tank 8 is filled with lubricating oil, and this lubricating oil has lubricating oil passages 10 having different opening positions. , 11 to be surely supplied to the bearing 7.
By the way, when the operation of the supercharger 1 is stopped, the operation of the main lubricating oil pump is also stopped. However, since the turbocharger rotor rotates with inertia for a while, it is necessary to lubricate the bearing 7 by effectively using the lubricating oil accumulated in the head tank 8 even after the main lubricating oil pump is stopped. Become. Therefore, when the lubricating oil passages 10 and 11 having different heights are provided and the remaining amount of the lubricating oil in the head tank 8 is large, the lubricating oil flows from the lubricating oil passage 10 having a high inlet height to all the bearings 7. When the remaining amount of the lubricating oil in the head tank 8 is small, the lubricating oil is supplied only from the lubricating oil passage 11 having a low inlet height to the bearing 7 on the supercharger turbine 2 side having a high temperature.

A space serving as an oil sump 12 is formed below the bearing stand 6, and the lubricating oil after lubricating the bearing 7 naturally falls, so that a predetermined amount can always be retained. Yes. The oil reservoir 12 is connected to a lubricating oil recovery pipe 13 for returning the lubricating oil to a lubricating oil tank (not shown) for supplying the lubricating oil to a main lubricating oil pump (not shown). The lubricating oil recovery pipe 13 is connected to a position where a predetermined oil level height is formed from the oil reservoir bottom surface 12 a in order to always retain a predetermined amount of lubricating oil in the oil reservoir 12. That is, since the oil reservoir 12 has a wall portion 12b having a predetermined height from the bottom surface 12a, the lubricating oil recovery pipe 13 is connected to the upper end portion of the wall portion 12b.
Reference numeral 14 in the figure denotes an outlet opening through which the lubricating oil is dropped from the bearing 7 to the oil reservoir 12, and 15 is an air vent of the oil reservoir 12.

The oil reservoir 12 is provided with an auxiliary lubricating oil pump 20 that is operated when the main lubricating oil pump is stopped. The auxiliary lubricating oil pump 20 is attached so as to substantially coincide with the bottom surface 12 a of the oil reservoir 12. An auxiliary lubricating oil pipe 21 that is connected to the auxiliary lubricating oil pump 20 and guides the lubricating oil in the oil reservoir 12 to the head tank 8 is provided. A check valve 22 is provided at an appropriate position of the auxiliary lubricating oil pipe 21 to prevent the lubricating oil from flowing back from the head tank 8 to the auxiliary lubricating oil pump 20 during operation of the main lubricating oil pump.
Therefore, during operation of the auxiliary lubricating oil pump 20, the lubricating oil in the oil reservoir 12 is supplied to the head tank 8 through the auxiliary lubricating oil pipe 21, and further, through the lubricating oil flow path 11 that opens to the bottom surface of the head tank 8. It is supplied to the bearing 7 through.

In order to detect the pressure of the lubricating oil supplied from the main lubricating oil pump, a pressure sensor 30 such as a pressure switch is provided at an appropriate position of the main lubricating oil pipe 9 described above. A detection signal such as a pressure value detected by the pressure sensor 30 is input to a control device 31 that controls ON / OFF of the auxiliary lubricating oil pump 20. That is, the auxiliary lubricating oil pump 20 is automatically activated by the control device 31 based on the detection signal of the pressure sensor 30 when the pressure of the lubricating oil flowing through the main lubricating oil pipe 9 drops below a predetermined value.
Further, a pressure gauge 32 and a thermometer 33 are provided at appropriate positions of the main lubricating oil pipe 9 as needed, so that the state of the lubricating oil flowing in the main lubricating oil pipe 9 can be visually determined.

  As described above, in the supercharger 1 described above, the turbocharger turbine 2 housed in the housing 5 and the shaft portion 4 of the compressor 3 are connected, and the bearing 7 installed on the bearing stand 6 in the housing 5 is the shaft portion. 4 is a device that rotatably supports 4 and a compressor 3 driven by a supercharger turbine 2 compresses combustion air of the internal combustion engine and supplies it to the combustion chamber. The supercharger 1 of the present invention is connected to a main lubricating oil pump and supplies a lubricating oil to the bearing 7, and is provided at the bottom of the bearing base 6 and lubricates the bearing 7, and then drops. Auxiliary lubrication for supplying the bearing 7 with lubricating oil retained in the oil reservoir 12 connected to an oil reservoir 12 for retaining a predetermined amount of lubricating oil and an auxiliary lubricating oil pump 20 operated when the main lubricating oil pump is stopped. And an oil system.

The main lubricating oil system in the illustrated supercharger 1 includes a main lubricating oil pipe 9 connected to a main lubricating oil pump, a head tank 8, lubricating oil passages 10 and 11, a bearing 7, and an outlet opening 14. , A closed circuit lubricating oil circulation path formed by the oil reservoir 12, the lubricating oil recovery pipe 13, and the lubricating oil tank.
The auxiliary lubricating oil system in the illustrated supercharger 1 includes an auxiliary lubricating oil pump 20, an auxiliary lubricating oil pipe 21, a check valve 22, a head tank 8, a lubricating oil flow path 11, a bearing 7, This is a closed circuit lubricating oil circulation path formed by the outlet opening 14 and the oil reservoir 12.

  Therefore, in the supercharger 1 described above, the main lubricating oil system that is connected to the main lubricating oil pump and supplies the lubricating oil to the bearing 7, and the lubrication that is provided at the bottom of the bearing base 6 and falls after the bearing 7 is lubricated. An auxiliary lubricating oil that is connected to an oil reservoir 12 that retains a predetermined amount of oil and an auxiliary lubricating oil pump 20 that is operated when the main lubricating oil pump is stopped, and that supplies the lubricating oil remaining in the oil reservoir 12 to the bearing 7. When the main lubricating oil pump is stopped, the auxiliary lubricating oil pump 20 can supply lubricating oil to the bearing 7 when the main lubricating oil pump is stopped.

That is, in the supercharger 1 of the present invention, the auxiliary lubricating oil pump 20 sucks the lubricating oil from the oil reservoir 12 in the supercharger 1 and supplies it to the bearing 7, and the lubricating oil after lubricating the bearing 7 is supplied. Since the oil falls to the oil reservoir 12, an auxiliary lubricating oil system is formed in which the lubricating oil in the oil reservoir 12 circulates in the supercharger 1 and is completed.
The auxiliary lubricating oil pump 20 is automatically started when the pressure of the lubricating oil flowing through the main lubricating oil pipe 9 falls below a predetermined value, so that the auxiliary lubricating oil pump 20 can be reliably connected when the main lubricating oil pump is stopped. It can start and supply the lubricating oil to the bearing 7.

  As a result, for example, when the marine diesel engine is opened, when it is necessary to stop the main lubricating oil pump and perform work such as maintenance, the supply of lubricating oil from the main lubricating oil system to the supercharger 1 is stopped. However, the lubricating oil can be supplied to the bearing 7 of the supercharger 1 from the auxiliary lubricating oil system. That is, even when the rotor of the turbocharger turbine 2 rotates at a low speed due to air inflow or the like in the engine room, the lubricating oil can be supplied from the auxiliary lubricating oil system to the bearing 7. Therefore, the occurrence of bearing damage can be prevented or suppressed. In other words, when the diesel engine itself and / or the turbocharger 1 is released and maintained, the turbocharger 1 in which the turbocharger rotor in the housing 5 rotates at a low speed ensures that bearing damage occurs due to lack of lubricating oil. Can be prevented or suppressed.

By the way, the supercharger 1 mentioned above is not limited to a large marine diesel engine, but can be applied to various internal combustion engines including a diesel engine for power generation.
In addition, this invention is not limited to embodiment mentioned above, In the range which does not deviate from the summary of this invention, it can change suitably.

It is a block diagram which shows the outline | summary of a supercharger. It is sectional drawing (shaft part cross section of FIG. 1) of the principal part which shows one Embodiment of the supercharger which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Supercharger 2 Supercharger turbine 3 Compressor 4 Shaft part 5 Housing 6 Bearing stand 7 Bearing 8 Head tank 9 Main lubricating oil piping 12 Oil reservoir 20 Auxiliary lubricating oil pump 21 Auxiliary lubricating oil piping 30 Pressure sensor 31 Controller

Claims (2)

A shaft portion of a turbocharger turbine and a compressor housed in a housing is connected, and a bearing installed on a bearing stand in the housing rotatably supports the shaft portion and is driven by the turbocharger turbine. In the supercharger in which the compressor compresses the combustion air of the internal combustion engine and supplies it to the combustion chamber,
A main lubricating oil system connected to a main lubricating oil pump to supply lubricating oil to the bearing;
An oil sump that is provided at the bottom of the bearing stand and retains a predetermined amount of lubricating oil that falls after lubricating the bearing;
An auxiliary lubricating oil system that is connected to an auxiliary lubricating oil pump that is operated when the main lubricating oil pump is stopped and supplies the lubricating oil remaining in the oil reservoir to the bearing;
A turbocharger characterized by comprising:   2. The supercharger according to claim 1, wherein the auxiliary lubricant pump is automatically started when the pressure of the lubricant flowing in the main lubricant system drops below a predetermined value.

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