JPH0432927B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power generation device that utilizes exhaust gas energy from an internal combustion engine.

For example, in a method to convert exhaust gas energy from an automobile internal combustion engine into actual torque or power and recover it, the exhaust energy is used to operate an exhaust turbine, and the driving force is transmitted to the internal combustion engine's crankshaft via a gear train. Attempts are being made to recover it.
However, this kind of exhaust energy recovery has poor follow-up to rotational fluctuations, etc., and the rotation of the exhaust turbine is extremely high, so it is difficult to put into practical use a speed reduction device to reduce the speed. It has not yet reached the practical stage.

On the other hand, the higher the rotational speed of the generator rotor, the greater the power generation capacity of a generator. Therefore, driving the generator with a high-speed rotating exhaust turbine that is operated by exhaust energy is an efficient way to use exhaust energy. It is the most effective means to use. The electric power generated by the generator is stored in a battery, and this electric power can be used to drive an electric motor and recover it as axial force, or used as a power source for other electrical systems to reduce the exhaust gas of the internal combustion engine. Energy can be recovered effectively.

The present invention has been made in view of the above points,
The purpose is to provide an exhaust power generation device that can effectively generate electricity using the exhaust energy of an internal combustion engine. The present invention is directed to an exhaust power generation device comprising an exhaust turbine, which is an exhaust turbine, and a generator driven by the exhaust turbine, and in which a turbine impeller shaft of the exhaust turbine and a rotor shaft of the generator are connected on the same axis.

Next, one embodiment of the exhaust power generation device according to the present invention will be described in detail using the drawings.

In FIG. 1, reference numeral 1 denotes an exhaust turbine, which includes a turbine housing 2 having a scroll portion 2a, and a turbine impeller 3 disposed within the housing 2.
The scroll portion 2a is connected to an exhaust pipe of an internal combustion engine, and the turbine impeller 3 is driven by the energy of the exhaust gas introduced into the scroll portion 2a.
is rotated, and exhaust gas is discharged from an exhaust outlet 2b provided in the axial direction through an exhaust pipe (not shown). A heat insulating wall 5 made of a heat-resistant metal such as stainless steel is attached to the inner wall of the scroll portion 2a through a heat insulating material 4 such as a ceramic fiber.
Further, a heat insulating guide 6 made of a heat insulating material such as ceramic material is disposed on the inner surface of the cylindrical portion on the exhaust port side of the turbine housing 2 to prevent heat dissipation of the exhaust gas.

The turbine impeller 3 is made of a ceramic material with excellent thermal strength, such as silicon nitride, and the turbine impeller shaft 3a is integrally formed. In this embodiment, the rotor shaft 11 of the generator 10, which will be described later and is disposed coaxially with the turbine impeller shaft 3a, is also integrally molded with the turbine impeller 3 and the turbine impeller shaft 3a by ceramic material. It is structured as follows. Further, in the case where the turbine impeller shaft 3a and the rotor shaft 11 of the generator 10 are formed separately from ceramic materials and are combined, the turbine impeller shaft 3a and the rotor shaft 11 can be connected to each other as shown in FIG. A connecting tube 7 made of a metal such as Kovar having a coefficient of thermal expansion approximately equal to that of the ceramic material is fitted onto the outer periphery of the end connected to the shaft 11, and the connecting tube 7 is connected by metallization. In addition,
The rotor shaft 11 is desirably made of a ceramic material having a large Young's modulus, such as cermet.
8 is a heat insulating material 9 on the side of the turbine housing 2.
The bearing housing is fixed by a clamping plate 91 which is disposed through the bearing housing and is tightened by a bolt 92, and the generator 10 can be attached to the bearing housing by the bolt 12.

The generator 10 includes the rotor shaft 11 disposed at the center of a generator casing 13, and a generator rotor made of a metal with excellent magnetization such as silicon steel, which is fitted and coupled to the rotor shaft 11. 14, and a stator coil 1 disposed outside the generator rotor 14.
5 and a bearing housing 16 attached to the side of the casing 13.

The bearing housings 8 and 16 have cylindrical bearing chambers 8a and 16a, and lubricating oil inlets 8b and 1 communicating with the bearing chambers 8a.
6b, a lubricating oil passage 8c communicating with the lubricating oil inlet;
and 16c, and lubricating oil discharge passages 8d and 16d communicating with the bearing chamber are formed, respectively.

20 is the bearing housing 8 and 16;
The fixed bearings are respectively disposed in bearing chambers 8a and 16a formed in the bearing chambers 8a and 16a, and an annular groove 20a communicating with the lubricating oil injection groove 8b and a radial groove 20a communicating with the annular groove 20a are formed in the outer center of the fixed bearing. A passage 20b is formed.

Reference numeral 21 denotes an oil float bearing rotatably disposed between the fixed bearing 20 and the rotor shaft 11 of the generator, and a radial passage 20b formed in the fixed bearing 20 is provided at the center of the outer circumference of the oil float bearing. The communicating annular groove 21a and the annular groove 2
A radial passage 21b communicating with 1a is formed.

Numeral 22 is a snap spring attached to the fixed bearing 20 on both sides of the float bearing 21 to restrict movement of the float bearing 21 in the axial direction.

Reference numeral 23 designates thrust bearings disposed between the fixed bearing 21 and the generator housing 13 and between the cover 24, respectively.

In the same figure, 25 is a positioning ring disposed between the thrust bearing 23 and the stepped portion formed on the rotor shaft 11, and 26 is a positioning ring disposed between the cover 24 and the rotor shaft 11. It is an oil seal ring.

The exhaust power generation device according to the present invention is configured as described above, and has the scroll portion 2a of the exhaust turbine 1.
The exhaust gas of the internal combustion engine introduced into the turbine acts on the turbine impeller 3 and is discharged from the exhaust port 2b.
This exhaust energy causes the turbine impeller 3 to
is rotated at high speed. This rotation is directly transmitted to the generator rotor shaft 11, which is integrated with the turbine impeller shaft 3a, so that the generator rotor 14, which is fixed to the rotor shaft 11,
Since it rotates at the same speed and at high speed, it is possible to generate electricity efficiently.

Next, lubrication of the bearing that pivotally supports the generator rotor shaft 11 will be explained. Lubricating oil is pumped by a hydraulic pump (not shown) through lubricating oil inlets 8b formed in the bearing housings 8 and 16.
and 16b, and supplies oil to the thrust bearing 23 portion through the lubricating oil passages 8c and 16c, and through the annular groove 20a and the radial passage 20b formed in the fixed bearing 20,
It enters the outer peripheral surface of the float bearing 21 and an annular groove 21a formed in the float bearing 21. The lubricating oil that has entered the annular groove 21a flows from the radial passage 21b between the inner circumferential surface of the float bearing 21 and the rotor shaft 11, forming a lubricating oil film therebetween. The lubricating oil leaking from the inner peripheral surface of the float bearing 21 flows into the bearing chambers 8a and 16.
a, and is returned to a lubricating oil tank (not shown) through lubricating oil discharge passages 8d and 16d.

According to this embodiment, the turbine impeller,
Since the turbine impeller shaft and the rotor shaft of the generator are made of ceramic material, these rotating systems can be made lightweight and can rotate at high speed, making it possible to obtain a highly efficient power generation device. Furthermore, since the generator rotor shaft is made of a ceramic material with a large Young's modulus, there is extremely little eccentricity or deformation even when the generator rotates at high speeds, and smooth operation can always be performed. Further, since the turbine impeller, the turbine impeller shaft, and the rotor shaft of the generator are integrally molded from ceramic material, manufacturing is easy and assembly work is not required. Furthermore, since the generator rotor shaft is supported by an oil float bearing, it is possible to prevent the rotor shaft, which is driven by the high-speed rotating exhaust turbine impeller, from seizing up and ensure smooth rotation at all times. I can do it.

As explained in detail above, the present invention has the turbine impeller, the turbine impeller shaft, and the rotor shaft of the generator made of ceramic material, so that these rotating systems can be made lightweight and can rotate at high speed. Since the shaft is made of ceramic material with a high Young's modulus, it is possible to achieve smooth high-speed rotation with extremely little eccentricity or deformation even when rotating at high speeds.In addition, the turbine impeller shaft of the exhaust turbine and the generator rotor shaft are the same. Since it is formed on the shaft, there is no need for any power transmission device to be interposed between the turbine impeller shaft and the generator rotor shaft, so there is no power loss, and the inertial mass is small, allowing for a highly responsive and efficient exhaust power generator. Obtainable.

Further, according to the present invention, since the turbine impeller shaft and the rotor shaft of the generator are formed on the same axis, the turbine impeller shaft and the rotor shaft can be supported by two bearings. ,
Friction due to bearing support can be minimized, and an efficient exhaust power generation device with less power loss can be obtained.

Further, according to the present invention, since the turbine impeller shaft and the rotor shaft of the generator are connected on the same axis, the turbine impeller shaft and the rotor shaft can be supported by two bearings. ,
Friction due to bearing support can be minimized, and an efficient exhaust power generation device with less power loss can be obtained.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing an embodiment of the power generating apparatus according to the present invention, and FIG. 2 is a cross-sectional view showing an example of a coupling mechanism between a turbine impeller and a generator rotor shaft used in the apparatus according to the present invention. DESCRIPTION OF SYMBOLS 1... Exhaust turbine, 2... Turbine housing, 3... Turbine impeller, 3a... Turbine impeller shaft, 8, 16... Bearing housing, 10... Generator, 11... Generator rotor shaft,
14... Generator rotor, 15... Stator coil, 20... Fixed bearing, 21... Float bearing, 23... Thrust bearing.

Claims (1)

[Scope of Claims] 1. Consisting of an exhaust turbine provided with a turbine impeller operated by exhaust energy of an internal combustion engine, and a generator driven by the exhaust turbine, the turbine impeller shaft of the exhaust turbine and An exhaust power generation device characterized in that a rotor shaft of a generator is formed on the same axis, and the turbine impeller, the turbine impeller shaft, and the rotor shaft of the generator are integrally molded from a ceramic material. 2. The exhaust power generation device according to claim 1, wherein the rotor shaft of the generator is supported by an oil float bearing.