JP2517541Y2 - Bearing mechanism of turbocharger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a bearing mechanism of a turbocharger having a sliding bearing, a floating bearing, and the like.

(Prior Art) FIGS. 5 and 6 show a conventional turbocharger,
A compressor rotor 2 and a turbine rotor 3 are fixed to both ends of the shaft 1, and the shaft 1 has a bush 4,
It is rotatably supported by 4'thrust bearing 5'and radial bearings 6, 6 '. The radial bearings 6, 6 ′ are held by a snap ring 7. 8a is an oil hole on the thrust bearing 5'side, 8b is an oil hole on the radial bearing 6'side, 8c is an oil hole on the bearing housing 11 side, 9'is a half-moon oil groove, 10 is a compressor housing, 12 is a turbine housing, 13
Is a plate seal, 14 is a plate sealing, and 15 is a sealing ring.

5 and 6, when the turbine rotor 3 rotates, the bushes 4, 4'and the compressor rotor 2 rotate via the shaft 1, and the rotation of the rotor 2 supercharges air. In the bearing part, radial bearings 6,6 '
The radial load is held by the thrust bearing 5'and the bushes 4, 4'hold the thrust load.

FIG. 7 is a sectional view of a bearing structure of a supercharger proposed in the conventional Japanese Utility Model Publication No. Sho 50-125648, in which a compressor blower 16 is provided at one end and a turbine rotor 17 is provided at the other end. A conical surface where both side walls face each other in the middle of the fixed shaft 18.
A bearing groove 20 serving as a groove 19 is formed, and the bearing groove 20 is fixed to the center housing 21 and is abutted against the conical surface of a bearing body 22 having conical surfaces on both side surfaces in the axial direction. It will be done.

(Problems to be Solved by the Invention) In the conventional turbocharger shown in FIGS. 5 and 6, the radial bearing 6'is provided on the thrust bearing 5'side in addition to the radial bearing 6 on the turbine rotor side. An oil hole 8b for supplying oil to the bearing 6'is provided in the thrust bearing 5
Side oil hole 8a and bearing housing 11 side oil hole 8c, and a snap ring 7 for holding the radial bearing 6'is necessary. As described above, the conventional mechanism has a drawback that the cost is high because two radial bearings are required.

Further, in the supercharger of FIG. 7, since the conical surfaces 19 are in contact with each other, the deflection in the thrust direction is large, and the contact area is large, so that the mechanical loss is large and the bearing portion is not a floating type, so There was a risk of seizure when a radial load was applied during rotation.

The present invention is to provide a bearing mechanism for a turbocharger which can solve the above-mentioned conventional problems by providing the thrust bearing portion with the function of a radial bearing and eliminating one of the radial bearings shown in FIG. Is.

[Constitution of device]

(Means for Solving the Problems) Therefore, the present invention has a turbocharger in which a turbine rotor and a compressor rotor are provided at both ends of a shaft, and the shaft is supported by a bearing housing via a radial bearing, a thrust bearing and a bush. In the above, the turbine rotor side supports the shaft with one radial bearing held in a bearing housing, and the compressor side is fixed to the first bush (4) between the shaft and the compressor rotor and the bearing housing. The thrust bearing (5) and the second bush (4 ') in this order, and the first bush is provided with a cylindrical portion extending between the outer peripheral surface of the shaft and the inner peripheral surface of the thrust bearing. A half-moon oil groove is provided on the inner peripheral surface of the thrust bearing facing the cylindrical portion, and a bearing ring is formed in the half-moon oil groove. Lubricating oil is supplied from an oil hole on the housing side through an oil hole provided in the thrust bearing, which is a means for solving the problem.

(Operation) When the turbine rotor rotates, the bush and the compressor rotor rotate via the shaft, and the rotation of the compressor rotor supercharges air. In the bearing part, the radial bearing, the thrust bearing and the bush hold the radial load, and the thrust bearing and the bush hold the thrust load, and the half-moon oil groove between the thrust bearing and the bush has an oil hole on the bearing housing side. Lubricant is supplied from the oil through the oil hole in the thrust bearing.

(Embodiment) The present invention will be described below with reference to embodiments of the drawings.
4 to 4 show an embodiment of the present invention. 1 to 4, 1 is a shaft, 2 is a compressor rotor, 3 is a turbine rotor, 4 and 4'are bushes, 6 is a radial bearing,
7 is a snap ring, 8a is an oil hole on the thrust bearing side, 8c is an oil hole on the bearing housing 11 side, 10 is a compressor housing, 12 is a turbine housing, 13 is a plate seal, 14 is a plate seal, and 15 is a seal ring. However, these are the same in configuration, function and effect as those having the same reference numerals in FIG. 5 and FIG.

The embodiment shown in FIGS. 1 to 4 of the present invention is different from the prior art in that the thrust bearing 5 has a function of a radial bearing, and the radial bearing 6'of FIGS.
The oil hole 8b on the radial bearing 6'side is also abolished accordingly.

By eliminating the radial bearing 6'as described above,
The radial bearing function is provided by providing the thrust bearing 5 with the half-moon oil groove 9 in addition to the oil hole 8a, and by providing the radial bearing 6 at the center of gravity of the shaft 1, the shaft 1 is supported. The bush 4 has a cylindrical portion 4a, the inner periphery of the cylindrical portion 4a is integral with the shaft 1 between the outer surface of the shaft 1, and the outer periphery of the cylindrical portion 4a is the inner peripheral surface of the thrust bearing 5. It is rotatably supported between and. During operation of the turbocharger, lubricating oil is supplied from the oil hole 8c through the oil hole 8a and the half-moon oil groove 9 to the space between the outer circumference of the cylindrical portion 4a of the bush 4 and the inner circumference of the thrust bearing 5, and between these members. Lubricating and cooling. On the other hand, the lubricating oil in the oil hole 8c is the radial bearing 6 and the shaft 1 on the turbine rotor 3 side.
It is also supplied to and between these parts, and also lubricates and cools this part.

Now, in FIG. 1, when the turbine rotor 3 rotates,
The bushes 4, 4 ′ and the compressor rotor 2 rotate via the shaft 1, and the rotation of the compressor rotor 2 supercharges air. In the bearing portion, the radial bearing 6, the thrust bearing 5 and the bush 4 hold the radial load, and the thrust bearing 5 and the bushes 4 and 4'hold the thrust load.

[Effect of device]

As described in detail above, in the present invention, the thrust bearing portion has the function of a radial bearing, and the half-moon oil groove is provided between the thrust bearing and the bush so that the bearing function is not impaired even at high rotation speed. A high-performance radial bearing can be omitted on the compressor rotor side, and the processing of the oil hole that was used to supply oil to this radial bearing can be omitted, so that cost reduction can be achieved and cost can be reduced compared to conventional bearing members. Even in this case, the bearing function equivalent to that of the conventional one can be provided.

[Brief description of drawings]

FIG. 1 is a side sectional view of a turbocharger showing an embodiment of the present invention, FIG. 2 is a detailed sectional view of an essential part in FIG. 1, and FIG.
FIG. 4 is an enlarged view of part A of FIG. 2, FIG. 4 is a sectional view taken along line BB of FIG. 3, and FIG.
FIG. 7 is a detailed sectional view of a main part in FIG. 5, and FIG. 7 is a side sectional view showing an example of a conventionally proposed supercharger. Description of main parts of the figure 1 …… Shaft 2 …… Compressor rotor 3 …… Turbine rotor 4,4 ′ …… Bushing 5 …… Thrust bearing 6 …… Radial bearing 7 …… Snap ring 8a …… Oil in thrust bearing Hole 8c …… Oil hole on bearing housing side 9 …… Half moon oil groove 10 …… Compressor housing 11 …… Bearing housing 12 …… Turbine housing

Claims (1)

(57) [Scope of utility model registration request] 1. A turbocharger having a turbine rotor and a compressor rotor at both ends of a shaft, the shaft being supported by a bearing housing via radial bearings, thrust bearings and bushes, wherein the turbine rotor side is a bearing housing. The held radial bearing supports the shaft, and the compressor side has a first bush (4) between the shaft and the compressor rotor, a thrust bearing (5) fixed to the bearing housing, and a second bush. The bush (4 ') is sandwiched in this order, and the first bush is provided with a cylindrical portion extending between the outer peripheral surface of the shaft and the inner peripheral surface of the thrust bearing, and the inner surface facing the cylindrical portion of the thrust bearing. A half-moon oil groove is provided on the circumferential surface, and the thrust shaft is inserted from the oil hole on the bearing housing side into the half-moon oil groove. Turbocharger bearing mechanism, characterized in that so as to supply lubricating oil through the oil hole provided on.