JPS6392817A - Thrust bearing of supercharger - Google Patents

Abstract

PURPOSE:To enable the bearing loss due to excessive oil quantity to be reduced, by providing oil discharge passages between oil sweeping grooves and the cutout at the lower end part, so that the oil quantity retained in oil discharge grooves can be reduced. CONSTITUTION:Oil is introduced into the oil retaining groove 3 of a thrust bearing 1, and is supplied to sliding surfaces 6. The oil which has lubricated the sliding surfaces 6 is subjected to a force being swept in the circumferential direction of a shaft by the centrifugal force caused by the rotation of a rotor shaft 13, and is introduced into oil sweeping grooves 7. The oil introduced into the oil discharge grooves passes through oil sweeping passages 9 which are communicated from the oil sweeping grooves 7 to the cutout at the lower end part, and is quickly swept into the oil drain passage 15 of a bearing box 11. Accordingly, since the oil having finished lubrication is quickly swept, the bearing loss of a supercharger due to the resistance of oil viscosity can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a supercharger, and particularly to a thrust bearing suitable for reducing bearing loss.

[Conventional technology]

In a conventional thrust bearing, as described in Japanese Utility Model Application No. 60-137128, there is a gap between an oil sweep groove formed in a closed loop and a notch provided at the lower end of the outer periphery.

It had a structure in which a convex end face was formed. In this structure, no consideration was given to reducing bearing loss due to oil viscosity that occurs during the process of oil supply to the thrust bearing and lubricant sweeping.

[Problem that the invention seeks to solve]

The above conventional technology does not take into consideration the reduction of bearing loss in the thrust bearing, and the oil supplied to the thrust bearing is lubricated by the convex end surface between the oil sweep groove and the upper end notch. This prevents the ability to quickly sweep the oil afterwards, and the amount retained in the oil sweep groove increases.
There is a problem of increased bearing loss due to excessive retention on the sliding surface of the rotor shaft and the sliding surface of the thrust bearing, which causes resistance to the rotation of the rotor shaft and reduces the efficiency of the turbocharger. Ta.

The purpose of the present invention is to solve the problem of excessive oil retention by using an oil sweep passage that communicates the oil sweep groove with the upper end notch to quickly sweep the oil and reduce bearing loss that impedes the rotation of the rotor shaft. It's about doing.

[Means for solving problems]

The above object is achieved by providing a structure in which an oil sweep passage is provided between the oil sweep groove and the upper end notch.

[Effect]

After the oil supplied to the thrust bearing part is lubricated by the oil sweep passage provided between the oil sweep groove and the upper end notch, the oil is quickly guided to the oil drawing passage from the oil sweep groove. The amount of oil retained in the oil sweep groove is reduced, and the bearing loss caused by the reduction in the rotatability of the rotor shaft caused by the excessive oil amount acting as resistance can be reduced.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. The thrust bearing 1 has a groove 3 for holding oil provided on an end surface 2 in contact with a bearing box, an oil passage 4 communicating with the groove and facing the rotor axis, and an oil passage 4 communicating with the oil passage and communicating with both sides of the thrust bearing. A through hole 5, a thrust bearing sliding plane 6 having a land shape and a tapered part provided around the oil through hole, a closed loop notch 8 provided around the sliding surface 6, and the oil sweeping groove 7. The structure includes an oil sweep passage 9 that communicates with the notch 8.

3 and 4 show the prior art. A closed loop oil sweep groove 7 provided around the thrust bearing sliding plane 6
This differs from the embodiment of the present invention in that a convex end surface 10 is formed between the notch 8 formed at the lower end of the outer periphery.

Next, the operation of one embodiment of the present invention is illustrated in FIG.

This will be explained while comparing with FIG. 6 which shows the operation of the prior art.

In FIG. 5, oil is conducted from the oil gear rally 12 of the bearing box 11 to the oil holding groove 3 of the thrust bearing 1, passes through the oil passage 4 communicating with the oil holding groove, and enters the rotor shaft 13 through the oil passage hole 5. Thrust bearing 14a on the incorporated rotating shaft side.

14b is supplied to the sliding surface 6. The oil that has lubricated the sliding surface 6 is swept out in the circumferential direction of the shaft due to the centrifugal force caused by the rotation of the rotor shaft 13, and is guided to the oil sweeping groove 7. The oil led to the oil sweep groove passes through an oil sweep passage 9 communicating from the oil sweep groove 7 to the upper end notch 8, and is quickly swept to the oil drain passage 15 of the bearing box 11.

In the prior art, as shown in FIG. 6, oil lubricates the sliding surface 6 from the oil passage 5 and is guided to the oil sweep groove 7 by the centrifugal force caused by the rotation of the rotor shaft 13, as in the embodiment of the present invention. However, the convex end surface 10 between the oil sweep t:It 7 and the upper end notch 8 becomes an obstacle during oil sweep,
The oil is not swept out quickly, and as a result, the oil retaining groove is filled with oil, which impedes the rotation of the rotor shaft 13 and the thrust bearings 14a and 14b on the rotor shaft side due to the large viscous resistance of the oil. Increases bearing loss in supercharger.

In this embodiment, as described above, since the oil that has finished lubrication is quickly swept away, the bearing loss of the supercharger due to oil viscous resistance can be reduced compared to the prior art. In addition, by reducing bearing loss, the turbocharger can be
The starting torque when the rotor shaft begins to rotate is also reduced, and the startup characteristics of the supercharger are also improved. Furthermore, since the oil viscous resistance during oil sweeping is reduced by the oil sweeping passage 9, the effect becomes even more pronounced even when the oil temperature is low and the viscosity is high.6 [Effects of the Invention] According to the present invention For example, bearing loss due to oil viscous resistance can be reduced, so as shown in Figures 7, 8, and 9, bearing loss performance and starting torque characteristics are improved, and the performance of the supercharger can be improved. This also has the effect of improving performance at low temperature start-up.

[Brief explanation of the drawing]

FIG. 1 is a front view of an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line A-A, FIG. The structure and operation diagram of one embodiment, and the sixth @ is the structure and operation diagram of the conventional technology. FIG. 7, FIG. 8, and FIG. 9 are diagrams showing the effects. 1... Thrust bearing, 9... Oil sweep passage.

Claims (1)

[Claims] 1. A turbine wheel, a rotor shaft connected to the wheel, a compressor wheel at the other end of the rotor shaft, and a radial wheel located between the turbine wheel and compressor wheel that supports the axial force in the radial direction of the shaft. In a thrust bearing for a supercharger, which has a thrust bearing that supports the bearing and the axial force in the thrust direction, and a bearing box that houses the bearing member, a groove that holds oil provided on an end surface that contacts the bearing box and communicates with the groove. At least one oil passage facing the rotor axis, at least one oil passage communicating with the oil passage and communicating with both sides of the thrust bearing, and at least one oil passage provided around the oil passage. A thrust bearing sliding plane having three or more land-shaped and tapered parts, a closed-loop oil sweep groove provided around the sliding plane, a notch formed at the lower end of the outer periphery, and the oil sweep A thrust bearing for a supercharger, characterized in that an oil sweep passage communicating between a groove and the notch is provided.