JP3095650B2 - Bearing metal variable phase type bearing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing metal variable phase bearing.

[0002]

2. Description of the Related Art As shown in FIG. 13, various types of plain bearings commonly used in rotary machines have an annular clearance 02 in a bearing metal 03 in which a rotating shaft 01 is fitted and fixed in a bearing hole of a bearing housing 10. And the annular clearance 02 is filled with lubricating oil. In this type of plain bearing, since the annular bearing metal 03 is fixed, the oil film coefficient cannot be changed during rotation of the rotating shaft 01.

[0003]

Generally, the vibration characteristics of a rotating shaft system are determined by the specifications of the shaft system and the oil film characteristics of the bearing as shown in FIG. In a normal rotating machine,
The specifications of the shaft system are almost determined when the type, output, and performance of the rotating machine are determined, but depending on the type, high-pressure turbines and the like receive not only the weight of the rotor but also steam reaction force that cannot be ignored under partial load conditions. Also, in some compressors, a tooth reaction force is applied in accordance with the load, so that the axial load direction may change. On the other hand, the oil film characteristics of a bearing not only vary greatly depending on the type of bearing, but also vary greatly depending on bearing specifications such as bearing width and bearing clearance. However, as described above, with conventional bearings, the oil film coefficient cannot be changed during the operation of a rotating machine, and therefore, in response to changes in operating conditions such as rotation speed and load, the critical speed, unbalanced response characteristics, and shaft system stability are determined in advance. Bearings must be designed in consideration of such factors. For this reason, in general, not only the quality of the bearing becomes excessive, but also the vibration characteristics are not always optimally designed depending on the conditions.

The present invention has been proposed in view of such circumstances, and exhibits an oil film characteristic which is optimal for the vibration characteristics of a rotating shaft, and provides a critical speed and an unbalanced response characteristic with respect to changes in operating conditions of the rotating shaft. It is an object of the present invention to provide a high-performance bearing metal variable-phase type bearing for improving the stability of the shaft system by changing the bearing.

[0005]

According to a first aspect of the present invention, there is provided a bearing metal variable phase bearing having a bearing housing.
And within the bearing housing,
The bearing housing is inserted so as to be relatively rotatable around the body rotation axis.
And the same bearing metal as the above-mentioned rotation axis of the same bearing metal.
Around the bearing housing.
The phase of the bearing metal with respect to the bearing housing
Bearing metal rotating means for changing the bearing metal rotation.
The driven means is formed integrally with the bearing metal on the driven side.
Of the bearing housing
The above-mentioned bearing meta through the teeth on the drive side and the teeth on the drive side
Around the rotation axis of the bearing metal.
The bearing metal by rotating relative to the
A shaft that changes the phase of the bearing housing by a predetermined amount
It is characterized by having a receiving metal rotating mechanism .

The bearing metal according to the second aspect of the present invention can be used.
Variable phase bearings consist of a bearing housing and the same bearing housing.
Within the bearing housing around its own pivot axis
Bearing metal inserted so as to be able to rotate relative to the bearing metal
The bearing metal around the rotation axis of the bearing housing
The bearing metal by rotating relative to the bearing.
The bearing metal turn to change the phase with respect to the bearing housing
Moving means, and the bearing metal rotating means is provided with the bearing housing.
Form between the inner peripheral surface of the housing and the outer peripheral surface of the bearing metal
The pressure introduced from one of the oil passages via the hydraulic switching circuit
Receives the above bearing metal under the circumferential pressure of oil
The bearing housing around the pivot axis of the metal itself
Relative to the bearing in one direction.
Phase of the barrel with respect to the bearing housing
A first hydraulic chamber which is changed by a predetermined amount when
Form between the inner peripheral surface of the housing and the outer peripheral surface of the bearing metal
And is introduced from the other oil passage through the hydraulic switching circuit.
Receiving the circumferential pressure of the pressurized oil
The bearing Ha maggots around the rotation axis of the bearing metal itself
Coaxial by rotating relative to the other direction
Set the phase of the receiving metal to the bearing housing
And a second hydraulic chamber for changing the direction by a predetermined amount.
And said that you are.

[0007]

According to such a configuration, the direction of the bearing load acting on the effective load surface of the bearing changes relatively by moving the bearing metal in the circumferential direction, so that the characteristics of the bearing oil film change. As a result, as shown in the mechanical equivalent model diagram of FIG. 5, the oil speed characteristics (spring and damping coefficient) of the bearing change, and the critical speed determined by the specifications of the shaft system and the oil speed characteristics of the bearing,
Imbalance response characteristics and shaft system stability can be changed. Thus, by moving and supporting the bearing metal in a phase in which the optimum bearing performance can be used in accordance with the operating condition of the rotating machine, the performance of the used bearing can be maximized and the optimal vibration characteristics can be obtained.

[0008]

EXAMPLES Referring to the drawings the actual施例of the present invention,
FIGS. 1, 2 and 3 are a longitudinal sectional view and a transverse sectional view showing a first embodiment, a second embodiment, and a third embodiment, respectively, of FIG.
FIG. 5 is a cross-sectional view showing the fourth embodiment, FIGS. 5 and 6 are mechanically equivalent model diagrams showing oil film characteristics of the first embodiment and the second embodiment shown in FIGS. FIG. 7, FIG. 8, FIG. 9, FIG. 10, and FIG. 11 show a dynamic model diagram showing oil film characteristics of the third embodiment, respectively, when the present invention is applied to a perfect circular bearing with an oil supply groove, applied to a two-arc bearing. When applied to offset bearings, when applied to 4TP bearings, 5T
FIG. 12 is a list showing a comparison of shaft system vibration characteristics between the bearing types shown in FIGS. 7 to 11 when applied to a P bearing.

In the upper drawing, the same reference numerals as those in FIG. 13 denote the same members as those in the same drawing. First, the first embodiment shown in FIG. Along with the teeth 05, the pinion 06 driven by the motor 07 meshes with the teeth 05, so that the phase can be adjusted by slightly moving the bearing metal 03 in the circumferential direction even during the rotation of the rotating shaft 01. And Here, reference numeral 10 denotes a housing that rotatably supports the outer periphery of the bearing metal 03.

Next, in the second embodiment shown in FIG. 2, in order to make the bearing metal 03 rotatable, teeth 08 are provided at one axial end of the bearing metal 03 partially or along the entire circumference. The phase of the bearing metal 03 is made variable even during the rotation of the rotating shaft 01 by meshing a tooth 08 with a pinion 06 driven by a motor 07. Such first and second
According to the embodiment, since the direction of the bearing load acting on the effective load surface of the bearing relatively changes, the characteristics of the bearing oil film (spring coefficient and damping coefficient) change. It changes the critical speed, unbalanced response characteristics and shaft system stability determined by the above, and exhibits optimal vibration characteristics.

Further, in the third embodiment shown in FIG. 3, lubricating oil is supplied from a radial oil supply hole 06 of the housing 10 surrounding the bearing metal 03 with an annular clearance 09 in the second embodiment shown in FIG. To generate a squeeze pressure in the annular gap 09. According to such a structure, FIG.
As shown in the mechanically equivalent model diagram of FIG. 1, the rotating shaft 01 has countless spring coefficients Kxx, Kxy, Kyx,
Kyy and attenuation coefficients ωCxx, ωCxy, ωCyx, ωC
yy, supported by the bearing metal 03, the bearing metal 03
Is the spring coefficient Kp based on the squeeze oil pressure of the annular clearance 09
x, supported by the housing 10 by the attenuation coefficient WCpx. As a result, in the third embodiment, by changing the rigidity ratio of the oil film characteristics of the movable bearing and the damper structure, there is no coupling term in the oil film coefficient, and the damper structure essentially has a favorable effect on the vibration characteristics of the shaft system. By increasing the contribution of the oil film characteristics to the shaft system vibration characteristics, the equivalent support stiffness Z _E is represented in the form shown in the figure, and a higher degree of optimization of the bearing characteristics is possible.

In the fourth embodiment shown in FIG.
Between a partition weir protruding radially inward of the bearing housing 13 in an annular space between the bearing metal 21 and the bearing housing 13, and a partition weir protruding radially outward of the bearing metal 21. Hydraulic section 1 with fan-shaped cross section
4 and 15 are provided, and the oil pressure supplied from the oil pressure source 19 is switched to the pipe 16 or the pipe 17 by the oil pressure switching circuit 18 so that the bearing metal 21 is rotated.
Here, lubricating oil between the rotating shaft 01 and the bearing metal 21 is supplied to the oil groove 1 having a fan-shaped cross section provided in the bearing housing 13.
1, through the oil hole 12 provided in the bearing metal 21. Further, the adjustment of the phase of the bearing metal 21 is performed by controlling the hydraulic pressure switching circuit 18 based on the signal of the shaft tachometer 20 to control the supply amount of the pressure oil of the hydraulic source 19 to the hydraulic chambers 14 and 15. is there.

As a result, when the present invention is applied to a sliding bearing having various structures as described below, as described later,
Excellent static characteristics and dynamic characteristics are obtained so as not to be compared with the conventional plain bearings shown in FIG.

First, FIG. 7 shows a case where the present invention is applied to a perfect circular bearing with an oil supply groove. FIG. 7 (A) is a hydraulic coefficient calculation mesh diagram, FIG. 7 (B) is a shaft center floating characteristic diagram, Figure (C)
Is a contour diagram of the Sommerfeld number, FIG. 4D is a contour diagram of the natural frequency, FIG. 4E is a contour diagram of the damping ratio, and FIG. 4F is a diagram of FIG. FIG. 8 is a contour diagram of the attenuation ratio in which (a) is superimposed. For example, the effect of the third embodiment of the present invention on the stability of the shaft system will be described with reference to FIG. First, when the rotational speed of the shaft is low and there is no sufficient load capability, a sufficient load capability can be obtained by performing a normal installation with the bearing load angle θ _w = 0 °. Here, when the rotational speed increases and the shaft center approaches the center of the bearing clearance 02, it can be seen that the unstable region where the damping ratio is negative is large at the normal bearing installation angle θ _w = 0 °. On the other hand, when the installation angle of the bearing metal is rotated clockwise by 30 °, the shaft center passes through the region where the stability is improved due to the influence of the oil supply groove, so that θ _w = 0 ° When θ _w = 30 °, the unstable region is very narrow. In this way, by changing the bearing installation angle, it is possible to change the vibration characteristics of the shaft system, and it is possible to optimize the vibration characteristics of the shaft system in the operating condition of the rotating machine that could not be considered with conventional bearings Becomes

FIG. 8 shows static and dynamic characteristics when the present invention is applied to a two-arc bearing. Here, the basic viewpoint of the drawing is the same as that of the case of the perfect circular bearing up to FIG. 11, but each characteristic diagram of FIG. 8 is simpler than that of the perfect circular bearing. This is because the oil is supplied from a position where the clearance in the left-right direction is wide, in other words, the position where the oil film pressure is unlikely to occur, and the influence of the oil supply groove is small.
The characteristic matters in relation to the arbitrary equilibrium point and the vibration characteristics of the shaft system in the two-arc bearing are summarized as follows. (1) The damping ratio increases with an increase in the shaft rotation speed in a normal use state of a two-arc bearing (θ _w = 0 °), but when the eccentricity exceeds approximately ε _b <0.5, the damping ratio conversely increases. When it becomes smaller and ε _b <0.2, the damping ratio becomes negative and becomes unstable. (2) Further, in the two-arc bearing, a region where the damping ratio is large is divided into an upper half and a lower half when the equilibrium position of the shaft center is around ε _b b0.7 of the bearing clearance region. (3) Therefore, it would be movement locus of the axis due to the rotation speed increase of the shaft by increasing the load theta _w is gradually shifted to a small area side damping ratio, or the improved stability is at least 60 ° You. (4) That is, in a two-arc bearing, the stability greatly changes depending on the bearing load direction and the positional relationship between the lower bearing metal. Therefore, there is a possibility that the stability can be improved by using this characteristic.

FIG. 9 shows a case where the present invention is applied to a two offset bearing, and FIGS. 9A to 9E show the relationship between an arbitrary equilibrium point of the two offset bearing and the vibration characteristics of the shaft system. The features are as follows. (1) The damping ratio is positive even in a region of about ε _b <0.1 as compared with a perfect circular bearing or a two-arc bearing, indicating that the stability is good. (2) A region having a large attenuation ratio and good stability is divided into an upper right portion and a lower left portion like an eyeball pattern and distributed. (3) Accordingly, 2 offset bearings Ru is also improved shaft system stability by appropriately selecting the installation angle of the 2-arc bearing as well as bearing load direction and the bearing.

FIG. 10 shows a case where the present invention is applied to a 4 tilting pad bearing (hereinafter referred to as a 4TP bearing). The characteristics of the shaft system vibration characteristics at an arbitrary equilibrium point are as follows. (1) From FIG. P. In the state of use of the bearing, O. P. (Load on pad) and L.
B. P. In (Load between pads), the shaft center floats linearly toward the center of the bearing, but when the load direction is shifted, the lifting characteristic shows a curved shape. (2) From FIG. For P, bearings, the contour diagram of the Sommerfeld number changes along the bearing clearance shape. This means that 4T. P. This shows that when the magnitude of the load is constant in the bearing, the bearing clearance becomes substantially constant regardless of the load direction. (3) From FIG. P. The natural frequency of the bearing is L. B. P. Although the change in the natural frequency is small with respect to the change in the load direction, O. P. Attention should be paid to the fact that the natural frequency greatly changes in the load direction close to that state. (4) From FIG. 4E, the stability margin is 4T. P. The bearing is L.L. B. P. It is possible to quantitatively confirm that it is better to use it.

FIG. 11 shows a case where the present invention is applied to a 5 tilting pad bearing (hereinafter referred to as a 5TP bearing), and the features are as follows. (1) 4T. P. L. compared to bearings B. P. And L. O.
P. Changes in vibration characteristics are small. 5T. P. Since multiple pads always share the load in the bearing,
It is considered that the vibration characteristics change continuously. (2) While the perfect circular bearing, the circular arc bearing, and the two offset bearing become unstable at the center of the bearing, 4T. P. 5T. Including bearings P. The bearing has the largest stability margin at the center of the bearing. (3) Therefore, T.I. P. Even in the case of using a bearing, it is possible to increase the stability margin by appropriately selecting the bearing specifications and reducing the eccentricity. (4) L. O. P. In 0.7 <ε _b <around 0.85, it is a large stable region of very damping ratio is aimed at this part design area is narrow, and attention is required because the range of change in the damping ratio is large is there.

When the characteristics of the above five types of bearings are illustrated,
As shown in FIG. 12, the tendency of the general stability is a conventional wisdom as, in particular, in the second offset bearings, found that increased stability at the installation angle of the bearing load angle theta _w and the bearing are changed did. In addition, it has been found that, in the case of a perfect circular bearing, the positional relationship between the load direction and the lubrication groove has a great effect on stability.

[0020]

According to such an embodiment, the following effects can be obtained. (1) Minimization of the resonance magnification of the critical speed By utilizing the fact that the oil film characteristics of the bearing differ depending on the equilibrium point of the shaft center, the bearing metal can be moved to the optimal bearing angle determined in advance analytically. In addition, the resonance magnification when passing through the critical speed can be minimized. (2) Optimization of Vibration Characteristics at Rated Rotation Speed It is possible to set a bearing angle that maximizes unbalanced response amplitude and shaft system stability at a specific rotation speed such as the rated rotation speed. (3) Optimization of vibration characteristics of shaft system with large changes in operating conditions In a shaft system whose vibration characteristics change due to load changes and other external factors, set the bearing angle to the optimum vibration characteristics for each condition. can do. Above, (1)-
In (3), it is common that the optimum angles of the bearings do not coincide with each other. In that sense, the conventional one is designed at the expense of some characteristics. Achieves excellent shaft system vibration characteristics.

In short, the bearing meta according to the first aspect of the present invention.
According to the variable phase bearing, the bearing housing and the bearing
The rotation axis of the bearing itself inside the housing
Bearing metal interleaved relative to the wire
Place the bearing metal around the rotation axis of the bearing metal.
The bearing is rotated by rotating relative to the bearing housing.
Shaft for changing the phase of metal relative to the bearing housing
Receiving metal turning means, and the bearing metal turning means,
The driven teeth formed integrally with the bearing metal
It is disposed on the bearing housing side and
The above bearing metal is coaxial through the meshing drive side teeth.
In the bearing housing around the pivot axis of the receiving metal
The bearing metal of the same bearing
Bearing metal that changes the phase for aging by a predetermined amount
Since the rotating mechanism is provided, the bearing of the bearing metal rotating means
By the operation of the metal rotation mechanism, the bearing metal is integrated
Disposed on the bearing housing side and the driven side teeth formed
Through the driven-side teeth and the driving-side teeth that mesh with each other,
Place the bearing metal around the axis of rotation of the bearing metal.
By rotating relative to the housing, the bearing
Of the bearing with respect to the bearing housing by the specified amount
Oil film characteristics that can be changed and are optimal for the vibration characteristics of the rotating shaft
And can be used to change the operating conditions of the rotating shaft.
By changing the critical speed and unbalanced response characteristics,
High performance bearing metal variable phase type that can achieve qualification
Bearing metal that is industrially extremely useful for obtaining bearings
A variable phase bearing can be provided.

The bearing metal according to the second aspect of the present invention can be used.
According to the phase-change bearing, the bearing housing and the bearing
Of the axis of rotation of the bearing housing
Bearing metal interposed so as to be relatively rotatable around the bearing
Metal around the rotation axis of the bearing metal
By rotating relative to the housing, the bearing
Bearings that change the phase of the
And the bearing metal rotating means,
Between the inner peripheral surface of the bearing housing and the outer peripheral surface of the bearing metal
Between the two oil passages via the hydraulic switching circuit
The bearing metal receives the pressure in the circumferential direction
The bearing housing is provided around the rotation axis of the bearing metal itself.
Relative rotation in one direction with respect to
The phase of the bearing metal with respect to the bearing housing
A first hydraulic chamber for changing the direction by a predetermined amount,
Between the inner peripheral surface of the bearing housing and the outer peripheral surface of the bearing metal
Formed from the other oil passage through the above hydraulic switching circuit.
The bearing meta is received by receiving circumferential pressure
Around the rotation axis of the bearing metal itself.
By rotating relative to the housing in the other direction.
Phase of the bearing metal above the bearing housing
And a second hydraulic chamber for changing the other direction by a predetermined amount.
The bearing metal turning means activates
The inner peripheral surface of the bearing housing and the outer peripheral surface of the bearing metal
The first hydraulic chamber formed during
Receives circumferential pressure due to pressure oil introduced from one oil passage.
And the bearing metal is rotated by the rotation of the bearing metal itself.
Around the axis in one direction with respect to the bearing housing
The bearing housing is made of the same bearing metal by relative rotation.
Phase in the above one direction by a predetermined amount.
Can be changed.
By operation, the inner peripheral surface of the bearing housing and the bearing
The second hydraulic chamber formed between the outer peripheral surface of the barrel and the
The pressure oil introduced from the other oil passage through the hydraulic switching circuit
Receiving the circumferential pressure, the bearing metal is
The bearing housing around the pivot axis of the barrel itself
The bearing can be rotated relative to the other direction.
Phase with respect to the bearing housing in the other direction
Can be surely changed by a predetermined amount.
Oil film characteristics optimized for the vibration characteristics of the rotating shaft according to the size of the oil
And can be used for changes in the operating conditions of the rotating shaft.
Change the critical speed and unbalanced response characteristics to improve the stability of the shaft system.
High performance bearing metal variable phase type bearing that can be achieved
Bearing metal variable position that can be obtained and is extremely useful in industry
A phase bearing can be provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view and a transverse sectional view showing a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view and a transverse sectional view showing a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional view and a transverse sectional view showing a third embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a fourth embodiment of the present invention.

FIG. 5 is an equivalent mechanical model diagram showing oil film characteristics of the first embodiment and the second embodiment shown in FIGS. 1 and 2;

FIG. 6 is an equivalent mechanical model diagram showing oil film characteristics of the third embodiment shown in FIG.

FIG. 7 is a diagram showing static and dynamic characteristics when the present invention is applied to a perfect circular bearing with an oil supply groove.

FIG. 8 is a diagram showing static and dynamic characteristics when the present invention is applied to a two-arc bearing.

FIG. 9 is a diagram showing static and dynamic characteristics when the present invention is applied to a two-offset bearing.

FIG. 10 is a diagram showing static and dynamic characteristics when the present invention is applied to a 4-tilting pad bearing.

FIG. 11 is a diagram showing static and dynamic characteristics when the present invention is applied to a 5-tilting pad bearing.

12 is a diagram showing a comparison of shaft system vibration characteristics according to each bearing type of FIGS. 7 to 11. FIG.

FIG. 13 is a longitudinal sectional view and a transverse sectional view showing a conventional plain bearing.

FIG. 14 is a general acceleration response characteristic diagram of a rotating machine.

[Explanation of symbols]

01 rotating shaft 02 lubricating oil (annular clearance) 03 bearing metal 04 lubrication pocket 05 teeth 06 pinion 07 motor 08 teeth 09 annular clearance 10 housing 11 oil groove 12 oil hole 13 bearing housing 14 hydraulic chamber 15 hydraulic chamber 16 piping 17 piping 18 hydraulic Circuit 19 Hydraulic source 20 Shaft tachometer 21 Bearing metal S Sommerfeld number θ _w Load angle ε _b Eccentricity 減 衰 Damping ratio L. O. P. LOP (Load on p
ad) L.R. B. P. LBP (Load betw)
een pad) T.E. P. Tilting pad

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-87702 (JP, A) JP-A-4-4525 (JP, U) JP-A-58-125718 (JP, U) JP-A-2- 30520 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F16C 17/00-17/26 F16C 21/00-27/08 F16C 33/00-33/28

Claims (2)

(57) [Claims] 1. A bearing housing, and inside the bearing housing.
Around its own axis of rotation relative to the bearing housing
The bearing metal inserted so as to be rotatable and the bearing metal
The bearing housing is arranged around the rotation axis of the bearing metal.
The bearing metal is rotated relative to the
Bearing metal rotation to change phase with respect to bearing housing
Means for rotating the bearing metal,
Driven teeth formed integrally with the bearing housing
Drive which is disposed on the driving side and meshes with the driven side teeth
Through the teeth on the side, the bearing metal above the bearing metal
Relative to the bearing housing around the axis of rotation
By moving the bearing, the bearing housing
Equipped with a bearing metal rotation mechanism that changes the phase
Bearing metal variable phase type shaft
Receiving. 2. The bearing housing and the inside of the bearing housing.
Around its own axis of rotation relative to the bearing housing
The bearing metal inserted so as to be rotatable and the bearing metal
The bearing housing is arranged around the rotation axis of the bearing metal.
The bearing metal is rotated relative to the
Bearing metal rotation to change phase with respect to bearing housing
Means for rotating the bearing metal,
Formed between the inner peripheral surface of the jing and the outer peripheral surface of the bearing metal
Pressure oil introduced from one of the oil passages via the hydraulic switching circuit
The bearing metal receives the circumferential pressure from
The bearing housing around the pivot axis of the barrel itself
The bearing can be rotated in one direction.
Phase of the bearing with respect to the bearing housing
A first hydraulic chamber for changing the bearing housing by a predetermined amount;
Formed between the inner peripheral surface of the jing and the outer peripheral surface of the bearing metal
And was introduced from the other oil passage through the above hydraulic switching circuit.
Coated with the above bearing metal by receiving circumferential pressure from pressurized oil
The bearing housing around the pivot axis of the receiving metal itself.
Bearing in the other direction relative to the bearing
The phase of the metal relative to the bearing housing is
A second hydraulic chamber for changing the direction by a predetermined amount.
A bearing metal variable phase type bearing, characterized in that: