JPS6253730B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a bearing pad, and more particularly to a support device for a bearing pad of a tail-tained pad type hydrodynamic gas bearing.

[Conventional technology]

As a bearing pad support device for a bearing that supports a shaft with a plurality of bearing pads, such as a tailing pad type hydrodynamic gas bearing, a measure as shown in FIG. 2 has been taken. That is, among the plurality of bearing pads 2a to 2c that support the shaft 1, the bearing pads 2b and 2c are supported by the fixed pivot 4 provided in the housing 3, and the remaining bearing pads 1
a is a pivot 5 slidably provided on the housing 3;
A spring 6 for preloading is provided on the back of the pivot 5. This preloading spring 6 plays the role of ensuring the vibration stability of the shaft 1 during high speed rotation. Further, as this type of bearing, there are those shown in US Pat. No. 3,497,276 and US Pat. No. 3,063,762.

[Problem that the invention seeks to solve]

However, in recent years, shaft rotation speeds have become faster. When the shaft rotates at such high speed,
Accordingly, the value of the preloading spring 6 must be increased in order to guarantee the vibration stability of the shaft. In this way, when the value of the preload spring 6 becomes large, no bearing clearance is formed between the bearing pad and the shaft, so the bearing pad comes into direct solid contact with the shaft during startup, and a very large startup torque is generated. This often resulted in the computer not being able to start.

On the other hand, U.S. Patent No. 3,063,762 discloses that the bearing clearance is initially set using a shim, but since this bearing clearance needs to be maintained at a minute value of, for example, about 5 μm, the machining process The work takes a lot of time, and if the machining dimensions of the clearance are incorrect, the optimal bearing clearance cannot be obtained, and as mentioned above, rotational contact between the shaft and the bearing pad may occur during startup. In addition, since the pivot shaft is guided by a guide hole with a small axial length, the pivot shaft may get stuck in the guide hole due to the bias load caused by incorrect deformation of the preload spring, and the bearing pad may not be properly aligned. It may not be possible to apply a preload.

The present invention has been made based on the above-mentioned issues, and it is possible to reduce the starting torque generated at the time of starting by ensuring a constant bearing clearance between the shaft and the bearing pad when the shaft is stationary, and also to transfer the preload to the bearing pad. The object of the present invention is to provide a bearing pad support device that can be applied accurately.

[Means for solving problems]

The above-mentioned object of the present invention is to provide a bearing in which a plurality of bearing pads for supporting a shaft are arranged in a housing, and the bearing pads are swingably supported by a pivot shaft provided in the housing. A holding frame is screwed into place, a flange for receiving a stopper is provided at the inner end of the housing of this holding frame, a guide hole is provided in this flange to guide the tip end of the pivot shaft, and a nut is screwed into the holding frame to be fixed. A guide hole for guiding the rear end side of the pivot shaft is provided in this nut, and the front end side and rear end side of the pivot shaft having a stopper that abuts the flange are respectively guided by the two guide holes. This is achieved by slidably guiding and arranging a preloading spring between the nut and the stop in the holding frame.

[Effect]

The bearing clearance between the bearing pad and the shaft can be set to a predetermined value by turning a holding frame with a pivot shaft, a preloading spring and a nut. In addition, even if the preload spring is improperly deformed due to the load acting on the bearing pad, the front end side and rear end side of the pivot shaft will be removed by the guide hole provided in the flange and the guide hole provided in the nut, respectively. Being slidably guided by the bore, the pivot shaft can accurately transmit the reaction force of the preloading spring to the bearing pad.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a bearing equipped with an example of the device of the present invention, and in this figure, the same reference numerals as in FIG. 2 are the same parts. Multiple bearing pads 2a~
Two bearing pads 2b and 2c of 2c are supported by a fixed pivot 4. The remaining bearing pad 2a is supported by a pivot shaft 7 which is movable radially relative to the axis of the shaft 1. This pivot shaft 7 is guided by a cylindrical holding frame 8, as will be described later. This holding frame 8 is screwed and fixed to the housing 3. A flange 8a is provided at the inner end of the housing of this cylindrical holding frame 8. This flange 8a has a guide hole 8 for guiding the raw end side of the pivot shaft 7a.
b is provided. A nut 10 for adjusting the spring force of the preload spring is screwed and fixed in the holding frame 8. This nut 10 is provided with a guide hole 10a for guiding the rear end of the pivot shaft 7. The pivot shaft 7 is provided with a stopper 9 that comes into contact with a flange 8a at the tip of the holding frame 8. The pivot shaft is slidably guided within the holding frame by a guide hole 8b of a flange 8a at its leading end and by a guide hole 10a of a nut 10 at its rear end. A preloading spring 11 is provided between the back of the stopper 9 and the nut 10 in the holding frame 8.

To install this support device, first, before screwing it into the housing 3, the nut 10 is set so that the pressing force of the preloading spring 11 is a required value. Next, the holding frame 8 containing the pivot shaft 7, preload spring 11, and nut 10 adjusted to this setting state is screwed into the housing 3, so that a slight gap is created between the bearing pad 2a and the shaft 1. Fix it.

With this configuration, since there is a gap between the shaft 1 and the bearing pads 2a to 2c when the shaft 1 is started, solid contact between the shaft 1 and the bearing pads 2a to 2c can be reduced. As a result, the starting torque can be reduced. After that, the rotation of the shaft 1 increases, and a gas lubricant film is formed between the bearing pads 2a to 2c and the shaft 1, and the pivot shaft 7 absorbs the preload by the spring force of the preload spring 11. Since it is applied to the bearing pad 2a, the vibration stability of the shaft 1 can be guaranteed. In addition, even if the preload spring is deformed into an incorrect shape due to the load from the bearing pad and a biasing force is generated with respect to the pivot axis, the pivot axis 7 is guided by the two guide holes 8b and 10a. The spring reaction force can be reliably transmitted to the bearing pad without galling between the guide holes 8b and 10a.

〔Effect of the invention〕

According to the present invention, a constant bearing clearance can be formed between the shaft and the bearing pad by rotating the holding frame, so that the starting torque can be significantly reduced. In addition, since the pivot shaft is guided in two places, the leading end and the rear end, even if the preloading spring is improperly deformed, the preload is transmitted to the bearing pad, improving the vibration stability of the shaft. This can be maintained at all times, and has the effect of stably supporting the shaft during startup and rotational conditions, as well as prolonging the life of the bearing pad.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a bearing equipped with an example of a bearing pad support device of the present invention, and FIG. 2 is a cross-sectional view of a bearing equipped with an example of a conventional bearing pad support device. 1...Shaft, 2a-2c...Bearing pad,
3...Housing, 4...Fixed pivot, 7...
Pivot axis, 8... Holding frame, 9... Stopper, 1
0... Nut, 11... Spring for preload.

Claims (1)

[Claims] 1. A bearing in which a plurality of bearing pads supporting a shaft are arranged in a housing, and the bearing pads are swingably supported by a pivot shaft provided in the housing, and a cylindrical holding frame is screwed and fixed to the housing, A flange for receiving a stopper is provided at the inner end of the housing of this holding frame, a guide hole is provided in this flange for guiding the tip end side of the pivot shaft, and a nut is screwed into the holding frame and fixed,
This nut is provided with a guide hole for guiding the rear end side of the pivot shaft, and the front end side and rear end side parts of the pivot shaft having a stopper that abuts the flange are slid through the two guide holes, respectively. A supporting device for a bearing pad, characterized in that a preloading spring is arranged between the nut and the stopper in the holding frame.