JPS6073124A - Rotary shaft floating device - Google Patents

Abstract

PURPOSE:To prevent an accident such as burnt damage or so of a bearing by providing a clearance detector for the bearing and driving a hydraulic pump to supply oil between a rotary shaft and the bearing when the detected value of said detector is reduced below the specified value. CONSTITUTION:A clearance detector 7 is provided for a bearing 2 and connected via a controller 8 to a hydraulic pump 4. When the value which is detected by the clearance detector 7 is reduced below the specified value, the hydraulic pump 4 is driven to supply oil between a rotary shaft 1 and the bearing 2. When an oil film on the bearing 2 becomes thin, high pressure oil is automatically fed to float the rotary shaft 1. Since an necessary oil film may be ensured by the above measure, an accident such as burnt damage or so of the bearing in a rotary machine may be prevented.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] [Technical Background of the Invention and Problems Therewith] Regarding the rotating shaft floating device for a rolling machine of the present invention [Technical background of the invention and its problems] Between the rotating shaft supported by a sliding bearing and the inner surface of the bearing A commonly used method is to supply high-pressure oil from a separate system for lubricating oil and float the rotating shaft to ensure the required amount of oil film. Incidentally, such floating of the rotating shaft is necessary when an oil film is not sufficiently formed during startup or at low speed, and becomes unnecessary when the oil film becomes thicker as the rotation increases. In fact, there is a concern that attempting to levitate the shaft by supplying high-pressure oil under high-speed rotation may impede the natural flow of oil due to rotation and cause unstable vibrations. Therefore, conventionally, the number of revolutions at which high pressure oil is supplied is determined in advance, and the high pressure oil is supplied or Fi is cut off at the determined number of revolutions.

However, if, for example, the bearing surface becomes damaged over time and the load capacity decreases and the oil film thickness becomes thinner, the above method of controlling the supply of high-pressure oil at a fixed rotation speed will still require the supply of high-pressure oil. In some situations, high pressure oil may be shut off, which may lead to accidents such as bearing burnout depending on the conditions.

[Object of the Invention] The present invention has been made in view of the above points, and an object of the present invention is to provide a rotating shaft flotation device capable of follow-up control for bearing load capacity or stone shape fluctuations.

[Summary of Departure J] In order to achieve the above object, the present invention provides a bearing for supporting a rotating shaft, and a non-contact type clearance provided on the bearing to detect the clearance rotation between the rotating shaft and the bearing. A detection device, an oil pump that starts when the clearance detected by the clearance detection device becomes smaller than a predetermined value, and the oil pump supplies oil between the rotating shaft and the bearing. It is characterized by what it did.

[Example of Brahma Fruit JJili] An embodiment of the present invention will be described below with reference to FIG. 1. FIG. 1 is a system diagram of the shaft floating device.

In this figure, (1) is the rotation axis, and this rotation axis (1
) is supported by the +Ilr bearing (2), to which oil (8) for floating the shaft is supplied from the oil film (6) via the oil pump (4) and check valve (5). be done. 1 more
In this embodiment, a non-contact type clearance detector (7) such as an eddy current element is provided at the bottom of the bearing (2), and the rotating shaft (
The signal of the flying height (9) in 1) is sent to the controller (8). The controller (8) issues a control signal to start the oil pump (4) when the floating height (9) of the rotating shaft (1) detected by the gap detector (tens) becomes smaller than a predetermined value. It is something.

According to this embodiment, the supply oil (8) for shaft levitation is supplied to the rotating shaft (1).
) is always supplied to levitate the shaft when the floating amount (9) of the oil i becomes small, so even if the oil i becomes thin for some reason during high-speed rotation, the necessary oil film can be safely ensured.

FIG. 2 is a system diagram of a shaft floating device showing another embodiment of the present invention. In this embodiment, two clearance detectors (7) are provided, a vertical clearance detector (7a) and a horizontal clearance detector (7b), and the vertical IH detected by each detector is installed in the control system.
An arithmetic unit α1) is provided which calculates the minimum gap (9C) from the gap (9a) and the horizontal gap (9b). In this example, when the minimum clearance (9C), which is the output of the calculator (10), becomes smaller than a predetermined value, the controller (8) issues a control signal to start the oil pump, so it moves horizontally. If the rotating shaft (υ) is eccentric, it is effective in ensuring the true minimum oil film thickness.

In the above embodiments, the control signals are used to start and stop the oil pump, but since the purpose of this control is to supply and stop high-pressure oil, for example, the control signals shown in FIGS. As shown in the figure, it can also be used to control the flow rate adjustment valve (formerly known as the cutoff valve (13)), and the control signal can be used to simultaneously stop the supply of high-pressure oil and monitor and monitor the oil film thickness. It can also have recording and V! reporting functions.

In the above embodiment, in order to simplify the explanation, the supply and stop of high-pressure oil was assumed to be based on the control signal α0), but reliability can be further increased by adding the rotation speed to the control factors.

[Effects of the Invention] As explained and clarified above, according to the invention, if the oil film on the bearing becomes thin due to some reason, such as scratches on the bearing surface or increased bearing load, high-pressure oil is automatically supplied. Since the oil can be supplied to float the shaft and secure the necessary oil film, accidents such as bearing burnout in the rotating machine can be prevented and safe operation can be continued.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing one embodiment of the rotating shaft floating device of the present invention, and FIGS. 2 to W4 are system diagrams showing other embodiments of the present invention, respectively. 3...Oil supply 4...Oil pump L 7a, 7b...Gap detector 8...For controller...Control signal agent Patent attorney Noriyuki Chika (and 1 other person) Fig. 1 Figure 2 // d

Claims (1)

[Claims] (1) A bearing that supports a rotating shaft, a non-contact clearance detection device that is installed on this bearing and detects the amount of clearance between the rotating shaft and the bearing, and the amount of clearance detected by this clearance detection device. 1. A rotating shaft flotation device comprising: an oil pump that is activated when the rotational axis becomes smaller than a predetermined value; and an oil film that supplies oil between the rotating shaft and the bearing by the oil pump. j21. A rotary shaft floating device according to claim 1, characterized in that a plurality of clearance detection devices are provided, and the minimum clearance is determined and determined by a calculation device based on the outputs of these devices.