Device for measuring deflection of long false shaft for centering and method of using the same

Abstract

The present invention discloses a device for measuring the deflection of a long dummy shaft for centering and a method for using the device. The device comprises a long dummy shaft, one end of a sleeve fixedly connected to a blind plate concentric with the long dummy shaft, one end of the long dummy shaft fixedly connected to an end flange concentric with the long dummy shaft, the long dummy shaft placed in the sleeve and concentric with the sleeve, and the end flange and the blind plate tightly connected; a first dial indicator, a second dial indicator, and a third dial indicator are installed between the end of the long dummy shaft away from the end flange and the inner wall of the sleeve, each measuring rod contacting the inner wall of the sleeve; the first dial indicator and the second dial indicator are symmetrical to the center of the long dummy shaft. In the measuring state, the line connecting the rotation centers of the pointers of the first and second dial indicators coincides with a plumb line passing through the center of the long dummy shaft, and the line connecting the rotation center of the pointer of the third dial indicator and the center of the long dummy shaft is perpendicular to the plumb line. The present invention accurately measures the downward deflection of the head of the long dummy shaft when it is in a horizontal state, thereby correcting the centering data, ensuring smooth installation and long-term stable operation of the equipment, and reducing the failure rate.

Description

Technical Field

[0001] The invention relates to the measurement of rotating equipment, in particular to a device for measuring the deflection of a long false shaft for centering and a use method thereof. Background Art

[0002] Centering mechanical equipment during installation is a common task in industrial installation projects. Often, because the intermediate shaft between the couplings of the equipment to be centered is long and the centering data cannot be directly measured using a dial indicator, a long dummy shaft is fabricated to hold the dial indicator for centering. Long dummy shafts can cause significant head deflection, which can cause deviations in the centering dial indicator readings, impacting equipment centering and installation quality. This is especially true for high-speed equipment, which requires very high centering tolerances. This deviation must be fully considered and accurately measured, and the centering data corrected. Otherwise, stable equipment operation and personnel safety will be compromised.

[0003] The Chinese utility model with authorization announcement number CN204439325U discloses a dummy shaft for repairing. The utility model measures the boring hole of the equipment to be repaired, but cannot measure the downward deflection of the end of the long dummy shaft. Summary of the Invention

[0004] The present invention aims to solve the above technical problems and provides a device for measuring the deflection of a long false shaft for centering and a method for using the device to ensure the accuracy of the centering data.

[0005] The present invention solves the technical problem and adopts the following technical solution:

[0006] A device for measuring the deflection of a long dummy shaft for centering, comprising a long dummy shaft, a dial indicator, and a sleeve, wherein one end of the sleeve is fixedly connected to a blind plate concentric therewith, one end of the long dummy shaft is fixedly connected to an end flange concentric therewith, the long dummy shaft is placed in the sleeve and concentric with the sleeve, and the end flange is tightly connected to the blind plate; a first dial indicator, a second dial indicator, and a third dial indicator are installed between the end of the long dummy shaft away from the end flange and the inner wall of the sleeve, and the measuring rods all contact the inner wall of the sleeve; the first dial indicator and the second dial indicator are symmetrical to the center of the long dummy shaft, and in a measuring state, the axes of the long dummy shaft and the sleeve are horizontal, the axes of the long dummy shaft and the sleeve are horizontal, the line connecting the rotation centers of the pointers of the first dial indicator and the second dial indicator coincides with a plumb line passing through the center of the long dummy shaft, and the line connecting the rotation center of the pointer of the third dial indicator and the center of the long dummy shaft is perpendicular to the plumb line.

[0007] A method for measuring the deflection of a long false shaft for centering, comprising the following steps:

[0008] Step A: The end flange is matched with the centering coupling to be connected, and the end flange is welded to one end of the long fake shaft and is concentric with the long fake shaft;

[0009] Step B, welding a blind plate concentric with one end of the sleeve;

[0010] Step C: Install the long fake shaft into the sleeve, with the end flange on the same side as the blind plate and connected to the blind plate, and the long fake shaft and sleeve concentric

[0011] Step D: Place the sleeve and the long fake shaft upright with the end flange and the blind plate facing downward. Install a first dial indicator, a second dial indicator, and a third dial indicator between the sleeve and the end of the long fake shaft. The first dial indicator and the second dial indicator are symmetrical to the center of the long fake shaft. The line connecting the rotation center of the needle of the third dial indicator and the center of the long fake shaft is perpendicular to the line connecting the rotation centers of the needles of the second and third dial indicators. Adjust the first, second, and third dial indicators so that the measuring rods of the three dial indicators are in good contact with the inner wall of the sleeve and the readings of the three dial indicators are returned to zero.

[0012] Step E: Place the sleeve with the dial indicator installed and the long dummy shaft horizontally so that the line connecting the rotation centers of the needles of the first dial indicator and the second dial indicator coincides with the plumb line passing through the center of the long dummy shaft;

[0013] Step F, read the reading X of the first dial indicator and the reading Y of the second dial indicator, and calculate the downward deflection Z=(X+Y) / 2 of the long fake shaft;

[0014] Step G: When centering the equipment with a long fake shaft, the vertical radial deviation M of the equipment coupling is measured with a centering dial indicator. The actual radial deviation L of the equipment coupling is equal to the radial deviation M minus the lower deflection Z.

[0015] Compared with the prior art, the present invention adopting the above technical solution has the following beneficial effects:

[0016] The device and method of the present invention can quickly and accurately measure the downward deflection of the head of the long dummy shaft when it is in a horizontal state, thereby correcting the centering data, ensuring smooth installation and long-term stable operation of mechanical equipment, especially high-speed equipment, and reducing the failure rate.

[0017] Furthermore, the optimization scheme of the present invention is:

[0018] One end of the long false shaft away from the end flange is retracted into the sleeve.

[0019] The first dial indicator, the second dial indicator and the third dial indicator are all installed on a dial indicator base, and the dial indicator base is magnetically attracted on the long fake shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present invention;

[0021] Figure 2 yes Figure 1 Left view of;

[0022] Figure 3 is a schematic diagram of a long dummy shaft and end flanges according to an embodiment of the present invention;

[0023] Figure 4 yes Figure 3 Left view of;

[0024] Figure 5 A front view of the sleeve and blind plate of an embodiment of the present invention;

[0025] Figure 6 yes Figure 5 Left view of;

[0026] Figure 7 This is a schematic diagram of long false shaft centering according to an embodiment of the present invention;

[0027] Figure 8 Schematic diagram of the rotation direction of the coupling according to an embodiment of the present invention.

[0028] In the figure: long fake shaft 1; end flange 2; sleeve 3; blind plate 4; first dial indicator 5; dial indicator base 5-1; second dial indicator 6; third dial indicator 7; bolt 8; equipment coupling 9; first centering dial indicator 10; second centering dial indicator 11. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below with reference to the accompanying drawings and examples.

[0030] See also Figure 1 、 Figure 2 This embodiment is a device for measuring the deflection of a long dummy shaft for centering, which is mainly composed of a long dummy shaft 1, an end flange 2, a sleeve 3, a blind plate 4, a first dial indicator 5, a second dial indicator 6 and a third dial indicator 7.

[0031] Long fake shaft 1 is a hollow shaft ( Figure 3 、 Figure 4 (As shown), it is made of a round tube with a length of 1200 mm, an outer diameter of 108 mm, and a wall thickness of 4 mm. A circular end flange 2 is welded to the right end of the long dummy shaft 1. End flange 2 is designed to be connected to the centering coupling (not shown). End flange 2 is concentric with the long dummy shaft 1 and has evenly distributed mounting holes.

[0032] The right end of the sleeve 3 is welded with a circular blind plate 4 ( Figure 5 、 Figure 6 As shown in the figure, the blind plate 4 has connecting holes corresponding to the mounting holes of the end flange 2, and the blind plate 4 is concentric with the sleeve 3. The long dummy shaft 1 and the end flange 2 are installed in the sleeve 3, with the end flange 2 facing inward. The end flange 2 and the blind plate 4 are tightly attached and fixed together by bolts 8. The long dummy shaft 1 is concentric with the sleeve 3, and the left end of the long dummy shaft 1 is retracted into the sleeve 3.

[0033] A first, second, and third dial indicators 5, 6, and 7 are mounted between the left end of the long dummy shaft 1 and the inner wall of the left end of the sleeve 3. Each of these indicators is mounted on three dial indicator holders 5-1, each magnetically attached to the long dummy shaft 1. The first and second dial indicators 5, 6 are symmetrical about the center of the long dummy shaft 1. In the measurement state, the line connecting the rotational centers of the pointers of the first and second dial indicators 5, 6, coincides with a plumb line passing through the center of the long dummy shaft 1. The line connecting the rotational center of the pointer of the third dial indicator 7 and the center of the long dummy shaft 1 is perpendicular to the plumb line. The measuring rod of the third dial indicator 7 forms a 90-degree angle with the measuring rods of the first and second dial indicators 5, 6, and 7. The measuring rods of the first, second, and third dial indicators all contact the inner wall of the sleeve 3.

[0034] The method of using the device for measuring the deflection of the long false shaft for centering is as follows:

[0035] Step A: The end flange 2 is matched with the centering coupling to be connected, and the end flange 2 is welded to the long dummy shaft 1, so that the end flange 2 and the long dummy shaft 1 are concentric;

[0036] Step B: Weld the blind plate 4 to the sleeve 3 to ensure that the blind plate 4 and the sleeve 3 are concentric;

[0037] Step C: Install the long dummy shaft 1 and the end flange 2 into the sleeve 3, with the end flange 2 facing inward and the end flange 2 and the blind plate 4 on the same side. The end flange 2 and the blind plate 4 are tightly connected by bolts 8, and the long dummy shaft 1 is concentric with the sleeve 3;

[0038] Step D, place the sleeve 3 and the long fake shaft 1 upright, with the axes of the sleeve 3 and the long fake shaft 1 coinciding with the plumb line, the end flange 2 and the blind plate 4 facing downward, and the first dial indicator 5, the second dial indicator 6 and the third dial indicator 7 installed between the inner wall of the sleeve 3 and the long fake shaft 1, the measuring rods of the three dial indicators all contact the inner wall of the sleeve 3, the first dial indicator 5 and the second dial indicator 6 are symmetrical to the center of the circle of the long fake shaft 1, the line connecting the rotation center of the needle of the third dial indicator 7 and the center of the circle of the long fake shaft 1 is perpendicular to the line connecting the rotation centers of the needles of the first dial indicator 5 and the second dial indicator 6, adjust the first dial indicator 5, the second dial indicator 6 and the third dial indicator 7 so that the measuring rods of the three dial indicators are in good contact with the inner wall of the sleeve 3, and rotate the dials of the three dial indicators to return the readings of the three dial indicators to zero;

[0039] Step E: Slowly lay down the sleeve 3 and the long fake shaft 1 with the dial indicators installed so that they are in a horizontal state, and make the line connecting the rotation centers of the pointers of the first dial indicator 5 and the second dial indicator 6 coincide with the plumb line passing through the center of the long fake shaft 1, and the first dial indicator 5 is located directly below the second dial indicator 6;

[0040] Step F, read the reading X of the first dial indicator 5 and the reading Y of the second dial indicator 6. The reading X of the first dial indicator 5 increases, and the reading Y of the second dial indicator 6 decreases. Calculate the downward deflection Z=(X+Y) / 2 of the long fake shaft. In this embodiment, Z=0.03 mm. The reading of the third dial indicator 7 remains unchanged. The function of the third dial indicator 7 is to monitor whether there is any side deflection while the long fake shaft 1 is deflecting downward.

[0041] Step G: When centering the equipment with the long fake shaft 1 ( Figure 7 、 Figure 8 As shown), the end flange 2 of the long fake shaft 1 is installed on the centering coupling, and the dial indicator seats 5-1 of the first centering dial indicator 10 and the second centering dial indicator 11 are magnetically attracted to the upper and lower parts of the end of the long fake shaft 1 respectively. The first centering dial indicator 10 and the second centering dial indicator 11 are respectively located above and below the equipment coupling 9, and the side measuring rods of the first centering dial indicator 10 and the second centering dial indicator 11 respectively contact the long fake shaft 1 coupling 9. The first centering dial indicator 10 and the second centering dial indicator 11 measure the vertical radial deviation M of the coupling 9, and the radial deviation M is corrected by the lower deflection Z. The actual radial deviation L of the long fake shaft 1 coupling 9 is equal to the radial deviation M minus the lower deflection Z.

[0042] The present invention can quickly and accurately measure the deflection of the end of the long dummy shaft when it is in a horizontal state, thereby correcting the centering data, ensuring smooth installation and long-term stable operation of mechanical equipment, especially high-speed equipment, and reducing the failure rate.

[0043] The above description is only a preferred embodiment of the present invention and does not limit the scope of the present invention. Any equivalent structural changes made using the contents of the present invention description and drawings are included in the scope of the present invention.

Claims

1. A method for measuring the deflection of a long false shaft for centering, comprising the following steps: Step A: The end flange is matched with the centering coupling to be connected, and the end flange is welded to one end of the long fake shaft and is concentric with the long fake shaft; Step B, welding a blind plate concentric with one end of the sleeve; Step C: Install the long dummy shaft into the sleeve, with the end flange on the same side as the blind plate and connected to the blind plate, and the long dummy shaft and the sleeve concentric; Step D: Place the sleeve and the long fake shaft upright with the end flange and the blind plate facing downward. Install a first dial indicator, a second dial indicator, and a third dial indicator between the sleeve and the end of the long fake shaft. The first dial indicator and the second dial indicator are symmetrical to the center of the long fake shaft. The line connecting the rotation center of the needle of the third dial indicator and the center of the long fake shaft is perpendicular to the line connecting the rotation centers of the needles of the second and third dial indicators. Adjust the first, second, and third dial indicators so that the measuring rods of the three dial indicators are in good contact with the inner wall of the sleeve and the readings of the three dial indicators are returned to zero. Step E: Place the sleeve with the dial indicator installed and the long dummy shaft horizontally so that the line connecting the rotation centers of the needles of the first dial indicator and the second dial indicator coincides with the plumb line passing through the center of the long dummy shaft; Step F, read the reading X of the first dial indicator and the reading Y of the second dial indicator, and calculate the downward deflection Z=(X+Y) / 2 of the long fake shaft; Step G: When centering the equipment with a long fake shaft, use a centering dial indicator to measure the vertical radial deviation M of the equipment coupling. The actual radial deviation L of the equipment coupling is equal to the radial deviation M minus the lower deflection Z; The device for measuring the deflection of the long dummy shaft for centering comprises a long dummy shaft and a dial indicator. It also includes a sleeve, one end of the sleeve is fixedly connected to a blind plate concentric with the sleeve, one end of the long fake shaft is fixedly connected to an end flange concentric with the sleeve, the long fake shaft is placed in the sleeve and concentric with the sleeve, and the end flange is tightly connected to the blind plate; The first dial indicator, the second dial indicator and the third dial indicator are installed between the end of the long fake shaft away from the end flange and the inner wall of the sleeve, and the measuring rods all contact the inner wall of the sleeve; the first dial indicator and the second dial indicator are symmetrical to the center of the long fake shaft. In the measuring state, the axis of the long fake shaft and the sleeve is horizontal, the line connecting the rotation centers of the pointers of the first dial indicator and the second dial indicator coincides with the plumb line passing through the center of the long fake shaft, and the line connecting the rotation center of the pointer of the third dial indicator and the center of the long fake shaft is perpendicular to the plumb line.

2. The measuring method of the device for measuring the deflection of a long false shaft for centering according to claim 1, characterized in that: One end of the long false shaft away from the end flange is retracted into the sleeve.

3. The measuring method of the device for measuring the deflection of a long false shaft for centering according to claim 1, characterized in that: The first dial indicator, the second dial indicator and the third dial indicator are all installed on a dial indicator base, and the dial indicator base is magnetically attracted on the long fake shaft.

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