A single-head screw pump stator cavity size measurement system

Abstract

A single-head screw pump stator cavity size measurement system. It mainly solves the problem that the complex inner cavity of the existing screw pump stator cannot be accurately detected. It is characterized in that: the base (1) is provided with a guide rail (2), and the guide rail (2) is respectively provided with a movable stator clamping device and a measuring device, and the stator clamping device is fixed to the screw pump stator (20); the measuring device includes a measuring seat (9), the measuring seat (9) is connected to a measuring hollow rod (10), and the front end of the measuring hollow rod (10) is connected to a rotatable measuring head (6), and the measuring head (6) is connected to a sensor (16) and an encoder (11) via a cable, and the measurement data is transmitted and displayed on an electronic display device (13). The single-head screw pump stator cavity size measurement system can accurately measure the inner diameter of each axial section of the stator cavity, and can also observe the surface of the stator cavity to determine the stator processing and manufacturing accuracy.

Description

Technical Field

[0001] The invention relates to the technical field of oil production engineering, in particular to a system for measuring the inner cavity size of a stator of a single-head screw pump. Background Art

[0002] There are two primary methods for manufacturing the stator of a single-head screw pump for oil production. One involves vulcanizing and bonding rubber within a metal jacket 2-10 meters in length, while the other involves assembling and docking multiple short, directly machined sections of the screw pump stator. Because the stator cavity of the screw pump has a complex, concave-convex double-helical groove with a small, long aperture, its molding and machining accuracy cannot be measured using conventional testing tools. The overall machining accuracy of the stator cavity directly impacts the assembly, performance, and lifespan of the single-head screw pump stator and rotor. If the major diameter, minor diameter, and lead of the stator cavity deviate significantly from the design values, or if the cross-sectional dimensions are poorly uniform, linear mismatch and interference will occur between the rotor and stator. This can lead to unsmooth rotation, jamming, and frictional wear, resulting in high friction loads, low efficiency, and a short service life. In severe cases, it can easily cause stalling.

[0003] Because the inner cavity of a screw pump stator is an elongated, complex, concave-convex double-helical groove, conventional methods are unable to inspect and test the inner cavity's molding accuracy. Instead, the stator is typically sectioned. Currently, manufacturers often rely on empirical comparison methods to measure the inner cavity dimensions of screw pump stators. For example, the test rod comparison method involves turning multiple cylindrical test rods with varying tolerances that approximate the stator's minor diameter. These rods are inserted into the stator bore from both ends of the stator cavity. The cylindrical test rod with the closest dimensions to the stator's inner diameter is used as the stator's minor diameter measurement. The major diameter is determined by measuring the major diameters at both ends of the stator cavity with a caliper and averaging them. This method carries significant measurement errors and is subject to numerous human influences. Using empirical measurements at both ends of the stator cavity as the dimensions of each axial cross-section of the stator cavity does not accurately reflect the dimensions of the stator's inner cavity, hindering product quality assessment and selection. Summary of the Invention

[0004] In order to overcome the problem that the complex inner cavity of the existing screw pump stator cannot be accurately detected, the present invention provides a single-head screw pump stator inner cavity size measurement system. The single-head screw pump stator inner cavity size measurement system can accurately measure the inner diameter of each axial section of the stator inner cavity, and at the same time can also observe the surface condition of the stator inner cavity to determine the stator processing and manufacturing accuracy.

[0005] The technical solution of the present invention is: a single-head screw pump stator inner cavity size measurement system, comprising a base, a guide rail provided on the base, a movable stator clamping device and a measuring device provided on the guide rail, and a screw pump stator fixed on the stator clamping device;

[0006] The measuring device includes a measuring seat, a measuring hollow rod is connected to the measuring seat, a rotatable measuring head is connected to the front end of the measuring hollow rod, and the measuring head is connected to the sensor and encoder through a cable to transmit and display the measured data on an electronic display device.

[0007] A positioning ruler and a grating ruler are respectively provided on the guide rails. The positioning ruler is located at the bottom of the stator clamping device, and the grating ruler is located at the bottom of the measuring device.

[0008] The measuring head includes a rotating body connected to the front end of a measuring hollow rod, the front end of the rotating body is connected to a measuring needle, the measuring needle is connected to a measuring head, and the measuring head is connected to a symmetrically arranged measuring rod; the measuring needle is connected to a sensor.

[0009] The front end of the rotating body is connected to the guide body, and a guide contact is provided on the outer surface of the guide body. The rotating body is located outside the measuring head, and the end of the measuring rod passes through the outer wall of the rotating body.

[0010] The measuring rod includes a long-axis measuring rod and a short-axis measuring rod, and the guide contact includes a long-axis guide contact and a short-axis guide contact; when measuring the long-axis inner cavity in the screw pump stator, the long-axis measuring rod is fixed on the measuring head, and the long-axis guide contact is fixed on the guide body; when measuring the short-axis inner cavity in the screw pump stator, the short-axis measuring rod is fixed on the measuring head, and the short-axis guide contact is fixed on the guide body.

[0011] The helix angle between the apex of the long axis measuring rod and the apex of the long axis guide contact is the same as the helix angle of the long axis of the screw pump stator, and the helix angle between the apex of the short axis measuring rod and the apex of the short axis guide contact is the same as the helix angle of the short axis of the screw pump stator.

[0012] An endoscope is fixed at the front end of the measuring hollow rod, and the endoscope is connected to the electronic display device through an endoscope cable.

[0013] The stator clamping device comprises a plurality of brackets which are slidably connected to the guide rails. A clamping seat is fixed on each bracket, and the stator of the screw pump passes through the clamping seat.

[0014] The sensor is connected to the electronic display device via a sensor cable, and the encoder is connected to the electronic display device via an encoder cable.

[0015] A cavity is provided inside the measuring hollow rod, and the sensor cable and the encoder cable pass through the cavity.

[0016] The present invention has the following beneficial effects: by adopting the above-mentioned scheme, the present invention solves the difficult problem that the complex long cavity of the single-head screw pump stator cannot be accurately detected, improves the accuracy and efficiency of ultra-deep spiral aperture measurement, and is beneficial to improving the manufacturing quality of the screw pump stator; the present invention can not only evaluate the overall processing and manufacturing accuracy of the single-head screw pump stator, but also provide reliable technical means for the reasonable matching of the screw pump stator and rotor, which is beneficial to improving the product quality, performance and life of the screw pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention;

[0018] Figure 2 、 Figure 3 is a schematic diagram of the measuring head;

[0019] Figure 4 This is a schematic diagram of the deck;

[0020] Figure 5 It is a schematic diagram of the measuring seat;

[0021] Figure 6 It is a cross-sectional view of the screw pump stator, where A is a schematic diagram of the long axis inner cavity and B is a schematic diagram of the short axis inner cavity.

[0022] In the figure, 1-base, 2-guide rail, 3-bracket, 4-ruler, 5-card holder, 5-1-top cover, 5-2-top cover bushing, 5-3-base, 5-4-base bushing, 5-5-card holder bolt, 6-measuring head, 6-1-guide body, 6-2-measuring rod, 6-3-measuring head, 6-4-measuring needle, 6-5-connector, 6-6-rotating body, 6-7-guide contact, 6-8-spring, 7-endoscope, 8-grating scale, 9-measuring seat, 9-1-measuring seat bolt, 9-2-bushing, 9-3-housing, 10-measuring hollow rod, 11-encoder, 12-encoder cable, 13-electronic display device, 14-handwheel, 15-support leg, 16-sensor, 17-sensor seat, 18-sensor cable, 19-endoscope cable, 20-screw pump stator. Implementation Method

[0023] The present invention will be further described below in conjunction with the accompanying drawings:

[0024] Depend on Figures 1 to 6As shown, a system for measuring the inner dimensions of a single-head screw pump stator comprises a base 1, on which is mounted a guide rail 2 supported by a plurality of legs 15. A movable stator clamping device and a measuring device are mounted on the guide rail 2, each of which is movable. A positioning scale 4 and a grating scale 8 are mounted on the guide rail 2. The positioning scale 4 is located at the bottom of the stator clamping device and is used to measure the movement distance of the stator clamping device. The grating scale 8 is located at the bottom of the measuring device and measures the movement distance of the measuring device in real time.

[0025] The stator clamping device includes a plurality of brackets 3, which are connected to the guide rail 2 and can slide along the guide rail 2. A holder 5 is fixed to each bracket 3, and the screw pump stator 20 passes through the holder 5. The holder 5 is composed of a top cover 5-1, a top cover bushing 5-2, a base 5-3, a base bushing 5-4, and a holder bolt 5-5. The base 5-3 is fixed to the bracket 3, and a base bushing 5-4 is provided inside the base 5-3. A top cover bushing 5-2 is provided inside the top cover 5-1. The base 5-3 and the top cover 5-1 are connected by a holder bolt 5-5 to fix the screw pump stator 20 to be tested. According to the different outer diameters of the screw pump stator 20 to be tested, top cover bushings 5-2 and base bushings 5-4 of different sizes are installed in combination. The top cover bushings 5-2 and base bushings 5-4 are made of wear-resistant non-metallic materials. According to the different lengths of the screw pump stator 20 to be tested, the holder 5 and the bracket 3 are evenly distributed on the supporting screw pump stator 20. The holder 5 can slide freely on the guide rail 2 through the connected bracket 3, and can also be fixed at a certain position as needed.

[0026] The measuring device includes several measuring seats 9, which are connected to the guide rail 2 via brackets. These seats can slide freely along the guide rail 2 or be fixed in place as needed. Each measuring seat 9 includes a housing 9-3, which houses a self-lubricating bushing 9-2. The housing and bushing are secured with measuring seat bolts 9-1. A hollow measuring rod 10 is located within the bushing 9-3 and passes through each of the measuring seats 9. A rotatable measuring head 6 is connected to the front end of the hollow measuring rod 10. This head 6 is connected to a sensor 16, which is connected to an electronic display device 13 via a sensor cable 18. The device also includes an encoder 11, which is fixed to the last measuring seat 9 and connected to the electronic display device 13 via an encoder cable 12. Measurement results from the measuring head 6 are transmitted and displayed on the electronic display device 13. An endoscope 7, an industrial endoscope, is also fixed to the front end of the hollow measuring rod 10 and connected to the electronic display device 13 via an endoscope cable 19. The electronic display device 13 records, stores, and displays the measured major and minor axis data of each cross-section of the stator's inner cavity, as well as images of the inner cavity surface. The measured data and images can be transmitted to a host computer, mobile phone, or other display device via wired or wireless means to generate SPC graphs or be read via a removable storage medium. A handwheel 14 is fixed to the rear end of the measuring hollow rod 10, which is rotated to advance or retract the measuring hollow rod 10.

[0027] The hollow measuring rod 10 has a cavity inside, through which the sensor cable 18 and the endoscope cable 19 pass. The sensor cable 18 is located at the center of the cavity, and the endoscope cable 19 is located off-center. The hollow measuring rod 10 can be installed as a single rod or in multiple sections, depending on the length of the screw pump stator 20 being measured, to meet measurement requirements.

[0028] The measuring head 6 includes a rotating body 6-6, which is connected to a sensor holder 17, which is connected to the front end of a measuring hollow rod 10. A sensor 16 is located within the sensor holder 17. During measurement, the rotating body 6-6 rotates, while the sensor 16, sensor holder 17, and measuring hollow rod 10 do not rotate synchronously. The front end of the rotating body 6-6 is connected to a stylus 6-4 via a connector 6-5. Stylus 6-4 is connected to a stylus 6-3, which is connected to a symmetrically arranged stylus rod 6-2. The rear end of the stylus 6-4 passes through the connector 6-5 and the rotating body 6-6, making contact with the sensor 16. When measuring the inner cavity of the screw pump stator, the end of the stylus rod 6-2 contacts the inner surface of the stator, and the stylus 6-4 transmits radial changes in the stator cavity to the sensor 16. The front end of the rotating body 6-6 is connected to a guide body 6-1. The rotating body 6-6 is located outside the stylus 6-3, and the end of the stylus rod 6-2 passes through the outer wall of the rotating body 6-6. Several guide contacts 6-7 are symmetrically connected to the outer surface of the guide body 6-1. Springs 6-8 are interposed between the inner ends of the guide contacts 6-7 and the guide body 6-1, providing radial flexibility for the guide contacts 6-7 to adapt to changes in the screw pump stator cavity. The guide body 6-1 ensures that the centerline of the measuring head 6-3 is aligned with the centerline of the screw pump stator 20 when the measuring head 6 moves along the helix angle of the screw pump stator 20.

[0029] The measuring rod 6-2 includes two specifications: a long-axis measuring rod and a short-axis measuring rod. Similarly, the guide contact 6-7 includes a long-axis guide contact and a short-axis guide contact. When measuring the long-axis inner cavity of the screw pump stator 20, the long-axis measuring rod is fixed on the measuring head 6-3, and the long-axis guide contact is fixed on the guide body 6-1. When measuring the short-axis inner cavity of the screw pump stator 20, the short-axis measuring rod is fixed on the measuring head 6-3, and the short-axis guide contact is fixed on the guide body 6-1. The positions of the above-mentioned measuring rods and guide contacts should ensure that: the helix angle between the apex of the long-axis measuring rod and the apex of the long-axis guide contact is the same as the helix angle of the long axis of the screw pump stator, and the helix angle between the apex of the short-axis measuring rod and the apex of the short-axis guide contact is the same as the helix angle of the short axis of the screw pump stator. Correspondingly, the measuring head 6 is set to two specifications according to the long axis and short axis of the stator inner cavity, and is replaced according to measurement needs.

[0030] The method of using the single-head screw pump stator inner cavity size measurement system is as follows:

[0031] 1. Place the screw pump stator 20 to be tested in the holder 5 and secure it with the holder bolts 5-5;

[0032] 2. Start the electronic display device 13, check the system operation, and set the relevant screw pump stator measurement parameters;

[0033] 3. When measuring the short axis of the screw pump stator 20, install the measuring head 6 for measuring the short axis at the front end of the hollow rod 10, and calibrate the probe 6-3 with a micrometer to ensure that the measured value measured by the probe is accurate after being displayed by the sensor and electronic display device in the measurement system. The specific method is as follows: when a certain dimension needs to be measured, fix the micrometer on this dimension, and then calibrate the probe within the micrometer. When the measurement value displayed on the digital display is consistent with the micrometer measurement value, the calibration is completed;

[0034] 4. Hold the hand wheel 14 and slowly push the measuring hollow rod 10 to insert the measuring head 6 into the stator cavity. Measure the minor axis dimensions and corresponding depths of each axial section of the stator cavity.

[0035] 5. After measuring the short axis size of the stator cavity, replace the short axis measuring head at the front end of the hollow rod 10 with the measuring head for measuring the long axis, and calibrate the probe 6-3 with a micrometer;

[0036] 6. Hold the handle 14 and slowly push the measuring hollow rod 10 to insert the measuring head 6 into the stator cavity. Measure the major axis dimensions and corresponding depths of each axial section of the stator cavity.

[0037] 7. If necessary, when measuring the major axis or minor axis size of the screw pump stator 20, you can also use the endoscope 7 to observe and inspect the surface of the screw pump stator 20, and take photos, videos,

[0038] 8. Process and analyze the measured inner cavity dimensions of the screw pump stator 20 to complete the measurement.

Claims

1. A single-head screw pump stator inner cavity size measurement system, comprising a base (1), characterized in that: The base (1) is provided with a guide rail (2), and a movable stator clamping device and a measuring device are respectively provided on the guide rail (2), and a screw pump stator (20) is fixed on the stator clamping device; The measuring device comprises a measuring seat (9), a measuring hollow rod (10) is connected to the measuring seat (9), a rotatable measuring head (6) is connected to the front end of the measuring hollow rod (10), and the measuring head (6) is connected to a sensor (16) and an encoder (11) via a cable, and the measured data is transmitted and displayed on an electronic display device (13); The guide rail (2) is provided with a positioning scale (4) and a grating scale (8), respectively. The positioning scale (4) is located at the bottom of the stator clamping device, and the grating scale (8) is located at the bottom of the measuring device. The measuring head (6) comprises a rotating body (6-6), the rotating body (6-6) being connected to the front end of a measuring hollow rod (10), the front end of the rotating body (6-6) being connected to a measuring needle (6-4), the measuring needle (6-4) being connected to a measuring head (6-3), the measuring head (6-3) being connected to a symmetrically arranged measuring rod (6-2); the measuring needle (6-4) being connected to a sensor (16); the front end of the rotating body (6-6) being connected to a guide body (6-1), the outer surface of the guide body (6-1) being provided with a guide contact (6-7), the rotating body (6-6) being located outside the measuring head (6-3), and the end of the measuring rod (6-2) passing through the outer wall of the rotating body (6-6); An endoscope (7) is fixed to the front end of the measuring hollow rod (10), and the endoscope (7) is connected to the electronic display device (13) via an endoscope cable (19).

2. The single-head screw pump stator inner cavity size measurement system according to claim 1, characterized in that: The measuring rod (6-2) includes a long-axis measuring rod and a short-axis measuring rod, and the guide contact (6-7) includes a long-axis guide contact and a short-axis guide contact; when measuring the long-axis inner cavity in the screw pump stator (20), the long-axis measuring rod is fixed on the measuring head (6-3), and the long-axis guide contact is fixed on the guide body (6-1); when measuring the short-axis inner cavity in the screw pump stator (20), the short-axis measuring rod is fixed on the measuring head (6-3), and the short-axis guide contact is fixed on the guide body (6-1).

3. The single-head screw pump stator inner cavity size measurement system according to claim 2, characterized in that: The helix angle between the apex of the long axis measuring rod and the apex of the long axis guide contact is the same as the helix angle of the long axis of the screw pump stator, and the helix angle between the apex of the short axis measuring rod and the apex of the short axis guide contact is the same as the helix angle of the short axis of the screw pump stator.

4. The single-head screw pump stator inner cavity size measurement system according to claim 1, characterized in that: The stator clamping device comprises a plurality of brackets (3), the brackets (3) being slidably connected to the guide rail (2), a holder (5) being fixed on each bracket (3), and the screw pump stator (20) passing through the holder (5).

5. The single-head screw pump stator inner cavity size measurement system according to any one of claims 1 to 4, characterized in that: The sensor (16) is connected to the electronic display device (13) via a sensor cable (18), and the encoder (11) is connected to the electronic display device (13) via an encoder cable (12).

6. The single-head screw pump stator inner cavity dimension measurement system according to claim 5, characterized in that: A cavity is provided inside the measuring hollow rod (10), and the sensor cable (18) and the encoder cable (12) pass through the cavity.

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