A shaft system structure capable of measuring the axial excitation force of an impeller.

Abstract

This invention relates to a shaft system structure capable of measuring the axial excitation force of an impeller, comprising a main shaft, a force-measuring component, and a conductive slip ring. On the shaft section near the rotating impeller mounting position, a cutting groove 1, a through hole 1, a through hole 2, a through hole 3, and another cutting groove 2 are sequentially arranged axially. Through hole 2 is orthogonal to the axis of the main shaft. Through holes 1 and 3, and cutting grooves 1 and 2 are arranged in an odd-symmetrical manner relative to through hole 2. The main shaft also has a force-measuring component mounting hole, and the axes of the force-measuring component mounting hole, through hole 2, and the main shaft are all orthogonal. A wire lead-out hole is also provided on the main shaft along the axial direction, communicating with the force-measuring component mounting hole. The conductive slip ring is fitted onto the main shaft. The force-measuring component is installed in the force-measuring component mounting hole and includes two strain gauges. The strain gauge wires are connected to the conductive slip ring through the wire lead-out hole, enabling energization and signal acquisition between the moving ring of the conductive slip ring and the strain gauges. This invention can accurately measure the axial excitation force of an impeller.

Description

Technical Field

[0001] This invention relates to the field of rotating impeller monitoring, and more specifically to a shaft system structure capable of measuring the axial excitation force of an impeller. Background Technology

[0002] During the operation of rotating equipment such as propellers, pumps, and fans, the interaction between the impeller and the medium causes the rotating shaft to be constantly subjected to axial excitation forces, which can easily lead to vibration and noise, and in severe cases, affect the stability of the equipment. Therefore, researching sensor structures that can accurately measure the impeller excitation force and thus obtain the impeller excitation mechanical characteristics during the impeller rotation process is particularly important for the design of low-vibration and low-noise turbomachinery.

[0003] Existing methods for measuring impeller excitation force include those that use spring scales or hydraulic devices to balance axial forces and take direct readings, and those that place sensors between the shaft and its mounting structure to transmit the axial force to the sensor's elastic element for measurement. These methods involve force transmission but do not directly measure the force on the shaft, thus their accuracy is difficult to guarantee. Another method involves a cylindrical sensor, which cuts off the main shaft and inserts a cylindrical sensor in the middle to measure the axial and radial excitation forces on the main shaft. This method directly measures the excitation force on the shaft, but it is highly destructive to the main shaft, and ensuring the coaxiality of the pump shaft and sensor during installation is difficult. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention proposes a shaft system structure capable of measuring the axial excitation force of an impeller. Through integrated layout and structural optimization, the dynamic axial force of the impeller during operation can be measured without altering the original shaft system components of the rotating equipment. The specific technical solution is as follows:

[0005] A shaft system structure capable of measuring the axial excitation force of an impeller includes a main shaft for mounting a rotating impeller, a force measuring component, and a conductive slip ring;

[0006] The area on the shaft section of the main shaft near the mounting position of the rotating impeller is the measurement area. Within the measurement area, there are cutting groove one, through hole one, through hole two, through hole three, and cutting groove two arranged sequentially along the axial direction. The axis of through hole two is orthogonal to the axis of the main shaft. Through hole one and through hole three are arranged in an odd-symmetrical manner with respect to through hole two. Cutting groove one and cutting groove two are arranged in an odd-symmetrical manner with respect to through hole two.

[0007] The main shaft is also provided with a force measuring component mounting hole, and the axis of the force measuring component mounting hole is orthogonal to the axis of the through hole and the axis of the main shaft.

[0008] The main shaft is also provided with a wire lead-out hole extending along the main shaft axis, and the wire lead-out hole is connected to the force measuring component mounting hole;

[0009] The conductive slip ring is sleeved on the main shaft and includes a stationary ring and a moving ring; the force measuring component is installed in the force measuring component mounting hole, and the force measuring component includes two strain gauges. The wires of the strain gauges are connected to the conductive slip ring through the wire lead-out hole. The moving ring of the conductive slip ring is energized and the strain gauges are used for signal acquisition.

[0010] Furthermore, the force measuring component also includes mounting cylinders at both ends and a measuring partition between the two mounting cylinders. Two strain gauges are attached to the same side of the measuring partition, with one strain gauge being attached in a direction parallel to the axis of the mounting cylinder and the other strain gauge being attached in a direction perpendicular to the axis of the mounting cylinder.

[0011] The mounting cylinder is interference-fitted with the mounting hole of the force measuring component.

[0012] Furthermore, the force measuring component mounting hole includes a cylindrical mounting hole and cylindrical lugs located on both sides of the cylindrical mounting hole, which are used to pass through the strain gauge wires when the cylindrical mounting is installed.

[0013] Furthermore, after the force measuring component is connected to the main shaft, it is fixed with tempered adhesive; the gap between the wire and the hole is sealed with waterproof sealant.

[0014] The beneficial effects of this invention are as follows:

[0015] This invention modifies the main shaft on which the rotating impeller is installed by drilling through holes and cutting grooves on the shaft section near the installation position of the rotating impeller, and arranges the through holes and cutting grooves in an odd symmetrical manner. A force measuring component is set in this area, so that the main shaft will undergo appropriate deformation under the action of the impeller excitation force, and the axial excitation force of the impeller can be accurately measured.

[0016] In this invention, the sensor's force measurement position is set at the shaft center. Since torque does not produce strain at the center of the circular shaft, interference from the torque on the shaft on the axial force measurement can be avoided. This invention directly measures the axial excitation force of the rotating spindle itself, resulting in higher data reliability compared to existing solutions. Attached Figure Description

[0017] Figure 1 This is an assembly diagram of the shaft system structure of the present invention capable of measuring the axial excitation force of the impeller.

[0018] Figure 2 An enlarged view of the main axis.

[0019] Figure 3 This is the main sectional view along the main axis.

[0020] Figure 4 A top view with the main axis as the axis.

[0021] Figure 5 This is a schematic diagram of the force measuring component.

[0022] Figure 6 This is a schematic diagram of a Wheatstone half-bridge circuit consisting of two strain gauges and a force measuring instrument.

[0023] In the figure, 1 is the main shaft, 2 is the force measuring component, 3 is the conductive slip ring, 101 is the first cutting groove, 102 is the first through hole, 103 is the second through hole, 104 is the third through hole, 105 is the second cutting groove, 106 is the mounting hole for the force measuring component, 107 is the lead-out hole for the wire, 201 is the mounting cylinder, 202 is the measuring partition, 203 is the strain gauge, 106-1 is the cylindrical mounting hole, and 106-2 is the cylindrical lug hole. Detailed Implementation

[0024] The present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. The purpose and effects of the present invention will become clearer. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0025] like Figure 1 As shown, one embodiment of the shaft system structure of the present invention capable of measuring the axial excitation force of an impeller includes a main shaft 1, a force measuring component 2, and a conductive slip ring 3.

[0026] Among them, such as Figures 2-4 As shown, the main shaft 1 replaces the original cylindrical shaft on which the rotating impeller is mounted. This main shaft 1 is a stepped shaft, and the area on the shaft section near the impeller mounting position is the measurement area. Within the measurement area, there are cutting groove 101, through hole 102, through hole 2 103, through hole 3 104, and cutting groove 2 105 arranged sequentially along the axial direction. Through hole 2 is located in the middle. The axis of through hole 2 103 is orthogonal to the axis of the main shaft 1. Through holes 102 and 3 104 are arranged with odd symmetry relative to through hole 2 103. Cutting groove 101 and cutting groove 2 105 are also arranged with odd symmetry relative to through hole 2 103. The depth of cutting groove 101 and cutting groove 2 105 is equal to the axial radius of the main shaft 1.

[0027] The spindle 1 is also provided with a force measuring component mounting hole 106. The force measuring component mounting hole 106 includes a cylindrical mounting hole 106-1 and cylindrical ear holes 106-2 located on both sides of the cylindrical mounting hole 106-1. The cylindrical ear holes 106-2 are used to pass through the strain gauge wire.

[0028] The axis of the force measuring component mounting hole 106 is orthogonal to the axis of the through hole 2 103 and the axis of the main shaft 1. That is, the axis of the force measuring component mounting hole 106, the axis of the through hole 2 103, and the axis of the main shaft 1 intersect at the same point, pointing to the three perpendicular directions of the coordinate axes respectively.

[0029] The main shaft 1 is also provided with a wire lead-out hole 107 extending along the main shaft axis. The wire lead-out hole 107 is connected to the force measuring component mounting hole 106 and is used for the lead-out of the strain gauge wire on the force measuring component.

[0030] The conductive slip ring 3 is mounted on the spindle 1 and includes a stationary ring and a moving ring.

[0031] like Figure 5 As shown, the force measuring component 2 is installed in the force measuring component mounting hole 106. The force measuring component 2 includes mounting cylinders 201 at both ends, a measuring partition 202 between the two mounting cylinders 201, and two strain gauges 203. The upper and lower planes of the measuring partition 202 are parallel to the axis of the mounting cylinders 201. After the mounting cylinders 201 are installed on the spindle 1, the upper and lower planes of the measuring partition 202 are perpendicular to the axis of the spindle 1. The two strain gauges 203 are pasted on the same side of the measuring partition 202, with one strain gauge pasted in a direction parallel to the axis of the mounting cylinders 201 and the other strain gauge pasted in a direction perpendicular to the axis of the mounting cylinders 201; the two strain gauges deform when the overall structure is subjected to axial force. The mounting cylinders 201 and the force measuring component mounting hole 106 are interference-fitted. After the force measuring component 2 is installed in the force measuring component mounting hole 106 of the spindle, it is fixed with tempered glue, and the gap between the wire and the hole is sealed with waterproof sealant. The wires of the two strain gauges 203 are led out through the wire lead-out hole 107 on the main shaft 1 and led out along the through hole on the side of the main shaft 1 to connect with the conductive slip ring 3. The conductive slip ring 3 connects to the strain gauges through the acquisition card to realize signal acquisition.

[0032] like Figure 6 As shown, the wires of the two strain gauges 203 are led out and connected to a force measuring instrument, forming a Wheatstone half-bridge circuit. The bridge circuit outputs the strain response based on the deformation of the strain gauges. To obtain the correspondence between the strain response and the axial excitation force, sensor calibration is required. That is, on the calibration platform, the force measuring instrument is connected, and different weights are suspended at the impeller end. The curves corresponding to the strain signal and the weights are plotted. After linear fitting, the proportionality coefficient Kz between strain and force is determined by the slope of the curve.

[0033] During the test, the axial force is calculated based on the strain response output by the strain bridge using the scaling factor Kz.

[0034] It will be understood by those skilled in the art that the above descriptions are merely preferred examples of the invention and are not intended to limit the invention. Although the invention has been described in detail with reference to the foregoing examples, those skilled in the art can still modify the technical solutions described in the foregoing examples or make equivalent substitutions for some of the technical features. All modifications and equivalent substitutions made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A shaft system structure capable of measuring the axial excitation force of an impeller, characterized in that, This includes the main shaft for mounting the rotating impeller, force measuring components, and conductive slip rings; The area on the shaft section of the main shaft near the mounting position of the rotating impeller is the measurement area. Within the measurement area, there are cutting groove one, through hole one, through hole two, through hole three, and cutting groove two arranged sequentially along the axial direction. The axis of through hole two is orthogonal to the axis of the main shaft. Through hole one and through hole three are arranged in an odd-symmetrical manner with respect to through hole two. Cutting groove one and cutting groove two are arranged in an odd-symmetrical manner with respect to through hole two. The main shaft is also provided with a force measuring component mounting hole, and the axis of the force measuring component mounting hole is orthogonal to the axis of the through hole and the axis of the main shaft. The main shaft is also provided with a wire lead-out hole extending along the main shaft axis, and the wire lead-out hole is connected to the force measuring component mounting hole; The conductive slip ring is sleeved on the main shaft and includes a stationary ring and a moving ring; the force measuring component is installed in the force measuring component mounting hole, and the force measuring component includes two strain gauges. The wires of the strain gauges are connected to the conductive slip ring through the wire lead-out hole. The moving ring of the conductive slip ring is energized and the strain gauges are used for signal acquisition. The force measuring component also includes mounting cylinders at both ends and a measuring partition between the two mounting cylinders. Two strain gauges are attached to the same side of the measuring partition, with one strain gauge being attached in a direction parallel to the axis of the mounting cylinder and the other strain gauge being attached in a direction perpendicular to the axis of the mounting cylinder.

2. The shaft system structure capable of measuring the axial excitation force of an impeller according to claim 1, characterized in that, The mounting cylinder is interference-fitted with the mounting hole of the force measuring component.

3. The shaft system structure capable of measuring the axial excitation force of an impeller according to claim 2, characterized in that, The force measuring component mounting hole includes a cylindrical mounting hole and cylindrical lug holes located on both sides of the cylindrical mounting hole, which are used to pass through the strain gauge wires when the cylindrical mounting is installed.

4. The shaft system structure capable of measuring the axial excitation force of an impeller according to claim 2, characterized in that, After the force measuring component is connected to the main shaft, it is fixed with tempered glue; the gap between the wire and the hole is sealed with waterproof sealant.

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