A pumping unit crank speed sensor

Abstract

The utility model discloses a pumping unit crank speed sensor, including core board, and the one end of core board is big head end and the other end is small head end, and big head end assembly has encoder component, and small head end assembly has support component, the encoder component includes metal knurl wheel, encoder rotating shaft, encoder gear and encoder shell, and metal knurl wheel is located on one side surface of core board, and the encoder rotating shaft of metal knurl wheel center is through core board and is connected with the encoder gear on the other side surface of core board, and the encoder gear cover is equipped with encoder shell, the encoder shell is circular, and the four mounting lugs are evenly distributed on the outer edge of shell, make the overall structure smaller, and the pumping unit crank speed sensor of the adaptability under low temperature is improved simultaneously.

Description

Technical Field

[0001] This utility model relates to a crank speed sensor for an oil pumping unit. Background Technology

[0002] In the application of electro-parametric dynamometer diagrams (EPDs) for oil pumping units, most methods employ crank proximity switches for triggering. The switch triggers once per revolution of the crank. While the number of strokes can be calculated from the trigger intervals, it doesn't accurately reveal the rotational speed at every moment, thus failing to distinguish between discrete and continuous rotation. Without continuous rotational speed, the angular acceleration of the crank cannot be accurately determined during crank-driven speed changes, making it impossible to calculate the crank's moment of inertia and perform precise, flexible control. To convert the torque from the motor side into an accurate polished rod dynamometer diagram, it's necessary to accurately measure the displacement of the polished rod and the angular velocity of the crank at every moment, a requirement that traditional crank proximity switch methods cannot meet.

[0003] Currently, in other similar applications, ABZ encoders combined with meter-counting wheels are often used for detection. However, the limited space in the crankshaft of an oil pump makes it impossible to install such products. Utility Model Content

[0004] To address the aforementioned problems, the purpose of this utility model is to provide a crank speed sensor for oil pumping units that results in a smaller overall structure and improves adaptability over a wide temperature range.

[0005] The technical solution for realizing this utility model is as follows: A crank speed sensor for an oil pumping unit includes a core plate, with one end being a large end and the other end being a small end. An encoder assembly is mounted on the large end, and a bracket assembly is mounted on the small end. The encoder assembly includes a knurled metal wheel, an encoder rotating shaft, an encoder gear, and an encoder housing. The knurled metal wheel is located on one side of the core plate, and the encoder rotating shaft at the center of the knurled metal wheel passes through the core plate and connects to the encoder gear on the other side of the core plate. The encoder gear is covered by an encoder housing. The encoder housing is circular, and four mounting protrusions are evenly distributed along its outer edge.

[0006] The bracket assembly includes a bracket fixing shaft, which is embedded in the core plate through a bearing. Its shaft is located on one side of the core plate and on the same side as the metal knurling wheel. An annular step is provided in the center of the bracket fixing shaft.

[0007] A spring is provided on the core plate below the bracket assembly. One end of the spring is installed on one side of the core plate by a spring fixing bolt, and the other end is installed on the outer surface of the bracket fixing shaft by a spring fixing bolt.

[0008] The core plate has two mounting screw holes in the center opposite each other, which are used to cooperate with spring fixing bolts.

[0009] The encoder shaft has a bearing fitted on one end near the encoder gear.

[0010] An encoder fixing shim is provided on the end face of the encoder gear near the encoder housing.

[0011] By adopting the above technical solution, this utility model replaces the proximity switch to achieve the purpose of calculating the continuous crank speed. Furthermore, to adapt to applications on various types of pumping units, a switch-type universal magnetic bracket is used for installation and fixing. The switch-type universal magnetic bracket connects to the bracket's fixed shaft, and its clips clamp and tighten the thinner cylindrical part of the fixed shaft. Opening the switch allows it to be attracted to any ferrous surface with a strong magnetic force. Compared to conventional nut-fixed mounting brackets, this offers greater flexibility in different application scenarios.

[0012] This invention uses an electromagnetic incremental gear encoder to achieve a narrower overall thickness; at the same time, to improve adaptability at low temperatures, a metal knurled wheel is used instead of a polyester amine wheel. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the front structure of this utility model; Figure 2 This is a schematic diagram of the rear structure of the present invention; Figure 3 This is a schematic diagram of the spring structure of this utility model; Figure 4 This is a schematic diagram of the encoder rotating shaft structure of this utility model; Figure 5 This is a schematic diagram of the auxiliary installation bracket structure of this utility model; In the attached diagram, 1 is the core plate, 2 is the knurled metal wheel, 3 is the encoder rotating shaft, 4 is the encoder gear, 5 is the encoder housing, 6 is the bracket fixing shaft, 7 is the annular step, 8 is the spring, 9 is the mounting screw hole, 10 is the bearing, 11 is the encoder fixing gasket, 12 is the auxiliary mounting bracket, 13 is the protrusion, 14 is the assembly slot, 15 is the mounting protrusion, and 16 is the locking block. Detailed Implementation

[0014] A crank speed sensor for an oil pumping unit includes a core plate 1, with a large end and a small end. An encoder assembly is mounted on the large end, and a bracket assembly is mounted on the small end. The encoder assembly includes a knurled metal wheel 2, an encoder rotating shaft 3, an encoder gear 4, and an encoder housing 5. The knurled metal wheel is located on one side of the core plate. The encoder rotating shaft, located in the center of the knurled metal wheel, passes through the core plate and connects to the encoder gear on the other side of the core plate. The encoder gear is covered by the encoder housing. The encoder housing is circular, with four mounting protrusions evenly distributed along its outer edge for installation assistance. The knurled metal wheel in the encoder assembly contacts the crank. The rotation of the crank drives the knurled metal wheel to rotate. Since the knurled metal wheel is connected to the encoder rotating shaft, the encoder rotating shaft drives the encoder gear to rotate, thereby detecting the crank speed. The encoder magnetic gear provides multiple magnetic field detection points. A Hall effect sensor chip located on the encoder housing detects these magnetic field changes and converts them into corresponding electrical signals. Specifically, when the Hall effect sensor chip detects a protruding tooth, it outputs a high-level signal; when it detects a tooth groove, it outputs a low-level signal. By recording the changes in these signal levels, the encoder's rotation angle can be accurately calculated. Because the encoder housing is thin and fits snugly with the encoder gears, the overall structural size can be greatly reduced, facilitating subsequent installation.

[0015] The support assembly includes a support fixing shaft 6, located on one side of the core plate, on the same side as the metal knurled wheel; an annular step 7 is provided in the center of the support fixing shaft. One end of the support fixing shaft, which mates with the core plate, has a cylindrical locking block 16 that engages a deep groove ball bearing and then engages into a hole at the top (gradiently smaller end) of the core plate; the other end of the support fixing shaft is connected to the pumping unit via a switchable universal magnetic support. The annular step ensures that the fixing screw at one end has sufficient space to insert and fix while the other end matches the locking slot on the core plate.

[0016] A spring 8 is installed on the core plate below the bracket assembly. One end of the spring is mounted on one side of the core plate by a spring fixing bolt, and the other end is mounted on the outer surface of the bracket fixing shaft by a spring fixing bolt. After the spring deforms, it provides tangential pressure to the encoder, enabling it to fully contact the crank surface, thereby increasing friction and preventing slippage and signal loss.

[0017] The core plate has two mounting screw holes 9 on one side center, opposite each other, for use with spring fixing bolts. When installing the spring, the installation position can be selected. Because there are two mounting screw holes, the spring installation position can be chosen according to the installation direction and spring size. The ultimate goal is to allow the spring to fully deform and apply a tangential force, ensuring the knurled wheel is fully pressed against the crank and rotates with the crank.

[0018] The encoder shaft is fitted with a bearing 10 at one end near the encoder gear. The bearing rotates the encoder shaft in cooperation with the encoder shaft.

[0019] An encoder fixing shim 11 is provided on the end face of the encoder gear near the encoder housing. The function of the shim is to press the gear tightly onto the bearing, so that the knurled wheel, bearing and encoder form a linkage structure and can rotate synchronously.

[0020] An auxiliary mounting bracket 12, which is annular in shape, is provided between the encoder housing and the core board. The outer edge of the auxiliary mounting bracket and the corresponding position of the mounting protrusion are each provided with a protrusion 13 for assembly with the mounting protrusion. Several assembly slots 14 are evenly distributed along the inner edge of the auxiliary mounting bracket. The encoder housing is fixed to the core board via the auxiliary mounting bracket, and the connection is made more secure by the engagement of the assembly slots with the locking blocks on the inner side of the encoder housing.

Claims

1. A crank speed sensor for an oil pumping unit, characterized in that, The system includes a core board, with one end being a large end and the other end a small end. The large end is equipped with an encoder assembly, and the small end is equipped with a bracket assembly. The encoder assembly includes a knurled metal wheel, an encoder rotating shaft, an encoder gear, and an encoder housing. The knurled metal wheel is located on one side of the core board, and the encoder rotating shaft in the center of the knurled metal wheel passes through the core board and connects to the encoder gear on the other side of the core board. The encoder gear is covered by an encoder housing. The encoder housing is circular, and four mounting protrusions are evenly distributed along the outer edge of the housing.

2. The crank speed sensor for an oil pumping unit according to claim 1, characterized in that, The bracket assembly includes a bracket fixing shaft, which is located on one side of the core plate and on the same side as the metal knurling wheel; the bracket fixing shaft has an annular step in the center.

3. The crank speed sensor for an oil pumping unit according to claim 1, characterized in that, A spring is provided on the core plate below the bracket assembly. One end of the spring is installed on one side of the core plate by a spring fixing bolt, and the other end is installed on the outer surface of the bracket fixing shaft by a spring fixing bolt.

4. The crank speed sensor for an oil pumping unit according to claim 1, characterized in that, The core plate has two mounting screw holes on one side of its center that are used in conjunction with spring fixing bolts.

5. The crank speed sensor for an oil pumping unit according to claim 1, characterized in that, The encoder shaft has a bearing fitted on one end near the encoder gear.

6. The crank speed sensor for an oil pumping unit according to claim 1, characterized in that, An encoder fixing shim is provided on the end face of the encoder gear near the encoder housing.

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