Tachometer

Abstract

The invention discloses a tachometer, and relates to the technical field of rotating speed detection, and the tachometer comprises a housing, an input device, a rotating speed detection device, a detection head, and a power supply assembly. The shell comprises a first shell body, a second shell body and a third shell body, the second shell body is arranged in the third shell body, and the first shell body is arranged in the second shell body; the input device penetrates through the first via hole, the second via hole and the third via hole and is provided with an input rotating shaft, and the rotating speed detection device is used for detecting the rotating speed of the input rotating shaft; the detection head is in transmission connection with the input rotating shaft and can synchronously rotate with the rotating shaft; according to the technical scheme provided by the invention, the housing, the input device, the rotating speed detection device, the detection head and the power supply assembly are arranged in the tachometer, the housing comprises the first housing, the second housing and the third housing, and the electrical elements are installed in the housing, so that the electronic elements in the tachometer work under the protection of the multi-layer housing, and the reliability of the tachometer is improved. And the stability and the reliability of the tachometer are improved.

Description

Technical Field

[0001] This invention relates to the field of rotational speed detection technology, and in particular to a tachometer. Background Technology

[0002] In the production processes of industries such as chemical, petroleum, and coal, a large number of mechanical equipment operate in explosive environments filled with flammable and explosive gases and dust, such as pumps in oil refineries and ventilation fans in coal mines. The rotational speed of these devices directly affects production efficiency and operational safety. Abnormal rotational speed may lead to equipment failure, material leakage, or even serious accidents such as explosions. A tachometer is an instrument used to measure the rotational speed of moving parts. Contact tachometers measure the rotational speed or linear velocity of the object being measured through their own contact joint, and are widely used in industrial equipment, automobile manufacturing, and machinery maintenance. In existing technologies, tachometers are mostly suitable for ordinary environments, but when applied in explosive environments, electrical sparks and static electricity generated by electrical components can easily become ignition sources for explosions. Therefore, in the face of complex and harsh industrial environments, the stability and reliability of traditional tachometers are poor, easily affected by factors such as high temperature, high humidity, and strong electromagnetic interference, and easily damaged by factors such as electrical sparks and static electricity, resulting in inaccurate measurement data and failing to provide reliable data for equipment operation. Summary of the Invention

[0003] The main objective of this invention is to provide a tachometer that aims to improve the stability and reliability of the tachometer.

[0004] To achieve the above objectives, the tachometer proposed in this invention includes: a housing, an input device, a speed detection device, a detection head, and a power supply assembly; the housing includes a first shell, a second shell, and a third shell, the second shell being disposed within the third shell, the first shell being disposed within the second shell, the first shell having a first through hole, the second shell having a second through hole corresponding to the first through hole, and the third shell having a third through hole corresponding to the second through hole; the input device is disposed through the first through hole, the second through hole, and the third through hole, and the input device has an input shaft extending outside the housing and rotatable, the input device being sealed and connected to the first through hole, the second through hole, and the third through hole respectively; the speed detection device is installed in the first shell, and the speed detection device is used to detect the speed of the input shaft; one end of the detection head is drively connected to the input shaft, and the other end of the detection head is detachably connected to the rotating shaft of the test piece to rotate synchronously with the rotating shaft; the power supply assembly is installed in the first shell, and the power supply assembly is electrically connected to the speed detection device.

[0005] In one embodiment, the input device includes: a fourth housing, an end cap, an input shaft, and a bearing; the fourth housing is provided with a first through hole, a second through hole, and a third through hole, and has an opening facing away from the outer housing; the bottom wall of the fourth housing has a first clearance hole along the axial direction of the input shaft; the end cap covers the opening, and the end cap has a second clearance hole along the axial direction of the input shaft; the input shaft is provided with the first clearance hole and the second clearance hole, and the input shaft is rotatably connected to the first clearance hole and the second clearance hole; a magnetic element is provided in the input shaft, and the magnetic element is signal-connected to the speed detection device; the bearing is sleeved on the outside of the input shaft to rotate synchronously with the input shaft.

[0006] In one embodiment, the input shaft includes a first input segment, a second input segment, and a third input segment arranged sequentially along the axial direction; an elastic element is provided between the first input segment and the second input segment, with both ends of the elastic element abutting against the first input segment and the second input segment respectively; an elastic element is provided between the second input segment and the third input segment, with both ends of the elastic element abutting against the second input segment and the third input segment respectively; and the detection head is detachably connected to the end of the first input segment away from the third input segment.

[0007] In one embodiment, a plurality of first limiting blocks are provided at one end of the first input segment near the second input segment. The first limiting blocks are spaced apart along the circumference of the first input segment, and the interval between any two adjacent first limiting blocks forms a first limiting groove. A plurality of second limiting blocks corresponding to the first limiting groove are provided at one end of the second input segment near the first input segment. The second limiting blocks are spaced apart along the circumference of the second input segment, and the second limiting blocks are inserted into the first limiting groove one-to-one.

[0008] And / or, the third input segment is provided with a plurality of third limiting blocks at one end near the second input segment, the third limiting blocks are arranged at intervals along the circumference of the third input segment, and the interval between any two adjacent third limiting blocks forms a second limiting groove. The second input segment is provided with a plurality of fourth limiting blocks corresponding to the second limiting groove at one end near the third input segment, the fourth limiting blocks are arranged at intervals along the circumference of the second input segment, and the fourth limiting blocks are inserted into the second limiting groove one-to-one.

[0009] In one embodiment, the input device further includes a cleaning assembly, which includes a support and at least one cleaning brush. The cleaning brush includes a handle and bristles at one end of the handle. The support is mounted on the fourth housing, and the end cap has a through hole for the handle to pass through. The cleaning brush is slidably disposed in the through hole. The end of the handle away from the bristles abuts against the support. When the detection head is mounted on the input shaft, the bristles abut against the side wall of the detection head.

[0010] In one embodiment, the rotational speed detection device includes a mounting base and a detection element. The detection element is mounted in the first housing via the mounting base. The detection element is spaced along the axial direction of the input shaft at one end of the input shaft near the first housing. The detection element is signal-connected to the magnetic component.

[0011] In one embodiment, the first housing includes a first body and a first end cap detachably connected to the first body, the first housing having a first opening facing one side, the first end cap closing onto the first opening;

[0012] And / or, the second housing includes a second body and a second end cap detachably connected to the second body, the second body having a second opening that opens toward a side close to the first opening, the second end cap closing onto the second opening;

[0013] And / or, the third housing includes a third body and a third end cap detachably connected to the third body, the third body having a third opening that opens toward a side close to the second opening, the third end cap closing onto the third opening;

[0014] The vias are respectively opened on the side walls of the first body, the second body, and the third body.

[0015] In one embodiment, the power supply assembly includes a mounting bracket and a power supply, the power supply being mounted in the first housing via the mounting bracket, and the speed detection device being electrically connected to the power supply.

[0016] In one embodiment, the tachometer further includes a display component, which includes a circuit component and a button component electrically connected to the circuit component. The circuit component is installed in the first housing and is electrically connected to the power supply component. The housing also has a display port and a button port. The display port is located on the housing corresponding to the display screen, and the button component is installed on the housing corresponding to the button port.

[0017] In one embodiment, the detection head includes a first connecting part and a second connecting part connected to each other. The end of the first connecting part away from the second connecting part is detachably connected to the input shaft, and the end of the second connecting part away from the first connecting part is detachably connected to the rotation shaft of the test piece.

[0018] The second connecting portion is spherical; or, the second connecting portion is disc-shaped; or, the second connecting portion is conical.

[0019] The technical solution of this invention employs a tachometer comprising a housing, an input device, a speed detection device, a detection head, and a power supply assembly. The housing includes a first housing, a second housing, and a third housing. The second housing is located within the third housing, and the first housing is located within the second housing. The first housing has a first through hole, the second housing has a second through hole corresponding to the first through hole, and the third housing has a third through hole corresponding to the second through hole. The input device is sealed and installed within the first, second, and third through holes. The input device has an input shaft that can rotate synchronously with the rotational axis of the workpiece under test to detect the speed of the workpiece. The remaining electrical components are installed within the housing. Under the protection of multiple layers of housing, the electronic components in the tachometer can operate in harsher industrial testing environments, thereby improving the stability and reliability of the tachometer. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of an embodiment of the tachometer provided by the present invention;

[0022] Figure 2 This is an exploded structural diagram of an embodiment of the tachometer provided by the present invention;

[0023] Figure 3 This is another exploded structural diagram of an embodiment of the tachometer provided by the present invention;

[0024] Figure 4 This is an exploded structural diagram of the input shaft in one embodiment of the tachometer provided by the present invention.

[0025] Explanation of icon numbers:

[0026] 100. Tachometer; 1. Housing; 11. First housing; 111. First through hole; 112. First body; 113. First end cap; 12. Second housing; 121. Second through hole; 122. Second body; 123. Second end cap; 13. Third housing; 131. Third through hole; 132. Third body; 133. Third end cap; 2. Input device; 21. Input shaft; 211. First input section; 211a. First limiting block; 212. Second input section; 212a. Second limiting block; 212b. Fourth limiting block; 213. Three input segments; 213a, third limit block; 214, elastic element; 22, fourth housing; 23, end cap; 231, second clearance hole; 232, through hole; 24, bearing; 25, cleaning assembly; 251, support; 252, cleaning brush; 252a, brush handle; 252b, brush bristles; 3, speed detection device; 31, mounting base; 32, detection element; 4, detection head; 41, first connecting part; 42, second connecting part; 5, power supply assembly; 51, fixing frame; 52, power supply; 6, display assembly; 61, circuit assembly; 62, button assembly.

[0027] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0030] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0031] In the production processes of industries such as chemical, petroleum, and coal, a large number of mechanical equipment operate in explosive environments filled with flammable and explosive gases and dust, such as pumps in oil refineries and ventilation fans in coal mines. The rotational speed of these devices directly affects production efficiency and operational safety. Abnormal rotational speed may lead to equipment failure, material leakage, or even serious accidents such as explosions. A tachometer is an instrument used to measure the rotational speed of moving parts. Contact tachometers measure the rotational speed or linear velocity of the object being measured through their own contact joint, and are widely used in industrial equipment, automobile manufacturing, and machinery maintenance. In existing technologies, tachometers are mostly suitable for ordinary environments, but when applied in explosive environments, electrical sparks and static electricity generated by electrical components can easily become ignition sources for explosions. Therefore, in the face of complex and harsh industrial environments, the stability and reliability of traditional tachometers are poor, easily affected by factors such as high temperature, high humidity, and strong electromagnetic interference, and easily damaged by factors such as electrical sparks and static electricity, resulting in inaccurate measurement data and failing to provide reliable data for equipment operation.

[0032] This invention proposes a tachometer 100.

[0033] Please see Figures 1 to 4In one embodiment of the present invention, the tachometer 100 includes: a housing 1, an input device 2, a speed detection device 3, a detection head 4, and a power supply assembly 5; the housing 1 includes a first housing 11, a second housing 12, and a third housing 13, the second housing 12 being disposed within the third housing 13, the first housing 11 being disposed within the second housing 12, the first housing 11 having a first through hole 111, the second housing 12 having a second through hole 121 corresponding to the position of the first through hole 111, and the third housing 13 having a third through hole 131 corresponding to the position of the second through hole 121; the input device 2 passes through the first through hole 111, the second housing 12 having a second through hole 12 ... the third housing 13 having a third through hole 131. Two through holes 121 and a third through hole 131 are provided. The input device 2 has an input shaft 21 that extends out of the housing 1 and is rotatable. The input device 2 is sealed to the first through hole 111, the second through hole 121 and the third through hole 131 respectively. The speed detection device 3 is installed in the first housing 11 and is used to detect the speed of the input shaft 21. One end of the detection head 4 is drivenly connected to the input shaft 21, and the other end of the detection head 4 is used to be detachably connected to the rotating shaft of the test piece so as to rotate synchronously with the rotating shaft. The power supply assembly 5 is installed in the first housing 11 and is electrically connected to the speed detection device 3.

[0034] In this embodiment, the outer shell 1 is arranged in three layers from the inside out. The multi-layered outer shell 1 can provide multiple layers of protection for the internal electrical components. Even if the outer layer of protection is damaged, the operator can detect and repair it in time. The electrical components installed inside the outer shell 1 can be effectively protected, enabling the tachometer 100 to be used stably in relatively harsh environments, such as explosions and high temperatures, thus improving the stability and reliability of the tachometer 100. Among them, the first shell 11 of the explosion-proof tachometer 100 is made of polyimide film and ceramic material, which is a material with high insulation and high temperature resistance to prevent the heat and sparks generated by the internal electrical components from being transferred to the outside. The second shell 12 is made of 304 stainless steel or higher strength metal material to form a high-strength metal protective layer in the middle layer of the outer shell 1, increasing the strength of the outer shell 1 and avoiding deformation from impacts and collisions during use. The third shell 13 adopts a composite multi-structure, including a primer layer, an intermediate layer, and a surface layer. The coating consists of two layers: a primer layer applied to the inner side of the intermediate layer, i.e., the side of the intermediate layer closest to the second housing 12, and a topcoat layer applied to the outer side of the intermediate layer; the primer layer is coated with an epoxy zinc-rich material with a thickness of 20-50 μm and a zinc content of ≥90% to provide electrochemical protection; the intermediate layer uses 50-100 μm thick glass fiber to reinforce the epoxy resin in the inner layer and improve its impermeability; the topcoat layer uses 30-50 μm thick fluorocarbon coating or polyurethane to provide the housing 1 with UV resistance and chemical corrosion resistance. The circuit assembly 61 located inside the housing 1 is cast according to the requirements of standard GB / T 3836.9-2021, and the circuit assembly 61 is covered by epoxy resin encapsulation to meet the explosion-proof requirements of this standard. By using multiple materials to create a multi-layered shell with different protective properties, the outer shell 1 can resist damage of various types. Then, according to current standards, the circuit component 61 is cast with epoxy resin. With this setup, the explosion-proof tachometer 100 can meet the requirements of Ex db mb IICT6 Gb and can be used in Zone 1 of hazardous areas with explosive gas atmospheres. The protection level reaches IP68, thus enabling stable operation in harsh environments.

[0035] Furthermore, the tachometer 100 has an input device 2, which is disposed through a first through hole 111, a second through hole 121, and a third through hole 131, and is sealed to multiple through holes. The sealing includes gas sealing, liquid sealing, and dust sealing to further prevent harmful components in the environment from entering through gaps between the inner wall of the through holes and the input device 2, further protecting the internal electrical components. The input device 2 has a rotatable input shaft 21, which can extend out of the housing 1 for transmission connection with a detection head 4. The detection head 4 is detachably connected to the rotational shaft of the workpiece under test. The rotation of the rotational shaft drives the detection head 4 to rotate synchronously, thereby driving the input shaft 21 to rotate synchronously. The rotational speed of the input shaft 21 is measured by the detection device inside the tachometer 100, thus obtaining the rotational speed of the workpiece under test.

[0036] Furthermore, the detection head 4 is detachably connected to the input shaft 21, allowing the tachometer 100 to replace the detection head 4 with different sizes and shapes as needed to adapt to different equipment. The connection between the detection head 4 and the rotating shaft can be abutment or threaded connection, etc. When the detection head 4 abuts against the rotating shaft, the end face of the rotating shaft near the detection head 4 has a groove that mates with the detection head 4. The detection head 4 can partially extend into the groove to abut against it or to have an interference fit. The friction between the detection head 4 and the groove drives the detection head 4 to rotate. In this case, the outer layer material of the detection head 4 can be made of a material with high friction, such as silicone, to increase the friction between the detection head 4 and the rotating shaft. When the outer wall of the rotating shaft has threads, a corresponding threaded hole can be opened in the detection head 4 along the axial direction. After screwing the rotating shaft into the threaded hole, the detachable connection between the detection head 4 and the rotating shaft can be achieved.

[0037] The technical solution of the present invention employs a tachometer 100 comprising a housing 1, an input device 2, a speed detection device 3, a detection head 4, and a power supply assembly 5. The housing 1 includes a first housing 11, a second housing 12, and a third housing 13. The second housing 12 is disposed within the third housing 13, and the first housing 11 is disposed within the second housing 12. The first housing 11 has a first through hole 111, the second housing 12 has a second through hole 121 corresponding to the position of the first through hole 111, and the third housing 13 has a third through hole 131 corresponding to the position of the second through hole 121. The input device 2 is sealed and installed in the first through hole 111, the second through hole 121, and the third through hole 131. The input device 2 has an input shaft 21 that can rotate synchronously with the rotation axis of the workpiece under test to detect the speed of the workpiece under test. The remaining electrical components are installed in the housing 1. Under the protection of the multiple layers of housing 1, the electronic components in the tachometer 100 can operate in harsher industrial testing environments, thereby improving the stability and reliability of the tachometer 100.

[0038] In one embodiment, the input device 2 includes: a fourth housing 22, an end cap 23, an input shaft 21, and a bearing 24; the fourth housing 22 is provided with a first through hole 111, a second through hole 121, and a third through hole 131, and has an opening facing away from the outer casing 1; the bottom wall of the fourth housing 22 is provided with a first clearance hole along the axial direction of the input shaft 21; the end cap 23 is provided over the opening, and the end cap 23 is provided with a second clearance hole 231 along the axial direction of the input shaft 21; the input shaft 21 is provided with the first clearance hole and the second clearance hole 231, and the input shaft 21 is rotatably connected to the first clearance hole and the second clearance hole 231; a magnetic element (not shown) is provided in the input shaft 21, and the magnetic element is signal-connected to the speed detection device 3; the bearing 24 is sleeved on the outside of the input shaft 21 to rotate synchronously with the input shaft 21.

[0039] See Figure 2 , Figure 3 In this embodiment, the fourth housing 22 is provided with the first through hole 111, the second through hole 121, and the third through hole 131. The outer wall of the fourth housing 22 is sealed to the inner walls of the first through hole 111, the second through hole 121, and the third through hole 131 to prevent gases, liquids, or dust from the industrial environment from entering the tachometer 100. The fourth housing 22 has an opening for the input shaft 21 and bearings 24 to enter and be fixed inside the housing. The end cover 23 then closes the opening to prevent the components inside the fourth housing 22 from falling out and to protect the internal components. The bottom of the fourth housing 22 has a first clearance hole along the axial direction, and the middle of the end cover 23 has a second clearance hole 231 along the axial direction. The first clearance hole and the second clearance hole 231 are coaxially arranged so that when the input shaft 21 passes through the first clearance hole and the second clearance hole 231, the rotation of the input shaft 21 is not affected, and the shaft can be limited by the first clearance hole and the second clearance hole 231. The bearing 24 is sleeved on the outside of the input shaft 21 and is connected to the input shaft 21 for transmission, so that the bearing 24 and the input shaft 21 rotate synchronously. The bearing 24 can support the input shaft 21 and prevent the input shaft 21 from wearing with other structural components during rotation. A magnetic component is embedded inside the input shaft 21. When the input shaft 21 rotates synchronously with the test piece, the magnetic component rotates with the input shaft 21 and generates a change in the magnetic field pole during rotation. The rotational speed of the input shaft 21 can be measured by detecting the change in the magnetic field pole of the magnetic component, thereby obtaining the rotational speed of the test piece.

[0040] See Figure 3 , Figure 4In one embodiment, the input shaft 21 includes a first input segment 211, a second input segment 212, and a third input segment 213 arranged sequentially along the axial direction. An elastic element 214 is provided between the first input segment 211 and the second input segment 212, with both ends of the elastic element 214 abutting against the first input segment 211 and the second input segment 212, respectively. The second input segment 212 and the third input segment 213 are also provided with an elastic element 214, with both ends abutting against the second input segment 212 and the third input segment 213, respectively. The detection head 4 is detachably connected to the end of the first input segment 211 furthest from the third input segment 213. The elastic element 214 abuts against adjacent output segments to automatically adjust the contact pressure between the detection head 4 and the rotating shaft of the test piece according to the rotational speed and operating state of the test piece. When the rotational speed is low, the input shaft 21 can appropriately increase the contact pressure to ensure stable signal acquisition; when the rotational speed is high, the input shaft 21 can appropriately reduce the contact pressure to reduce wear and energy loss. This pressure-adaptive structure improves the service life and measurement accuracy of the tachometer 100. Specifically, the third input section 213 has a groove near the second input section 212, where a magnetic component is placed and fixed in place with adhesive, thus securing the magnetic component to the input shaft 21.

[0041] See Figure 3 , Figure 4 In one embodiment, a plurality of first limiting blocks 211a are provided at one end of the first input segment 211 near the second input segment 212. The first limiting blocks 211a are spaced apart circumferentially along the first input segment 211, and the gap between any two adjacent first limiting blocks 211a forms a first limiting groove. A plurality of second limiting blocks 212a corresponding to the first limiting groove are provided at one end of the second input segment 212 near the first input segment 211. The second limiting blocks 212a are spaced apart circumferentially along the second input segment 212, and are inserted one-to-one into the first limiting groove. In the middle; and / or, the third input segment 213 is provided with a plurality of third limiting blocks 213a at one end near the second input segment 212. The third limiting blocks 213a are arranged at intervals along the circumference of the third input segment 213. The interval between any two adjacent third limiting blocks 213a forms a second limiting groove. The second input segment 212 is provided with a plurality of fourth limiting blocks 212b at one end near the third input segment 213. The fourth limiting blocks 212b are arranged at intervals along the circumference of the second input segment 212. The fourth limiting blocks 212b are inserted one-to-one into the second limiting groove.

[0042] In this embodiment, by inserting the second limiting block 212a into the first limiting groove one-to-one, the transmission connection between the first input segment 211 and the second input segment 212 can be realized, so that the first input segment 211 and the second input segment 212 rotate synchronously. The elastic element 214 is disposed in the central cavity formed by the multiple limiting blocks arranged in the circumferential direction. While ensuring the elasticity of the elastic element 214, it can also be limited by the limiting blocks to prevent it from falling out of the cavity. Similarly, by inserting the fourth limiting block 212b into the second limiting groove one-to-one, the transmission connection between the second output segment and the third output segment can be realized, while the elastic element 214 is limited in the central cavity formed by the multiple limiting blocks arranged in the circumferential direction. Thus, while ensuring the transmission connection of multiple output segments, a stable installation space is provided for the elastic element 214, the connection structure between the elastic element 214 and the input end is simplified, and it is convenient for the operator to replace the elastic element 214 when its elasticity is insufficient.

[0043] See Figure 1 , Figure 2 In one embodiment, the input device 2 further includes a cleaning component 25, which includes a support 251 and at least one cleaning brush 252. The cleaning brush 252 includes a handle 252a and bristles 252b disposed at one end of the handle 252a. The support 251 is mounted on the fourth housing 22, and the end cap 23 has a through hole 232 for the handle 252a to pass through. The cleaning brush 252 is slidably disposed in the through hole 232. The end of the handle 252a away from the bristles 252b abuts against the support 251. When the detection head 4 is mounted on the input shaft 21, the bristles 252b abut against the side wall of the detection head 4. Since the detection head 4 is driven to rotate by the rotating shaft of the workpiece during detection, the cleaning device is used to generate friction through the relative movement between the rotation of the detection head 4 and the cleaning brush 252 during the detection process, so that the detection head 4 automatically removes dust, oil and other impurities from its outer surface during rotation to maintain good contact performance. Meanwhile, the device is made of explosion-proof materials to prevent static electricity or sparks from being generated by the friction between the brush bristles 252b and the surface of the detection head 4 during the cleaning process, and the tachometer 100 ensures safe operation in an explosive environment.

[0044] In one embodiment, the rotational speed detection device 3 includes a mounting base 31 and a detection element 32. The detection element 32 is mounted in the first housing 11 via the mounting base 31. The detection element 32 is spaced along the axial direction of the input shaft 21 at one end of the input shaft 21 near the first housing 11. The detection element 32 is signal-connected to the magnetic component. The detection element 32 is fixed in the first housing 11 via the mounting base 31. The detection element 32 is a Hall sensor, which can use the Hall effect to convert the position signal generated during rotation into a potential change signal. When the magnetic lines of force of the magnetic component pass through the sensor, a Hall potential is generated. After amplification and shaping, the Hall potential is converted into an electrical signal for use by the lower-level components.

[0045] See Figure 2 In one embodiment, the first housing 11 includes a first body 112 and a first end cap 113 detachably connected to the first body 112. The first housing 11 has a first opening facing one side, and the first end cap 113 closes to the first opening. And / or, the second housing 12 includes a second body 122 and a second end cap 123 detachably connected to the second body 122. The second body 122 has a second opening facing the side near the first opening, and the second end cap 123 closes to the second opening. And / or, the third housing 13 includes a third body 132 and a third end cap 133 detachably connected to the third body 132. The third body 132 has a third opening facing the side near the second opening, and the third end cap 133 closes to the third opening. Through holes are correspondingly formed on the sidewalls of the first body 112, the second body 122, and the third body 132. The first housing 11, the second housing 12, and the third housing 13 form a multi-layered nested structure to enhance the protection of the electrical components inside the inner housing 1, thereby improving the stability and reliability of the sensor.

[0046] In one embodiment, the power supply assembly 5 includes a mounting bracket 51 and a power supply 52. ​​The power supply 52 is mounted in the first housing 11 via the mounting bracket 51, and the speed detection device 3 is electrically connected to the power supply 52. ​​The power supply 52 is fixed in the housing via the mounting bracket 51 and is used to supply power to the electronic components in the device to ensure the operation of the equipment.

[0047] In one embodiment, the tachometer 100 further includes a display component 6, which includes a circuit component 61 and a button component 62 electrically connected to the circuit component 61. The circuit component 61 is installed in the first housing 11 and is electrically connected to the power supply component 52 5. The housing 1 also has a display port and a button port. The display port is located on the housing 1 corresponding to the display screen, and the button component 62 is installed on the housing 1 corresponding to the button port. The display screen is used to display the rotational speed value measured by the tachometer 100 and other parameters. The button component 62 can control the tachometer 100 to operate or stop in a preset manner through the circuit component 61. The housing 1 is also provided with explosion-proof glass at the location corresponding to the display port to protect the display screen from damage in harsh environments.

[0048] See Figure 2 In one embodiment, the detection head 4 includes a first connecting portion 41 and a second connecting portion 42 connected to each other. The end of the first connecting portion 41 away from the second connecting portion 42 is detachably connected to the input shaft 21, and the end of the second connecting portion 42 away from the first connecting portion 41 is detachably connected to the rotation shaft of the workpiece under test. The second connecting portion 42 is spherical; or, it is disc-shaped; or, it is conical. By setting the second connecting portion 42 of the detection head 4 into various different shapes, the detection head 4 can adapt to the structure of workpieces under test of different sizes and shapes, thereby measuring the rotational speed of more different types of equipment.

[0049] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A tachometer, characterized in that, include: The outer casing includes a first housing, a second housing, and a third housing. The second housing is disposed inside the third housing, and the first housing is disposed inside the second housing. The first housing has a first through hole, the second housing has a second through hole at the position corresponding to the first through hole, and the third housing has a third through hole at the position corresponding to the second through hole. An input device is provided through the first through hole, the second through hole, and the third through hole. The input device has an input shaft that extends out of the housing and is rotatable. The input device is sealed to the first through hole, the second through hole, and the third through hole, respectively. A rotational speed detection device is installed in the first housing, and the rotational speed detection device is used to detect the rotational speed of the input shaft; The detection head has one end connected to the input rotating shaft and the other end detachably connected to the rotating shaft of the workpiece to be tested, so as to rotate synchronously with the rotating shaft. as well as A power supply assembly is installed in the first housing and is electrically connected to the speed detection device.

2. The tachometer as described in claim 1, characterized in that, The input device includes: A fourth housing is provided with the first through hole, the second through hole and the third through hole passing through it. The fourth housing has an opening that opens toward the side opposite to the outer casing. The bottom wall of the fourth housing has a first clearance hole along the axial direction of the input shaft. An end cap is provided over the opening, and the end cap has a second clearance hole along the axial direction of the input shaft; An input shaft is provided, passing through the first clearance hole and the second clearance hole. The input shaft is rotatably connected to the first clearance hole and the second clearance hole. A magnetic element is provided in the input shaft, and the magnetic element is signal-connected to the speed detection device. A bearing is sleeved on the outside of the input shaft to rotate synchronously with the input shaft.

3. The tachometer as described in claim 2, characterized in that, The input shaft includes a first input segment, a second input segment, and a third input segment arranged sequentially along the axial direction; an elastic element is provided between the first input segment and the second input segment, with both ends of the elastic element abutting against the first input segment and the second input segment respectively; an elastic element is provided between the second input segment and the third input segment, with both ends of the elastic element abutting against the second input segment and the third input segment respectively; the detection head is detachably connected to the end of the first input segment away from the third input segment.

4. The tachometer as described in claim 3, characterized in that, The first input segment has a plurality of first limiting blocks at one end near the second input segment. The first limiting blocks are spaced apart along the circumference of the first input segment, and the gap between any two adjacent first limiting blocks forms a first limiting groove. The second input segment has a plurality of second limiting blocks at one end near the first input segment that correspond to the first limiting groove. The second limiting blocks are spaced apart along the circumference of the second input segment, and the second limiting blocks are inserted into the first limiting groove one-to-one. And / or, the third input segment is provided with a plurality of third limiting blocks at one end near the second input segment, the third limiting blocks are arranged at intervals along the circumference of the third input segment, and the interval between any two adjacent third limiting blocks forms a second limiting groove. The second input segment is provided with a plurality of fourth limiting blocks corresponding to the second limiting groove at one end near the third input segment, the fourth limiting blocks are arranged at intervals along the circumference of the second input segment, and the fourth limiting blocks are inserted into the second limiting groove one-to-one.

5. The tachometer as described in claim 3, characterized in that, The input device further includes a cleaning assembly, which includes a support and at least one cleaning brush. The cleaning brush includes a handle and bristles at one end of the handle. The support is mounted on the fourth housing. The end cap has a through hole for the handle to pass through, and the cleaning brush is slidably disposed in the through hole. The end of the handle away from the bristles abuts against the support. When the detection head is mounted on the input shaft, the bristles abut against the side wall of the detection head.

6. The tachometer as described in claim 2, characterized in that, The rotational speed detection device includes a mounting base and a detection element. The detection element is mounted in the first housing via the mounting base. The detection element is spaced along the axial direction of the input shaft at one end of the input shaft near the first housing. The detection element is signal-connected to the magnetic component.

7. The tachometer as described in claim 1, characterized in that, The first housing includes a first body and a first end cap detachably connected to the first body. The first housing has a first opening facing one side, and the first end cap closes to the first opening. And / or, the second housing includes a second body and a second end cap detachably connected to the second body, the second body having a second opening that opens toward a side close to the first opening, the second end cap closing onto the second opening; And / or, the third housing includes a third body and a third end cap detachably connected to the third body, the third body having a third opening that opens toward a side close to the second opening, the third end cap closing onto the third opening; The vias are respectively opened on the side walls of the first body, the second body, and the third body.

8. The tachometer as described in claim 1, characterized in that, The power supply assembly includes a mounting bracket and a power supply. The power supply is mounted in the first housing via the mounting bracket, and the speed detection device is electrically connected to the power supply.

9. The tachometer as described in claim 1, characterized in that, The tachometer also includes a display component, which includes a circuit component and a button component electrically connected to the circuit component. The circuit component is installed in the first housing and is electrically connected to the power supply component. The housing also has a display port and a button port. The display port is located on the housing corresponding to the display screen, and the button component is installed on the housing corresponding to the button port.

10. The tachometer as described in claim 1, characterized in that, The detection head includes a first connecting part and a second connecting part that are connected to each other. The end of the first connecting part away from the second connecting part is detachably connected to the input rotating shaft, and the end of the second connecting part away from the first connecting part is detachably connected to the rotating shaft of the workpiece to be tested. The second connecting portion is spherical; or, the second connecting portion is disc-shaped; or, the second connecting portion is conical.

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