CN209946191U

CN209946191U - Flange type magnetic fluid rotating speed sensor

Info

Publication number: CN209946191U
Application number: CN201920783935.XU
Authority: CN
Inventors: 李翔; 余鹏; 牛小东
Original assignee: Southwest University of Science and Technology
Current assignee: Southwest University of Science and Technology; Southern University of Science and Technology
Priority date: 2019-05-28
Filing date: 2019-05-28
Publication date: 2020-01-14
Anticipated expiration: 2029-05-28

Abstract

The utility model discloses a flange type magnetofluid speed sensor, which comprises a shell, a lower end cover arranged on the shell and an upper end cover provided with a flange plate; the induction electrode is arranged on the shell and used for inducing and recording the on-off times of the current in the speed measuring circuit; the speed measuring shaft is arranged on the shell and penetrates through the shell, the upper end cover and the lower end cover; the speed measuring rotor is arranged in the shell and used for measuring the rotation number of turns of the speed measuring shaft through the on-off times of current; the tachometer rotor comprises a sleeve and an input electrode which is arranged on the sleeve and is provided with a tachometer circuit; a speed measuring cavity for measuring speed is formed among the upper end cover, the lower end cover and the shell, the speed measuring cavity is provided with a certain gap, and magnetic fluid with non-magnetic conductive particles for controlling the on-off of a sensing circuit is arranged in the gap so as to improve the response speed, stability, reliability and economy of the magnetic fluid rotating speed sensor.

Description

Flange type magnetic fluid rotating speed sensor

Technical Field

The utility model relates to a sensor technical field especially relates to a flange formula magnetic current body speed sensor.

Background

A rotation speed sensor is a sensor that converts the rotation speed of a rotating object into an electrical output. In addition, most of the conventional rotating speed sensors need to use precise micro-processing to manufacture a sensor core component, firstly, the sensor needs a complex microstructure in design, secondly, the processing cost required by the special structure is usually very high, and the cost of the whole rotating speed sensor is suddenly increased.

Accordingly, the prior art is yet to be improved and developed.

SUMMERY OF THE UTILITY MODEL

In view of the not enough of above-mentioned prior art, the utility model aims to provide a flange formula magnetic current body speed sensor to solve the problem that current mechanical structure formula speed sensor is unreliable, operational environment requires more, production and processing cost is higher.

The technical scheme of the utility model as follows:

a flange type magnetofluid speed sensor comprises a shell, a lower end cover arranged at the bottom of the shell, and an upper end cover arranged at the top of the shell and provided with a flange; the induction electrode is arranged on the shell and used for inducing and recording the on-off times of the current in the speed measuring circuit; the speed measuring shaft is arranged on the shell and penetrates through the shell, the upper end cover and the lower end cover; the speed measuring rotor is arranged in the shell and used for measuring the rotation number of turns of the speed measuring shaft through the on-off times of current; the tachometer rotor comprises a sleeve and an input electrode which is arranged on the sleeve and is provided with a tachometer circuit; a speed measuring cavity for measuring speed is formed among the upper end cover, the lower end cover and the shell, a certain gap is formed in the speed measuring cavity, and magnetic fluid for controlling the on-off of the sensing circuit is arranged in the gap.

The utility model discloses a further setting, the sleeve is made for magnetic material, the input electrode laminating is in connect tacho circuit's input on the telescopic surface.

According to a further arrangement of the present invention, the magnetic fluid is a magnetic fluid with non-magnetic conductive particles; the shell is made of a non-magnetic material, the sensing electrode is attached to the surface of the shell, and the sensing electrode is externally connected with a speed measuring circuit and used for sensing speed measuring current.

The utility model discloses a further setting, the upper end cover with between the rotor tests the speed and the lower extreme cover with it adjusts the ring all to be provided with the magnetic seal between the rotor to test the speed.

The utility model discloses a further setting, the setting of magnetic seal adjusting ring is in the speed measuring cavity, and be used for the adjustment the size in speed measuring cavity inner space.

The utility model discloses a further setting, the upper end cover with the lower end cover seals in order to form the upper and lower both ends of sensor respectively the cavity of testing the speed, just the upper end cover with the lower end cover all is provided with the seal groove.

The utility model discloses a further setting, the axle that tests the speed is rotational speed input shaft and/or the minor axis through coupling joint rotational speed input shaft.

The utility model discloses a further setting, be provided with on the speed measuring rotor and be used for connecting and transmitting the axle that tests the speed with rotary motion's key between the rotor tests the speed.

The utility model discloses a further setting, the internal surface of the rotor that tests the speed and the surface of the axle that tests the speed all seted up with the feather key keyway of key adaptation.

The utility model discloses a further setting, the sleeve that the sleeve was made for the permanent magnet, it is used for providing magnetic field, and the magnetic field intensity in this magnetic field is greater than 0.1 tesla.

The utility model provides a flange formula magnetic current body speed sensor, the utility model has the advantages of it is following: (1) the magnetic fluid rotating speed sensor has simple structure, compact design and relatively independent parts, and is convenient to maintain and overhaul; (2) the magnetic fluid rotating speed sensor of the utility model has good interchangeability, and can realize modularization, serialization and rapid design; (3) the magnetic fluid rotating speed sensor of the utility model has no special requirements on the working environment and can adapt to various special environments; (4) the utility model utilizes the self characteristics of the magnetic fluid and can adapt to the rotation speed measurement under the condition of high-speed rotation; (5) the sensor has no special requirement on the length size of a sensing area and can be made to be very small. Compared with the prior art, the utility model discloses compact structure, response time is shorter, more traditional pure mechanical structure formula magnetic fluid speed sensor, magnetic fluid speed sensor has simple structure, and the processing cost is lower, and the magnetic fluid has good sealed, heat dissipation and lubricating property again simultaneously, can be applied to dust, under water wait extreme environment, has greatly improved magnetic fluid speed sensor's response speed, stability, reliability and economic nature.

Drawings

Fig. 1 is a perspective view of a middle flange type magnetofluid speed sensor according to the present invention.

Fig. 2 is the schematic diagram of the flange-type magnetofluid speed sensor of the present invention.

Fig. 3 is the schematic structural diagram of the lower end cap and the test shaft in the flange-type magnetofluid speed sensor of the present invention.

Fig. 4 is the assembly schematic diagram of the flange-type magnetofluid speed sensor of the present invention.

Fig. 5 is an enlarged view of a portion a in fig. 4.

Fig. 6 is the schematic view of the speed measuring rotor with input electrode of the flange-type magnetofluid speed sensor of the present invention.

Fig. 7 is the utility model discloses a flange formula magnetic current body revolution speed sensor's test axle and rotor connection schematic diagram that tests the speed.

Fig. 8 is a schematic diagram of the self-assembly experimental result of the nano-copper ball particles under the microscope of the present invention.

Fig. 9 is a schematic view of a sensor housing of the flange-type magnetofluid speed sensor according to the present invention.

Fig. 10 is a schematic view of a flange seal end cover with a seal groove of the flange-type magnetofluid speed sensor of the present invention.

The various symbols in the drawings: 1. a housing; 2. a lower end cover; 3. an upper end cover; 4. a speed measuring shaft; 5. a speed measuring rotor; 51. a sleeve; 52. an input electrode; 6. an induction electrode; 7. a key; 8. a magnetic seal adjusting ring; 9. sealing the groove.

Detailed Description

The utility model provides a flange formula magnetic current body speed sensor, for making the utility model discloses a purpose, technical scheme and effect are clearer, clear and definite, and it is right that the following reference is made to the figure and the example is lifted the utility model discloses further detailed description. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1 to 10, the present invention provides a preferred embodiment of a flange-type mhd speed sensor.

As shown in fig. 1 to 5, a flange-type magnetic fluid speed sensor includes a casing 1 and a lower end cap 2 disposed at the bottom of the casing 1, the casing 1 is mainly used as an external support member of the magnetic fluid speed sensor, and further includes an upper end cap 3 disposed at the top of the casing 1 and provided with a flange, specifically, in order to prevent magnetic materials from affecting the magnetic field distribution of the magnetic fluid speed sensor, the casing 1 is made of non-magnetic materials, similarly, referring to fig. 10, the flange-type upper end cap 3 is also made of non-magnetic materials, and the flange thereon is axially mounted, the casing 1 is further provided with an induction shaft 4 penetrating through the casing 1, the upper end cap 3 and the lower end cap 2, please refer to fig. 6 continuously, the speed sensor further includes an induction electrode 6 disposed on the casing 1 for inducing and recording the number of on-off times of current in a speed measurement circuit, specifically, the sensing electrode 6 is attached to the surface of the housing 1 and is externally connected with a tachometer circuit for sensing tachometer current, and a tachometer rotor 5 arranged inside the housing 1 for measuring the number of revolutions of said tachometer shaft 4 by the number of current make and break, please continue to refer to figure 7, the tacho rotor 5 comprises a sleeve 51 and an input electrode 52 carrying a tacho circuit arranged on the sleeve 51, the sleeve 51 preferably being made of a magnetic material, preferably, the magnetic material is a permanent magnet, the input electrode 52 is attached to the outer surface of the sleeve 51 and connected to the input of the tachometer circuit, as shown in fig. 4, a speed measuring cavity for measuring speed is formed among the upper end cover 3, the lower end cover 2 and the shell 1, a certain gap is formed in the speed measuring cavity, the gap is provided with a magnetic fluid with non-magnetic conductive particles for controlling the on-off of the sensing circuit.

The flange type magnetic fluid speed sensor has the working principle that the sleeve 51 made of magnetic material is used for providing a magnetic field, the ferrofluid mixed with non-magnetic conductive particles can be self-assembled along the direction of a magnetic induction line under the action of a certain magnetic field to form a chain structure, and the chain structure can realize the communication between two circuits, so that the closing and the disconnection of a sensor circuit can be realized by controlling the state of the magnetic fluid changed by the magnetic field. When the speed measuring shaft 4 drives the speed measuring rotor 5 to rotate, the input electrode 52 which is attached to the surface of the sleeve 51 and connected with the input end of the speed measuring circuit can sequentially pass through the induction electrode 6 arranged on the inner wall of the shell 1, the input electrode 52 is connected with the induction electrode 6 through the ferrofluid to realize current conduction, the induction electrode 6 on the shell 1 is set to be one, a plurality of input electrodes 52 are uniformly distributed on the sleeve 51, the number of the input electrodes 52 is the number of times of the current on-off of the rotation circle of the speed measuring rotor 5, so that the number of the rotation of the speed measuring rotor 5 is measured through the number of the current on-off times, and the measurement of the rotating.

Through the technical scheme, the utility model discloses a non-contact magnetic current body speed sensor is compact structure not only, response time is shorter, more traditional pure mechanical structure formula magnetic current body speed sensor, magnetic current body speed sensor simple structure, each part is relatively independent, convenient maintenance and maintenance, good interchangeability has, can realize the modularization, serialization and quick design, utilize magnetic current self characteristic, can adapt to the rotational speed measurement under the high-speed rotatory situation, and the processing cost is lower, the magnetic current body has good sealed again simultaneously, heat dissipation and lubricating property, can be applied to the dust, wait the polar ring under water, magnetic current body speed sensor's response speed has greatly been improved, and high stability, reliability and economic nature.

Further, the size of the speed measuring cavity is designed according to a self-assembly experiment, and the number of the input electrodes 52 of the speed measuring rotor 5 is designed according to the width of the speed measuring cavity and the requirement of measuring the rotating speed, wherein the input electrodes 52 are symmetrically arranged for measuring the rotating speed at a constant speed, and the input electrodes 52 are asymmetrically arranged according to the actual requirement when the rotating speed is accelerated and only part of rotating angles or reciprocating rotation is concerned.

Further, a sensor shell is designed according to the installation environment and the position size, an induction electrode 6 is installed on the inner surface of the sensor shell, the actual effective gap delta of the sensor cavity is adjusted through the thickness of a magnetic seal adjusting ring 8, wherein delta is less than L, and L is the length of the self-assembly chain structure measured through experiments;

the size δ of the cavity gap is determined by the self-assembly experiment in the step S1, and the rotation factor is considered, so the actual size is slightly smaller than the length L of the self-assembly chain structure measured by the experiment, and the value range is L/4< δ < L.

Further, the magnetic fluid is a ferrofluid with non-magnetic conductive particles, the magnetic field strength of the ferrofluid with non-magnetic conductive particles prepared by the water-based magnetic fluid is more than 0.2T (Tesla), the magnetic field strength of the ferrofluid with non-magnetic conductive particles prepared by the oil-based magnetic fluid is more than 0.1T (Tesla), and common materials comprise neodymium iron boron permanent magnets and ferrite permanent magnets.

Referring to fig. 8, the non-magnetic conductive particles are prepared by mixing a certain amount of micro-or nano-scale non-magnetic conductive particles into a temperature-sensitive insulating magnetic fluid, and maintaining the uniform mixture state thereof by a retaining agent (e.g., styrene or phosphate buffer), including nano-scale copper powder, nano-scale aluminum powder, nano-scale silver wires, carbon nanotubes, etc.

Specifically, magnetic fluids of different base carrier fluids are selected for suspension dissolution through the physical and chemical properties of the nonmagnetic micro conductive particles, the temperature-sensitive insulating magnetic fluid has good heat dissipation performance, the temperature-sensitive insulating magnetic fluid is generally commonly used, the commonly used temperature-sensitive insulating magnetic fluid comprises magnetic fluids such as water base, oil base, ester base, fluoroether oil and the like, the base carrier fluid can be prepared by using solvents such as water, engine oil, hydroxy oil and the like, experimental measurement is needed after preparation, and the self-assembly efficiency of self-assembly with the chain length L under the designed magnetic field intensity is required to reach 80%.

The common temperature-sensing insulating magnetofluid comprises magnetofluids such as water-based magnetofluids, oil-based magnetofluids, ester-based magnetofluids, fluoroether oil and the like, the magnetofluids with different magnetization strengths are selected by comprehensively considering the viscosity, pressure and economy of experimental fluids, the higher the magnetization strength is, the more obvious the solid characteristics of the magnetofluids are, the self-assembly efficiency can be greatly improved, meanwhile, the resistance caused by the magnetic viscosity can be greatly increased, and the factors of the resistance caused by the magnetic viscosity and the self-assembly efficiency need to be comprehensively considered during design.

In one embodiment, the gap of the tachometer chamber is mainly used for storing and filling the ferrofluid mixed with the non-magnetic conductive particles, preferably, the size of the gap is between 100 and 500 micrometers, the specific size design needs to be determined according to the specific rotating speed, the gap requirement is smaller when the rotating speed is higher, and the gap requirement is reduced when the rotating speed is lower. Preferably, the sensor has no special requirement on the length size of the sensing area, can be made to be small, and the gap of the sensor cavity can be smaller than 50 microns under the condition that the technology allows.

Further, referring to fig. 2 and 9, magnetic seal adjusting rings 8 for preventing the mixed solution of the magnetic fluid from leaking are disposed between the upper end cover 3 and the tachometer rotor 5 and between the lower end cover 2 and the tachometer rotor 5.

Specifically, the magnetic seal adjusting ring 8 mainly utilizes the characteristic that the magnetic viscosity of the magnetic fluid is increased under the action of a magnetic field, for a water-based magnetic fluid, the magnetic field intensity of the permanent magnet is greater than 0.2T (tesla), for an oil-based magnetic fluid, the magnetic field intensity of the permanent magnet is greater than 0.1T (tesla), and the common materials include neodymium iron boron permanent magnet and ferrite permanent magnet. The clearance of the speed measuring cavity is mainly composed of the inner wall of the shell 1 of the sensor, the upper end cover 3, the lower end cover 2, the magnetic seal adjusting ring 8 and the gap between the speed measuring rotor 5, the mixed solution of the magnetic fluid is arranged in the clearance, and the solution leakage of the magnetic fluid can be effectively prevented through the magnetic seal adjusting ring 8.

Preferably, the magnetic seal adjusting ring 8 is arranged in the speed measuring cavity and used for adjusting the distance between the inner gap of the speed measuring cavity, specifically, the shape and the size of the magnetic seal adjusting ring 8 can be adjusted to a certain extent, so that the distance between the inner gap of the speed measuring cavity can be adjusted.

Further, referring to fig. 2, the upper end cover 3 and the lower end cover 2 are both provided with a sealing groove 9, and the upper end cover and the lower end cover 2 are respectively used for sealing the upper end and the lower end of the sensor to form the speed measuring cavity, specifically, the upper end cover 3 with the sealing groove 9 and the lower end cover 2 are used for sealing an inner space to form the speed measuring cavity, the sealing groove 9 can effectively seal the end face of the sensor, wherein the upper end cover 3 with the sealing groove 9 is provided with an end cover sealing permanent magnet mounting groove for mounting a permanent magnet to further seal the flange plate type upper end cover 3, and a gap of 0.02 to 0.2 mm needs to be left between the permanent magnet and the sealing surface.

Further, the speed measuring shaft 4 is a rotation speed input shaft and/or a short shaft connected with the rotation speed input shaft through a coupling.

Specifically, the speed measuring shaft 4 is made of a non-magnetic material, or a lead layer is plated on the surface of the speed measuring shaft, when the shaft diameter of the measured shaft is large and non-magnetic, the speed can be measured by directly connecting the speed measuring shaft with the key 7, and when the shaft diameter of the measured shaft is weak magnetic and is thin or thick, the shaft coupling is required to be connected to the speed measuring shaft 4.

Preferably, referring to fig. 2, the tachometer rotor 5 is provided with a key 7 for connecting and transmitting the rotational motion between the tachometer shaft 4 and the tachometer rotor 5, and specifically, the key 7 and the tachometer rotor 5 with the input electrode 52 are mounted on the tachometer shaft 4 according to the test position of the input electrode 52 on the tachometer rotor 5 corresponding to the sensing electrode 6.

Preferably, referring to fig. 3 and 7, the inner surface of the tachometer rotor 5 and the outer surface of the tachometer shaft 4 are both provided with a sliding key groove adapted to the key 7.

Specifically, will test the speed rotor 5 and be connected with axle 4 that tests the speed through key 7, its simple structure, conveniently maintain in the maintenance, can adapt to the rotational speed measurement under the high-speed rotatory situation simultaneously, wherein, test the speed axle 4 through key 7 with sleeve 51 connects, and whole sleeve 51 need carry out the disturbance that mechanical dynamic balance test arouses with balanced load.

To sum up, the utility model provides a flange formula magnetic current body revolution speed sensor, foretell non-contact magnetic current body revolution speed sensor is compact structure not only, response time is shorter, more traditional pure mechanical structure formula magnetic current body revolution speed sensor, magnetic current body revolution speed sensor simple structure, each part is relatively independent, convenient maintenance and maintenance, have good interchangeability, can realize the modularization, serialization and quick design, utilize magnetic current self characteristic, can adapt to the rotational speed measurement under the high-speed rotatory situation, this sensor does not have special requirement to the length and size of sensing area, very little that can do, under the condition that the technique allows, the gap of sensor cavity can be less than 50 mu m, and the processing cost is lower, and the magnetic current body has good sealed, heat dissipation and lubricating property again, can be applied to dust, the equal polar ring environment under water, the response speed of magnetic current body revolution speed sensor has greatly been improved, Stability, reliability and economy.

It is to be understood that the invention is not limited to the above-described embodiments, and that modifications and variations may be made by those skilled in the art in light of the above teachings, and all such modifications and variations are intended to be included within the scope of the invention as defined in the appended claims.

Claims

1. A flange type magnetofluid speed sensor comprises a shell and a lower end cover arranged at the bottom of the shell, and is characterized by also comprising an upper end cover which is arranged at the top of the shell and is provided with a flange; the induction electrode is arranged on the shell and used for inducing and recording the on-off times of the current in the speed measuring circuit; the speed measuring shaft is arranged on the shell and penetrates through the shell, the upper end cover and the lower end cover; the speed measuring rotor is arranged in the shell and used for measuring the rotation number of turns of the speed measuring shaft through the on-off times of current; the tachometer rotor comprises a sleeve and an input electrode which is arranged on the sleeve and is provided with a tachometer circuit; a speed measuring cavity for measuring speed is formed among the upper end cover, the lower end cover and the shell, a certain gap is formed in the speed measuring cavity, and magnetic fluid for controlling the on-off of the sensing circuit is arranged in the gap.

2. The sensor of claim 1, wherein the sleeve is made of a magnetic material, and the input electrode is attached to the outer surface of the sleeve and connected to the input end of the tachometer circuit.

3. The sensor of claim 1, wherein the magnetic fluid is a magnetic fluid with non-magnetic conductive particles; the shell is made of a non-magnetic material, the induction electrode is attached to the inner surface of the shell, and the induction electrode is externally connected with a speed measuring circuit and used for inducing speed measuring current.

4. Sensor according to claim 1, characterised in that magnetic sealing adjustment rings are provided both between the upper cover and the tachometer rotor and between the lower cover and the tachometer rotor.

5. The sensor of claim 4, wherein said magnetic seal adjustment ring is disposed within said tachometer cavity and is configured to adjust the size of the gap within said tachometer cavity.

6. The sensor according to claim 1, wherein the upper end cap and the lower end cap respectively seal the upper end and the lower end of the sensor to form the speed measuring cavity, and each of the upper end cap and the lower end cap is provided with a sealing groove.

7. Sensor according to claim 1, wherein the tacho shaft is a tacho input shaft and/or a stub shaft connected to the tacho input shaft by a coupling.

8. Sensor according to claim 7, characterised in that said tachometric rotor is provided with keys for connecting and transmitting the rotary motion between said tachometric shaft and said tachometric rotor.

9. The sensor of claim 8, wherein the inner surface of the tachometer rotor and the outer surface of the tachometer shaft are both provided with a sliding key groove adapted to the key.

10. A sensor according to claim 2, wherein the sleeve is a sleeve of permanent magnets for providing a magnetic field having a field strength greater than 0.1 tesla.