An encoder suitable for extreme temperature environments

Abstract

The present invention relates to the technical field related to encoders, and discloses an encoder suitable for extreme temperature environments, including a shell and an end cover sealed and connected to an opening of the shell, a through hole is provided in the center of the end cover, a first shaft sleeve is rotatably arranged in the through hole, the first shaft sleeve extends into the shell and is connected to a second shaft sleeve, the end cover has a first normal temperature cavity, a laser emitting component is arranged in the first normal temperature cavity, a temperature insulating annular cylinder is arranged in the inner cavity of the shell, the temperature insulating annular cylinder has an annular cavity, a transparent annular cover is sealed and arranged at the annular opening of the annular cavity, the transparent annular cover divides the inner cavity of the shell into a temperature-resistant cavity and a second normal temperature cavity, the temperature-resistant cavity is located between the first normal temperature cavity and the second normal temperature cavity, when the device switches to low temperature resistance, the internal circulation is started, part of the gas in the first normal temperature cavity passes through the air inlet, flows through the heating resistor wire, and flows back to the negative pressure gap through the second air outlet, the hot gas circulates back and forth in the first normal temperature cavity and the second normal temperature cavity, providing a good working temperature for the electronic components.

Description

Technical Field

[0001] The present invention belongs to the technical field related to encoders, and more specifically, particularly relates to an encoder suitable for extreme temperature environments. Background Art

[0002] A photoelectric encoder is a sensor that converts the mechanical geometric displacement on the output shaft into pulses or digital quantities through photoelectric conversion. It uses the principle of grating diffraction to achieve the conversion from displacement to digital. It is mainly composed of a code disk, a light-emitting element, and a photosensitive element. Photoelectric encoders are widely used in various industrial automation systems to measure rotation angles or positions. They detect rotation angles or positions by emitting light and receiving reflected light. The generated electrical signals can be received and processed by the control system to achieve real-time monitoring and control of the rotation speed.

[0003] The photoelectric encoder is an angle measuring device that converts spatial angle information into digital information. However, the current photoelectric encoder has a maximum range of -40~100℃. However, in Antarctic drilling, 10,000-meter deep wells, aerospace and other environments, there are large temperature differences, microwave radiation, electromagnetic field interference, etc., which are not enough to meet the requirements. Therefore, it is necessary to study the structure and materials of the photoelectric encoder code disk, sensor housing materials and sealing materials, the structure of the light emitter and optical path receiving components, the temperature resistance of the materials, the circuit system and the data transmission method under high and low temperature environments. The existing photoelectric encoder still has the following technical problems:

[0004] The existing photoelectric encoder is not equipped with any heat preservation mechanism. Due to the limitations of materials and structures, the existing structure will undergo deformation, stress strain, and dissolution in high and low temperature environments, affecting the accuracy and normal operation of the encoder.

[0005] Therefore, in view of this, the existing structure and defects are studied and improved, and an encoder suitable for extreme temperature environments is provided, in order to achieve a more practical and valuable purpose. Summary of the invention

[0006] The present invention provides an encoder suitable for extreme temperature environments, which is used to overcome the above-mentioned defects in the prior art.

[0007] The purpose and efficacy of an encoder suitable for extreme temperature environments of the present invention are achieved by the following specific technical means: an encoder suitable for extreme temperature environments, comprising a shell and an end cover sealed and connected to an opening of the shell, a through hole being provided at the center of the end cover, a first shaft sleeve being rotatably arranged in the through hole, the first shaft sleeve extending into the shell and being connected to a second shaft sleeve, the end cover having a first normal temperature cavity, a laser emitting element being arranged in the first normal temperature cavity, a temperature insulating annular cylinder being arranged in the inner cavity of the shell, the temperature insulating annular cylinder having an annular cavity, a transparent annular cover being sealed and arranged at the annular opening of the annular cavity, the transparent annular cover dividing the inner cavity of the shell into a temperature resistant cavity and a second normal temperature cavity, the temperature resistant cavity being located between the first normal temperature cavity and the second normal temperature cavity, a code disk being arranged in the temperature resistant cavity, the inner ring of the code disk being fixedly sleeved on the first shaft sleeve, an optical fiber being arranged in connection with the light emitting end of the laser emitting element, the optical fiber extending from the first normal temperature cavity to the temperature resistant cavity A light-transmitting mirror is arranged in the normal temperature cavity, and the end of the optical fiber close to the code disk is provided with a light-transmitting mirror, and an annular circuit board is arranged in the second normal temperature cavity, the first normal temperature cavity has an annular opening facing the first sleeve, the diameter of the first sleeve expands at the annular opening to form an annular convex body, the first sleeve has a first central cavity, and the annular convex body has an air outlet groove, the air outlet groove connects the first central cavity and the first normal temperature cavity, a heating resistance wire is arranged in the wall body of the first normal temperature cavity, a first air outlet is arranged on the side of the second normal temperature cavity facing the second sleeve, the second sleeve has a second central cavity connected with the first central cavity, an air inlet is arranged in the wall body of the second central cavity, the diameter of the second sleeve at the air inlet is smaller than the diameter of the first sleeve at the annular convex body, the air inlet is connected to the first air outlet, a first flow channel is arranged in the wall body of the first normal temperature cavity, a second flow channel is arranged in the wall body of the second normal temperature cavity, and the second flow channel is connected with the first flow channel.

[0008] A further technical solution is that the inner wall of the first constant temperature chamber is fixedly connected to a limiting ring, the limiting ring extends toward the annular convex body, and the limiting ring has an inner conical surface, the annular convex body has an outer conical surface matching the inner conical surface, a negative pressure gap is formed between the inner conical surface and the outer conical surface, and the limiting ring has a cavity for accommodating the heating resistance wire, the wall of the cavity is provided with an air inlet and a second air outlet, the air inlet is connected to the first constant temperature chamber, and the second air outlet is connected to the negative pressure gap.

[0009] A further technical solution is that a central axis is arranged in the first central cavity, an air flow gap is formed between the central axis and the first central cavity, one end of the first sleeve extends to the outside of the outer shell and is fixedly sleeved with an annular disk, the annular disk has a centrifugal exhaust port, and a first ventilation groove connecting the centrifugal exhaust port and the first central cavity is opened on the first sleeve. A switching open loop is fixedly arranged at the position of the central axis located at the first ventilation groove, the switching open loop has a second ventilation groove, and the switching open loop rotates with the central axis to close or open the first ventilation groove, and the diameter of the annular disk is larger than the diameter of the annular convex body.

[0010] A further technical solution is that the central axis passes through the first central cavity and continues to extend into the second central cavity, an air inlet blind hole is opened at one end of the central axis, a ventilation hole is opened on the wall of the air inlet blind hole, the ventilation hole connects the air inlet blind hole with the second central cavity, the opening of the air inlet blind hole is connected to the outside atmosphere, a tail sleeve is fixedly arranged in the second central cavity, the inner wall of the tail sleeve is recessed to form an arc-shaped groove, and the central axis rotates in the tail sleeve to align the ventilation hole with the arc-shaped groove or to stagger the ventilation hole with the arc-shaped groove.

[0011] A further technical solution is that a slider is fixedly arranged on the outer side of the central shaft, the second sleeve has a limiting groove, the slider is confined in the limiting groove, the central shaft is threadedly connected to the first sleeve, a limiting telescopic rod is arranged at one end of the outer shell away from the end cover, the axial end of the limiting telescopic rod can resist the second sleeve to limit the rotation of the second sleeve, and an elastic reset member for pushing the slider to return to its original position is also arranged in the limiting groove.

[0012] According to a further technical solution, a head sleeve is installed at the opening of the first sleeve, the head sleeve has a first internal thread, the center shaft has a first external thread matching the first internal thread, and a tail sleeve is fixedly installed at the opening of the second sleeve, the tail sleeve has a second internal thread, and the center shaft has a second external thread matching the second internal thread.

[0013] A further technical solution also includes a temperature sensor and a control unit. The temperature sensor is installed in the first normal temperature chamber, the control unit is arranged on a ring-shaped circuit board, the signal output end of the temperature sensor is electrically connected to the signal receiving end of the control unit, and the signal output end of the control unit is electrically connected to the limiting telescopic rod.

[0014] A further technical solution is that a plurality of connecting columns are fixedly arranged at the bottom of the insulating annular cylinder, and the ends of the connecting columns are connected to the annular circuit board so that the annular circuit board is suspended in the second normal temperature chamber, and an insulating layer is arranged on the inner wall of the second normal temperature chamber and an insulating layer is arranged on the inner wall of the first normal temperature chamber.

[0015] A further technical solution is that the through hole in the center of the end cover protrudes outward to form a bearing mounting shell, a head bearing is arranged in the bearing mounting shell, the first sleeve passes through the inner ring of the head bearing, a sealing gasket is arranged between the head bearing and the inner wall of the bearing mounting shell, the end of the limit ring extends close to the head bearing to form an abutment portion, and a sealing gasket is arranged at the portion where the abutment portion abuts against the head bearing.

[0016] According to a further technical solution, the inner wall of the housing has an annular groove, a tail bearing is arranged in the annular groove, the second sleeve extends into the inner ring of the tail bearing and is fixedly connected to the inner ring of the tail bearing, and a sealing ring is arranged at the opening of the annular groove.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention can adapt to high-temperature and low-temperature working conditions by arranging internal and external circulations. When the device switches to low-temperature resistance, only the internal circulation is started, and the first sleeve rotates at a high speed driven by the central shaft, and the first sleeve drives the annular convex body to rotate. Since the diameter of the annular convex body is relatively large, the gas in the air outlet slot is subjected to centrifugal action and has a tendency to flow outward into the first normal temperature chamber. The gas in the second normal temperature chamber is drawn into the first normal temperature chamber through the first central chamber, and the gas in the first normal temperature chamber is replenished to the second normal temperature chamber through the first flow channel and the second flow channel in turn, thereby forming a complete internal circulation. The gas in the first normal temperature chamber is heated by the heating resistance wire during the circulation process, so that the temperatures in the first normal temperature chamber and the second normal temperature chamber are kept close to normal temperature, thereby playing a role in resisting low temperature. Use: the annular convex body rotates at a high speed, and the air and the surface of the annular convex body have a certain viscosity. The rotation of the annular convex body can drive part of the gas in the negative pressure gap to flow out to the first constant temperature chamber, and negative pressure is formed in the negative pressure gap. Under the action of the negative pressure, part of the gas in the first constant temperature chamber passes through the air inlet, flows through the heating resistance wire, and flows back to the negative pressure gap through the second air outlet, completing a heating cycle. The hot air circulates back and forth in the first constant temperature chamber and the second constant temperature chamber, providing a good working temperature for the electronic components. The temperature in the temperature-resistant chamber is affected by the first constant temperature chamber and the second constant temperature chamber on both sides, and the temperature adaptability will also be improved. By setting a temperature-resistant chamber and arranging low-temperature resistant optical fibers and code discs in the temperature-resistant chamber, the volume of the chamber used for heating can be reduced and energy consumption can be reduced.

[0019] When the device is switched to the heat dissipation state, the internal circulation and the external circulation are started at the same time, the first sleeve drives the annular disk to rotate at a high speed, the gas in the centrifugal exhaust port is subjected to the centrifugal force, the gas is drawn outward, and the external gas passes through the air inlet blind hole, the ventilation hole, the arc-shaped groove, the first central cavity, the second ventilation groove, the first ventilation groove and the centrifugal exhaust port in turn, forming a flowing gas in the first central cavity. The above-mentioned air flow path is the external circulation. At the same time, the heating resistor wire cuts off the power supply, and the internal circulation between the first normal temperature cavity and the second normal temperature cavity is also carried out synchronously. The internal circulation and the external circulation share the same channel, namely the first central cavity and the second central cavity. Therefore, the cold air supplemented from the outside to the first central cavity and the second central cavity can flow through the internal circulation to cool down, and the hot air flowing into the second central cavity from the air inlet of the internal circulation can also be discharged to the outside through the first central cavity and the centrifugal exhaust port to achieve good heat dissipation function. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0022] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 is a side view of the connecting frame of the present invention;

[0024] Figure 3 is an isometric three-dimensional schematic diagram of the present invention;

[0025] Figure 4 yes Figure 2 Cross-section of the middle AA;

[0026] Figure 5 yes Figure 4 A partial enlarged schematic diagram of

[0027] Figure 6 It is a schematic diagram of the path of the internal circulation of gas in the present invention;

[0028] Figure 7 It is an enlarged schematic diagram of the structure of the annular convex body in the present invention;

[0029] Figure 8 It is a schematic diagram of the path when the internal circulation and external circulation of gas in the present invention work together;

[0030] Fig. 9 yes Figure 4 Sectional view at the middle BB;

[0031] Fig.10 is a cross-sectional view of the limiting groove in the present invention;

[0032] Fig.11 It is a cross-sectional view of the arc-shaped groove in the present invention.

[0033] Description of reference numerals:

[0034] 10 housing, 11 connecting frame, 13 locking ear, 14 fixing ear, 16 end cover, 17 mounting vertical surface, 18 locking bolt, 19 tail bearing, 20 head bearing, 21 first sleeve, 22 second sleeve, 23 center axis, 25 temperature insulating annular cylinder, 26 transparent annular cover, 27 first normal temperature cavity, 28 temperature resistant cavity, 29 second normal temperature cavity, 30 laser emitting element, 31 optical fiber, 32 light transmitting mirror, 33 code disk, 34 scale, 35 photosensitive element, 37 annular circuit board, 40 limit groove, 42 sealing ring, 43 first flow channel, 44 first Second flow channel, 45 first air outlet, 46 air inlet, 47 first central cavity, 48 air outlet groove, 49 annular convex body, 50 air inlet, 51 heating resistor, 52 limiting ring, 55 negative pressure gap, 56 second air outlet, 57 annular disk, 58 centrifugal exhaust outlet, 59 head sleeve, 60 first ventilation groove, 61 second ventilation groove, 62 switching open loop, 63 air inlet blind hole, 64 ventilation hole, 65 tail sleeve, 66 arc groove, 67 slider, 70 temperature sensor, 71 limiting telescopic rod, 72 second central cavity, 73 connecting column. DETAILED DESCRIPTION

[0035] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0036] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0037] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] See attached Figure 1 To Attachment Fig.11, an encoder suitable for extreme temperature environment, including a housing 10 and an end cover 16 sealed and connected to the opening of the housing 10, a through hole is provided at the center of the end cover 16, a first shaft sleeve 21 is rotatably arranged in the through hole, the first shaft sleeve 21 extends into the housing 10 and is connected to a second shaft sleeve 22, the end cover 16 has a first normal temperature cavity 27, a laser emitting element 30 is arranged in the first normal temperature cavity 27, an inner cavity of the housing 10 is provided with a temperature-insulating annular cylinder 25, the temperature-insulating annular cylinder 25 has an annular cavity, and at the annular opening of the annular cavity A transparent annular cover 26 is provided to seal the inner cavity of the housing 10, and the transparent annular cover 26 divides the inner cavity of the housing 10 into a temperature-resistant cavity 28 and a second normal temperature cavity 29. The temperature-resistant cavity 28 is located between the first normal temperature cavity 27 and the second normal temperature cavity 29. A code disk 33 is provided in the temperature-resistant cavity 28. The inner ring of the code disk 33 is fixedly sleeved on the first shaft sleeve 21. An optical fiber 31 is connected to the light emitting end of the laser emitting element 30. The optical fiber 31 extends from the first normal temperature cavity 27 into the temperature-resistant cavity 28, and a light-transmitting mirror is provided at the end of the optical fiber 31 close to the code disk 33. 32, an annular circuit board 37 is arranged in the second normal temperature chamber 29, the first normal temperature chamber 27 has an annular opening facing the first sleeve 21, the diameter of the first sleeve 21 expands at the annular opening to form an annular convex body 49, the first sleeve 21 has a first central cavity 47, the annular convex body 49 has an air outlet groove 48, the air outlet groove 48 connects the first central cavity 47 and the first normal temperature chamber 27, a heating resistance wire 51 is arranged in the wall of the first normal temperature chamber 27, and the second normal temperature chamber 29 faces the second sleeve 22. A first air outlet 45 is provided on one side, the second sleeve 22 has a second central cavity 72 connected to the first central cavity 47, an air inlet 46 is provided on the wall of the second central cavity 72, the diameter of the second sleeve 22 at the air inlet 46 is smaller than the diameter of the first sleeve 21 at the annular protrusion 49, the air inlet 46 is connected to the first air outlet 45, a first flow channel 43 is provided on the wall of the first normal temperature cavity 27, a second flow channel 44 is provided on the wall of the second normal temperature cavity 29, and the second flow channel 44 is connected to the first flow channel 43.

[0039] In this embodiment, the code disk 33 is made of high-purity high-temperature resistant quartz, and the working temperature of the code disk is maintained at -100°C~1100°C. The optical fiber 31 uses sapphire optical fiber as the light guide material, which is temperature-resistant at -100°C~1000°C.

[0040] The laser emitting element 30 adopts 450~465nm collimated laser. In this device, sealing material is arranged at the joints. The sealing material is used to seal the first normal temperature chamber 27, the temperature resistant chamber 28 and the second normal temperature chamber 29. The sealing material adopts polyimide material with a temperature resistance range of -200~400℃.

[0041] A photosensitive element 35 is arranged on the annular circuit board 37, and a scale 34 is also arranged between the photosensitive element 35 and the code disk 33. The side of the end cover 16 has mutually opposite mounting vertical surfaces 17. A connecting frame 11 is also arranged on the end cover 16. Fixing ears 14 are symmetrically arranged on the sides of the connecting frame 11. Two symmetrical fixing ears 14 are clamped on the outside of the mounting vertical surface 17. The fixing ears 14 are locked on the mounting vertical surface 17 by locking bolts 18. The side of the connecting frame 11 also has two opposite locking ears 13.

[0042] Preferably, the inner wall of the first constant temperature chamber 27 is fixedly connected to a limiting ring 52, the limiting ring 52 extends toward the annular protrusion 49, and the limiting ring 52 has an inner conical surface, the annular protrusion 49 has an outer conical surface matching the inner conical surface, and a negative pressure gap 55 is formed between the inner conical surface and the outer conical surface. The limiting ring 52 has a cavity for accommodating the heating resistor wire 51, and the wall of the cavity is provided with an air inlet 50 and a second air outlet 56, the air inlet 50 is connected to the first constant temperature chamber 27, and the second air outlet 56 is connected to the negative pressure gap 55.

[0043] Preferably, a central shaft 23 is arranged in the first central cavity 47, and an air flow gap is formed between the central shaft 23 and the first central cavity 47. One end of the first sleeve 21 extends to the outside of the outer shell 10 and is fixedly sleeved with an annular disk 57. The annular disk 57 has a centrifugal exhaust port 58. The first sleeve 21 is provided with a first ventilation groove 60 connecting the centrifugal exhaust port 58 and the first central cavity 47. A switching open loop 62 is fixedly arranged at the position of the central shaft 23 located at the first ventilation groove 60. The switching open loop 62 has a second ventilation groove 61. The switching open loop 62 rotates with the central shaft 23 to close or open the first ventilation groove 60. The diameter of the annular disk 57 is greater than the diameter of the annular protrusion 49.

[0044] Preferably, the center shaft 23 passes through the first center cavity 47 and continues to extend into the second center cavity 72, an air inlet blind hole 63 is provided at one end of the center shaft 23, a ventilation hole 64 is provided on the wall of the air inlet blind hole 63, the ventilation hole 64 connects the air inlet blind hole 63 with the second center cavity 72, the opening of the air inlet blind hole 63 is connected to the outside atmosphere, a tail sleeve 65 is fixedly arranged in the second center cavity 72, the inner wall of the tail sleeve 65 is recessed to form an arc-shaped groove 66, and the center shaft 23 rotates in the tail sleeve 65 to align the ventilation hole 64 with the arc-shaped groove 66 or to stagger the ventilation hole 64 with the arc-shaped groove 66.

[0045] Preferably, a slider 67 is fixedly arranged on the outer side of the central shaft 23, the second sleeve 22 has a limiting groove 40, the slider 67 is confined in the limiting groove 40, the central shaft 23 is threadedly connected to the first sleeve 21, and a limiting telescopic rod 71 is arranged at one end of the outer shell 10 away from the end cover 16, the axial end of the limiting telescopic rod 71 can resist the second sleeve 22 to limit the rotation of the second sleeve 22, and an elastic reset member for pushing the slider 67 to reset is also arranged in the limiting groove 40.

[0046] Preferably, a head sleeve 59 is installed at the opening of the first sleeve 21, the head sleeve 59 has a first internal thread, the center shaft 23 has a first external thread matching the first internal thread, and a tail sleeve 65 is fixedly installed at the opening of the second sleeve 22, the tail sleeve 65 has a second internal thread, and the center shaft 23 has a second external thread matching the second internal thread.

[0047] Preferably, it also includes a temperature sensor 70 and a control unit, the temperature sensor 70 is installed in the first normal temperature chamber 27, the control unit is arranged on the annular circuit board 37, the signal output end of the temperature sensor 70 is electrically connected to the signal receiving end of the control unit, and the signal output end of the control unit is electrically connected to the limiting telescopic rod 71.

[0048] Preferably, a plurality of connecting columns 73 are fixedly arranged at the bottom of the insulating annular cylinder 25, and the ends of the connecting columns 73 are connected to the annular circuit board 37 so that the annular circuit board 37 is suspended in the second normal temperature chamber 29, and an insulating layer is arranged on the inner wall of the second normal temperature chamber 29, and an insulating layer is arranged on the inner wall of the first normal temperature chamber 27.

[0049] Preferably, the through hole in the center of the end cover 16 protrudes outward to form a bearing mounting shell, a head bearing 20 is arranged in the bearing mounting shell, the first sleeve 21 passes through the inner ring of the head bearing 20, a sealing gasket is arranged between the head bearing 20 and the inner wall of the bearing mounting shell, and the end of the limit ring 52 extends close to the head bearing 20 to form an abutment portion, and a sealing gasket is arranged at the portion where the abutment portion abuts against the head bearing 20.

[0050] Preferably, the inner wall of the housing 10 has an annular groove, in which the tail bearing 19 is arranged, the second sleeve 22 extends into the inner ring of the tail bearing 19 and is fixedly connected to the inner ring of the tail bearing 19, and a sealing ring 42 is arranged at the opening of the annular groove.

[0051] Specific use of the present invention:

[0052] The connecting frame 11 is installed on the equipment to be tested. For example, the connecting frame 11 and the housing 10 are installed on the tail of the motor using bolts, and the shaft of the motor is coaxially fixedly connected to the central axis 23 of the device. The motor is started and drives the central axis 23 to rotate. The central axis 23 drives the code disk 33 to rotate in the temperature-resistant chamber 28 through the first sleeve 21. The laser emitting element 30 is started and emits laser. The laser passes through the code disk 33 through the optical fiber 31 and the light-transmitting mirror 32, and the laser further passes through the transparent annular cover 26 into the second normal temperature chamber 29, and is finally detected by the photosensitive element 35 to realize the basic function of the encoder.

[0053] This device has low temperature resistance, and the specific working process is:

[0054] The temperature sensor 70 detects the ambient temperature. When the ambient temperature is lower than the set value, the control unit sends a signal to the limit telescopic rod 71, and the limit telescopic rod 71 extends to abut the first sleeve 21. The center shaft 23 continues to rotate under the drive of the motor, and relative rotation occurs between the center shaft 23 and the first sleeve 21, so that the first ventilation groove 60 and the second ventilation groove 61 are offset, cutting off the connection between the centrifugal exhaust port 58 and the first center cavity 47, and the ventilation hole 64 and the arc groove 66 are also synchronously offset, cutting off the connection between the second center cavity 72 and the air inlet blind hole 63, so that the connection between the first center cavity 47 and the outside is completely cut off, preparing for the subsequent heating internal circulation.

[0055] The first sleeve 21 rotates at a high speed driven by the central shaft 23, and the first sleeve 21 drives the annular convex body 49 to rotate. Since the diameter of the annular convex body 49 is relatively large, the gas in the air outlet slot 48 is subjected to the centrifugal effect and has a tendency to flow outward into the first normal temperature chamber 27. The gas in the second normal temperature chamber 29 is drawn into the first normal temperature chamber 27 through the first central chamber 47, and the gas in the first normal temperature chamber 27 is replenished back to the second normal temperature chamber 29 through the first flow channel 43 and the second flow channel 44 in turn, thereby forming a complete internal circulation. The gas in the first normal temperature chamber 27 is heated by the heating resistor 51 during the circulation process, so that the temperature in the first normal temperature chamber 27 and the second normal temperature chamber 29 is kept close to normal temperature, thereby playing a role in resisting low temperature.

[0056] like Figure 6 As shown, the annular convex body 49 rotates at a high speed, and the air and the surface of the annular convex body 49 have a certain viscosity. The rotation of the annular convex body 49 can drive part of the gas in the negative pressure gap 55 to flow out into the first normal temperature chamber 27, and negative pressure is formed in the negative pressure gap 55. Under the action of the negative pressure, part of the gas in the first normal temperature chamber 27 passes through the air inlet 50, flows through the heating resistor wire 51, and flows back to the negative pressure gap 55 through the second air outlet 56, completing a heating cycle.

[0057] This device also has high-temperature heat dissipation capability, and the specific working process is:

[0058] The temperature sensor 70 detects the ambient temperature. When the ambient temperature is higher than the set value, the control unit sends a signal to the limit telescopic rod 71, and the limit telescopic rod 71 extends to disengage from the first sleeve 21. Under the push of the elastic reset member, the slider 67 drives the center axis 23 to rotate relative to the second sleeve 22 to reset, so that the first ventilation groove 60 and the second ventilation groove 61 are aligned, the centrifugal exhaust port 58 is connected to the first central cavity 47, and the ventilation hole 64 and the arc groove 66 are also synchronously aligned, and the second central cavity 72 is connected to the air inlet blind hole 63.

[0059] The first sleeve 21 drives the annular disk 57 to rotate at high speed, and the gas in the centrifugal exhaust port 58 is subjected to the centrifugal force, and the gas is drawn outward, and the external gas passes through the air inlet blind hole 63, the ventilation hole 64, the arc groove 66, the first central cavity 47, the second ventilation groove 61, the first ventilation groove 60 and the centrifugal exhaust port 58 in sequence, forming a flowing gas in the first central cavity 47. The above-mentioned air flow path is an external circulation. At the same time, the heating resistor wire 51 cuts off the power supply, and the internal circulation between the first normal temperature cavity 27 and the second normal temperature cavity 29 is also carried out synchronously. The internal circulation and the external circulation share the same channel, namely the first central cavity 47 and the second central cavity 72. Therefore, the cold air supplemented from the outside to the first central cavity 47 and the second central cavity 72 can flow through the internal circulation to cool down, and the hot air flowing into the second central cavity 72 from the air inlet 46 can also be discharged to the outside through the first central cavity 47 and the centrifugal exhaust port 58 to achieve a good heat dissipation function.

[0060] The embodiments of the present invention are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

Claims

1. An encoder suitable for extreme temperature environments, comprising a housing and an end cover sealed at an opening of the housing, characterized in that: A through hole is provided at the center of the end cover, and a first shaft sleeve is rotatably arranged in the through hole, the first shaft sleeve extends into the shell and is connected to the second shaft sleeve, the end cover has a first normal temperature cavity, a laser emitting element is arranged in the first normal temperature cavity, a temperature insulating annular cylinder is provided in the inner cavity of the shell, the temperature insulating annular cylinder has an annular cavity, a transparent annular cover is sealed at the annular opening of the annular cavity, the transparent annular cover separates the inner cavity of the shell into a temperature resistant cavity and a second normal temperature cavity, the temperature resistant cavity is located between the first normal temperature cavity and the second normal temperature cavity, a code disk is provided in the temperature resistant cavity, the inner ring of the code disk is fixedly sleeved on the first shaft sleeve, an optical fiber is connected to the light emitting end of the laser emitting element, the optical fiber extends from the first normal temperature cavity into the temperature resistant cavity, and a light transmitting mirror is provided at the end of the optical fiber close to the code disk, an annular circuit board is provided in the second normal temperature cavity, the first A normal temperature cavity has an annular opening facing the first sleeve, the diameter of the first sleeve expands at the annular opening to form an annular convex body, the first sleeve has a first central cavity, the annular convex body has an air outlet groove, the air outlet groove connects the first central cavity and the first normal temperature cavity, a heating resistance wire is arranged in the wall of the first normal temperature cavity, a first air outlet is provided in the second normal temperature cavity on a side facing the second sleeve, the second sleeve has a second central cavity connected to the first central cavity, an air inlet is provided in the wall of the second central cavity, the diameter of the second sleeve at the air inlet is smaller than the diameter of the first sleeve at the annular convex body, the air inlet is connected to the first air outlet, a first flow channel is provided in the wall of the first normal temperature cavity, a second flow channel is provided in the wall of the second normal temperature cavity, and the second flow channel is connected to the first flow channel.

2. The encoder suitable for extreme temperature environment according to claim 1, characterized in that: The inner wall of the first constant temperature chamber is fixedly connected to a limiting ring, the limiting ring extends toward the annular convex body, and the limiting ring has an inner conical surface, the annular convex body has an outer conical surface matching the inner conical surface, a negative pressure gap is formed between the inner conical surface and the outer conical surface, the limiting ring has a cavity for accommodating a heating resistance wire, the wall of the cavity is provided with an air inlet and a second air outlet, the air inlet is connected to the first constant temperature chamber, and the second air outlet is connected to the negative pressure gap.

3. The encoder suitable for extreme temperature environment according to claim 1, characterized in that: A central axis is arranged in the first central cavity, and an air flow gap is formed between the central axis and the first central cavity. One end of the first sleeve extends to the outside of the outer shell and is fixedly sleeved with an annular disk, and the annular disk has a centrifugal exhaust port. A first ventilation groove connecting the centrifugal exhaust port and the first central cavity is provided on the first sleeve. A switching open loop is fixedly arranged at the position of the central axis located at the first ventilation groove, and the switching open loop has a second ventilation groove. The switching open loop rotates with the central axis to close or open the first ventilation groove, and the diameter of the annular disk is larger than the diameter of the annular convex body.

4. The encoder suitable for extreme temperature environment according to claim 3, characterized in that: The central axis passes through the first central cavity and continues to extend into the second central cavity, an air inlet blind hole is provided at one end of the central axis, a ventilation hole is provided on the wall of the air inlet blind hole, the ventilation hole connects the air inlet blind hole and the second central cavity, the opening of the air inlet blind hole is connected to the outside atmosphere, a tail sleeve is fixedly arranged in the second central cavity, the inner wall of the tail sleeve is recessed to form an arc-shaped groove, and the central axis rotates in the tail sleeve to align the ventilation hole with the arc-shaped groove or to stagger the ventilation hole with the arc-shaped groove.

5. The encoder suitable for extreme temperature environment according to claim 4, characterized in that: A slider is fixedly arranged on the outer side of the central shaft, the second sleeve has a limiting groove, the slider is confined in the limiting groove, the central shaft is threadedly connected to the first sleeve, a limiting telescopic rod is arranged at one end of the outer shell away from the end cover, the axial end of the limiting telescopic rod can abut against the second sleeve to limit the rotation of the second sleeve, and an elastic reset member for pushing the slider to return to its original position is also arranged in the limiting groove.

6. The encoder suitable for extreme temperature environment according to claim 5, characterized in that: A head sleeve is installed at the opening of the first sleeve, the head sleeve has a first internal thread, and the center shaft has a first external thread that matches the first internal thread. The tail sleeve is fixedly installed at the opening of the second sleeve, the tail sleeve has a second internal thread, and the center shaft has a second external thread that matches the second internal thread.

7. The encoder suitable for extreme temperature environment according to claim 5, characterized in that: It also includes a temperature sensor and a control unit, the temperature sensor is installed in the first normal temperature chamber, the control unit is arranged on the annular circuit board, the signal output end of the temperature sensor is electrically connected to the signal receiving end of the control unit, and the signal output end of the control unit is electrically connected to the limiting telescopic rod.

8. The encoder suitable for extreme temperature environment according to claim 1, characterized in that: A plurality of connecting columns are fixedly arranged at the bottom of the insulating annular cylinder, and the ends of the connecting columns are connected to the annular circuit board so that the annular circuit board is suspended in the second normal temperature chamber. An insulating layer is arranged on the inner wall of the second normal temperature chamber, and an insulating layer is arranged on the inner wall of the first normal temperature chamber.

9. The encoder suitable for extreme temperature environment according to claim 2, characterized in that: The through hole in the center of the end cover protrudes outward to form a bearing mounting shell, a head bearing is arranged in the bearing mounting shell, the first sleeve passes through the inner ring of the head bearing, a sealing gasket is arranged between the head bearing and the inner wall of the bearing mounting shell, the end of the limit ring extends close to the head bearing to form an abutment portion, and a sealing gasket is arranged at the portion where the abutment portion abuts against the head bearing.

10. The encoder suitable for extreme temperature environment according to claim 1, characterized in that: The inner wall of the housing has an annular groove, a tail bearing is arranged in the annular groove, the second sleeve extends into the inner ring of the tail bearing and is fixedly connected to the inner ring of the tail bearing, and a sealing ring is arranged at the opening of the annular groove.

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