Current insulation blocking device and processing and manufacturing method and application thereof

Abstract

The invention discloses a current insulation blocking device which comprises an annular gap formed in an electric conductor, an inner electric conductor and an outer electric conductor, the inner electric conductor and the outer electric conductor are separated due to the arrangement of the annular gap, a plurality of mounting grooves communicated with the annular gap are formed in one end of the annular gap, and the inner diameter of the mounting grooves is larger than that of the annular gap. A ceramic insulating pin is arranged in the mounting groove; the invention further provides a processing and manufacturing method of the current insulation blocking device and a motor comprising the current insulation blocking device. The current insulation blocking device has the advantages of being simple in structure, higher in mechanical performance, insulating performance and weather resistance, high in matching and positioning precision, good in size stability, convenient to replace and maintain, longer in service life, capable of guaranteeing reliable application of a transmission system in the whole life cycle and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical insulation, and in particular to a current insulation blocking device, a processing and manufacturing method thereof, and an application thereof. Background Art

[0002] Bearing and gear electrical corrosion failures have always been a major industry technical problem that has plagued motor and gearbox transmission systems, seriously affecting the reliable operation of transmission systems. With the increase in motor power and the use of inverter modulation technology, the problem of bearing and gear electrical corrosion has become particularly prominent. Therefore, when designing motors and gearboxes, measures must be taken to block the shaft current circuit to prevent bearing and gear electrical corrosion failures and ensure the reliability of the transmission system. To prevent bearing and gear electrical corrosion, the industry currently generally uses insulating blocking structures such as insulating bearings, insulating bearing seats, insulating end covers or insulating flanges to block the shaft current circuit.

[0003] Practice shows that insulating bearings have a good insulation effect on the low-frequency current generated by the motor itself, but due to the thin insulation layer, generally <1mm, the insulation effect on high-frequency shaft current cannot be guaranteed, especially for large bearings, the insulation impedance is small, the capacitance is large, and the insulation effect is poor. In addition, the manufacturing cost of large insulating bearings is expensive and the manufacturing process is complicated, so large bearings generally rarely use insulating bearings to prevent bearing electrical corrosion. The insulating bearing seat is to add an insulating blocking structure between the outer ring of the bearing and the bearing seat, and the insulating end cover is to add an insulating blocking structure between the bearing seat and the end cover, thereby blocking the electrical path formed by the bearing, the bearing seat and the end cover to avoid bearing electrical corrosion. The insulating bearing seat or insulating end cover is an insulating structure proposed based on stationary non-rotating parts. The insulating components are all made of organic insulating materials such as non-weft tape, fiber composite laminated tube and laminate. The insulating flange is for the integrated system of the generator gearbox of the semi-direct-drive wind turbine. The generator does not have an independent shaft system (including bearings). During the operation of the generator, the generator rotor, shaft system and gearbox bearing constitute an electrical path, and there is a risk of electrical corrosion of the gearbox bearing and gear, which is an insulating structure proposed based on the rotating parts. The insulating flange is an insulating component added between the rotor bracket and the hollow shaft of the gearbox. In addition to bearing the gravity and vibration of the generator like the insulating components of the stationary parts, the insulating components also bear rotational torque and centrifugal force, etc. The working conditions are worse than those of the insulating components of the stationary parts. The insulating components are also made of organic insulating materials such as non-weft tapes, fiber composite laminated tubes and laminates.

[0004] The current insulating blocking structures such as insulating end covers, insulating bearing seats and insulating flanges are insulated between the two conductors’ matching stoppers and connecting bolts. The matching stoppers use non-weft tapes or fiber composite laminated tubes, and the connecting bolts use fiber composite laminated tubes and laminated boards. The insulating structure has three functions. First: insulation, blocking shaft current. The current insulating structure can block shaft current to a certain extent, but they are all made of insulating organic materials such as non-weft tapes, fiber composite laminated tubes and laminated boards, and the thickness of the insulating layer is generally ≤6mm. The insulating performance of the insulating material will be greatly reduced after being damp. Second: load-bearing function. The bolts at the static insulating structure mainly play a tightening role, mainly bearing the gravity and vibration of the motor; the connecting bolts at the rotating insulating structure also need to bear the harsh working conditions such as rotational torque and centrifugal force. The insulating material is an organic material, and its mechanical strength, environmental weather resistance and creep resistance are average, which can easily cause material failure and loosen the bolts at the insulation connection, resulting in a high risk of use; Third: The insulating structure at the joint of the conductor plays a role in matching and positioning. The insulating material is an organic material, and its material dimensional stability is poor, deformation is large, and matching accuracy is low, which causes the coaxiality of the stator and rotor to decrease, and the unilateral magnetic pull and centrifugal force of the generator to increase, resulting in increased vibration and noise of the generator. In addition, the existing insulation structure is inconvenient to replace and maintain, which can easily lead to damage to the insulation structure at the joint. With the increase of motor power and the extension of motor service life, the mechanical life, electrical life and aging durability of the existing insulation structure are extremely worrying. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a current insulation blocking device and its processing and manufacturing method and its application, which has the advantages of simple structure and stronger mechanical properties, insulation properties and weather resistance, high matching positioning accuracy, good dimensional stability, convenient replacement and maintenance, longer service life, and can ensure reliable operation of the transmission system throughout its life cycle.

[0006] The technical solution provided by the present invention is as follows: A current insulation blocking device comprises an annular gap formed on a conductor and an inner conductor and an outer conductor separated by the setting of the annular gap, one end of the annular gap is provided with a plurality of mounting grooves penetrating the annular gap, the inner diameter of the mounting groove is larger than the inner diameter of the annular gap, and a ceramic insulating pin is provided in the mounting groove.

[0007] Preferably, the inner diameter of the annular gap is not less than 6 mm.

[0008] Preferably, the ceramic insulating pin is arranged in the mounting groove by means of an interference fit connection.

[0009] Preferably, a pressure plate is fixedly provided at the connection end surface between the ceramic insulating pin and the outer conductor, and at the connection end surface between the ceramic insulating pin and the inner conductor.

[0010] Preferably, the pressing plate is an annular structure.

[0011] Preferably, the annular gap is naturally filled with insulating air or filled with insulating glue.

[0012] A method for manufacturing the above-mentioned current isolation and blocking device comprises the following steps: S1. Before processing, the inner conductor and the outer conductor are a whole, the whole is processed as a blank, several installation grooves are processed in place, and then a ring gap with a certain thickness is processed; S2. Install the ceramic insulating pin into the installation groove; S3, machining the annular gap through and separating the inner conductor and the outer conductor; S4. The entire current insulation blocking device is finely processed to eliminate installation deformation and ensure the coaxiality of the inner and outer conductors and the accuracy of accessories.

[0013] A motor, wherein the above-mentioned current insulation and blocking device or the current insulation and blocking device prepared by the above-mentioned preparation method is installed on the stationary part of the motor.

[0014] Preferably, the current insulation blocking device described above or the current insulation blocking device prepared by the above-mentioned manufacturing method is installed between the bearing seat and the end cover of the motor; the end cover of the motor and the outer conductor constitute an integral structure, and the inner conductor and the bearing seat of the motor constitute an integral structure; or the end cover of the motor and the outer conductor are connected by a bolt assembly, and the bearing seat of the motor and the inner conductor are connected by a bolt assembly.

[0015] A motor, wherein the above-mentioned current insulation and blocking device or the current insulation and blocking device prepared by the above-mentioned manufacturing method is installed on the rotating part of the motor.

[0016] Preferably, the above-mentioned current insulation blocking device or the current insulation blocking device prepared by the above-mentioned manufacturing method is installed between the rotor bracket and the gear box of the motor; the flange of the motor and the inner conductor form an integral structure, and the rotor bracket of the motor and the outer conductor form an integral structure; or the flange of the motor and the inner conductor are connected by a bolt assembly; the rotor bracket of the motor and the outer conductor are connected by a bolt assembly.

[0017] The present invention has the following advantages over the prior art: 1. The annular gap between the inner conductor and the outer conductor of the current insulation blocking device of the present invention can be set as required. Generally, the gap is set to be ≥6mm. The mechanical properties of the present invention are not affected by the thickness of the annular gap between the inner conductor and the outer conductor. Since the annular gap that plays a major insulating role in the present invention is larger in size and has a smaller capacitance, it can better block the shaft current loop, thereby ensuring that the bearings and gears are completely free from the risk of electrical corrosion.

[0018] 2. The current insulation blocking device of the present invention adopts ceramic insulating pins to connect the inner conductor and the outer conductor. The ceramic insulating pins are inorganic materials with excellent mechanical properties, insulation properties and weather resistance, thereby ensuring the reliability of the transmission system throughout its life cycle; at the same time, the ceramic insulating pins are inorganic materials with good dimensional stability and strong material creep resistance.

[0019] 3. For rotating insulating parts, the connecting bolts at the joint of the insulating structure of the existing scheme not only have to withstand the gravity and vibration of the motor, but also need to withstand the harsh working conditions such as rotational torque and centrifugal force. The insulating material is an organic material, and its mechanical strength, environmental weather resistance and creep resistance are average, which can easily cause material failure, resulting in loosening of the bolts at the insulating connection at the joint, and the use risk is high; while the connecting bolts at the joint of the conductor in the current insulation blocking device of the present invention only play a connecting and tightening role, and the transmission torque is achieved through the ceramic insulating pin, thereby optimizing the force of the connecting bolts at the joint, and greatly reducing the risk of loosening of the connecting bolts.

[0020] 4. The insulating structure at the joint of the conductor in the existing scheme plays a role in matching and positioning. The insulating material is an organic material with poor dimensional stability, large deformation, and low matching accuracy, which can easily cause the coaxiality of the stator and rotor to decrease, increase the unilateral magnetic pull and centrifugal force of the generator, and increase the vibration and noise of the generator. However, the joint of the conductor of the present invention is a direct steel-to-steel match without an insulating structure. In addition, the insulating structure of the present invention is an integral fine-processing after assembly, and the coaxiality of the inner and outer conductors is good, and the matching accuracy is high, which can ensure the accuracy and coaxiality of the conductor joint, thereby reducing the vibration and noise of the motor.

[0021] 5. The existing insulation components are composed of organic materials such as non-weft belts, fiber composite laminated tubes and laminated boards. The insulation components at the flange joints are easily damaged during replacement and maintenance. However, the present invention has no insulation components at the joints, which makes replacement and maintenance simple and convenient, and the insulation structure will not be damaged. The current insulation blocking device of the present invention can be used not only on the stationary parts of the motor, but also on the rotating parts of the motor, and has a good effect of suppressing shaft current, thereby avoiding electrical corrosion of moving parts (such as bearings, gears, etc.). BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present 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 recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 Schematic diagram of the structure of the current insulation blocking device in an embodiment of the present invention; Figure 2 It is an AA cross-sectional view in an embodiment of the present invention; Figure 3 It is an enlarged view of point Ⅰ in the embodiment of the present invention; Figure 4 It is an enlarged view of point II in the embodiment of the present invention; Figure 5 It is a structural schematic diagram of a current insulation blocking device installed on a stationary part of a small motor in an embodiment of the present invention; Figure 6 It is a structural schematic diagram of a current insulation blocking device installed on a stationary part of a large motor in an embodiment of the present invention; Figure 7 It is a structural schematic diagram of a current insulation blocking device installed on a rotating part of a small motor in an embodiment of the present invention; Figure 8 It is a structural schematic diagram of a current insulation blocking device installed on a rotating component of a small motor in an embodiment of the present invention.

[0024] Reference numerals: 1. Annular gap; 2. Inner conductor; 3. Outer conductor; 4. Ceramic insulating pin; 5. Pressure plate; 6. Bearing seat; 7. Rotor bracket; 8. End cover; 9. Bolt assembly; 10. Flange. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0026] like Figure 1-8As shown, an embodiment of the present invention provides a current insulation blocking device, including an annular gap 1 opened on a conductor and an inner conductor 2 and an outer conductor 3 separated by the setting of the annular gap 1, one end of the annular gap 1 is provided with a plurality of mounting grooves penetrating the annular gap 1, the inner diameter of the mounting groove is larger than the inner diameter of the annular gap 1, and a ceramic insulating pin 4 is provided in the mounting groove.

[0027] In this embodiment, the inner conductor 2 and the outer conductor 3 are made of metal materials, such as steel, aluminum, aluminum alloy, etc.; the ceramic insulating pin 4 is made of ceramic insulating material, such as aluminum oxide, silicon carbide, zirconium oxide and other ceramic materials. Considering the machinability, the ceramic insulating pin 4 is generally a solid or hollow cylindrical pin structure, and can also be a conical pin, a rectangular pin, a cube pin, an arc pin, a polyhedron pin, etc. The number of ceramic insulating pins 4 is preferably three or more, which are arranged uniformly or unevenly in the installation groove in the circumferential direction.

[0028] In this embodiment, the inner diameter of the annular gap 1 is preferably not less than 6 mm, which plays a role in completely blocking the shaft current loop. The inner diameter of the annular gap 1 can be set as required. The annular gap 1 is naturally filled with isolated air or potted with insulating glue to play an insulating and sealing role. The center line of the installation groove is generally set near the center line of the annular gap 1.

[0029] In this embodiment, the ceramic insulating pin 4 is arranged in the installation groove by means of interference fit. The ceramic insulating pin 4 can be installed in the installation groove by heating the inner conductor 2 and the outer conductor 3, freezing the ceramic insulating pin 4 or cold pressing the ceramic insulating pin 4, so as to connect the inner conductor 2 and the outer conductor 3. A pressing plate 5 is fixedly provided at the connecting end surface of the ceramic insulating pin 4 and the outer conductor 3, and at the connecting end surface of the ceramic insulating pin and the inner conductor 2. The pressing plate 5 is an annular structure, and the pressing plate 5 can be a metal structure or a non-metallic structure with high strength. The pressing plate 5 can be fixed on the end surfaces of the inner conductor 2 and the outer conductor 3 by means of welding or bolts, so as to prevent the ceramic insulating pin 4 from being damaged by collision and falling off in the axial direction.

[0030] A method for manufacturing the above-mentioned current insulation blocking device comprises the following steps: S1. Before processing, the inner conductor 2 and the outer conductor 3 are a whole, the whole is processed as a blank, a number of mounting grooves are processed in place, and then an annular gap 1 with a certain thickness is processed; S2, install the ceramic insulating pin 4 into the installation groove; S3, machining the annular gap 1 through and separating the inner conductor 2 and the outer conductor 3; S4. The entire current insulation blocking device is finely processed to eliminate installation deformation and ensure the coaxiality of the inner and outer conductors and the accuracy of accessories.

[0031] A small motor, wherein the above-mentioned current insulation blocking device or the current insulation blocking device prepared by the above-mentioned manufacturing method is installed between the bearing seat 6 and the end cover 8 of the motor (on the stationary part of the motor); the end cover 8 of the motor and the outer conductor 3 form an integral structure, which is directly connected to the machine base by bolts, and the inner conductor 2 and the bearing seat 6 of the motor form an integral structure, which cooperates with the outer ring of the bearing to isolate the electrical path between the bearing and the machine base, thereby protecting the bearing from electrical corrosion.

[0032] In other embodiments, for large motors, considering the difficulty of processing large parts, a split structure can be considered, in which the end cover 8 of the motor is connected to the outer conductor 3 by a bolt assembly 9, and the end cover 8 is further connected to the base, and the bearing seat 6 of the motor is connected to the inner conductor 2 by a bolt assembly 9, and the bearing seat 6 is then matched with the bearing, thereby isolating the electrical path between the bearing and the bearing seat, thereby protecting the bearing from electrical corrosion.

[0033] A small motor (for example, for a semi-direct drive generator gearbox integrated system, the generator has no independent shaft system. During the operation of the generator, the generator rotor, shaft system, and gearbox bearings constitute an electrical path, and there is a risk of electrical corrosion of the gearbox bearings and gears). The above-mentioned current insulation blocking device or the current insulation blocking device prepared by the above-mentioned manufacturing method is installed between the rotor bracket 7 of the motor and the gearbox (on the rotating parts of the motor). The flange 10 of the motor and the inner conductor 2 form an integral structure, and the rotor bracket 7 of the motor and the outer conductor 3 form an integral structure. When the generator set is working, the blade drives the gearbox shaft system to rotate through the main shaft, and transmits it to the ceramic insulating pin 4 through the inner conductor 2. The ceramic insulating pin 4 transmits the torque to the outer conductor 3 by bearing the shear force, thereby driving the rotor bracket 7 to rotate, so as to realize the generator power generation.

[0034] In other embodiments, for large motors, the flange 10 of the motor is connected to the inner conductor 2 by a bolt assembly 9; the rotor bracket of the motor is connected to the outer conductor by a bolt assembly 9. When the generator set is working, the blade drives the gearbox shaft system to rotate through the main shaft, and the torque is transmitted to the inner conductor 2 through the flange 10. The ceramic insulating pin 4 transmits the torque to the outer conductor 3 by bearing the shear force, driving the rotor bracket 7 to rotate, thereby realizing the generator to generate electricity.

[0035] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A current insulation blocking device, characterized in that: The invention comprises an annular gap (1) formed on a conductor, and an inner conductor (2) and an outer conductor (3) separated by the provision of the annular gap (1), wherein one end of the annular gap (1) is provided with a plurality of mounting grooves which penetrate the annular gap (1), the inner diameter of the mounting groove being larger than the inner diameter of the annular gap (1), and a ceramic insulating pin (4) being provided in the mounting groove.

2. The current isolation and blocking device according to claim 1, characterized in that: The inner diameter of the annular gap (1) is not less than 6 mm.

3. The current isolation and blocking device according to claim 1, characterized in that: The ceramic insulating pin (4) is arranged in the installation groove by means of an interference fit connection.

4. The current isolation and blocking device according to claim 3, characterized in that: A pressure plate (5) is fixedly provided at the connection end surface between the ceramic insulating pin (4) and the outer conductor (3), and at the connection end surface between the ceramic insulating pin (4) and the inner conductor (2).

5. The current isolation and blocking device according to claim 4, characterized in that: The pressing plate (5) is an annular structure.

6. The current insulation blocking device according to any one of claims 1 to 5, characterized in that: The annular gap (1) is naturally filled with insulating air or filled with insulating glue.

7. A method for manufacturing a current insulation blocking device according to any one of claims 1 to 6, characterized in that: The steps are as follows: S1. Before processing, the inner conductor (2) and the outer conductor (3) are a whole, and the whole is processed into a blank, a plurality of mounting grooves are processed in place, and then an annular gap (1) with a certain thickness is processed; S2, installing the ceramic insulating pin (4) into the installation groove; S3, machining the annular gap (1) through and separating the inner conductor (2) and the outer conductor (3); S4. The entire current insulation blocking device is finely processed as a whole to eliminate installation deformation and ensure the coaxiality and accessory accuracy of the inner conductor (2) and the outer conductor (3).

8. A motor, characterized in that: The stationary part of the motor is installed with the current insulation and blocking device described in any one of claims 1 to 6 or the current insulation and blocking device prepared by the manufacturing method described in claim 7.

9. A motor, characterized in that: The rotating part of the motor is installed with the current insulation and blocking device described in any one of claims 1 to 6 or the current insulation and blocking device prepared by the manufacturing method described in claim 7.

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