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

Abstract

The invention discloses a current insulation blocking mechanism 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 width of the mounting grooves is larger than that of the annular gap. An insulating ceramic block is arranged in the mounting groove, at least two mounting holes are formed in the insulating ceramic block, and bolt assemblies are arranged in the mounting holes respectively and used for fixedly connecting the insulating ceramic block with the inner conductor and the outer conductor respectively; the invention further provides a processing and manufacturing method of the current insulation blocking mechanism and a motor comprising the current insulation blocking mechanism. According to the current insulation blocking mechanism provided by the invention, shaft current loop blocking is carried out through the insulation ceramic block and the annular gap, so that moving parts are prevented from electric corrosion risks, and the current insulation blocking mechanism has the advantages of being convenient to replace and maintain, long in service life 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 mechanism, 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 mechanism, a processing and manufacturing method thereof, and an application thereof. The current insulation blocking mechanism blocks the axial current circuit through an insulating ceramic block and an annular gap, thereby protecting the moving parts from the risk of electrical corrosion, and has the advantages of easy replacement and maintenance, and a long service life.

[0006] The technical solution provided by the present invention is as follows: A current insulation blocking mechanism 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 width of the mounting groove is greater than the width of the annular gap, an insulating ceramic block is arranged in the mounting groove, at least two mounting holes are arranged on the insulating ceramic block, and bolt assemblies are respectively arranged in the mounting holes for connecting and fixing the insulating ceramic block to the inner conductor and the outer conductor respectively.

[0007] Preferably, a gasket is provided above the connection between the bolt assembly and the insulating ceramic block.

[0008] Preferably, the width of the annular gap is not less than 6 mm.

[0009] Preferably, the insulating ceramic block is arranged in the mounting groove by a clearance fit connection.

[0010] Preferably, the mounting holes of the insulating ceramic blocks are all through holes, and the diameter of the through holes is 1 to 2 mm larger than the diameter of the screws in the bolt assembly.

[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 insulation blocking mechanism 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 block into the installation groove, and connect the ceramic insulating block to the inner conductor and the outer conductor respectively through two bolt assemblies; 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 mechanism or the current insulation and blocking mechanism prepared by the above-mentioned preparation method is installed on the stationary part of the motor.

[0014] A motor, wherein the rotating part of the motor is equipped with the above-mentioned current insulation and blocking mechanism or the current insulation and blocking mechanism prepared by the above-mentioned preparation method.

[0015] The present invention has the following advantages over the prior art: The current insulation blocking mechanism of the present invention blocks the shaft current loop through the annular gap between the insulating ceramic block and the inner and outer conductors, thereby protecting the moving parts (such as bearings, gears, etc.) from the risk of electrical corrosion. The current insulation blocking mechanism can be used not only on stationary parts but also on rotating parts to block the shaft current. The width of the annular gap of the current insulation blocking mechanism (the gap used for insulation) is generally set to be ≥6mm, which can completely block the shaft current loop; the current insulation blocking mechanism of the present invention transmits torque to the inner conductor, the outer conductor, and the connecting bolts through the insulating ceramic block, and the connecting bolts at the matching stop of the conductor only play a fixing role, thereby greatly reducing the risk of loosening and failure of the connecting bolts at the matching stop; and the current insulation blocking mechanism is not set at the matching stop of the conductor, which can ensure the accuracy and coaxiality of the matching stop, thereby reducing the vibration and noise of the motor; and the insulating ceramic block of the current insulation blocking machine is an inorganic material with high mechanical strength, excellent insulation performance, good environmental weather resistance, good dimensional stability, easy replacement and maintenance of the insulation structure, and long service life, which can protect the bearings and gears of the transmission system from the risk of electrical corrosion throughout the life cycle, thereby ensuring the reliable use of the transmission system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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.

[0017] Figure 1 It is a structural schematic diagram of a current insulation blocking mechanism 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 mechanism 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 mechanism 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 mechanism installed on a rotating component of a small motor in an embodiment of the present invention; Figure 8It is a schematic structural diagram of a current insulation blocking mechanism installed on a rotating component of a small motor in an embodiment of the present invention.

[0018] Reference numerals: 1. Annular gap; 2. Inner conductor; 3. Outer conductor; 4. Ceramic insulating block; 5. Bolt assembly; 6. Gasket; 7. End cover; 8. Bearing seat; 9. Rotor bracket; 10. Flange. DETAILED DESCRIPTION

[0019] 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.

[0020] like Figure 1-8 As shown, an embodiment of the present invention provides a current insulation blocking mechanism, including an annular gap 1 opened on the 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 width of the mounting groove is greater than the width of the annular gap 1, an insulating ceramic block 4 is provided in the mounting groove, at least two mounting holes are provided on the insulating ceramic block 4, and bolt assemblies 5 are respectively provided in the mounting holes for connecting and fixing the insulating ceramic block 4 to the inner conductor 2 and the outer conductor 3 respectively. Gaskets are provided above the connection between the bolt assembly 5 and the insulating ceramic block 4.

[0021] In this embodiment, the width of the annular gap 1 can be set as required. Generally, the width of the annular gap 1 is not less than 6 mm, which plays a role in completely blocking the shaft current loop. The distance between the center line of the installation groove and the center line of the annular gap 1 is not more than 2 mm. The annular gap 1 can be directly isolated from the air, or can be filled with epoxy glue to play an insulating and sealing role.

[0022] In this embodiment, the inner conductor 2 and the outer conductor 3 are made of metal materials, such as steel, aluminum, aluminum alloy, etc. Bolt holes are processed on the inner conductor 2 and the outer conductor 3.

[0023] In this embodiment, the insulating ceramic block 4 is arranged in the installation groove by a clearance fit connection method to facilitate the installation of the insulating ceramic block 4. The number of insulating ceramic blocks 4 is preferably three or more, and they are evenly or unevenly arranged in the installation groove in the circumferential direction. The insulating ceramic block 4 can be a solid or hollow cylindrical pin structure, or a tapered pin, a rectangular pin, a square pin, an arc-shaped pin, etc. The insulating ceramic block 4 can be a ceramic material such as aluminum oxide, silicon carbide, zirconium oxide, etc.

[0024] In this embodiment, the mounting holes of the insulating ceramic block 4 are all through holes, and the diameter of the through holes is 1 to 2 mm larger than the diameter of the screws in the bolt assembly 5 .

[0025] A method for manufacturing the above-mentioned current insulation blocking mechanism 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 2 with a certain thickness is processed; S2, install the ceramic insulating block 4 into the installation groove, and connect the ceramic insulating block 4 to the inner conductor 2 and the outer conductor 3 respectively through two bolt assemblies 5; 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.

[0026] A motor, wherein the above-mentioned current insulation and blocking mechanism or the current insulation and blocking mechanism prepared by the above-mentioned preparation method is installed on the stationary part of the motor.

[0027] For small motors, the current insulation blocking mechanism of this embodiment is set between the machine base and the bearing, the outer conductor 3 is made into one piece with the end cover 7, and is directly connected to the machine base by bolts, and the inner conductor 2 is directly made into one piece with the bearing seat 8, and cooperates with the outer ring of the bearing, so as to isolate the electrical path between the bearing and the machine base and prevent the bearing from being corroded by electricity. For large motors, considering the difficulty of processing large parts, a split structure can be considered, and the current insulation blocking mechanism of this embodiment is added between the bearing seat 8 and the end cover 7, the outer conductor 3 is connected to the end cover 7 by bolts, and the end cover 7 is further connected to the machine base, the inner conductor 2 is connected to the bearing seat 8 by bolts, and the bearing seat 8 is further cooperated with the bearing, so as to isolate the electrical path between the bearing and the bearing seat 8 and prevent the bearing from being corroded by electricity.

[0028] A motor, wherein the above-mentioned current insulation blocking mechanism or the current insulation blocking mechanism prepared by the above-mentioned manufacturing method is installed on the rotating parts of the motor (for example, for a semi-direct drive generator gearbox integrated system, the generator does not have an independent shaft system, and 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).

[0029] For small motors, the shaft current insulation blocking mechanism of this embodiment is directly installed between the generator rotor bracket 9 and the gearbox shaft, the inner conductor 2 is directly integrated with the flange 10, and the outer conductor 3 is directly integrated with the rotor bracket 9. When the generator set is working, the blade drives the gearbox shaft system to rotate through the main shaft, and transmits it to the insulating ceramic block 4 through the inner conductor 2. The connecting bolts of the insulating ceramic block 4 transmit the torque to the outer conductor 3 by bearing the shear force, thereby driving the rotor bracket 9 to rotate, so as to achieve the generator to generate electricity. For large motors, considering the difficulty of processing large parts, a split structure can be considered, and the shaft current insulation blocking mechanism of this embodiment is installed between the generator rotor bracket 9 and the flange 10, the inner conductor 2 is connected to the flange 10 by bolts, and the outer conductor 3 is connected to the rotor bracket 9 by bolts. When the generator set is working, the blade drives the gearbox shaft system to rotate through the main shaft, and transmits it to the inner conductor 2 through the flange 10. The connecting bolts of the insulating ceramic block 4 transmit the torque to the outer conductor 3 by bearing the shear force, thereby driving the rotor bracket 9 to rotate, thereby achieving the generator to generate electricity.

[0030] Compared with the existing insulating bearing seat, insulating bearing chamber or insulating flange, which uses insulating materials such as non-weft tape, fiber composite laminated tube and laminated board to achieve insulation, the current insulation blocking mechanism of this embodiment has the following advantages: 1. The thickness of the non-weft belt, fiber composite laminate tube and laminated board of the existing solution is generally 2-6 mm. The thicker the insulation layer, the worse the mechanical properties. However, the width of the annular gap 1 of the current insulation blocking mechanism of this embodiment can be set as required. Generally, the gap thickness is set to be ≥6 mm. The mechanical properties of the current insulation blocking mechanism of this embodiment are not affected by the width of the annular gap 1. Since the insulation gap (width of the annular gap 1) of the current insulation blocking mechanism of this embodiment is large, it has a smaller capacitance and can better block the shaft current loop, thereby ensuring that the bearings and gears are completely free from the risk of electrical corrosion. 2. The existing organic insulating materials such as weftless belts, fiber composite laminated tubes and laminated boards are greatly affected by environmental factors. The insulation performance will be greatly reduced after being damp, and the mechanical strength will also be greatly reduced with aging. The current insulation blocking mechanism of this embodiment adopts an insulating ceramic block 4 to connect the inner conductor 2 and the outer conductor 3. The insulating ceramic block 4 is an inorganic material with good mechanical properties, insulation properties and weather resistance, so as to ensure the reliability of the transmission system throughout its life cycle; 3. For rotating insulating components, the connecting bolts at the joints of the insulating structure of the existing solution 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 joints, and high risk of use; while the connecting bolts at the joints of the conductors of the current insulation blocking mechanism of this embodiment only play a connecting and tightening role, and the torque transmission is achieved through the connecting bolts at the connection between the insulating ceramic block 4 and the inner conductor 2 and the outer conductor 3, thereby optimizing the force on the connecting bolts at the joints and greatly reducing the risk of loosening of the connecting bolts; 4. In the existing scheme, the insulating structure at the joint of the conductor plays a role in fitting and positioning. The insulating material is an organic material with poor dimensional stability, large deformation, and low fitting accuracy, which can easily lead to reduced coaxiality of the stator and rotor, increased unilateral magnetic pull and centrifugal force of the generator, and increased vibration and noise of the generator. However, the joint of the conductor of the current insulation blocking mechanism of this embodiment is a direct steel-to-steel fit without an insulating structure. Moreover, the insulating structure of the current insulation blocking mechanism of this embodiment is an integral fine-machined shape after assembly. The inner conductor 2 and the outer conductor 3 have good coaxiality and high fitting accuracy, which can ensure the accuracy and coaxiality of the conductor joint, thereby reducing motor vibration and noise; 5. The insulating components of the existing scheme are composed of organic materials such as non-weft tape, fiber composite laminate tube and laminate, which have poor dimensional stability, are easy to deform, and have weak creep resistance; while the insulating ceramic block 4 of the current insulation blocking mechanism of this embodiment is made of inorganic material, has good dimensional stability, and has strong creep resistance; 6. 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 replacement and maintenance are easily damaged; while the current insulation blocking mechanism of this embodiment adopts a gap fit between the insulation ceramic block 4 and the installation groove, the insulation ceramic block 4 is easy to install and disassemble, the insulation components are simple to replace and maintain, and the insulation structure will not be damaged; 7. The current insulation blocking mechanism of this embodiment 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.).

[0031] 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 mechanism, 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 annular gap. One end of the annular gap (1) is provided with a plurality of mounting grooves penetrating the annular gap (1). The width of the mounting grooves is greater than the width of the annular gap (1). An insulating ceramic block (4) is provided in the mounting groove. The insulating ceramic block (4) is provided with at least two mounting holes. Bolt assemblies (5) are respectively provided in the mounting holes for connecting and fixing the insulating ceramic block (4) to the inner conductor (2) and the outer conductor (3).

2. The current isolation and blocking mechanism according to claim 1, characterized in that: Gaskets (6) are provided above the connection points between the bolt assembly (5) and the insulating ceramic block (4).

3. The current isolation and blocking mechanism according to claim 1, characterized in that: The width of the annular gap (1) is not less than 6 mm.

4. The current isolation and blocking mechanism according to claim 1, characterized in that: The distance between the center line of the installation groove and the center line of the annular gap (1) is no more than 2 mm.

5. The current isolation and blocking mechanism according to claim 1, characterized in that: The insulating ceramic block (4) is arranged in the installation groove by means of a clearance fit connection.

6. The current insulation blocking mechanism according to any one of claims 1 to 5, characterized in that: The mounting holes of the insulating ceramic block (4) are all through holes, and the diameter of the through holes is 1 to 2 mm larger than the diameter of the screws in the bolt assembly (5).

7. The current insulation and blocking mechanism 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.

8. A method for processing and manufacturing the current insulation and blocking mechanism according to any one of claims 1 to 7, 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 block (4) into the installation groove, and connecting the ceramic insulating block (4) to the inner conductor (2) and the outer conductor (3) respectively through two bolt assemblies (5); 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).

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

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

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