An automatic grinding device for heavy water reactor mechanical seal structure hub seal surface

Abstract

The application discloses an automatic grinding device for a heavy water reactor mechanical seal structure wheel hub sealing surface, and belongs to the technical field of nuclear power station sealing equipment. The device comprises a base plate, a grinding head assembly, a clamping assembly, a transmission assembly and an electric control system which are installed on the base plate, and the distance from the upper surface of the grinding head assembly to the lower surface of the base plate is less than 50 mm. The grinding head assembly is used for grinding the wheel hub sealing surface of a workpiece to be machined, the clamping assembly is used for clamping and positioning the outer edge of the wheel hub of the workpiece to be machined, and the transmission assembly is used for providing transmission power. The distance from the upper surface of the grinding head assembly to the lower surface of the base plate is less than 50 mm, so the device can be placed in the narrow space of 50 mm between the wheel hub and the end part, thereby realizing clamping, centering and grinding of the sealing surface of the device, and solving the engineering requirement of grinding and repairing the conical sealing surface of the wheel hub under the working condition of on-site implementation of the heavy water reactor mechanical seal mechanism.

Description

Technical Field

[0001] This invention relates to the field of nuclear power plant sealing equipment technology, specifically to an automatic grinding device for the hub sealing surface of a heavy water reactor mechanical seal structure, and further to an automatic grinding device for the high-pressure self-tightening flange sealing surface in a heavy water reactor nuclear power plant mechanical seal mechanism. Background Technology

[0002] A heavy water reactor nuclear power plant core consists of hundreds of fuel channels arranged in a close-packed manner within a confined space. Each fuel channel has a diameter of less than 200 mm, a center-to-center distance of less than 300 mm, and a minimum distance of approximately 100 mm between channels. The distribution of the fuel channels is shown in [reference needed]. Figure 1 As shown. The fuel channel inlet and outlet are connected to the water supply pipe via high-pressure self-tightening flanges. This type of high-pressure self-tightening flange is a mechanical seal mechanism, consisting of end components, sealing rings, a hub (or flange), and a compression fitting flange, etc. (See...) Figure 2 As shown, the end component sealing surface and the sealing ring sealing lip form a sealing pair, and the hub sealing surface and the sealing ring sealing lip form a sealing pair. Tightening the bolts causes the ferrule to press against the hub, thereby clamping the sealing ring between the upper flange and the end component. The mechanical seal is achieved through the tight contact between the sealing ring sealing lip and the upper and lower sealing surfaces. As the pressure boundary of the fuel passage in a heavy water reactor unit, leakage in the high-pressure self-tightening flange will directly affect the safe and stable operation of the unit.

[0003] The wheel hub is made of SA105 steel, which is high in strength. Its sealing surface is located in an area approximately 10mm high at the opening. Figure 3 As shown, the sealing surface is a conical surface, which forms a sealing contact pair with the sealing lip of the sealing ring. The sealing is achieved by relying on the elastic deformation of the sealing lip and the principle of mechanical sealing.

[0004] High-pressure self-tightening flanges, as the pressure boundary of fuel passages in heavy water reactor units, operate under harsh environments such as high temperature, high pressure, and boric acid water media for extended periods. They are prone to two types of damage: first, pitting corrosion and mechanical vibration wear on the sealing surface; second, scratches on the sealing surface caused by improper assembly. Over long-term operation, these damages may lead to seal contact failure, resulting in leakage from the high-pressure self-tightening flange. Therefore, if damage to the hub sealing surface is found during the maintenance of a high-pressure self-tightening flange, repair is necessary to ensure the sealing performance of the mechanical seal. The repair methods vary depending on the specific damage. For scratches, wear, and shallow corrosion spots, grinding and polishing are required to remove the damage affecting the seal. However, since the fuel passage cannot be disassembled, the repair of the hub sealing surface must be completed on-site in a radioactive environment. Furthermore, due to the confined space of the high-pressure self-tightening flange, the hub and end components can only be separated by a maximum of about 50mm, making manual grinding difficult and unable to guarantee the uniformity and precision of the sealing surface dimensions. In addition, to ensure the stability and circumferential uniformity of the grinding process, the grinding equipment must be securely clamped to the hub and maintain coaxiality with the hub sealing surface as much as possible. These characteristics dictate that the equipment for grinding the hub sealing surface must be able to operate in the confined and complex space surrounding the mechanical seal mechanism without interfering with surrounding components or other parts of the same component. Simultaneously, the equipment operates in a radioactive environment, requiring it to be lightweight, easy to install and remove, quick to use, and highly stable. The grinding equipment also needs to be securely fixed to the hub and centered to ensure the stability and uniformity of the grinding process.

[0005] Therefore, it is necessary to design a dedicated automatic grinding device for the hub sealing surface of the mechanical seal mechanism to achieve the grinding work of the sealing surface. Summary of the Invention

[0006] The purpose of this invention is to provide an automatic grinding device for the hub sealing surface of a heavy water reactor mechanical seal mechanism. Addressing the need for refined grinding and removal of damage such as pitting corrosion, vibration wear, and scratches on the hub sealing surface of a heavy water reactor mechanical seal mechanism, this device achieves automatic grinding of the hub sealing surface, restoring its surface roughness and dimensional uniformity, thereby ensuring the sealing performance of the mechanical seal mechanism. It provides an important grinding function for the repair of the hub sealing surface of a heavy water reactor mechanical seal mechanism and offers an important processing tool for on-site grinding and repair of the hub sealing surface of a heavy water reactor mechanical seal mechanism.

[0007] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0008] This invention provides an automatic grinding device for the hub sealing surface of a mechanical seal structure in a heavy water reactor, comprising:

[0009] Chassis;

[0010] A grinding head assembly is mounted on the chassis and is used to grind the hub sealing surface of the workpiece to be processed; the distance from the upper surface of the grinding head assembly to the lower surface of the chassis is less than 50 mm.

[0011] A clamping assembly is mounted on the chassis and connected to the grinding head assembly. The clamping assembly is used to clamp, position, and center the outer edge of the hub of the workpiece to be processed, so as to realize the installation and fixation of the heavy water reactor mechanical seal structure in a confined space environment.

[0012] A transmission assembly, which is mounted on the chassis and connected to the clamping assembly, is used to provide transmission power for grinding the wheel hub sealing surface;

[0013] An electronic control system is connected to the tail of the transmission assembly, and the electronic control system is used to control the operation of the grinding head assembly, the clamping assembly and the transmission assembly.

[0014] Furthermore, in the automatic grinding device for the hub sealing surface of the mechanical seal structure of heavy water reactor, the chassis includes a housing and a disc, the housing is fixedly mounted on the side end face of the disc, and a circular hole for connecting the grinding head assembly is provided at the center of the disc.

[0015] Furthermore, in the automatic grinding device for the hub sealing surface of the mechanical seal structure of heavy water reactor, the chassis also includes a limiting ring, which is used to axially limit the hub sealing surface of the workpiece to be processed. The limiting ring is installed on the bottom end face of the disc and is positioned close to the circular hole.

[0016] Furthermore, in the aforementioned automatic grinding device for the hub sealing surface of a heavy water reactor mechanical seal structure, the grinding head assembly includes: a rotating shaft, a chuck, a pin, a spring, a grinding head housing, and a grinding head.

[0017] The output end of the rotating shaft passes through the chassis and is connected to the transmission assembly;

[0018] The chuck is fixed to the input end of the rotating shaft, and a groove is provided along the circumference of the chuck. The spring is fixed in the groove of the chuck by the pin.

[0019] The grinding head housing has a groove on its inner side for mounting the chuck. The grinding head is fixed to the chuck by the pin, and the grinding head is mounted on the outer side of the grinding head housing. Further, in the automatic grinding device for the hub sealing surface of a heavy water reactor mechanical seal structure, the clamping assembly includes: a second motor, a motor mounting base, and a claw head.

[0020] The second motor is installed in the motor mounting bracket, and the motor mounting bracket is fixed to the chassis. The claw head is connected to the output end of the second motor.

[0021] Furthermore, in the automatic grinding device for the hub sealing surface of the mechanical seal structure of heavy water reactor, the number of the second motors is four, and the second motors are evenly installed on the chassis.

[0022] Furthermore, in the automatic grinding device for the hub sealing surface of the mechanical seal structure of heavy water reactor, the number of claws is four, and the four claws are used to position the outer edge of the hub of the workpiece to be processed.

[0023] Furthermore, in the aforementioned automatic grinding device for the hub sealing surface of the mechanical seal structure of a heavy water reactor, the transmission assembly includes: a driven wheel, a conveyor belt, a driving wheel, a motor mounting plate, a transmission gear set, a first motor, a motor housing, a transmission rod, a main rotating shaft, a protective sleeve, and heat sinks.

[0024] The driven wheel and the driving wheel are connected by a conveyor belt. The driven wheel is mounted on the chassis and is connected to the grinding head assembly.

[0025] The drive wheel is mounted on the motor mounting plate, which is mounted on the chassis and the motor housing. The first motor is mounted on the motor housing and connected to the drive shaft. The drive shaft is connected to the transmission gear set. Both the transmission gear set and the drive wheel are sleeved on the transmission rod, and the transmission gear set drives the drive wheel to rotate through the transmission rod. The protective sleeve is mounted on the motor housing and is used for fixing and protecting the main rotating shaft. The heat sink is mounted on the motor housing and is used for heat dissipation.

[0026] Furthermore, in the automatic grinding device for the hub sealing surface of the mechanical seal structure of heavy water reactor, the transmission component further includes a connecting plug, which is installed on the first motor and connected to the electrical control system via a communication line.

[0027] Furthermore, in the automatic grinding device for the hub sealing surface of the mechanical seal structure of heavy water reactor, the single grinding amount of the automatic grinding device is less than 0.01 mm.

[0028] The present invention has the following beneficial effects:

[0029] This invention provides an automatic grinding device for the hub sealing surface of a heavy water reactor mechanical seal mechanism. The device uses a grinding head assembly to grind the hub sealing surface of the workpiece. The grinding head of the assembly can float up and down to achieve close contact with the conical sealing surface to be processed, thus ensuring uniform processing. A clamping assembly is used to clamp and position the outer edge of the hub of the workpiece, and a transmission assembly provides transmission power. The distance between the upper surface of the grinding head assembly and the lower surface of the chassis is less than 50mm, allowing it to fit into the narrow 50mm space between the hub and the end component. This enables the device to clamp, center, and grind the sealing surface, solving the engineering need for grinding and repairing the conical sealing surface of the hub in the field operation of a heavy water reactor mechanical seal mechanism.

[0030] The automatic grinding device for the hub sealing surface of the mechanical seal mechanism of heavy water reactors provided by this invention has a simple and lightweight structure, avoids redundant structures, is lightweight and portable, and is easy to load, unload and operate. It can meet the requirements of rapid processing in low-altitude environments, and the grinding process is stable. It also meets the requirements of the confined space when repairing the hub sealing surface on site, realizing the grinding and repair of the hub sealing surface of the mechanical seal mechanism of heavy water reactors. It can be applied to the maintenance of the mechanical seal structure of heavy water reactors. Attached Figure Description

[0031] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0032] Figure 1 This is a schematic diagram of the fuel channel distribution in the background art of this invention;

[0033] Figure 2 This is a schematic diagram of a mechanical seal mechanism in the background art of this invention;

[0034] Figure 3 This is a schematic diagram of the hub sealing surface of the mechanical seal mechanism in the background art of this invention;

[0035] Figure 4 This is a schematic diagram of the automatic grinding device for the hub sealing surface of the mechanical seal structure of a heavy water reactor in an embodiment of the present invention;

[0036] Figure 5 This is a schematic diagram of the chassis structure in the automatic grinding device for the hub sealing surface of the mechanical seal structure of a heavy water reactor in an embodiment of the present invention;

[0037] Figure 6 This is a half-sectional schematic diagram of the grinding head assembly in the automatic grinding device for the hub sealing surface of the mechanical seal structure of a heavy water reactor in an embodiment of the present invention.

[0038] Figure 7 This is a schematic diagram of the clamping component in the automatic grinding device for the hub sealing surface of the mechanical seal structure of a heavy water reactor, as described in an embodiment of the present invention.

[0039] Figure 8 This is a schematic diagram of the transmission component in the automatic grinding device for the hub sealing surface of the mechanical seal structure of a heavy water reactor, as described in an embodiment of the present invention.

[0040] Figure 9 This is a cross-sectional structural diagram of the transmission component in the automatic grinding device for the hub sealing surface of the mechanical seal structure of a heavy water reactor, as shown in the embodiment of the present invention.

[0041] The markings and corresponding component names in the attached diagram are as follows:

[0042] In the diagram: 1-Chassis, 2-Grinding head assembly, 3-Clamping assembly, 4-Transmission assembly, 5-Electrical control system, 6-Housing, 7-Disc, 8-Limit ring, 9-Rotating shaft, 10-Chuck, 11-Pin, 12-Spring, 13-Grinding head housing, 14-Grinding head, 15-Claw head, 16-Second motor, 17-Motor mounting base, 18-Driven wheel, 19-Conveyor belt, 20-Driving wheel, 21-Motor mounting plate, 22-Transmission gear set, 23-First motor, 24-Motor housing, 25-Transmission rod, 26-Main rotating shaft, 27-Protective sleeve, 28-Heat sink, 29-Connecting plug. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0045] Example

[0046] Please refer to Figure 4-9 This invention provides an automatic grinding device for the hub sealing surface of a heavy water reactor mechanical seal structure, comprising:

[0047] Chassis 1;

[0048] Grinding head assembly 2 is mounted on chassis 1 and is used to grind the hub sealing surface of the workpiece to be processed; the distance between the upper surface of grinding head assembly 2 and the lower surface of chassis 1 is less than 50mm.

[0049] Clamping assembly 3 is mounted on chassis 1 and connected to grinding head assembly 2. Clamping assembly 3 is used to clamp and position the outer edge of the hub of the workpiece to be processed and to center it so as to realize the installation and fixation of the heavy water reactor mechanical seal structure in a confined space environment.

[0050] Transmission assembly 4 is mounted on chassis 1 and connected to clamping assembly 3. Transmission assembly 4 is used to provide transmission power for grinding the wheel hub sealing surface.

[0051] An electronic control system is connected to the tail of the transmission assembly 4. The electronic control system is used to control the operation of the grinding head assembly 2, the clamping assembly 3 and the transmission assembly 4.

[0052] This invention provides an automatic grinding device for the hub sealing surface of a heavy water reactor mechanical seal mechanism. The device uses a grinding head assembly to grind the hub sealing surface of the workpiece. The grinding head of the assembly can float up and down to achieve close contact with the conical sealing surface to be processed, thus ensuring uniform processing. A clamping assembly is used to clamp and position the outer edge of the hub of the workpiece, and a transmission assembly provides transmission power. The distance between the upper surface of the grinding head assembly and the lower surface of the chassis is less than 50mm, allowing it to fit into the narrow 50mm space between the hub and the end component. This enables the device to clamp, center, and grind the sealing surface, solving the engineering need for grinding and repairing the conical sealing surface of the hub in the field operation of a heavy water reactor mechanical seal mechanism.

[0053] In some feasible embodiments, the chassis 1 includes a housing 6 and a disc 7. The housing 6 is mounted and fixed to the side end face of the disc 7, and a circular hole for connecting the grinding head assembly 2 is provided at the center of the disc 7. The housing 6 is integrally formed from high-strength aluminum alloy and includes a bottom shell, side wall shells, and a rectangular shell. The side wall shells have circumferential threaded holes, and the rectangular shells have threaded holes on their sides. The disc 7 is fastened to the housing 6 with screws, and a circular hole is provided in the center of the disc 7 for connecting the rotating head, allowing the rotating shaft 9 to pass through.

[0054] In some feasible embodiments, the chassis 1 also includes a limiting ring 8, which is used to axially limit the hub sealing surface of the workpiece to be processed. The limiting ring 8 is installed on the bottom end face of the disc 7 and is positioned close to the circular hole. The limiting ring 8 is fixed to the disc 7 by bolts to achieve axial limiting between the device and the hub sealing surface of the workpiece to be processed.

[0055] In some feasible embodiments, the grinding head assembly 2 includes: a rotating shaft 9, a chuck 10, a pin 11, a spring 12, a grinding head housing 13, and a grinding head 14. The output end of the rotating shaft 9 passes through the chassis 1 and is connected to the transmission assembly 4. The chuck 10 is fixed to the input end of the rotating shaft 9, and a groove is formed along the circumference of the chuck 10. The spring 12 is fixed in the groove of the chuck 10 by the pin 11. The inner side of the grinding head housing 13 is provided with a slot for mounting the chuck 10. The grinding head 14 is fixed to the chuck 10 by the pin 11 and is mounted on the outer side of the grinding head housing 13. The grinding head housing 13 floats up and down through the chuck 10, the pin 11, and the spring 12, and can also drive the grinding head 13 to float up and down, thereby conforming to the conical sealing surface to be processed.

[0056] The outer side of the grinding head housing 13 is conical, and it can be replaced according to the angle of the conical sealing surface to be processed. The grinding head 14 is a conical structure made of different grinding materials. It can also be replaced with sandpaper according to the grinding requirements and attached to the grinding head housing 13 to process the conical sealing surface.

[0057] Specifically, the rotating shaft 9 passes through the base 1 of the disc 7 and connects to the transmission assembly 4 for power transmission; the chuck 10 is fixed to the rotating shaft 9 via a pin engagement, and the pin 11 is fixed to the chuck 10 by spot welding. The spring 12 is fixed in the groove of the chuck 10 by the pin 11; the inner circumferential side of the grinding head housing 13 has a slot and a limiting pin, which are fixed to the pin 11 via the slot and axially limited by the spring 12; the grinding head 14 is made of sandpaper or diamond abrasive, which is applied to the grinding head housing 13 with adhesive, and the high-speed rotation of the grinding head 14 achieves the grinding of the sealing surface. The pin 11 can be either cross-shaped or straight-lined. The material of the grinding head 14 can be sandpaper or diamond abrasive, which can be adjusted according to the actual process requirements of the sealing surface to be processed, or according to the diameter, taper, and height of the conical sealing surface to be processed.

[0058] In some feasible embodiments, the clamping assembly 3 includes: a second motor 16, a motor mounting base 17, and a claw head 15.

[0059] The second motor 16 is installed inside the motor mounting base 17, and the motor mounting base 17 is fixed to the chassis 1. The claw head 15 is connected to the output end of the second motor 16. Specifically, the motor mounting base 17 is fixed to the disc 7 of the chassis 1 by bolts, the second motor 16 is fixed to the motor mounting base 17 by bolts, and the claw head 15 is connected to the output shaft of the second motor 16, which clamps the outer edge of the wheel hub.

[0060] In some feasible embodiments, the number of second motors 16 is four, and the second motors 16 are evenly mounted on the chassis 1.

[0061] In some feasible embodiments, the number of claw heads 15 is four, which position the outer edge of the hub of the workpiece to be processed. Four sets of second motors 16 and the corresponding four claw heads 15 are controlled and linked by an electronic control system, thereby causing the claw heads 15 to retract. This makes it easier to press the outer edge of the hub with the claw heads 15 and to achieve fixation with the outer edge of the hub more easily through friction. In other embodiments of the invention, the number and size of the claw heads 15 can be changed to adapt to different types of hubs (flanges) or flanges with conical sealing surfaces.

[0062] In some feasible ways, refer to Figure 8-9 The transmission assembly 4 includes: a driven wheel 18, a driving wheel 20, a motor mounting plate 21, a transmission gear set 22, a first motor 23, a motor housing 24, a transmission rod 25, a main rotating shaft 26, a protective sleeve 27, and a heat sink 28.

[0063] Driven wheel 18 and driving wheel 20 are connected by conveyor belt 19. Driven wheel 18 is mounted on chassis 1 and is connected to grinding head assembly 2.

[0064] The drive wheel 20 is mounted on the motor mounting plate 21, which is mounted on the chassis 1 and the motor housing 24. The first motor 23 is mounted on the motor housing 24, and its output end is connected to the drive shaft 26. Preferably, the output end is fixedly connected to the drive shaft 26, thereby driving the drive shaft 26 to rotate. The transmission gear set 22 is sleeved and fixed on the drive shaft 26, and rotates accordingly with the rotation of the drive shaft 26. Preferably, the transmission gear set 22 may include two meshing angular gears. One angular gear is sleeved on the drive shaft 26, and the other angular gear is sleeved on the transmission rod 25. The two mesh, thereby driving the transmission rod 25 to rotate. At the same time, the drive wheel 20 is also sleeved on the transmission rod 25 and can rotate accordingly.

[0065] The driven wheel 18 is a large wheel, fixed to the housing 6 of the chassis 1 via a bearing assembly and connected to the rotating shaft 9 of the grinding head assembly 2. The driven wheel 18 is connected to the driving wheel 20 via a conveyor belt 19. The driving wheel 20 is fixed to the motor mounting plate 21 with screws, and the motor mounting plate 21 is fixed to the chassis 1 with four sets of bolts. The motor housing 24 is fixed to the motor mounting plate 21 with bolts. The first motor 23 is connected to the motor housing 24 via a series of bolts. The first motor 23 includes a radiator, a reducer, and other structures, and transmits power to the driving wheel 20 via a transmission gear set 22. The first motor 23 is connected to the electronic control system via a connector 29 and can transmit signals.

[0066] In some feasible embodiments, the transmission assembly 4 further includes a connector 29, which is mounted on the first motor 23 and is connected to the electronic control system via a communication line.

[0067] In some feasible methods, the grinding amount per pass of the automatic grinding device is less than 0.01 mm. The grinding time for each pass is set via an electronic control system to ensure that the grinding amount per pass is less than 0.01 mm, thus avoiding over-grinding.

[0068] The automatic grinding device for the hub sealing surface of the mechanical seal structure of heavy water reactors provided by this invention has the following working principle:

[0069] (1) After using the four-jaw head of the clamping assembly to perform rough positioning with the outer edge of the hub of the workpiece to be processed, the second motor is started to drive the four-jaw head to retract inward, so as to realize the clamping positioning and centering of the clamping assembly with the outer edge of the hub.

[0070] (2) The limiting ring is used to limit the lower surface of the hub of the workpiece to be processed and ensure that the device has no horizontal degree of freedom; the spring rebound force is used to achieve contact and pressing between the grinding head and the hub sealing surface of the workpiece to be processed; the feed and pressing state in the vertical direction is changed by changing the spring.

[0071] (3) The first motor is started remotely by the electronic control system, which drives the small wheel to move. The large wheel and the centering plate are rotated by the belt. The centering plate eventually drives the grinding head to rotate. The outer surface of the grinding head is covered with sandpaper or diamond abrasive of different grits to replace the head.

[0072] (4) A high-speed rotating grinding head grinds the sealing surface with sandpaper or diamond head.

[0073] (5) Set the grinding time for each grinding session through the electronic control system to ensure that the grinding amount per session is less than 0.01 mm and avoid over-grinding.

[0074] (6) Depending on the grit of different sandpapers or diamonds, a series of repair work can be carried out on the sealing surface, from coarse grinding to fine grinding to polishing.

[0075] The automatic grinding device for the hub sealing surface of the mechanical seal structure of heavy water reactors provided by this invention can be installed in a narrow space with a maximum distance of 50mm between the hub and the end component of the mechanical seal mechanism of heavy water reactors. The device is clamped and fixed to the hub and centered with the sealing surface through a four-jaw mechanism. The device can grind the sealing surface under on-site hub sealing surface maintenance conditions, and the uniformity of the grinding process is ensured by the floating centering of the grinding head. The use of a sandpaper grinding head can ensure that the grinding amount in a single pass is 0.01mm. Through a series of operations such as rough grinding, precision grinding, and polishing, the surface roughness of the grinding sealing surface can reach below 0.4μm.

[0076] The automatic grinding device for the hub sealing surface of the mechanical seal structure of a heavy water reactor provided by this invention is electrically driven and includes a four-jaw clamping positioning center and floating centering function. The clamping method is stable and can achieve centering with the hub sealing surface. The grinding process is stable and the circumferential grinding is uniform, meeting the processing requirements for hub sealing surface grinding. This device has been used to complete the grinding and repair of the hub sealing surface on a 1:1 test device of the mechanical seal mechanism of the fuel channel of a CANDU-6 heavy water reactor. It can also be applied to the grinding and repair of conical sealing surfaces of other similar flanges.

[0077] The above specific embodiments further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An automatic grinding device for the hub sealing surface of a mechanical seal structure in a heavy water reactor, characterized in that, include: Chassis (1); Grinding head assembly (2), which is mounted on the chassis (1), is used to grind the wheel hub sealing surface of the workpiece to be processed; the distance from the upper surface of the grinding head assembly (2) to the lower surface of the chassis (1) is less than 50 mm; Clamping assembly (3), the clamping assembly (3) is mounted on the chassis (1) and the clamping assembly (3) is connected to the grinding head assembly (2). The clamping assembly (3) is used to clamp and position the outer edge of the hub of the workpiece to be processed and to center it so as to realize the installation and fixation of the heavy water reactor mechanical seal structure in a narrow space environment. Transmission assembly (4), which is mounted on the chassis (1) and connected to the clamping assembly (3), is used to provide transmission power for grinding the wheel hub sealing surface; An electronic control system (5) is connected to the tail of the transmission assembly (4). The electronic control system is used to control the operation of the grinding head assembly (2), the clamping assembly (3) and the transmission assembly (4). The grinding head assembly (2) includes: a rotating shaft (9), a chuck (10), a pin (11), a spring (12), a grinding head housing (13), and a grinding head (14). The output end of the rotating shaft (9) passes through the chassis (1) and is connected to the transmission assembly (4); The chuck (10) is fixed to the input end of the rotating shaft (9), and a groove is provided along the circumference of the chuck (10). The spring (12) is fixed in the groove of the chuck (10) by the pin (11). The grinding head housing (13) has a slot for mounting the chuck (10) on its inner side. The grinding head (14) is fixed to the chuck (10) by the pin (11). The grinding head (14) is mounted on the outer side of the grinding head housing (13). The clamping assembly (3) includes: a claw head (15), a second motor (16), and a motor mounting base (17). The second motor (16) is installed in the motor mounting base (17), and the motor mounting base (17) is fixed on the chassis (1). The claw head (15) is connected to the output end of the second motor (16). The number of the second motors (16) is four, and the second motors (16) are evenly installed on the chassis (1); The number of claws (15) is four, and the four claws (15) are used to position the outer edge of the hub of the workpiece to be processed.

2. The automatic grinding device for the hub sealing surface of a heavy water reactor mechanical seal structure according to claim 1, characterized in that, The chassis (1) includes a housing (6) and a disc (7). The housing (6) is mounted and fixed on the side end face of the disc (7). A circular hole for connecting the grinding head assembly (2) is provided at the center of the disc (7).

3. The automatic grinding device for the hub sealing surface of a heavy water reactor mechanical seal structure according to claim 2, characterized in that, The chassis (1) also includes a limiting ring (8), which is used to limit the axial movement of the hub sealing surface of the workpiece to be processed. The limiting ring (8) is installed on the bottom end face of the disc (7) and is located close to the circular hole.

4. The automatic grinding device for the hub sealing surface of a heavy water reactor mechanical seal structure according to claim 1, characterized in that, The transmission assembly (4) includes: a driven wheel (18), a conveyor belt (19), a driving wheel (20), a motor mounting plate (21), a transmission gear set (22), a first motor (23), a motor housing (24), a transmission rod (25), a main rotating shaft (26), a protective sleeve (27), and a heat sink (28). The driven wheel (18) and the driving wheel (20) are connected by a conveyor belt (19). The driven wheel (18) is mounted on the chassis (1) and is connected to the grinding head assembly (2). The drive wheel (20) is mounted on the motor mounting plate (21), the motor mounting plate (21) is mounted on the chassis (1), the motor mounting plate (21) is mounted on the motor housing (24), the first motor (23) is mounted on the motor housing (24), and the output end of the first motor (23) is connected to the main rotating shaft (26). The main rotating shaft (26) is connected to the transmission gear set (22). The transmission gear set (22) and the drive wheel (20) are both sleeved on the transmission rod (25), and the transmission gear set (22) drives the drive wheel (20) to rotate through the transmission rod (25). The protective sleeve (27) is mounted on the motor housing (24). The protective sleeve (27) is used for fixing and protecting the main rotating shaft (26). The heat sink (28) is mounted on the motor housing (24) and is used for heat dissipation.

5. The automatic grinding device for the hub sealing surface of a heavy water reactor mechanical seal structure according to claim 4, characterized in that, The transmission assembly (4) further includes a connector (29), which is mounted on the first motor (23) and is connected to the electronic control system (5) via a communication line.

6. The automatic grinding device for the hub sealing surface of a heavy water reactor mechanical seal structure according to claim 1, characterized in that, The grinding volume of the automatic grinding device in a single pass is less than 0.01 mm.

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