Rotary grinding mechanism and metallographic grinder thereof

Abstract

The utility model is applicable to the technical field of metallographic grinding, and provides a rotary grinding mechanism and a metallographic grinder thereof, the rotary grinding mechanism comprises a rotating unit and a grinding unit; the rotating unit comprises a rotating driving device, a rotating shaft, a first bearing, a first bearing seat, a second bearing, a second bearing seat, a pre-tightening elastic piece and a jacking piece; the rotary driving device is in linkage connection with the rotating shaft; the first bearing and the second bearing sequentially sleeve the outer side of the rotating shaft in the axial direction of the rotating shaft; the inner ring of the first bearing is fixedly connected with the rotating shaft; the outer ring of the first bearing is connected to the first bearing seat; the outer ring of the second bearing is connected to the second bearing seat; the jacking piece is arranged on the second bearing seat and jacks the inner ring of the second bearing in the axial direction and towards the first bearing; a pre-tightening elastic piece is connected between the first bearing inner ring and the second bearing inner ring; the grinding unit is connected with the rotating shaft. The grinding path of the grinding surface of the metallographic specimen can be changed, and the grinding precision can be prevented from being influenced.

Description

Technical Field

[0001] The utility model relates to the technical field of metallographic grinding, in particular to a rotary grinding mechanism and a metallographic grinding machine thereof. Background Art

[0002] Metallographic specimen is an important and commonly used method for observing the cross-sectional microstructure of a sample. Metallographic samples can be various materials such as metal materials, alloys, ceramics, composite materials, electronic circuit boards, integrated chips, etc. A sample preparation method is to wrap and seal the sample with a special liquid resin and then perform grinding and polishing. It is widely used in the electronics industry, metal / plastic / ceramic product industry, automotive parts and accessories manufacturing industry, communication equipment, scientific research, and the structural observation of electronic components, such as flip chips, aluminum / copper process structures, COMS, POP, etc., PCB structure and via hole observation, PCBA solder joint observation, LED structure observation, IMC observation, capacitance, paint thickness, coating, and the structural observation of metals and parts. The grinding machine is an essential equipment in the grinding and polishing process.

[0003] In the existing fully automatic metallographic grinding machine, during use, with the change of market demand and the improvement of customer requirements, its structure can no longer meet the new needs. In the grinding process, the grinding claws grab the mold box and grind on the grinding disc. The metallographic specimen is sealed in the mold box, and the surface to be ground of the metallographic specimen is the grinding surface. The grinding path is the continuous position passed by the grinding disc during cutting on the grinding surface. During the grinding process, once the grinding disc starts, it will not randomly change the rotation direction. For a single metallographic specimen, on a certain grinding disc, from the moment the grinding surface contacts the grinding disc until the grinding is completed and leaves the grinding disc, during this process, the rotation direction of the grinding disc is always in one direction. Therefore, the grinding path on the grinding surface is always the same path. In the practical process, the materials of different specimens are different. Some materials have low hardness and are ductile, such as copper, aluminum, tin, etc. During the grinding process, if the grinding is always carried out along the same grinding path, phenomena such as wire drawing will occur, affecting the grinding quality. For some specimens, due to multiple layers of materials, when grinding along the same grinding path, some parts are always not ground in place. Therefore, in order to improve the grinding quality, it is necessary to change the grinding path during the grinding process so that the grinding surface is ground under different directions of cutting force during the grinding process.

[0004] In summary, the existing structure is obviously inconvenient and defective in actual use, so it is necessary to be improved. Content of the Utility Model

[0005] Aiming at the above defects, the purpose of the utility model is to provide a rotary grinding mechanism and a metallographic grinding machine thereof, which can not only change the grinding path of the grinding surface of the metallographic specimen during the grinding process, improve the grinding quality, but also avoid the displacement between components from affecting the grinding accuracy.

[0006] To achieve the above object, the present utility model provides a rotary grinding mechanism for the lifting mechanism of a metallographic grinding machine, including:

[0007] A rotating unit, which includes a rotation driving device, a rotating shaft, a first bearing, a first bearing seat, a second bearing, a second bearing seat, a preloading elastic member, and a jacking member; the rotation driving device is linked with the rotating shaft to drive the rotating shaft to rotate; the first bearing and the second bearing are sequentially sleeved on the outer side of the rotating shaft along the axial direction of the rotating shaft; the first bearing inner ring of the first bearing is fixedly connected to the rotating shaft; the first bearing outer ring of the first bearing is connected to the first bearing seat; the second bearing outer ring of the second bearing is connected to the second bearing seat; the jacking member is arranged on the second bearing seat and jacks up the second bearing inner ring of the second bearing axially and towards the first bearing; the preloading elastic member is connected between the first bearing inner ring and the second bearing inner ring;

[0008] A grinding unit, connected to the rotating shaft.

[0009] According to the rotary grinding mechanism, the rotating unit further includes a third bearing and a third bearing seat; the third bearing is sleeved on the outer side of the rotating shaft; the third bearing inner ring of the third bearing is fixedly connected to the rotating shaft; the third bearing outer ring of the third bearing is connected to the third bearing seat; the third bearing is located on the side of the second bearing away from the first bearing; a boss abuts against the side of the third bearing inner ring away from the second bearing, and the boss is integrally formed with the rotating shaft; the outer diameter of the boss is greater than the inner diameter of the third bearing inner ring, and the outer diameter of the boss is less than or equal to the outer diameter of the third bearing inner ring.

[0010] According to the rotary grinding mechanism, the preloading elastic member is a preloading spring;

[0011] A first retaining ring is arranged between the preloading spring and the first bearing inner ring; the outer diameter of the side of the first retaining ring in contact with the first bearing inner ring is less than or equal to the outer diameter of the first bearing inner ring, and the outer diameter of the side of the first retaining ring in contact with the preloading spring is greater than or equal to the outer diameter of the preloading spring;

[0012] A second retaining ring is arranged between the preloading spring and the second bearing inner ring; the outer diameter of the side of the second retaining ring in contact with the second bearing inner ring is less than or equal to the outer diameter of the second bearing inner ring, and the outer diameter of the side of the second retaining ring in contact with the preloading spring is greater than or equal to the outer diameter of the preloading spring;

[0013] The jacking member is a set screw.

[0014] According to the rotary grinding mechanism, the rotating unit further includes a first fastening nut which is screwed into the rotating shaft and tightly connects the inner ring of the first bearing to the rotating shaft.

[0015] According to the rotary grinding mechanism, the rotating unit further includes a second fastening nut which is screwed into the rotating shaft and tightly connects the inner ring of the third bearing to the rotating shaft.

[0016] According to the rotary grinding mechanism, the inner diameter of the inner ring of the second bearing is greater than the outer diameter of the rotating shaft.

[0017] According to the rotary grinding mechanism, the rotary driving device includes a cylinder support arm, a rotary driving cylinder, and a cylinder rocker arm. The rotary driving cylinder is installed on the cylinder support arm, and the piston rod of the rotary driving cylinder is linked and connected to the rotating shaft through the cylinder rocker arm.

[0018] According to the rotary grinding mechanism, the grinding unit includes a grinding claw driving cylinder and grinding claws. The grinding claw driving cylinder is linked and connected to the grinding claws to drive the grinding claws to close or open; the grinding claw driving cylinder is connected to the rotating shaft.

[0019] According to the rotary grinding mechanism, it further includes a buffer unit and a frame body. The buffer unit includes a guide rail, at least one slider, a bearing substrate, a fixed stop block, a downward pressing spring, and a positioning block; the guide rail is installed on the frame body, and the guide rail is arranged parallel to the stroke trajectory of the rotating unit driven by the lifting mechanism of the metallographic grinding machine; the slider is slidably arranged on the guide rail; the bearing substrate is arranged on the slider; the bearing substrate is provided with a positioning groove; the positioning block is installed on the frame body and located in the positioning groove to limit the stroke trajectory of the bearing substrate; the fixed stop block is arranged on the frame body, and a downward pressing spring is connected between the fixed stop block and the bearing substrate. The downward pressing spring is configured to generate a downward pressure on the bearing substrate so that the positioning groove abuts against the positioning block and is in the initial position;

[0020] The first bearing seat and the second bearing seat are installed on the bearing substrate.

[0021] To achieve the above object, the present utility model provides a metallographic grinding machine, which includes a lifting mechanism and a grinding disc, and further includes the rotary grinding mechanism described in any one of the above; the lifting mechanism is connected to the rotary grinding mechanism to drive the rotary grinding mechanism to move up or down on the grinding disc.

[0022] The rotary grinding mechanism provided by the present utility model is used on the lifting mechanism of a metallographic grinding machine. It includes a rotary unit and a grinding unit. The lifting mechanism of the metallographic grinding machine can drive the rotary grinding mechanism to displace axially. The grinding unit is used to grasp a metallographic specimen for grinding on the metallographic grinding machine. The rotary unit can drive the grinding unit to rotate, thereby driving the metallographic specimen to rotate to change the grinding path of the grinding surface of the metallographic specimen. The rotary unit includes a rotary driving device, a rotating shaft, a first bearing, a first bearing seat, a second bearing, a second bearing seat, a pre-tightening elastic member, and a jacking member. The rotating shaft is driven to rotate by the rotary driving device. The rotating shaft is connected to the grinding unit so that the rotary unit and the grinding unit form an integral body, further driving the grinding unit to rotate. The rotating shaft is coaxially arranged with the first bearing and the second bearing, and the rotating shaft rotates in the first bearing and the second bearing. Due to the process limitations of bearings in the prior art, it is difficult to achieve no clearance between the inner ring of the bearing and the rolling balls and between the rolling balls and the outer ring of the bearing, so that the rotating shaft generates displacement along its axial direction in the bearing, affecting the grinding accuracy. In order to avoid the influence of the bearing clearance on the grinding accuracy, the rotary unit jacks up the inner ring of the second bearing axially and towards the direction of the first bearing through the jacking member, and further jacks up the inner ring of the first bearing through the pre-tightening elastic member. The outer ring of the first bearing and the outer ring of the second bearing are respectively fixed on the first bearing seat and the second bearing seat, thereby reducing or eliminating the axial clearance of the bearing and avoiding the displacement of the rotating shaft from affecting the grinding accuracy. The rotary grinding mechanism is used on the lifting mechanism of the metallographic grinding machine. The lifting mechanism controls the displacement of the rotary grinding mechanism according to the grinding amount. When the lifting mechanism of the metallographic grinding machine malfunctions and the displacement of the rotary grinding mechanism is greater than the grinding amount of the metallographic specimen, the reaction force generated may cause damage to the structures of the rotary grinding mechanism and the lifting mechanism. In order to protect the structure, the rotary grinding mechanism may further include a buffer unit and a frame body. The frame body can support the buffer unit, the rotary unit, and the grinding unit. The buffer unit includes a guide rail, at least one slider, a bearing substrate, a fixed stop, a downward pressure spring, and a positioning block. The rotary unit is installed on the bearing substrate. The bearing substrate slides on the guide rail through the slider. When the reaction force is too large, the bearing substrate slides, driving the entire rotary grinding mechanism to deviate from the initial position. Due to the blocking of the fixed stop on the downward pressure spring, when the bearing substrate slides, it squeezes the downward pressure spring, and the downward pressure spring undergoes elastic deformation to reduce the influence of the reaction force on each structure. As the metallographic specimen is ground, the reaction force gradually decreases, and the downward pressure of the downward pressure spring pushes the bearing substrate back to the initial position, that is, the bearing substrate drives the rotary grinding mechanism back to the initial position, avoiding the influence of the displacement of the rotary grinding mechanism on the grinding accuracy. The initial position is defined by the positioning block and the positioning groove of the bearing substrate. The buffer unit is arranged on the frame body. The rotary unit is connected to the buffer unit together with the grinding unit. Connecting the frame body to the lifting mechanism of the metallographic grinding machine can enable the buffer unit, the rotary unit, and the grinding unit to move up and down as a whole on the lifting mechanism. Description of the Drawings

[0023] Figure 1 is a schematic structural view of a bearing provided by the prior art;

[0024] Figure 2 is a schematic view of the state where the first bearing inner ring, the second bearing inner ring, or the third bearing inner ring of an embodiment of the present invention is jacked up axially; the arrow indicates the jacking direction;

[0025] Figure 3A is a schematic view of the state when a grinding unit of an embodiment of the present invention grabs a metallographic specimen and grinds it on a grinding disc of a metallographic grinding machine at a first angle;

[0026] Figure 3B is a schematic view of the grinding path of the grinding surface of a metallographic specimen when a grinding unit of an embodiment of the present invention grabs a metallographic specimen and grinds it on a grinding disc of a metallographic grinding machine at a first angle; the arrow on the metallographic specimen indicates the grinding path of the grinding surface of the metallographic specimen, and the arrow on the grinding disc indicates the rotation direction of the grinding disc;

[0027] Figure 4A is a schematic view of the state when a grinding unit of an embodiment of the present invention grabs a metallographic specimen and grinds it on a grinding disc of a metallographic grinding machine at a second angle;

[0028] Figure 4B is a schematic view of the grinding path of the grinding surface of a metallographic specimen when a grinding unit of an embodiment of the present invention grabs a metallographic specimen and grinds it on a grinding disc of a metallographic grinding machine at a second angle; the arrow on the metallographic specimen indicates the grinding path of the grinding surface of the metallographic specimen, and the arrow on the grinding disc indicates the rotation direction of the grinding disc;

[0029] Figure 5 is a schematic structural view of a rotary grinding mechanism of an embodiment of the present invention;

[0030] Figure 6 is a partial structural schematic view of a rotating unit of an embodiment of the present invention;

[0031] Figure 7 is a schematic view of the state where the bearing substrate of a buffer unit of an embodiment of the present invention is in an initial position;

[0032] Figure 8 is a schematic structural view of a metallographic grinding machine of an embodiment of the present invention. Detailed Description of the Invention

[0033] In order to make the objectives, technical solutions and advantages of the present utility model more clear and understandable, the present utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0034] It should be understood that if there appear such terms as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., the orientation or positional relationship indicated by these terms is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation to the present application.

[0035] It should be noted that if an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. If an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the present application are only for the purpose of illustration and do not represent the only implementation manner.

[0036] See Figures 2 to 6 , in an embodiment of the present utility model, a rotary grinding mechanism 100 is provided for the lifting mechanism 200 of a metallographic grinding machine 400, including:

[0037] A rotating unit 10, which includes a rotation driving device 11, a rotating shaft 12, a first bearing 13, a first bearing seat 133, a second bearing 14, a second bearing seat 143, a pre-tightening elastic member 15 and a jacking member 16; the rotation driving device 11 is linked with the rotating shaft 12 to drive the rotating shaft 12 to rotate; the first bearing 13 and the second bearing 14 are sequentially sleeved on the outer side of the rotating shaft 12 along the axial direction of the rotating shaft 12; the first bearing inner ring 131 of the first bearing 13 is fixedly connected to the rotating shaft 12; the first bearing outer ring 132 of the first bearing 13 is connected to the first bearing seat 133; the second bearing outer ring 142 of the second bearing 14 is connected to the second bearing seat 143; the jacking member 16 is disposed on the second bearing seat 143 and jacks up the second bearing inner ring 141 of the second bearing 14 along the axial direction and towards the direction of the first bearing 13; a pre-tightening elastic member 15 is connected between the first bearing inner ring 131 and the second bearing inner ring 141;

[0038] The grinding unit 20 is connected to the rotating shaft 12.

[0039] In this embodiment, the rotary grinding mechanism 100 is used on the lifting mechanism 200 of the metallographic grinding machine 400. The metallographic grinding machine 400 is used to grind or polish the metallographic specimen 6. The rotary grinding mechanism 100 can be used not only in the grinding process but also in the polishing process. When grinding the metallographic specimen 6, the lifting mechanism 200 is used to control the displacement of the rotary grinding mechanism 100 in its axial direction according to the grinding amount of the metallographic specimen 6, so that the metallographic specimen 6 is ground to the position of its grinding line. The rotary grinding mechanism 100 includes a rotating unit 10 and a grinding unit 20. The grinding unit 20 is used to grasp the metallographic specimen 6 and grind it on the metallographic grinding machine 400. The rotating unit 10 can drive the grinding unit 20 to rotate, thereby driving the metallographic specimen 6 to rotate to change the grinding path of the grinding surface of the metallographic specimen 6. For example, the grinding unit 20 grasps the metallographic specimen 6 and grinds it on the grinding disk 300 of the metallographic grinding machine 400 at a first angle (see Figure 3A ). During the grinding process, the rotation direction of the grinding disk 300 remains unchanged, and the grinding path of the grinding surface of the metallographic specimen 6 is as shown in Figure 3B . After grinding for a period of time, the rotating unit 10 drives the grinding unit 20 to drive the metallographic specimen 6 to rotate to a second angle. The rotation direction of the grinding disk 300 remains unchanged, and the grinding unit 20 grasps the metallographic specimen 6 and grinds it on the grinding disk 300 of the metallographic grinding machine 400 at the second angle (see Figure 4A ), and the grinding path of the grinding surface of the metallographic specimen 6 is as shown in Figure 4B . Of course, during the grinding process, according to the process requirements, the rotating unit 10 can drive the grinding unit 20 to drive the metallographic specimen 6 to switch back and forth between the first angle and the second angle. Thus, the rotating unit 10 drives the grinding unit 20 to rotate to different angles to change the grinding path of the grinding surface of the metallographic specimen 6. Specifically, the rotating shaft 12 of the rotating unit 10 is driven to rotate by the rotation driving device 11. The rotating shaft 12 is connected to the grinding unit 20 so that the rotating unit 10 and the grinding unit 20 form an integral body, further driving the grinding unit 20 to rotate. The rotating shaft 12 is coaxially arranged with the first bearing 13 and the second bearing 14, and the rotating shaft 12 rotates in the first bearing 13 and the second bearing 14. See Figure 1, due to the process limitations of bearings in the prior art, there is a first gap 3 between the inner ring 1 of the bearing and the ball 2 and a second gap 5 between the ball 2 and the outer ring 4 of the bearing. It is difficult to achieve zero clearance, which may cause the rotating shaft 12 to displace axially within the bearing and affect the grinding accuracy. To avoid the influence of the bearing clearance on the grinding accuracy, the first inner bearing ring 131 in the rotating unit 10 forms an integral body with the second inner bearing ring 141 through a preloading elastic member 15. When the second inner bearing ring 141 is jacked up axially and towards the first bearing 13 by the jacking member 16, the first inner bearing ring 131 is also jacked up by the preloading elastic member 15. The first outer bearing ring 132 and the second outer bearing ring 142 are respectively fixed to the first bearing seat 133 and the second bearing seat 143 and are stationary. At this time, there is a misalignment between the first inner bearing ring 131 and the first outer bearing ring 132, causing the ball to be tightly fitted axially with the first inner bearing ring 131 and the ball to be tightly fitted axially with the first outer bearing ring 132 (see Figure 2 ), thereby reducing or eliminating the axial clearance of the first bearing 13. When the first inner bearing ring 131 receives a force to be jacked up axially, the rotating shaft 12 fixedly connected thereto also receives a force to be jacked up axially, avoiding the displacement of the rotating shaft 12 and affecting the grinding accuracy. Since the rotating shaft 12 is fixedly connected to the first inner bearing ring 131, optionally, the rotating shaft 12 and the first inner bearing ring 131 are fixedly connected by a first fastening nut 18. The first fastening nut 18 is screwed into the rotating shaft 12 to fixedly connect the first inner bearing ring 131 and the rotating shaft 12, so that the rotating shaft 12, the first inner bearing ring 131, the preloading elastic member 15, and the second inner bearing ring 141 are connected as a whole. When the rotating shaft 12 rotates, the first inner bearing ring 131 rotates accordingly, further driving the preloading elastic member 15 and the second inner bearing ring 141 to rotate accordingly. Thus, the second bearing 14 can not only provide a force to jack up the first inner bearing ring 131 axially through the preloading elastic member 15 to reduce or eliminate the axial clearance of the first bearing 13, but also ensure that the preloading elastic member 15 rotates accordingly, avoiding damage to the preloading elastic member 15 by the rotating force.

[0040] As an optional embodiment, see Figure 5 and Figure 6, the rotating unit 10 further includes a third bearing 17 and a third bearing seat 173; the third bearing 17 is sleeved outside the rotating shaft 12; the third bearing inner ring 171 of the third bearing 17 is fixedly connected to the rotating shaft 12; the third bearing outer ring 172 of the third bearing 17 is connected to the third bearing seat 173; the third bearing 17 is located on the side of the second bearing 14 away from the first bearing 13; a boss 121 abuts against the side of the third bearing inner ring 171 away from the second bearing 14, and the boss 121 is integrally formed with the rotating shaft 12; the outer diameter of the boss 121 is greater than the inner diameter of the third bearing inner ring 171, and the outer diameter of the boss 121 is less than or equal to the outer diameter of the third bearing inner ring 171.

[0041] In this embodiment, the rotation of the rotating shaft 12 can be further stabilized by the third bearing 17. The third bearing inner ring 171 is fixedly connected to the rotating shaft 12. Optionally, the rotating shaft 12 and the third bearing inner ring 171 are fixedly connected by a second fastening nut 19. The second fastening nut 19 is screwed into the rotating shaft 12 to fixedly connect the third bearing inner ring 171 and the rotating shaft 12, and the boss 121 integrally formed with the rotating shaft 12 abuts against the side of the third bearing 17 away from the second bearing 14. Thus, the first bearing inner ring 131 and the third bearing inner ring 171 are connected into a whole through the rotating shaft 12. When the first bearing inner ring 131 receives a force that jacks it up in its axial direction, the rotating shaft 12 and the third bearing inner ring 171 also receive a force that jacks them up in their axial directions, thereby reducing or eliminating the clearance of the third bearing 17 in its axial direction and preventing the rotating shaft 12 from displacing and affecting the grinding accuracy.

[0042] As an alternative embodiment, refer to Figure 6 , the preloading elastic member 15 is a preloading spring;

[0043] A first retaining ring 151 is arranged between the preloading spring and the first bearing inner ring 131; the outer diameter of the side of the first retaining ring 151 in contact with the first bearing inner ring 131 is less than or equal to the outer diameter of the first bearing inner ring 131, and the outer diameter of the side of the first retaining ring 151 in contact with the preloading spring is greater than or equal to the outer diameter of the preloading spring;

[0044] A second retaining ring 152 is arranged between the preloading spring and the second bearing inner ring 141; the outer diameter of the side of the second retaining ring 152 in contact with the second bearing inner ring 141 is less than or equal to the outer diameter of the second bearing inner ring 141, and the outer diameter of the side of the second retaining ring 152 in contact with the preloading spring is greater than or equal to the outer diameter of the preloading spring;

[0045] The jacking member 16 is a set screw.

[0046] In this embodiment, the rotating shaft 12 penetrates into the inner rings 131 of the first bearing, the inner rings 141 of the second bearing, and the inner rings 171 of the third bearing. The rotating shaft 12 is tightly fitted between the inner rings 131 of the first bearing and the inner rings 171 of the third bearing, and the rotating shaft 12 and the inner rings 141 of the second bearing can be installed without contact. A preloading spring is installed between the inner ring 131 of the first bearing and the inner ring 141 of the second bearing. A first retaining ring 151 is installed between the preloading spring and the inner ring 131 of the first bearing, and the first retaining ring 151 presses against the inner ring 131 of the first bearing. A second retaining ring 152 is installed between the preloading spring and the inner ring 141 of the second bearing, and the second retaining ring 152 presses against the inner ring 141 of the second bearing. A first fastening nut 18 is inserted through the rotating shaft 12 and is arranged in close contact with the inner ring 131 of the first bearing. The first fastening nut 18 is tightened against the inner ring 131 of the first bearing after being lifted by the lifting member 16. A second fastening nut 19 is installed in close contact with the inner ring 171 of the third bearing. After the first fastening nut 18 is tightened, the second fastening nut 19 is then tightened against the inner ring 171 of the third bearing. The lifting member 16 is a set screw and is arranged on the second bearing housing 143 to lift the inner ring 141 of the second bearing. The set screw can adjust the preloading force of the preloading spring. If the set screw is tightened a little in the direction of the preloading spring, the inner ring 141 of the second bearing moves in the direction of the preloading spring. As a result, the preloading spring is further compressed, the elastic force of the preloading spring increases, and the preloading force increases. If the set screw is loosened a little in the direction away from the preloading spring, the inner ring 141 of the second bearing moves in the direction away from the preloading spring, reducing the compression degree of the preloading spring, the elastic force of the preloading spring decreases, and the preloading force decreases. Since the set screw is installed on the second bearing housing 143 and is fixed, the inner ring 141 of the second bearing will not be displaced due to the preloading force of the preloading spring under the support of the set screw. Thus, the preloading spring always generates a force that jacks up the inner ring 131 of the first bearing in its axial direction. The preloading spring presses against the inner ring 131 of the first bearing through the first retaining ring 151. Because the preloading spring has a preloading force that jacks up in the axial direction, the inner ring 131 of the first bearing is always jacked up in the axial direction, thereby reducing or eliminating the axial clearance of the first bearing 13. A boss 121 abuts against the rotating shaft 12 on the side of the third bearing 17 away from the second bearing 14. The boss 121 is integrally formed with the rotating shaft 12. The outer diameter of the boss 121 is larger than the inner diameter of the inner ring 171 of the third bearing, and the outer diameter of the boss 121 is smaller than or equal to the outer diameter of the inner ring 171 of the third bearing. Thus, the inner ring 171 of the third bearing is installed on the boss 121, and the boss 121 and the second fastening nut 19 tightly clamp the inner ring 171 of the third bearing. Since the first fastening nut 18 and the second fastening nut 19 tightly hold the rotating shaft 12, the first fastening nut 18, the inner ring 131 of the first bearing, the second fastening nut 19, and the inner ring 171 of the third bearing are connected into a whole through the rotating shaft 12.The first fastening nut 18 is subjected to the force that jacks it up axially by the pre-tightening spring transmitted through the first bearing inner ring 131, thereby driving the rotating shaft 12 to have a jacking-up force axially. The boss 121 of the rotating shaft 12 drives the third bearing inner ring 171 to also have a jacking-up force axially, thereby reducing or eliminating the clearance of the third bearing 17 axially.

[0047] As an optional embodiment, the inner diameter of the second bearing inner ring 141 is larger than the outer diameter of the rotating shaft 12. That is, the second bearing inner ring 141 and the rotating shaft 12 are installed without contact, and the rotating shaft 12 can slide in the second bearing inner ring 141, reducing the wear of the rotating shaft 12 on the second bearing 14.

[0048] As an optional embodiment, refer to Figure 5 , the rotation driving device 11 includes a cylinder support arm 111, a rotation driving cylinder 112, and a cylinder rocker arm 113. The rotation driving cylinder 112 is installed on the cylinder support arm 111, and the piston rod 1121 of the rotation driving cylinder 112 is linked and connected to the rotating shaft 12 through the cylinder rocker arm 113. The piston rod 1121 of the rotation driving cylinder 112 performs reciprocating telescopic motion, and converts the reciprocating telescopic motion of the piston rod 1121 into a rotational motion through the cylinder rocker arm 113, thereby driving the rotating shaft 12 to rotate. Of course, the rotation driving device 11 can also be a driving motor, and the output shaft of the driving motor is connected to the rotating shaft 12 to drive the rotating shaft 12 to rotate.

[0049] As an optional embodiment, refer to Figure 5 , the grinding unit 20 includes a grinding claw driving cylinder 21 and grinding claws 22. The grinding claw driving cylinder 21 is linked and connected to the grinding claws 22 to drive the grinding claws 22 to close or open; the grinding claw driving cylinder 21 can control the grinding claws 22 to close or open to grasp or release the metallographic specimen 6. The grinding claw driving cylinder 21 is connected to the rotating shaft 12.

[0050] As an optional embodiment, refer to Figure 7, the rotary grinding mechanism 100 further includes a buffer unit 30 and a frame body 40. The buffer unit 30 includes a guide rail 31, at least one slider 32, a bearing base plate 33, a fixed stop 34, a downward pressing spring 35, and a positioning block 36. The guide rail 31 is installed on the frame body 40 and is arranged parallel to the travel trajectory of the rotary unit 10 driven by the lifting mechanism 200 of the metallographic grinding machine 400. The slider 32 is slidably arranged on the guide rail 31. The bearing base plate 33 is arranged on the slider 32. The bearing base plate 33 is provided with a positioning groove 331. The positioning block 36 is installed on the frame body 40 and is located in the positioning groove 331 to limit the travel trajectory of the bearing base plate 33. The fixed stop 34 is arranged on the frame body 40, and a downward pressing spring 35 is connected between the fixed stop 34 and the bearing base plate 33. The downward pressing spring 35 is configured to generate a downward pressure on the bearing base plate 33 so that the positioning groove 331 abuts against the positioning block 36 and is in the initial position 361.

[0051] The first bearing seat 133 and the second bearing seat 143 are installed on the bearing base plate 33.

[0052] In this embodiment, the rotary grinding mechanism 100 is used on the lifting mechanism 200 of the metallographic grinding machine 400. The lifting mechanism 200 controls the displacement of the rotary grinding mechanism 100 according to the grinding amount. When an abnormality occurs in the lifting mechanism 200 of the metallographic grinding machine 400 and the downward displacement of the rotary grinding mechanism 100 is greater than the grinding amount of the metallographic specimen 6, the reaction force generated may cause structural damage to the rotary grinding mechanism 100 and the lifting mechanism 200. To protect the structure, the rotary grinding mechanism 100 may further include a buffer unit 30 and a frame body 40. The frame body 40 can support the buffer unit 30, the rotary unit 10, and the grinding unit 20 so that each unit is integrated. The buffer unit 30 can play a buffering role to avoid impacts on each structure. The fixed stop 34 can be fixed on the side substrate of the frame body 40. A downward pressure spring 35 is installed between the fixed stop 34 and the bearing substrate 33. Since the fixed stop 34 is fixed and the bearing substrate 33 is installed on the slider 32 and can move, and the rotary unit 10 and the grinding unit 20 are installed on the bearing substrate 33 as a whole, the downward pressure spring 35 is configured to have a downward pressure to push the bearing substrate 33 to the initial position 361. This can not only make the bearing substrate 33 return to the initial position 361 when it deviates from the initial position 361, but also make the rotary unit 10 and the grinding unit 20 have a downward pressure to press the metallographic specimen 6 grabbed by the grinding unit 20 against the grinding disc 300 of the metallographic grinding machine 400 for grinding. The initial position 361 of the bearing substrate 33 and the end position after the bearing substrate 33 deviates from the initial position 361 are restricted by the positioning groove 331 and the positioning block 36. Under the action of the downward pressure spring 35, the rotary grinding mechanism 100 can return to the initial position 361 after deviating from the initial position 361, avoiding the influence of the displacement of the bearing substrate 33 on the grinding accuracy. When the grinding unit 20 grabs the metallographic specimen 6 for grinding, the downward pressure spring 35 can also ensure that the downward pressure is continuous, enabling the grinding disc 300 to stably grind the metallographic specimen 6. For example, during the grinding process, if the displacement speed of the rotary grinding mechanism 100 controlled by the lifting mechanism 200 is greater than the cutting speed of the grinding disc 300 on the metallographic specimen 6, the reaction force of the grinding disc 300 on the metallographic specimen 6 will increase. At this time, the rotary grinding mechanism 100 moves, and the rotary grinding mechanism 100 temporarily deviates from the initial position 361. Due to the existence of the downward pressure spring 35, the compressed downward pressure spring 35 will also give a greater downward pressure. During the process of cutting the metallographic specimen 6, the downward pressure spring 35 gradually pushes the bearing substrate 33 to reset. When all the grinding amounts of the metallographic specimen 6 are cut, that is, when grinding to the grinding line position of the metallographic specimen 6, the rotary grinding mechanism 100 also returns to the initial position 361 under the action of the downward pressure spring 35, avoiding the influence of the displacement of the rotary grinding mechanism 100 on the grinding accuracy.

[0053] See Figure 8, in an embodiment of the present utility model, a metallographic grinding machine 400 is further provided, which includes a lifting mechanism 200, a grinding disc 300, and the rotary grinding mechanism 100 described in any one of the above; the lifting mechanism 200 is connected to the rotary grinding mechanism 100 to drive the rotary grinding mechanism 100 to perform upward or downward movement away from or close to the grinding disc 300 on the grinding disc 300. The rotary grinding mechanism 100 can be driven by a moving mechanism to directly above the grinding disc 300 and then driven by the lifting mechanism 200 to perform lifting and lowering.

[0054] It should be noted that for the metallographic grinding machine 400 provided in the embodiment of the present invention, the specific implementation and the technical effects generated by its rotary grinding mechanism 100 are the same as those of the rotary grinding mechanism 100 in the foregoing embodiment. For the sake of brief description, for the parts not mentioned in the embodiment of the metallographic grinding machine 400, reference may be made to the corresponding content in the embodiment of the rotary grinding mechanism 100.

[0055] In summary, the rotary grinding mechanism provided by the present utility model includes a rotary unit and a grinding unit. The grinding unit is used to grasp a metallographic specimen and grind it on a metallographic grinding machine. The rotary unit can drive the grinding unit to rotate, thereby driving the metallographic specimen to rotate, so as to change the grinding path of the grinding surface of the metallographic specimen. The rotary unit includes a rotary driving device, a rotating shaft, a first bearing, a first bearing seat, a second bearing, a second bearing seat, a pre-tightening elastic member, and a jacking member; the rotating shaft is driven to rotate by the rotary driving device, and the rotating shaft is connected to the grinding unit so that the rotary unit and the grinding unit form an integral body, further driving the grinding unit to rotate. The rotating shaft rotates in the first bearing and the second bearing. Due to the process limitations of the bearings in the prior art, it is difficult to achieve no clearance between the inner ring of the bearing and the balls, and between the balls and the outer ring of the bearing, so that the rotating shaft generates displacement along its axial direction in the bearing, affecting the grinding accuracy. In order to avoid the influence of the bearing clearance on the grinding accuracy, the rotary unit jacks up the inner ring of the second bearing axially through the jacking member, and further jacks up the inner ring of the first bearing through the pre-tightening elastic member, while the outer ring of the first bearing and the outer ring of the second bearing are respectively fixed on the first bearing seat and the second bearing seat, thereby reducing or eliminating the axial clearance of the bearing and avoiding the displacement of the rotating shaft from affecting the grinding accuracy. The rotary grinding mechanism is used on the lifting mechanism of a metallographic grinding machine. The lifting mechanism controls the displacement of the rotary grinding mechanism according to the grinding amount. When the lifting mechanism of the metallographic grinding machine malfunctions and the displacement of the rotary grinding mechanism is greater than the grinding amount of the metallographic specimen, the reaction force generated may cause damage to the structures of the rotary grinding mechanism and the lifting mechanism. In order to protect the structure, the rotary grinding mechanism may further include a buffer unit and a frame body. The frame body can support the buffer unit, the rotary unit, and the grinding unit. The buffer unit includes a guide rail, at least one slider, a bearing substrate, a fixed block, a downward pressure spring, and a positioning block; the rotary unit is installed on the bearing substrate, and the bearing substrate slides on the guide rail through the slider. When the reaction force is too large, the bearing substrate slides and drives the entire rotary grinding mechanism to deviate from the initial position. Due to the blockage of the fixed block on the downward pressure spring, the bearing substrate squeezes the downward pressure spring when sliding, and the downward pressure spring undergoes elastic deformation to reduce the influence of the reaction force on each structure. As the metallographic specimen is ground, the reaction force gradually decreases, and the downward pressure of the downward pressure spring pushes the bearing substrate back to the initial position, that is, the bearing substrate drives the rotary grinding mechanism back to the initial position, avoiding the influence of the displacement of the rotary grinding mechanism on the grinding accuracy. The initial position is defined by the positioning block and the positioning groove of the bearing substrate. The buffer unit is arranged on the frame body, the rotary unit is connected to the buffer unit together with the grinding unit, and the frame body is connected to the lifting mechanism of the metallographic grinding machine, so that the buffer unit, the rotary unit, and the grinding unit can move up and down as a whole on the lifting mechanism.

[0056] Of course, the present utility model may also have many other embodiments. Without departing from the spirit and essence of the present utility model, those skilled in the art can make various corresponding changes and deformations according to the present utility model. However, these corresponding changes and deformations should all fall within the protection scope of the appended claims of the present utility model.

Claims

1. A rotary grinding mechanism, used on the lifting mechanism of a metallographic grinding machine, characterized in that: include: A rotating unit, comprising a rotating drive device, a rotating shaft, a first bearing, a first bearing seat, a second bearing, a second bearing seat, a preload elastic member and a lifting member; the rotating drive device is linked to the rotating shaft to drive the rotating shaft to rotate; the first bearing and the second bearing are sequentially sleeved on the outer side of the rotating shaft along the axial direction of the rotating shaft; the first bearing inner ring of the first bearing is tightly connected to the rotating shaft; the first bearing outer ring of the first bearing is connected to the first bearing seat; the second bearing outer ring of the second bearing is connected to the second bearing seat; the lifting member is arranged on the second bearing seat, and lifts the second bearing inner ring of the second bearing along the axial direction and toward the first bearing; the preload elastic member is connected between the first bearing inner ring and the second bearing inner ring; A grinding unit is connected to the rotating shaft.

2. The rotary grinding mechanism according to claim 1, characterized in that: The rotating unit also includes a third bearing and a third bearing seat; the third bearing is sleeved on the outer side of the rotating shaft; the third bearing inner ring of the third bearing is tightly connected to the rotating shaft; the third bearing outer ring of the third bearing is connected to the third bearing seat; the third bearing is located on the side of the second bearing away from the first bearing; a boss is abutted on the side of the third bearing inner ring away from the second bearing, and the boss is integrally formed with the rotating shaft; the outer diameter of the boss is larger than the inner diameter of the inner ring of the third bearing, and the outer diameter of the boss is smaller than or equal to the outer diameter of the inner ring of the third bearing.

3. The rotary grinding mechanism according to claim 1, characterized in that: The preload elastic member is a preload spring; A first pressing ring is arranged between the preload spring and the first bearing inner ring; the outer diameter of the side of the first pressing ring in contact with the first bearing inner ring is less than or equal to the outer diameter of the first bearing inner ring, and the outer diameter of the side of the first pressing ring in contact with the preload spring is greater than or equal to the outer diameter of the preload spring; A second pressing ring is arranged between the preload spring and the second bearing inner ring; the outer diameter of the side of the second pressing ring in contact with the second bearing inner ring is less than or equal to the outer diameter of the second bearing inner ring, and the outer diameter of the side of the second pressing ring in contact with the preload spring is greater than or equal to the outer diameter of the preload spring; The lifting piece is a set bolt.

4. The rotary grinding mechanism according to claim 1, characterized in that: The rotating unit further includes a first fastening nut, which is screwed into the rotating shaft and fastens the first bearing inner ring to the rotating shaft.

5. The rotary grinding mechanism according to claim 2, characterized in that: The rotating unit further includes a second fastening nut which is screwed into the rotating shaft and fastens the third bearing inner ring to the rotating shaft.

6. The rotary grinding mechanism according to claim 1, characterized in that: The inner diameter of the second bearing inner ring is greater than the outer diameter of the rotating shaft.

7. The rotary grinding mechanism according to claim 1, characterized in that: The rotary drive device comprises a cylinder support arm, a rotary drive cylinder and a cylinder rocker arm. The rotary drive cylinder is mounted on the cylinder support arm, and a piston rod of the rotary drive cylinder is linked to the rotating shaft via the cylinder rocker arm.

8. The rotary grinding mechanism according to claim 1, characterized in that: The grinding unit comprises a grinding claw driving cylinder and a grinding claw, wherein the grinding claw driving cylinder is linked to the grinding claw to drive the grinding claw to close or open; The grinding claw driving cylinder is connected to the rotating shaft.

9. The rotary grinding mechanism according to claim 1, characterized in that: The frame body also includes a buffer unit and a frame body, wherein the buffer unit includes a guide rail, at least one slider, a bearing base plate, a fixed stopper, a downward pressure spring and a positioning block; the guide rail is mounted on the frame body, and the guide rail is arranged parallel to the travel trajectory of the rotating unit driven by the lifting mechanism of the metallographic grinder; the slider is slidably arranged on the guide rail; the bearing base plate is arranged on the slider; the bearing base plate is provided with a positioning groove; the positioning block is mounted on the frame body and is located in the positioning groove to limit the travel trajectory of the bearing base plate; the fixed stopper is arranged on the frame body, and a downward pressure spring is connected between the fixed stopper and the bearing base plate, and the downward pressure spring is configured to generate downward pressure on the bearing base plate so that the positioning groove and the positioning block are in an initial position after being abutted against each other; The first bearing seat and the second bearing seat are installed on the bearing base plate.

10. A metallographic grinding machine, comprising a lifting mechanism and a grinding disc, characterized in that: It also includes the rotary grinding mechanism according to any one of claims 1 to 9; the lifting mechanism is connected to the rotary grinding mechanism to drive the rotary grinding mechanism to ascend or descend on the grinding disc.

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