Thin oil vibration exciter with rotating shaft dynamic balance adjustment function

Abstract

The utility model relates to the field of vibration exciters, in particular to a thin oil vibration exciter with a rotating shaft dynamic balance adjusting function, which comprises a vibration exciter shell and a transmission shaft, bearings are sleeved on two sides of the middle of the transmission shaft, outer rings of the bearings are abutted against an inner ring of the vibration exciter shell, and an oil stirring sheet is arranged on the transmission shaft between the bearings. Eccentric blocks are arranged at the two ends of the transmission shaft, sealing structures for sealing the interior of the vibration exciter shell are detachably arranged at the two ends of the vibration exciter shell, and at least one adjusting mechanism for adjusting the balance of the transmission shaft is coaxially and rotationally arranged on the transmission shaft. According to the thin oil vibration exciter with the rotating shaft dynamic balance adjustment function, the balance state of the transmission shaft can be adjusted by changing the centrifugal force of the transmission shaft, and the situations that abrasion of parts such as a bearing and a shaft seal is accelerated due to long-time unbalance of the transmission shaft, oil leakage occurs or the parts are damaged, the working efficiency of a unit is reduced, and the service life of the unit is prolonged are avoided.

Description

Technical Field

[0001] The utility model relates to the field of vibrators, in particular to a thin oil vibrator with a rotating shaft dynamic balance adjustment function. Background Art

[0002] The oil vibrator is a device that works on the principle of oil film lubrication and excitation. It is mainly used to generate exciting force to drive related machinery or objects to vibrate or move.

[0003] Existing thin oil vibrators often add oil strippers on the shaft to push the oil in the oil pool to reduce the cooling rate, so the shaft is prone to imbalance when used for a long time. The imbalance of the exciter rotor can lead to a series of adverse consequences. First, the rotor imbalance will cause repeated bending and internal stress of the rotor, which may cause fatigue damage and fracture of the rotor. Secondly, the rotor imbalance will generate vibration and noise, which will accelerate the wear of parts such as bearings and shaft seals, thereby reducing the working efficiency and service life of the unit. Therefore, how to overcome the above-mentioned technical problems and defects has become a key issue that needs to be solved. Utility Model Content

[0004] The purpose of the invention of the utility model is to overcome the defects described in the background technology, thereby realizing a thin oil vibrator with dynamic balancing adjustment of the rotating shaft. The device can adjust the balance state of the transmission shaft by changing the centrifugal force of the transmission shaft, so as to avoid the long-term imbalance of the transmission shaft which accelerates the wear of bearings, shaft seals and other parts, and causes oil leakage or parts damage, thereby reducing the working efficiency and service life of the unit.

[0005] In order to achieve the above-mentioned invention object, the technical solution of the utility model is: a thin oil vibrator with dynamic balancing adjustment of the rotating shaft, including a vibrator housing and a transmission shaft, and the two ends of the transmission shaft pass through the vibrator housing. Bearings are sleeved on both sides of the middle part of the transmission shaft, and the outer ring of the bearing abuts against the inner ring of the vibrator housing. An oil-spreading plate is arranged on the transmission shaft between the bearings, and the oil-spreading plate is located in an oil pool opened inside the vibrator housing, and oil is spread in the oil pool to immerse the oil into various parts of the transmission shaft more quickly for cooling. Eccentric blocks are arranged at both ends of the transmission shaft. Both ends of the vibrator housing are detachably provided with a sealing structure that closes the interior of the vibrator housing, and the interior of the vibrator is sealed to avoid oil leakage. At least one adjustment mechanism for adjusting the balance of the transmission shaft is coaxially arranged on the transmission shaft. The unbalanced transmission shaft is balanced and adjusted to avoid damage to components.

[0006] In the above-mentioned thin oil vibrator with shaft dynamic balance adjustment, the vibrator housing has oil passages connected to the oil pool and the outside respectively, and the vibrator housing is provided with an oil drain bolt that blocks the oil passage and connects to the outside, and the thin oil in the oil pool is transported to various parts for cooling through the oil passage. The vibrator housing is provided with a detachable protective shell on the outside, and the vibrator is protected by the protective shell.

[0007] In the above-mentioned thin oil vibrator with shaft dynamic balance adjustment, at least one boss is fixedly provided in the middle of the transmission shaft, and the oil stripper is detachably provided on the boss.

[0008] In the above-mentioned thin oil vibrator with dynamic balancing adjustment of the rotating shaft, the eccentric block is detachably arranged on the transmission shaft by means of bolts and a flat key on the transmission shaft, and a weight plate is detachably arranged on the outer end of the eccentric block by means of bolts, and the amplitude of the vibrator can be changed by changing the number of weight plates.

[0009] In the above-mentioned thin oil vibrator with shaft dynamic balancing adjustment, the sealing structure includes an end cover detachably provided at the end of the vibrator housing.

[0010] An oil retaining ring for blocking the bearing position is nested on one side of the end cover facing the exciter housing, and the inner ring of the oil retaining ring is sleeved on the transmission shaft.

[0011] A sealing ring is nested on the side of the end cover facing away from the exciter housing. The inner ring of the sealing ring is sleeved on the transmission shaft, and the outer side of the sealing ring abuts against the eccentric block.

[0012] A sealing gasket is sleeved on the transmission shaft between the oil retaining ring and the sealing ring, a skeleton oil seal is arranged between the sealing gasket and the end cover, and a sealing ring is sleeved on the transmission shaft between the sealing gasket and the sealing ring.

[0013] In the above-mentioned thin oil vibrator with dynamic balancing adjustment of the rotating shaft, the adjustment mechanism includes a limit ring coaxially provided on the transmission shaft, and the limit ring is sleeved on the limit ring. The limit ring is detachably provided with an adjustment ring, and the adjustment ring is fixed to the limit ring by limit bolts evenly distributed around its outer ring and threadedly connected thereto, and the bottom end of the limit bolt passes through the adjustment ring and abuts against the outer ring of the limit ring. The limit ring is threaded with adjustment bolts evenly distributed around the circumference, and the bottom end of the adjustment bolt faces the limit ring, and a weight block is provided on the top of the adjustment bolt. The centrifugal force of the transmission shaft is changed by changing the position of the weight block, thereby adjusting the imbalance of the transmission shaft to prevent the transmission shaft from being in an unbalanced state for a long time.

[0014] In the above-mentioned thin oil vibrator with dynamic balancing adjustment of the rotating shaft, a guide ring is provided on the side of the adjusting bolt facing the adjusting ring. A guide groove is provided on the adjusting ring below the adjusting bolt, and a display rod is slidably provided inside the guide groove. The display rod moves in the guide ring through a guide wheel rotatably provided on one side of its end, and a scale group is provided on the display rod. A support ring extending into the guide ring is fixedly provided on the adjusting bolt, and the guide wheel rolls on the support ring. The position of the weight block relative to the adjusting ring can be visually observed, which is convenient for adjusting the balance of the transmission shaft.

[0015] Compared with the prior art, the thin oil vibrator with shaft dynamic balance adjustment of the utility model has at least the following beneficial effects:

[0016] 1. The utility model of the thin oil vibrator with shaft dynamic balancing adjustment is provided with an oil pool opened inside the vibrator housing and an oil stripper arranged on the transmission shaft, which can realize oil stripping from the oil pool, so that the oil enters the position on the transmission shaft that needs lubrication and cooling more quickly, so that the temperature of the vibrator is reduced more quickly during operation, the wear during operation is reduced, and the service life is extended.

[0017] 2. The utility model has a thin oil vibrator with a dynamic balancing adjustment of the rotating shaft, and both ends of the vibrator housing are detachably provided with sealing structures for sealing the interior of the vibrator housing. The sealing of the vibrator is achieved through multiple sealing structures, thereby ensuring the stability of the internal structure of the vibrator and reducing the wear and tear generated when the vibrator is working. At the same time, the possibility of oil leakage of the vibrator is greatly avoided, thereby extending the service life of the vibrator.

[0018] 3. The utility model provides a thin oil vibrator with a shaft dynamic balance adjustment, and at least one adjustment mechanism for adjusting the balance of the transmission shaft is coaxially arranged on the transmission shaft. The balance state of the transmission shaft can be adjusted by changing the centrifugal force of the transmission shaft, thereby preventing the long-term imbalance of the transmission shaft from accelerating the wear of parts such as bearings and shaft seals, causing oil leakage or parts damage, and reducing the working efficiency and service life of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is an overall cutaway schematic diagram of the thin oil vibrator with shaft dynamic balance adjustment of the utility model;

[0020] Figure 2 The utility model is a thin oil vibrator with a rotating shaft dynamic balance adjustment Figure 1 A magnified image of area A;

[0021] Figure 3 It is a schematic diagram of the exploded structure of the regulating mechanism of the thin oil vibrator with rotating shaft dynamic balance regulation of the utility model;

[0022] Figure 4It is a schematic diagram of the guide groove position of the thin oil vibrator with shaft dynamic balance adjustment of the utility model;

[0023] Figure 5 The utility model is an exploded schematic diagram of a guide ring and a guide wheel of a thin oil vibrator with a rotating shaft dynamic balance adjustment.

[0024] In the figure: 1. Vibrator housing; 2. Transmission shaft; 3. Bearing; 4. Oil stripper; 5. Oil pool; 6. Eccentric block;

[0025] 7. Sealing structure; 71. End cover; 72. Oil retaining ring; 73. Sealing ring; 74. Sealing gasket; 75. Framework oil seal; 76. Sealing ring;

[0026] 8. Adjustment mechanism; 81. Limiting ring; 82. Limiting ring; 83. Adjustment ring; 84. Limiting bolt; 85. Adjustment bolt; 86. Weight block; 87. Guide ring; 88. Guide groove; 89. Display rod; 90. Guide wheel; 91. Scale group; 92. Support ring;

[0027] 9. Oil circuit; 10. Oil drain bolt; 11. Protective shell; 12. Boss; 13. Weight plate. DETAILED DESCRIPTION

[0028] The following is a more detailed description of the thin oil vibrator with shaft dynamic balancing adjustment of the utility model in conjunction with the accompanying drawings and through specific implementation methods.

[0029] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0030] See also Figure 1-Figure 5The thin oil vibrator with shaft dynamic balancing adjustment of this embodiment can adjust the balance state of the transmission shaft 2 by changing the centrifugal force of the transmission shaft 2, so as to avoid the long-term imbalance of the transmission shaft 2, which accelerates the wear of the bearing 3, shaft seal and other parts, causes oil leakage or parts damage, and reduces the working efficiency and service life of the unit. In this embodiment, it mainly includes an exciter housing 1 and a transmission shaft 2, and both ends of the transmission shaft 2 pass through the exciter housing 1. Bearings 3 are sleeved on both sides of the middle part of the transmission shaft 2, and the outer ring of the bearing 3 abuts against the inner ring of the exciter housing 1. The bearing 3 supports the transmission shaft 2 in the middle part of the exciter housing 1, so that the transmission shaft 2 rotates on the bearing 3. An oil stripper 4 is arranged on the transmission shaft 2 between the bearings 3. The oil stripper 4 can be set as a rectangular, curved or arc-shaped bowl-shaped structure with a concave middle part according to actual needs. The oil stripper 4 is located in an oil pool 5 opened inside the exciter housing 1. At least one boss 12 is fixedly arranged in the middle of the transmission shaft 2, and the oil-pushing sheet 4 is detachably arranged on the boss 12. A plurality of bosses 12 can be arranged according to actual conditions. The oil-pushing sheet 4 pushes the oil in the oil pool 5, so that the oil is immersed in various parts of the transmission shaft 2 more quickly for cooling.

[0031] The vibrator housing 1 has an oil circuit 9 connected to the oil pool 5 and the outside world. The vibrator housing 1 is provided with an oil drain bolt 10 connected to the blocked oil circuit 9 and the outside world. The thin oil brought up by the oil stripper 4 is transported to various parts through the oil circuit 9 for cooling. When the thin oil is replaced, the oil drain bolt 10 can be rotated to discharge and pour the thin oil from the oil circuit 9. The vibrator housing 1 is detachably provided with a protective shell 11 on the outside, which fixes and protects the vibrator housing 1 to avoid damage during operation.

[0032] To achieve a vibration effect. Figure 1 In this embodiment, both ends of the transmission shaft 2 are provided with eccentric blocks 6. The eccentric blocks 6 are detachably provided on the transmission shaft 2 by bolts and flat keys on the transmission shaft 2, and the eccentric blocks 6 are swung by the rotation of the transmission shaft 2, thereby realizing external vibration. The outer end of the eccentric block 6 is detachably provided with a weight plate 13 by bolts, and the number of weight plates 13 can be changed according to actual conditions, thereby changing the amplitude of vibration and the energy output to the outside.

[0033] In order to achieve the sealing of the exciter. In this embodiment, see Figure 1 and Figure 2, both ends of the exciter housing 1 are detachably provided with a sealing structure 7 for sealing the interior of the exciter housing 1. The sealing structure 7 includes an end cover 71 detachably provided at the end of the exciter housing 1, and the end cover 71 is fixed to the exciter housing 1 by bolts. An oil retaining ring 72 for blocking the position of the bearing 3 is nested on the side of the end cover 71 facing the exciter housing 1, and the inner ring of the oil retaining ring 72 is sleeved on the transmission shaft 2. The movement of the bearing 3 is blocked by the oil retaining ring 72, so that the interior of the exciter is stable and the wear during operation is reduced. A sealing ring 73 is nested on the side of the end cover 71 facing away from the exciter housing 1, and the inner ring of the sealing ring 73 is sleeved on the transmission shaft 2, and the outer side of the sealing ring 73 is in contact with the eccentric block 6. A sealing gasket 74 is sleeved on the transmission shaft 2 between the oil retaining ring 72 and the sealing ring 73, and a skeleton oil seal 75 is provided between the sealing gasket 74 and the end cover 71. A sealing ring 76 is sleeved on the transmission shaft 2 between the sealing gasket 74 and the sealing ring 73. The end cover 71, the oil retaining ring 72, the sealing ring 73, the sealing gasket 74, the skeleton oil seal 75 and the sealing ring 76 cooperate with each other to achieve sealing inside the vibrator, ensure the stability of the internal structure of the vibrator, reduce the wear and tear generated when the vibrator is working, and at the same time greatly avoid the possibility of oil leakage of the vibrator, thereby extending the service life of the vibrator.

[0034] In order to achieve the dynamic balance adjustment of the shaft. Figure 1 , Figure 3 , Figure 4 and Figure 5 , at least one adjusting mechanism 8 for adjusting the balance of the transmission shaft 2 is coaxially rotatably arranged on the transmission shaft 2. The adjusting mechanism 8 can be arranged in multiples according to the actual situation, and its size and shape can also be determined according to the actual situation. The adjusting mechanism 8 includes a limiting ring 81 coaxially opened on the transmission shaft 2, and a limiting ring 82 is sleeved on the limiting ring 81. The inner and outer rings of the limiting ring 82 are both uneven frosted structures and are open structures. The limiting ring 81 is detachably provided with an adjusting ring 83, and the adjusting ring 83 is fixed on the limiting ring 81 through limiting bolts 84 evenly arranged on the circumference of its outer ring and threadedly connected thereto, and the bottom end of the limiting bolt 84 passes through the adjusting ring 83 and abuts against the outer ring of the limiting ring 82. When the position of the adjusting ring 83 needs to be fixed, the limiting ring 82 is squeezed by the limiting bolt 84 to make it fit on the limiting ring 81, and the friction force is increased by the surface of the frosted structure of the limiting ring 82.

[0035] The limiting ring 82 is threaded with adjusting bolts 85 evenly distributed around the circumference, the bottom ends of the adjusting bolts 85 face the limiting ring 82, and the top ends of the adjusting bolts 85 are provided with weight blocks 86. When the transmission shaft 2 is unbalanced and needs to be adjusted, the centrifugal force generated by the weight blocks 86 is changed by changing the position of the corresponding adjusting bolts 85 relative to the transmission shaft 2, thereby keeping the transmission shaft 2 in a balanced state when rotating.

[0036] A guide ring 87 is provided on the side of the adjusting bolt 85 facing the adjusting ring 83. A guide groove 88 is provided on the adjusting ring 83 below the adjusting bolt 85. A display rod 89 is slidably provided inside the guide groove 88. The display rod 89 moves inside the guide ring 87 through a guide wheel 90 rotatably provided on one side of the end thereof. A scale group 91 is provided on the display rod 89. A support ring 92 extending into the guide ring 87 is fixedly provided on the adjusting bolt 85, and the guide wheel 90 rolls on the support ring 92. When adjusting the position of the weight-added block 86 relative to the transmission shaft 2, the guide wheel 90 on the display rod 89 rolls on the support ring 92 inside the guide ring 87, so that as the adjusting bolt 85 rotates, the guide wheel 90 drives the display rod 89 to slide in the guide groove 88. At this time, the height of the display rod 89 extending out of the guide groove 88 can be checked by directly observing the scale group 91, so that the staff can adjust the balance conveniently.

[0037] The method of using the thin oil vibrator with dynamic balancing adjustment of the rotating shaft of the utility model is as follows: first, install the oil stripper plate on the protrusion, then sleeve the bearing 3 on the transmission shaft 2, and place it inside the vibrator housing 1. Sequentially sleeve the oil retaining ring 72, the sealing gasket 74, the end cover 71, the skeleton oil seal 75, the sealing ring 76 and the sealing ring 73 on the transmission shaft 2, and fix the end cover 71 on the vibrator housing 1 by bolts. Fix the eccentric block 6 to the transmission shaft 2 by bolts and flat keys to limit the sealing ring 73, so as to stabilize the internal structure of the vibrator, reduce the wear generated when the vibrator is working, and greatly avoid the possibility of oil leakage of the vibrator, thereby extending the service life of the vibrator. Then, sleeve the limit ring 82 on the limit ring 81, and sleeve the adjustment ring 83 on the limit ring 82. When fixing the position of the adjustment ring 83, squeeze the limit ring 82 by the limit bolt 84 to make it fit on the limit ring 81, and increase the friction by the surface of the frosted structure of the limit ring 82. The protective shell 11 is fixed to the exciter housing 1 , and the exciter housing 1 is fixed and protected by the protective shell 11 to avoid being damaged by foreign objects during operation.

[0038] When the vibrator is working, the thin oil in the oil pool 5 is transported faster through the oil circuit 9 to the position that needs cooling and lubrication through the oil stripper 4, so that the vibrator can be cooled quickly, the wear during operation can be reduced, and the service life can be extended. The number of weight-increasing plates 13 can be changed according to actual conditions, thereby changing the amplitude of vibration and the energy output to the outside. When the vibrator has been working for a long time and the transmission shaft 2 is unbalanced, the position limit of the adjustment ring 83 can be loosened by turning the limit bolt 84. Then turn the adjustment ring 83 to rotate the weight block 86 to the appropriate position, and turn the limit bolt 84 again to squeeze the limit ring 82 to make it fit on the limit ring 81, and increase the friction force through the surface of the frosted structure of the limit ring 82, so that the adjustment ring 83 is fixed.

[0039] Then the adjusting bolt 85 can be rotated to change the position of the weight block 86 relative to the transmission shaft 2, and the centrifugal force generated by the weight block 86 can be changed, so that the transmission shaft 2 can maintain a balanced state when rotating. In this process, the guide wheel 90 on the display rod 89 rolls on the support ring 92 inside the guide ring 87, so that as the adjusting bolt 85 rotates, the guide wheel 90 drives the display rod 89 to slide in the guide groove 88. At this time, the height of the display rod 89 extending out of the guide groove 88 can be directly observed by observing the scale group 91, which is convenient for the staff to adjust the balance. In this way, the balance state of the transmission shaft 2 is adjusted by changing the centrifugal force of the transmission shaft 2, so as to avoid the long-term imbalance of the transmission shaft 2, which accelerates the wear of the bearing 3, shaft seal and other parts, and causes oil leakage or part damage, thereby reducing the working efficiency and service life of the unit.

[0040] Unless otherwise defined, the technical or scientific terms used herein shall have the usual meanings understood by persons of ordinary skill in the field to which the present invention belongs. The use of "one" or "an" and other similar words in the specification and claims of this application does not necessarily indicate a quantitative limitation. "Include" or "comprises" and other similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and other similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0041] The exemplary implementation of the present invention is described in detail above with reference to the preferred embodiments. However, it can be understood by those skilled in the art that, without departing from the concept of the present invention, various modifications and variations can be made to the above-mentioned specific embodiments, and various combinations of the various technical features and structures proposed in the present invention can be made without exceeding the protection scope of the present invention.

Claims

1. A thin oil vibrator with shaft dynamic balance adjustment, characterized in that: The invention comprises an exciter housing (1) and a transmission shaft (2), wherein both ends of the transmission shaft (2) pass through the exciter housing (1), bearings (3) are sleeved on both sides of the middle part of the transmission shaft (2), the outer ring of the bearing (3) abuts against the inner ring of the exciter housing (1), an oil stripper (4) is arranged on the transmission shaft (2) between the bearings (3), and the oil stripper (4) is located in an oil pool (5) provided inside the exciter housing (1), eccentric blocks (6) are arranged at both ends of the transmission shaft (2), sealing structures (7) for sealing the inside of the exciter housing (1) are detachably arranged at both ends of the exciter housing (1), and at least one adjusting mechanism (8) for adjusting the balance of the transmission shaft (2) is coaxially rotatably arranged on the transmission shaft (2).

2. The thin oil vibrator with shaft dynamic balance adjustment according to claim 1, characterized in that: An oil passage (9) connected to the oil pool (5) and the outside world is provided inside the vibrator housing (1), an oil drain bolt (10) for blocking the oil passage (9) from connecting to the outside world is provided on the vibrator housing (1), and a protective shell (11) is detachably provided outside the vibrator housing (1).

3. The thin oil vibrator with shaft dynamic balance adjustment according to claim 1, characterized in that: At least one boss (12) is fixedly arranged in the middle of the transmission shaft (2), and the oil-releasing plate (4) is detachably arranged on the boss (12).

4. The thin oil vibrator with shaft dynamic balance adjustment according to claim 1, characterized in that: The eccentric block (6) is detachably mounted on the transmission shaft (2) via bolts and a flat key on the transmission shaft (2), and a weight-increasing plate (13) is detachably mounted on the outer end of the eccentric block (6) via bolts.

5. The thin oil vibrator with shaft dynamic balance adjustment according to claim 1, characterized in that: The sealing structure (7) comprises an end cover (71) detachably provided at the end of the exciter housing (1); An oil retaining ring (72) for blocking the position of the bearing (3) is nested on the side of the end cover (71) facing the exciter housing (1), and the inner ring of the oil retaining ring (72) is sleeved on the transmission shaft (2); A sealing ring (73) is nested on the side of the end cover (71) facing away from the exciter housing (1), the inner ring of the sealing ring (73) is sleeved on the transmission shaft (2), and the outer side of the sealing ring (73) is in contact with the eccentric block (6); A sealing gasket (74) is sleeved on the transmission shaft (2) between the oil retaining ring (72) and the sealing ring (73), a skeleton oil seal (75) is provided between the sealing gasket (74) and the end cover (71), and a sealing ring (76) is sleeved on the transmission shaft (2) between the sealing gasket (74) and the sealing ring (73).

6. The thin oil vibrator with shaft dynamic balance adjustment according to claim 1, characterized in that: The adjustment mechanism (8) comprises a limit ring (81) coaxially arranged on the transmission shaft (2), a limit ring (82) being sleeved on the limit ring (81), an adjustment ring (83) being detachably arranged on the limit ring (81), the adjustment ring (83) being fixed on the limit ring (81) by limit bolts (84) uniformly arranged on the circumference of the outer ring and threadedly connected to the limit ring, the bottom end of the limit bolt (84) passing through the adjustment ring (83) abuts against the outer ring of the limit ring (82), the limit ring (82) being threadedly arranged with adjustment bolts (85) uniformly arranged on the circumference, the bottom end of the adjustment bolt (85) facing the limit ring (82), and a weight block (86) being arranged on the top end of the adjustment bolt (85).

7. The thin oil vibrator with shaft dynamic balance adjustment according to claim 6, characterized in that: A guide ring (87) is provided on one side of the adjusting bolt (85) facing the adjusting ring (83); a guide groove (88) is provided on the adjusting ring (83) below the adjusting bolt (85); a display rod (89) is slidably provided inside the guide groove (88); the display rod (89) moves inside the guide ring (87) through a guide wheel (90) rotatably provided on one side of the end of the display rod (89); a scale group (91) is provided on the display rod (89); a support ring (92) extending into the guide ring (87) is fixedly provided on the adjusting bolt (85); and the guide wheel (90) rolls on the support ring (92).

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