Replaceable head torque sleeve for vacuum pump lock nut

Abstract

The utility model discloses a replaceable head fixed torque sleeve for vacuum pump locking nut relates to the technical field of dismouting tool, including sleeve body, replaceable tightening head and set screw, replaceable tightening head inboard is distributed four integral clamping jaw, on one hand through the installation positioning with sleeve body stop groove, realizes the stop of structure itself and prevents the rotation, on the other hand through the use positioning with locking nut card slot, realizes the drive with rotation in the tightening process, sleeve body outside and clamping jaw present certain angle and distribute several set screw holes, use set screw to realize the fastening and dismounting of replaceable tightening head. The integral locking nut fixed torque sleeve of present use has solved the problems, such as the easy damage of clamping jaw, the need of more root cleaning parts of cutter round angle, the big processing difficulty of clamping jaw and the high processing cost, and also solved the problems, such as the unfirm fastening mode of split locking nut fixed torque sleeve, the damage of vacuum pump locking mechanism or tool itself caused by the insufficient positioning precision.

Description

Technical Field

[0001] This utility model relates to the field of disassembly and assembly tools, specifically to a replaceable head constant torque sleeve for a vacuum pump locking nut. Background Technology

[0002] A lock nut is a fastener used in conjunction with a locking washer to prevent loosening through axial locking. Lock nuts are widely used in high-speed rotating machinery such as vacuum pumps. They can be used to secure bearing assemblies, providing high preload through fine threads to ensure rotor concentricity while preventing loosening or axial movement of the bearings due to high-speed rotation. Lock nuts can also be used to tighten shaft seal assemblies in vacuum pumps, preventing gas leakage and ensuring vacuum levels. Furthermore, lock nuts can be used in magnetic levitation vacuum pumps to secure permanent magnets or couplings, ensuring stable power transmission.

[0003] The high-speed rotation of a vacuum pump generates high-frequency vibrations, and load changes produce large impact loads, often resulting in resonance. Using conventional tightening tools and methods such as hammering and hook wrenches for installation cannot fully guarantee the reliability of the locking nut in the vacuum pump. It is necessary to use a conversion sleeve that can provide higher torque and achieve constant torque for installation and removal.

[0004] Existing integral locking nut torque sleeves suffer from problems such as easy damage to the chucks, numerous need for root cleaning of the tool fillet, high machining difficulty of the chucks, and high machining costs. The patent announcement number CN213765688U proposes a shaft-end locking nut tightening fixture. However, this structure is unsuitable for the use conditions of tightening locking nuts on vacuum pumps. On the one hand, its tightening method is insufficient to provide reliable tightening force for the locking nut within a safe range; on the other hand, it does not limit the positioning depth of the chucks, which increases the friction of the locking washer, hindering the relative rotation between the locking nut and the locking washer during tightening, thus causing damage to the locking mechanism. Utility Model Content

[0005] The purpose of this utility model is to overcome the above-mentioned shortcomings and provide a replaceable head constant torque sleeve for vacuum pump locking nuts.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A replaceable head torque sleeve for a vacuum pump locking nut includes a sleeve body and a replaceable tightening head. The front end of the sleeve body is provided with a circular protrusion, on which stop grooves are evenly distributed. The inner side of the replaceable tightening head is evenly distributed with integrated claws. One end of the integrated claw engages with the stop groove to achieve axial positioning and achieves circumferential anti-rotation function in the horizontal direction, and the other end engages with the groove of the first locking nut.

[0008] Includes a set screw, which secures the sleeve body to the replaceable tightening head.

[0009] The bottom end of the axial extension of the replaceable tightening head chuck extends out of the bottom of the circular body.

[0010] The total length of the replaceable tightening head is L1 = L2 + L3, where L2 is the length of the circular body of the replaceable tightening head and L3 is the length of the axial extension of the chuck.

[0011] The total length of the replaceable tightening head is 1.5-3 times the thickness of the first locking nut.

[0012] The circular protrusion at the front end of the sleeve body, which is the mounting part of the replaceable tightening head, includes a first outer circle, and the outer circle of the circular protrusion at the front end of the first outer circle is a second outer circle.

[0013] The diameter of the second outer circle is smaller than the diameter of the first outer circle, and the stop grooves are evenly distributed on the first and second outer circles.

[0014] The first outer circle and the second outer circle intersect to form an axial positioning surface for the installation of a replaceable tightening head.

[0015] The radius R of the fillet between the root circle of the evenly distributed claws on the inner side of the replaceable tightening head and the claws is 0.09-0.5mm.

[0016] The smaller the radius R of the fillet, the larger the contact area between the claw, the slot, and the stop slot.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] This utility model provides a replaceable head torque-regulating sleeve for vacuum pump locking nuts, including a sleeve body and a replaceable tightening head. The sleeve body has a circular protrusion at its front end, with evenly distributed stop grooves on the protrusion. The replaceable tightening head has an integrated jaw evenly distributed on its inner side. One end of the jaw engages with the stop groove for axial positioning, and the other end engages with the groove of the first locking nut. The integrated jaw achieves both installation positioning with the stop groove of the sleeve body and circumferential anti-rotation function in the horizontal direction, thus achieving structural anti-rotation. It also achieves usage positioning with the locking nut groove, allowing for rotation during tightening. This solves the problems of unreliable fastening methods and insufficient positioning accuracy in split-type locking nut torque-regulating sleeves, which can cause damage to the vacuum pump locking mechanism or the tooling itself. Furthermore, it addresses the problems of easily damaged jaws, numerous tool fillet areas requiring root cleaning, high jaw machining difficulty, and high processing costs associated with existing integral locking nut torque-regulating sleeves. By changing the tightening head with different inner diameters / tooth profiles, it can be adapted to a variety of non-standard lock nuts, expanding the application scenarios.

[0019] Furthermore, the integrated chuck reduces the number of parts in traditional split locking mechanisms, lowering the failure rate and extending service life.

[0020] Furthermore, multiple set screw holes are evenly distributed on the outer side of the sleeve body at a certain angle to the jaws, allowing for the tightening and loosening of the replaceable tightening head using set screws.

[0021] Furthermore, the radius R of the fillet between the root circle of the evenly distributed claws on the inner side of the replaceable tightening head and the claw is 0.09-0.5mm. The smaller the fillet radius, the larger the contact area between the claw and the groove of the first locking nut and the stop groove of the sleeve body, which can provide greater torque to the locking nut and generate greater stopping force between the claw and the sleeve body. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of this utility model;

[0023] Figure 2 This is a schematic diagram of the lock nut structure;

[0024] Figure 3 This is a schematic diagram of the sleeve body;

[0025] Figure 4 This is a schematic diagram of the replaceable tightening head;

[0026] Figure 5 This is a diagram showing one usage state of this utility model;

[0027] Explanation of reference numerals in the figure: 1. Sleeve body; 11. Stop groove; 12. First outer circle; 13. Second outer circle; 14. Third outer circle; 2. Replaceable tightening head; 21. Claw; 3. Set screw; 4. First locking nut; 41. Slot; 100. Vacuum pump; 101. Replaceable head torque sleeve for vacuum pump locking nut; 102. Second locking nut; 103. Locking washer; 104. Rotor; 105. Bearing. Detailed Implementation

[0028] To further understand the present invention, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments. It should be understood that the embodiments are merely illustrative and not intended to limit the scope of the invention.

[0029] Example 1

[0030] like Figures 1-4As shown, a replaceable head torque-regulating sleeve for a vacuum pump locking nut includes a sleeve body 1, a replaceable tightening head 2, and a set screw 3. The sleeve body 1 has a circular protrusion at its front end, with evenly distributed stop grooves 11 on the protrusion. The replaceable tightening head 2 has four evenly distributed integrated claws 21 on its inner side. One end of each claw 21 engages with the stop groove 11 for axial positioning, and the other end engages with the groove 41 of the first locking nut 4. The integrated claws 21 achieve assembly positioning with the sleeve body 1 and functional positioning with the first locking nut 4. Four set screw holes are evenly distributed on the outer side of the sleeve body 1 at a 45° angle to the claws 21. The set screw 3 enables the tightening and loosening of the replaceable tightening head 2 and the sleeve body 1.

[0031] Preferred, such as Figure 2 and Figure 4 As shown, the replaceable tightening head 2 has four integrated claws 21 evenly distributed on its inner side. The claws 21 correspond to the four slots 41 of the first locking nut 4. The width of the claw 21 is B1=be; b is the width of the slot 41 of the first locking nut 4; e is the assembly clearance (not shown), which is 0.1-0.3mm; more preferably, e is 0.2mm.

[0032] Preferred, such as Figure 2 and Figure 4 As shown, the root circle of the four integrated claws 21 evenly distributed on the inner side of the replaceable tightening head 2 has a diameter D2=d2+f, where d2 is the outer diameter of the first locking nut 4; f is the assembly clearance (not shown), which is 0.8-1.2mm; more preferably, f is 1mm.

[0033] Preferred, such as Figure 4 As shown, the outer diameter D of the replaceable tightening head 2 is 1.2-1.4 times D2; more preferably, it is 1.3 times D2.

[0034] Preferred, such as Figure 4 As shown, the radius R of the corner between the root circle of the four integrated jaws 21 evenly distributed on the inner side of the replaceable tightening head 2 and the jaw 21 is 0.09-0.5mm; more preferably, R is 0.3mm. The smaller the corner radius, the larger the contact area between the jaw 21 and the groove 41 of the first locking nut 4 and the stop groove 11 of the sleeve body 1, which can provide greater torque to the locking nut and generate greater stopping force between the jaws and the sleeve body 1. The minimum diameter of the conventional cutting wire in wire EDM is 0.18mm, so the minimum radius is 0.09mm. A larger diameter can be achieved by changing the cutting wire or programming.

[0035] Preferred, such as Figure 4 As shown, the end faces of the four integrated jaws 21 evenly distributed on the inner side of the replaceable tightening head 2 are aligned at a distance L = l + g; as Figure 2As shown, l is the distance between the bottom of the groove of the first locking nut 4 and the groove, and g is the assembly clearance (not shown), which is 0.1-0.3 mm; more preferably, g is 0.2 mm.

[0036] Preferred, such as Figure 4 As shown, the total length L1 of the replaceable tightening head 2 is L2 + L3, where L2 is the length of the circular body of the replaceable tightening head 2, and its value is 1.5-3 times T; more preferably, it is 2 times T, such as... Figure 2 As shown, T is the thickness of the first locking nut 4. L3 is the axial extension length of the four integrated claws 21 evenly distributed on the inner side of the replaceable tightening head 2, and its value is... Double L2; more preferably, take L2 times.

[0037] Preferred, such as Figure 3 As shown, the maximum outer circle of the sleeve body 1 is the first outer circle 12, and its diameter D' is similar to the outer circle diameter D of the replaceable tightening head 2; more preferably, the values ​​are equal.

[0038] Preferred, such as Figure 3 As shown, the circular protrusion at the front end of the first outer circle 12 of the sleeve body 1 forms the second outer circle 13. The diameter of the second outer circle 13 is smaller than the diameter of the first outer circle 12. The stop groove 11 is evenly formed on the sides of the first and second outer circles, i.e., on the circular protrusion, in a cross shape. The diameter of the second outer circle 13, D3 = D2 - h, is the assembly clearance (not shown), which is 0.1-0.2 mm; more preferably, h is 0.15 mm. The first outer circle 12 and the second outer circle 13 intersect to form the mounting axial positioning surface of the replaceable tightening head 2.

[0039] Preferred, such as Figure 1 and 3 As shown, the height of the second outer circle 13 protrusion of the sleeve body 1 is L4 = L2 - T + i, where i is the safety clearance dimension, which is 1.8-2.2 mm; more preferably, i is 2 mm.

[0040] Example 2

[0041] A replaceable head torque sleeve for a vacuum pump locking nut, its assembly and usage are as follows:

[0042] like Figures 1-5As shown, a second locking nut 102 of the vacuum pump 100 is installed on the rotor 104 using a replaceable head torque sleeve 101 to limit the axial movement of the bearing 105. A locking washer 103 is provided between the second locking nut 102 and the bearing 105. The locking washer 103 includes an inner claw and an outer claw. The inner claw of the locking washer 103 locks the rotor 104, and the outer claw locks the second locking nut 102. The bearing 105 and the locking washer 103 are clamped and fixed by the shoulder of the rotor 104 and the second locking nut 102, realizing bidirectional locking between the second locking nut 102 and the rotor 104. The design incorporates reasonable safety clearance dimensions to ensure sufficient contact area between the chuck 21 and the second locking nut 102 for locking the bearing 105, while also reasonably limiting the positioning depth of the chuck. This prevents the torque sleeve from contacting the locking washer 103, which could increase the friction of the locking washer 103, hindering the relative rotation between the second locking nut 102 and the locking washer 103 during tightening, and thus causing damage to the locking mechanism.

[0043] Preferred, such as Figure 1 and 3 As shown, four stop grooves 11 are evenly distributed on the circular protrusion at the front end of the sleeve body 1. The groove width B2 = B1 + j, where j is the assembly clearance (not shown), and its value is 0.15-0.25 mm; more preferably, j is 0.2 mm. The groove depth L5 = L4 + L3 + k, where k is the over-positioning clearance dimension, and its value is 0.2-0.4 mm; more preferably, k is 0.25 mm.

[0044] Preferred, such as Figure 1 and 3 As shown, the sharp corner where the second outer circle 13 of the sleeve body 1 intersects with the side face of the stop groove 11 is chamfered. The chamfer size is C×45°, where C is 0.3-1mm; more preferably, C is 0.5mm. The size of the chamfer here is related to the radius of the fillet between the root circle of the chuck 21 and the chuck 21, and should ensure that there is no interference after assembly.

[0045] Preferred, such as Figure 1 and 3 As shown, the rear end of the first outer circle 12 of the sleeve body 1 is a connecting conical surface, and the conical surface angle α is 15-45°; more preferably, α is 30°.

[0046] Preferred, such as Figure 5 As shown, the side length S of the central square hole at the rear end wall of the replaceable head constant torque sleeve 101 for vacuum pump locking nut is S=s+m, where s is the side length of the square tenon of the constant torque wrench (not shown), and m is the assembly clearance, which is 0.08-0.12mm; more preferably, m is 0.1mm.

[0047] Preferred, such as Figure 1As shown, four set screws 3 are evenly distributed between the sleeve body 1 and the replaceable tightening head 2 to further tighten the replaceable tightening head 2. The set screws 3 are evenly distributed at 45° with the jaws 4 in the circumferential direction, and the set screws 3 are located at the center of the circular protrusion at the front end of the sleeve body 1 in the axial direction.

[0048] Preferred, such as Figure 1 As shown, the sleeve body 1 is made of conventional tooling materials such as Q235, 45 steel or 40Cr, which saves manufacturing costs while ensuring functionality.

[0049] Preferred, such as Figure 1 As shown, the replaceable tightening head 2 is made of materials with higher hardness, such as 65Mn, Cr12 or Cr12MoV, which increases the deformation resistance of the jaw 21 and allows the jaw 21 to withstand higher torque, meeting the torque requirements of the locking nut in the high-speed rotating mechanism of the vacuum pump. For frequently used scenarios, the tooling life can be increased by several times or even tens of times.

[0050] Furthermore, such as Figure 1 and 3 As shown, the connecting cone surface of the sleeve body 1 is the transition cone surface between the first outer circle 12 and the third outer circle 14. The third outer circle 14 is the hand-held outer circle, and the diameter of the hand-held outer circle should be a size suitable for the operator to hold. The third outer circle 14 is machined with knurled patterns for easy hand-holding.

[0051] Furthermore, such as Figure 1 and 5 As shown, the inner diameter and depth of the sleeve body 1 should be such that the outer diameter of the vacuum pump end shaft of this type of locking nut can enter without causing interference. For a vacuum pump with a single power source, its drive shaft is longer than the driven shaft, and its extension is used to install the motor. Therefore, the inner diameter of the sleeve body 1 should be sufficient to allow the longer drive shaft to be used without interference, and thus it is also suitable for the installation of the locking nut on the drive side of the driven shaft, making it universal.

[0052] Furthermore, such as Figure 1 and 4 As shown, the four integrated jaws 21 evenly distributed on the inner side of the replaceable tightening head 2, the extension of the jaws 21, and the root circle of the jaws 21 can all be machined using wire cutting, and a small root radius can be formed. It is not easy and costly to machine jaws and form a small root radius on a conventional milling and boring machine. The improved structure can solve this problem well and save manufacturing costs.

[0053] Furthermore, such as Figure 1 and 3As shown, the four retaining grooves 11 of the sleeve body 1 can also be machined using wire EDM, and a smaller root radius can be formed. Machining retaining grooves and forming a smaller root radius on a conventional milling and boring machine is not easy and is costly. The improved structure can solve this problem well and save manufacturing costs.

[0054] Furthermore, such as Figure 1 As shown, the replaceable tightening head 2 can be quickly removed after damage, and the sleeve body 1 and the set screw 3 can be retained. Only the replaceable tightening head 2 needs to be replaced, which is suitable for high-paced vacuum pump assembly and maintenance sites.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of this utility model. Any modifications or equivalent substitutions that do not depart from the spirit and scope of this utility model should be covered within the protection scope of the claims of this utility model.

Claims

1. A replaceable head constant torque sleeve for a vacuum pump locking nut, characterized in that, Includes a sleeve body (1) and a replaceable tightening head (2). The sleeve body (1) has a circular protrusion at the front end, and a stop groove (11) is evenly distributed on the circular protrusion. The replaceable tightening head (2) has an integrated claw (21) evenly distributed on the inner side. One end of the integrated claw (21) cooperates with the stop groove (11) to achieve axial positioning, and the other end cooperates with the groove (41) of the first locking nut (4).

2. The replaceable head constant torque sleeve for a vacuum pump locking nut according to claim 1, characterized in that, Includes a set screw (3) which secures the sleeve body (1) to the replaceable tightening head (2).

3. A replaceable head constant torque sleeve for a vacuum pump locking nut according to claim 1, characterized in that, The bottom end of the axial extension of the replaceable tightening head (2) claw (21) extends out of the bottom of the circular body.

4. A replaceable head constant torque sleeve for a vacuum pump locking nut according to claim 3, characterized in that, The total length of the replaceable tightening head (2) is L1=L2+L3, where L2 is the length of the circular body of the replaceable tightening head (2) and L3 is the length of the axial extension of the claw (21).

5. A replaceable head constant torque sleeve for a vacuum pump locking nut according to claim 4, characterized in that, The total length of the circular body of the replaceable tightening head (2) is 1.5-3 times the thickness of the first locking nut (4).

6. A replaceable head constant torque sleeve for a vacuum pump locking nut according to claim 1, characterized in that, The circular protrusion at the front end of the sleeve body (1) includes a first outer circle (12), and the outer circle of the circular protrusion at the front end of the first outer circle (12) is a second outer circle (13).

7. A replaceable head constant torque sleeve for a vacuum pump locking nut according to claim 6, characterized in that, The diameter of the second outer circle (13) is smaller than the diameter of the first outer circle (12), and the stop groove (11) is evenly opened on the first outer circle (12) and the second outer circle (13).

8. A replaceable head constant torque sleeve for a vacuum pump locking nut according to claim 7, characterized in that, The first outer circle (12) and the second outer circle (13) intersect to form the mounting axial positioning surface of the replaceable tightening head (2).

9. A replaceable head constant torque sleeve for a vacuum pump locking nut according to claim 1, characterized in that, The radius R of the fillet between the root circle of the claws (21) evenly distributed on the inner side of the replaceable tightening head (2) and the claws (21) is 0.09-0.5mm.

10. A replaceable head constant torque sleeve for a vacuum pump locking nut according to claim 9, characterized in that, The smaller the radius R of the fillet, the larger the contact area between the claw (21), the slot (41), and the stop slot (11).

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