Reverse planetary roller screw rod grinding mechanism

Abstract

The utility model belongs to the technical field of reverse type planetary roller screw grinding, and particularly relates to a reverse type planetary roller screw grinding rod mechanism. The mechanism comprises an energy absorption base, a fixed rod body, a flexible shaft, a grinding wheel and a bearing assembly. An oil mist path is formed through an oil mist connector and an oil mist outlet in the energy absorption base, a gap of a bearing assembly is lubricated through oil mist, friction is reduced, and the rotating speed of the flexible shaft is increased; the front end of the flexible shaft is provided with a bending angle consistent with a lead angle, so that automatic alignment of the grinding wheel is realized; the cooling liquid channel sprays cooling liquid to the surface of the grinding wheel, abrasion is reduced, and machining precision is improved. The problems that an existing grinding rod mechanism is poor in lubricating effect and low in rotating speed, and a grinding wheel is prone to abrasion are solved, and grinding efficiency and internal thread smoothness are remarkably improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to reverse type planetary roller screw grinding technical field, concretely relates to a reverse type planetary roller screw grinding mechanism. BACKGROUND

[0002] The existing reverse type planetary roller screw grinding uses grinding mechanism when grinding the internal thread, and the grinding mechanism lubricates the internal bearing assembly through liquid lubricating oil, and this lubrication mode is not conducive to the improvement of the grinding wheel speed, therefore, how to improve the grinding mechanism to improve the grinding wheel speed is a technical problem to be solved. UTILITY MODEL CONTENTS

[0003] The problem to be solved is to provide a grinding mechanism with higher grinding wheel speed for the reverse type planetary roller screw.

[0004] The utility model provides the following technical scheme for the above problems: a reverse type planetary roller screw grinding mechanism, comprising:

[0005] An energy absorption base is provided with an oil mist interface and an oil mist outlet;

[0006] A fixed rod body is sleeved at one end in the energy absorption base, and a rotating cavity and rod body channels two and three that communicate the oil mist interface and the oil mist outlet are arranged inside the fixed rod body;

[0007] A bearing assembly comprises an inner rotating shaft and an outer shaft sleeve in clearance fit; the rod body channels two and three are in communication with the clearance between the inner rotating shaft and the outer shaft sleeve;

[0008] A flexible shaft is rotatably connected in the rotating cavity through the bearing assembly, and the end away from the energy absorption base is sleeved in the grinding wheel.

[0009] Preferably, the inner rotating shaft is provided with a perforation for the flexible shaft to pass through, and a threaded channel is arranged outside the inner rotating shaft; the outer shaft sleeve is provided with a shaft sleeve inlet hole and a shaft sleeve outlet hole.

[0010] Preferably, the rod body channel two communicates the oil mist interface and the threaded channel through the shaft sleeve inlet hole, and the rod body channel three communicates the oil mist outlet and the threaded channel through the shaft sleeve outlet hole, forming an oil mist path.

[0011] Preferably, the inner rotating shaft further comprises a rotating shaft shoulder on the outside and a rotating shaft thread at the end, and the end of the flexible shaft is provided with a special shaft head that is connected with the rotating shaft thread through threads.

[0012] Preferably, one end of the rotating cavity is a bearing assembly cavity, and the outer shaft sleeve is fixed to the inner wall of the bearing assembly cavity through an integrally formed shaft sleeve shoulder.

[0013] Preferably, the energy-absorbing base is also provided with a cooling liquid channel, and the fixed rod body further comprises a rod channel I, wherein the cooling liquid channel is connected with a cooling liquid inlet and the rod channel I is connected to the grinding wheel area.

[0014] Preferably, the special shaft head is internally provided with a shaft head internal thread matched with the rotating shaft thread, for fastening the grinding wheel.

[0015] Preferably, the flexible shaft is provided with a bending angle at the front end connected with the bearing assembly, and the bending angle is consistent with the thread angle of the ground internal thread; and the part of the flexible shaft before bending is perpendicular to the plane where the energy-absorbing base is located.

[0016] Preferably, the fixed rod body is welded after interference fit with the opening of the energy-absorbing base.

[0017] Compared with the prior art, the utility model provides a reverse type planetary roller screw grinding rod mechanism, has the following beneficial effects: the oil mist path is used to replace the traditional liquid lubrication, so that the friction in the bearing assembly is reduced, the rotating speed of the flexible shaft is increased by more than 30%, and the rotating speed of the grinding wheel is further increased; the cooling liquid channel can cool the grinding wheel in time, and the temperature of the grinding wheel is reduced by more than 30%, so that the grinding wheel is not easy to be damaged, and the internal thread has higher smoothness; the fixed rod body is made of high-hardness material and is interference-welded with the energy-absorbing base, the length-diameter ratio is increased by 40%, and the grinding depth is increased. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is an appearance schematic view of the utility model;

[0019] Figure 2 It is a sectional view schematic view in the utility model; Figure 1

[0020] Figure 3 It is another angle sectional view schematic view of the utility model;

[0021] Figure 4 It is an enlarged schematic view of A in the utility model; Figure 2

[0022] Figure 5 It is a bearing assembly schematic view of the utility model;

[0023] Figure 6 It is an internal rotating shaft structure schematic view of the utility model;

[0024] ​​Explanation of reference signs: 1, energy absorbing base; 11, oil mist interface; 12, oil mist inlet channel; 13, oil mist outlet channel; 14, oil mist outlet; 15, cooling liquid inlet; 16, cooling liquid channel; 2, fixed rod body; 21, rod channel one; 22, rod channel two; 221, lead-in channel; 23, rod channel three; 231, lead-out channel; 24, rotating cavity; 241, bearing assembly cavity; 242, annular step; 3, flexible shaft; 31, special shaft head; 32, internal thread of shaft head; 4, grinding wheel; 5, bearing assembly; 51, inner rotating shaft; 511, perforation; 512, rotating shaft shoulder; 513, rotating shaft thread; 514, threaded channel; 52, outer shaft sleeve; 521, shaft sleeve inlet hole; 522, shaft sleeve outlet hole; 523, shaft sleeve shoulder. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the utility model will be described below with reference to the drawings in the embodiments of the utility model:

[0026] The reverse planetary roller screw is applied to the fields of artificial intelligence and intelligent manufacturing due to its high bearing capacity and high precision. The internal thread of the reverse planetary roller screw needs to be ground in the production and processing process. The existing grinding rod driven grinding wheel rotating grinding structure has an unsatisfactory lubrication effect and cannot meet the high-speed grinding requirement. In addition, the grinding effect is easily reduced due to the wear of the grinding wheel in the grinding process. In order to solve the above problems, the utility model provides a reverse planetary roller screw grinding rod mechanism, as shown in the figure, which comprises an energy absorbing base 1, a fixed rod body 2, a flexible shaft 3, a grinding wheel 4 and a bearing assembly 5. The fixed rod body 2 is welded after interference fit with the opening of the energy absorbing base 1. The energy absorbing base 1 is provided with an oil mist interface 11 and an oil mist outlet 14. One end of the fixed rod body 2 is sleeved in the energy absorbing base 1. The fixed rod body 2 is internally provided with a rotating cavity 24. The rotating cavity 24 is provided with a rod channel two 22 and a rod channel three 23 on both sides. The rod channel two 22 and the rod channel three 23 are respectively connected with the oil mist interface 11 and the oil mist outlet 14. The energy absorbing base 1 can also be provided with a cooling liquid channel 16. The fixed rod body 2 is provided with a rod channel one 21 in cooperation with the cooling liquid channel 16. The cooling liquid channel 16 is connected with the cooling liquid inlet 15, the rod channel one 21 and the region of the grinding wheel 4. The cooling liquid cools the grinding wheel 4 in the grinding process.

[0027] The flexible shaft 3 is rotationally connected in the rotating cavity 24 and is sleeved in the grinding wheel 4 at the end away from the energy absorbing base 1.

[0028] The bearing assembly 5 includes an inner rotating shaft 51 and an outer bushing 52 with clearance fit. The end of the rotating cavity 24 is provided with a bearing assembly cavity 241. The outer bushing 52 is fixed to the inner wall of the bearing assembly cavity 241 by an integrally formed bushing shoulder 523. The inner rotating shaft 51 is provided with a through hole 511 for the flexible shaft 3 to pass through. The outer bushing 52 is provided with a bushing inlet hole 521 and a bushing outlet hole 522. The rod channel 22 connects the gap between the oil mist interface 11 and the inner rotating shaft 51 and the outer bushing 52 through the bushing inlet hole 521. The rod channel 3 23 connects the gap between the oil mist outlet 14 and the inner rotating shaft 51 and the outer bushing 52 through the bushing outlet hole 522 to form an oil mist path. The inner rotating shaft 51 also includes an outer rotating shaft shoulder 512 and a rotating shaft thread 513 at the end. The end of the flexible shaft 3 is provided with a special shaft head 31, which is connected to the rotating shaft thread 513 by a thread. The specially designed shaft head 31 has an internal thread 32 that matches the shaft thread 513, which is used to fasten the grinding wheel 4.

[0029] The flexible shaft 3 has a bending angle at the front end connected to the inner rotating shaft 51, and the bending angle is consistent with the thread helix angle of the ground internal thread; the part of the flexible shaft 3 before bending is perpendicular to the plane of the energy-absorbing base 1.

[0030] like Figure 2 As shown, one end of the fixed rod 2 is sleeved inside the energy-absorbing base 1. The fixed rod 2 has a rotating cavity 24. One end of the flexible shaft 3 passes through the rotating cavity 24, and the other end is sleeved inside the grinding wheel 4. The flexible shaft 3 rotates within the rotating cavity 24. During the rotation of the flexible shaft 3 within the rotating cavity 24, it drives the grinding wheel 4 to rotate synchronously, achieving the grinding of the internal thread. In the design, the hardness of the fixed rod 2 is greater than that of the energy-absorbing base 1 to increase the length-to-diameter ratio. During connection, the opening of the energy-absorbing base 1 is interference-fitted with the fixed rod 2, and the fixed rod 2 is welded to the energy-absorbing base 1. This increases the length-to-diameter ratio of the fixed rod 2, which in turn increases the grinding depth of the grinding rod mechanism. The flexible shaft 3 passes through the inner rotating shaft 51 and the rotating cavity 24 in sequence, and can then be connected to the output end of the drive motor via a flexible shaft connector. After the drive motor starts, it drives the flexible shaft connector to rotate, thereby driving the flexible shaft 3 to rotate. Figure 4 , 5As shown in Figure 6, the outer bushing 52 is fitted onto the inner shaft 51 with a gap between them. The part of the inner shaft 51 that contacts the outer bushing 52 includes a threaded channel 514. The threaded channel 514 is located on the outer periphery of the inner shaft 51 and is used to guide oil mist, which helps the oil mist to be fully distributed in the gap between the outer bushing 52 and the inner shaft 51, thus improving the lubrication effect. The inner shaft 51 includes a through hole 511, a shaft shoulder 512, a shaft thread 513, and a threaded channel 514. The through hole 511 passes through the inner shaft 51 and is used to pass through the flexible shaft 3. One end of the flexible shaft 3 passes through the through hole 511, and the other end is provided with a special shaft head 31. The shaft shoulder 512 is located on the outside of the inner shaft 51, and the shaft thread 513 is located at one end of the inner shaft 51. The shaft thread 513 is screwed into the internal thread 32 of the special shaft head 31. The outer bushing 52 is connected by an integrally formed bushing shoulder 523. Fixed to the inner wall of the bearing assembly cavity 241 and not rotating with the flexible shaft 3, the bushing shoulder 523 is polygonal rather than circular, which makes the interference fit between it and the inner wall of the bearing assembly cavity 241 more secure. Specifically, the outer end of the bearing assembly cavity 241 is provided with an annular step 242 that interferes with the bushing shoulder 523. The outer diameter of the bushing shoulder 523 is larger than the outer diameter of the rotating shaft shoulder 512, ensuring that the inner rotating shaft 51 can rotate with the flexible shaft 3. The grinding wheel 4 is firmly fixed between the rotating shaft shoulder 512 and the special shaft head 31.

[0031] Reference Figure 2 , Figure 4 The oil mist inlet 11 is located at the top of the oil mist inlet channel 12, and the oil mist outlet 14 is connected to the end of the oil mist outlet channel 13. The second rod channel 22 connects the oil mist inlet 11 and the threaded channel 514, and the third rod channel 23 connects the oil mist outlet 14 and the threaded channel 514. The bushing inlet hole 521 connects the second rod channel 22 and the threaded channel 514 through the inlet channel 221, and the bushing outlet hole 522 connects the third rod channel 23 and the threaded channel 514 through the outlet channel 231. When the grinding rod mechanism is working, the oil mist flow path is as follows: oil mist inlet 11, oil mist inlet channel 12, second rod channel 22, inlet channel 221, threaded channel 514, outlet channel 231, third rod channel 23, oil mist outlet channel 13, and oil mist outlet 14. The design of the above oil mist flow path allows the oil mist to travel smoothly in the above flow path, effectively reducing friction in the bearing assembly 5 and increasing the rotational speed of the flexible shaft 3.

[0032] like Figure 4 As shown, the flexible shaft 3 has a bending angle β at its front end connected to the inner rotating shaft 51. Since the flexible shaft 3 is set perpendicular to the end face of the grinding wheel 4 after bending, the angle of inclination of the grinding wheel 4 relative to the vertical direction is also β. The angle β is the thread helix angle of the internal thread being ground. Therefore, it is only necessary to adjust the bending angle of the flexible shaft 3 according to the thread helix angle. The part of the flexible shaft 3 before bending is perpendicular to the plane of the energy-absorbing base 1. In this way, during grinding, it is only necessary to insert the fixing rod 2 into the workpiece. The grinding wheel 4 itself has a thread helix angle, and there is no need to manually adjust the angle.

[0033] In use, the outer shaft sleeve 52 is sleeved on the inner rotating shaft 51, the shaft sleeve shoulder 523 is fixed against the annular step 242 in the bearing assembly cavity 241, the grinding wheel 4 is slid through one end of the flexible shaft 3 to the side close to the special shaft head 31, then one end of the flexible shaft 3 is sequentially threaded through the perforation 511, the rotating cavity 24 and the energy absorption base 1, the special shaft head 31 is fixed with the inner rotating shaft 51 through the rotating shaft thread 513, and the flexible shaft 3 can be driven by the driving motor through the flexible shaft connector after passing through the energy absorption base 1. When grinding the workpiece, the grinding rod mechanism is deeply inserted into the workpiece hole, the driving motor is started, and the driving motor rotates the flexible shaft 3 in the rotating cavity 24, and the inner rotating shaft 51 and the grinding wheel 4 rotate together to grind the workpiece hole. In the process of grinding, the oil mist flows into the threaded channel 514 through the rod body channel two 22 for lubrication, and the used oil mist is discharged from the grinding rod mechanism through the rod body channel three 23. The oil mist grinding effect can greatly improve the rotating speed of the flexible shaft 3 and improve the grinding efficiency due to the liquid lubricating oil. When deep hole grinding is performed, the external cooling mechanism cannot effectively cool the grinding wheel, and the cooling liquid channel of the utility model can directly cool the grinding wheel and the workpiece friction point inside the deep hole. High-pressure cooling liquid is sprayed onto the grinding wheel 4 through the cooling liquid inlet 15, the cooling liquid channel 16 and the rod body channel one 21 to cool the grinding wheel 4. In this way, the grinding wheel 4 can be kept at a relatively low temperature for a long time and is not easy to be worn out, and the surface finish of the product is better. It should be noted that CBN grinding wheel is generally used for reverse planetary roller screw grinding, and CBN grinding wheel needs high linear speed to achieve the effect. Low speed and low cooling will greatly reduce the effect of CBN grinding wheel. The actual production verification effect of the structure of the utility model combined with CBN grinding wheel is as follows:

[0034]

[0035] The reverse planetary roller screw grinding rod mechanism optimizes the oil mist path design, combines the structure of the high-hardness fixed rod body and the soft shaft bending angle adaptive thread angle, realizes efficient lubrication of the bearing assembly, improves the grinding wheel rotating speed and increases the grinding depth. The introduction of the cooling liquid channel further reduces the grinding wheel temperature and prolongs the service life. The mechanism is suitable for internal thread grinding of high-precision reverse planetary roller screws, can significantly improve the grinding wheel rotating speed and the grinding wheel life, and ensures the grinding efficiency and the grinding finish.

[0036] The above embodiments are only part of the embodiments of the utility model, but not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model.

Claims

1. A reverse planetary roller screw grinding mechanism, characterized by: The utility model relates to an energy-absorbing base (1) provided with an oil mist interface (11) and an oil mist outlet (14), a fixed rod body (2) with one end sleeved in the energy-absorbing base (1) and provided with a rotating cavity (24) and a rod body channel two (22) and a rod body channel three (23) communicating the oil mist interface (11) and the oil mist outlet (14), a bearing assembly (5) including a gap-fitted inner rotating shaft (51) and outer shaft sleeve (52), the rod body channel two (22) and the rod body channel three (23) both communicating with the gap between the inner rotating shaft (51) and the outer shaft sleeve (52), a flexible shaft (3) rotatably connected in the rotating cavity (24) through the bearing assembly (5) and sleeved in a grinding wheel (4) at one end away from the energy-absorbing base (1). The inner rotating shaft (51) is provided with a perforation (511) for the flexible shaft (3) to pass through, and the outer rotating shaft (51) is provided with a threaded channel (514), and the outer shaft sleeve (52) is provided with a shaft sleeve inlet hole (521) and a shaft sleeve outlet hole (522). The rod body channel two (22) communicates the oil mist interface (11) and the threaded channel (514) through the shaft sleeve inlet hole (521), the rod body channel three (23) communicates the oil mist outlet (14) and the threaded channel (514) through the shaft sleeve outlet hole (522), and an oil mist path is formed. The inner rotating shaft (51) further includes an outer rotating shaft shoulder (512) and a rotating shaft screw thread (513) at the end, and the end of the flexible shaft (3) is provided with a special shaft head (31) connected with the rotating shaft screw thread (513) through threads. One end of the rotating cavity (24) is a bearing assembly cavity (241), and the outer shaft sleeve (52) is fixed to the inner wall of the bearing assembly cavity (241) through an integrally formed shaft sleeve shoulder (523).

2. The reverse planetary roller screw nut mechanism of claim 1, wherein: The energy-absorbing base (1) is further provided with a cooling liquid channel (16), and the fixed rod body (2) further includes a rod body channel one (21), and the cooling liquid channel (16) communicates a cooling liquid inlet (15) and the rod body channel one (21) to the area of the grinding wheel (4).

3. The reverse planetary roller screw nut mechanism of claim 2, wherein: The special shaft head (31) is internally provided with a shaft head internal thread (32) matched with the rotating shaft screw thread (513) for fastening the grinding wheel (4).

4. The reverse planetary roller screw nut mechanism of claim 3, wherein: The flexible shaft (3) is provided with a bending angle at the front end connected with the bearing assembly (5), and the bending angle is consistent with the thread rise angle of the ground internal thread; the part of the flexible shaft (3) before bending is perpendicular to the plane where the energy-absorbing base (1) is located.

5. The reverse planetary roller screw nut mechanism of claim 1, wherein: The fixed rod body (2) and the energy-absorbing base (1) are welded after interference fit of the opening.

6. The reverse planetary roller screw nut mechanism of claim 1, wherein: ​ 7. The reverse planetary roller screw nut mechanism of claim 4, wherein: ​ 8. The reverse planetary roller screw nut mechanism of claim 1, wherein: ​ 9. The reverse planetary roller screw nut mechanism of claim 1, wherein: ​

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