Unloading lead screw transmission mechanism applied to numerical control vertical grinding machine

Abstract

The invention relates to the field of machine tools, in particular to an unloading lead screw transmission mechanism applied to a numerical control vertical grinding machine. The problem that a lead screw pair lever of an existing large-specification numerical control vertical grinding machine is prone to deformation, and the feeding precision is affected is mainly solved. An output shaft of the servo motor (21) is connected with a bearing inner sleeve (8) through a synchronous belt (6), and the bearing inner sleeve (8) and the lead screw nut (15) are fixed through a screw; the left end and the right end of the lead screw (5) are supported through the left supporting seat (1) and the right supporting seat (16) respectively, the left end of the lead screw (5) is connected with the left locking nut (2), the right end of the lead screw (5) is connected with the right locking nut (17), and the belleville spring (4) is arranged between the left locking nut (2) and the left supporting seat (1). The unloading lead screw transmission mechanism applied to the numerical control vertical grinding machine can effectively eliminate the influence of lateral force on a lead screw pair, stable power transmission is achieved, and therefore the feeding precision of a machine tool is improved.

Description

Technical Field

[0001] The invention relates to the field of machine tools, in particular to a load-releasing screw transmission mechanism applied to a numerically controlled vertical grinder. Background Art

[0002] At present, some large-sized slewing bearings and gears are commonly used in the wind power industry. These large-sized bearings and gears are processed by large-sized vertical turning machines and turning-milling machine tools, and the surface roughness of the processed parts is relatively low. In order to improve the surface quality and precision level of the processed parts, the application of large-sized CNC vertical grinders is particularly important. This type of machine tool has the characteristics of high precision, high rigidity and high efficiency, and can realize precision grinding of parts, thereby significantly improving the surface quality and precision level of parts. By using large-sized CNC vertical grinders for processing, it can not only meet the demand for high-precision parts in the wind power industry, but also improve the reliability and durability of parts, providing a strong guarantee for the stable operation of wind power equipment.

[0003] However, due to the long stroke of the current large-scale CNC vertical grinder, the transmission force of the screw pair during the feed transmission process can easily cause the screw pair lever to deform, affecting the feed accuracy. Summary of the invention

[0004] In order to overcome the disadvantage that the screw pair lever of the existing large-scale CNC vertical grinder is prone to deformation and affects the feeding accuracy, the present invention provides a unloading screw transmission mechanism applied to the CNC vertical grinder. The unloading screw transmission mechanism applied to the CNC vertical grinder can effectively eliminate the influence of the lateral force on the screw pair, realize stable power transmission, and thus improve the feeding accuracy of the machine tool.

[0005] The technical solution of the present invention is: a load-releasing screw transmission mechanism used in a CNC vertical grinder, comprising a screw, a screw nut connected to the outside of the screw, and a servo motor, wherein the output shaft of the servo motor is connected to an inner sleeve of a bearing through a synchronous belt, and the inner sleeve of the bearing and the screw nut are fixed by screws; the left and right ends of the screw are respectively supported by a left support seat and a right support seat, and the left end of the screw is connected to a left locking nut, and the right end is connected to a right locking nut, and a disc spring is provided between the left locking nut and the left support seat.

[0006] Furthermore, the servo motor output shaft is connected to a motor pulley, the outer side of the end of the inner sleeve of the bearing is connected to a screw pulley, and the motor pulley and the screw pulley are connected by a synchronous belt.

[0007] Furthermore, a motor flange is fixed on the output shaft of the servo motor, and the motor pulley is connected to the motor flange.

[0008] Furthermore, an angular contact ball bearing is arranged outside the inner sleeve of the bearing, and a bearing sleeve is arranged outside the inner sleeve of the angular contact ball bearing; the servo motor is fixed on the base, and the bearing sleeve is connected to the base by bolts.

[0009] Furthermore, the left end of the angular contact ball bearing is respectively provided with an inner ring end cover and an outer ring end cover, wherein the inner ring end cover is connected to the bearing inner sleeve, and the outer ring end cover is connected to the bearing sleeve; and a first oil seal block and a second oil seal block arranged alternately are provided between the angular contact ball bearing and the inner ring end cover and the outer ring end cover.

[0010] Furthermore, there are four angular contact ball bearings, which are divided into two groups. Each group of angular contact ball bearings is located at both ends of the bearing inner sleeve, and the two groups of angular contact ball bearings are separated by the bearing inner ring and the bearing outer ring.

[0011] Furthermore, the right end of the bearing sleeve is connected to the rear end cover, the outer ring of the angular contact ball bearing is limited by the rear end cover, and the inner ring is limited by the bearing inner sleeve.

[0012] Furthermore, a spring washer is provided between the disc spring and the left locking nut.

[0013] The present invention has the following beneficial effects: (1) In the present invention, the servo motor drives the screw nut to rotate through the synchronous belt, so that the moving part moves left and right along the screw. The transmission form of the nut and the high performance characteristics of the screw nut mechanism itself are used to ensure that the screw remains stable during the transmission process, effectively solving the centrifugal force problem that may be generated during the rotation of a long screw, avoiding the centrifugal force from affecting the feed speed, and increasing the service life of the screw pair. At the same time, due to the use of synchronous belt transmission, it can not only transmit power, but also avoid the influence of vibration on the screw pair during the transmission process to a limited extent, thereby ensuring the stability and accuracy of the transmission.

[0014] (2) A disc spring is provided at the end of the screw to pre-stretch the screw, thereby offsetting the thermal expansion and contraction effect of the material caused by temperature changes and reducing the influence of temperature on the transmission accuracy of the screw pair; and it can largely overcome the deformation of the screw lever caused by gravity, thereby maintaining the straightness and transmission accuracy of the screw pair and improving the reliability and durability of the entire transmission mechanism.

[0015] (2) Two groups of four angular contact ball bearings are used, which can only withstand large lateral forces and transmit the lateral forces to the base through the bearing inner sleeve and the bearing sleeve. In this way, the lateral forces are ultimately applied to the moving parts without causing any external force influence on the screw assembly parts, thereby achieving the unloading effect of the screw pair.

[0016] Therefore, the present invention realizes efficient and stable transmission of power and effectively removes lateral force through the coordinated work of components such as servo motor, synchronous belt, screw pulley, bearing inner sleeve, screw pair nut and angular contact ball bearing, and at the same time, combined with the application of disc spring at the end of the screw, ensures the transmission accuracy and stability of the screw pair. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 yes Figure 1 Enlarged view of point I in the middle.

[0018] In the figure, 1-left screw support seat, 2-locking nut, 3-spring washer, 4-disc spring, 5-screw, 6-synchronous belt, 7-screw pulley, 8-bearing inner sleeve, 9-outer ring end cover, 10-inner ring end cover, 11-angular contact ball bearing, 12-bearing inner ring, 13-bearing outer ring, 14-bearing sleeve, 15-screw nut, 16-right screw support seat, 17-right locking nut, 18-rear end cover, 19-first oil seal block, 20-second oil seal block, 21-servo motor, 22-motor plate, 23-base, 24-motor pulley, 25-motor flange. DETAILED DESCRIPTION

[0019] The present invention is described in detail below in conjunction with the accompanying drawings and embodiments, and the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by “up”, “down”, “left”, “right”, “inside”, “outside”, “top”, “bottom”, etc. are all based on the directions or positional relationships shown in the accompanying drawings. The purpose is only to facilitate the description of the present invention and simplify the description. It does not indicate or imply that the referred parts must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0021] Depend on Figure 1 , Figure 2 As shown, a load-relief screw transmission mechanism for a CNC vertical grinder includes a screw 5, and the screw 5 is externally connected to a screw nut 15 to form a set of screw pairs. The transmission mechanism also includes a servo motor 21, and the servo motor 21 is fixed to a base 22 through a motor plate 21, and the base 22 is fixed to a moving part of the machine tool, so when the servo motor 21 and the base 22 move, the moving part of the machine tool can be driven to move.

[0022] The output shaft of the servo motor 21 is connected to the bearing inner sleeve 8 through the synchronous belt 6, and the bearing inner sleeve 8 is fixed to the lead screw nut 15 by screws. Specifically, the motor flange 25 is connected to the output shaft of the servo motor 21, and the motor flange 25 is connected to the motor pulley 24; the outer side of the end of the bearing inner sleeve 8 is fixed to the lead screw pulley 7 by screws, and the motor pulley 24 and the lead screw pulley 7 are connected by the synchronous belt 6. In this way, after the servo motor 21 is started, the bearing inner sleeve 8 is driven to rotate through the synchronous belt 6, and the bearing inner sleeve 8 drives the lead screw nut 15 to rotate along the lead screw 5. The lead screw nut 15 also moves axially while rotating along the lead screw 5, thereby driving the bearing inner sleeve 8, the servo motor 21, the base 22 and the moving parts of the machine tool to move axially along the lead screw 5.

[0023] The outer side of the bearing inner sleeve 8 is provided with an angular contact ball bearing 11. There are two groups of angular contact ball bearings 11, which are four in total. The two groups of angular contact ball bearings are separated by the bearing inner ring 12 and the bearing outer ring 13. The inner side of the angular contact ball bearing 11 is the bearing inner sleeve 8, and the outer side is provided with a bearing sleeve 14. The bearing sleeve 14 is connected to the base 23 by bolts, and one end of the bearing sleeve 14 corresponding to the lead screw nut 16 is connected to the rear end cover 18. The right end of the angular contact ball bearing 11 is limited by the bearing inner sleeve 8 and the rear end cover 18 respectively, and the left end of the angular contact ball bearing 11 is provided with an inner ring end cover 10 and an outer ring end cover 9 respectively, wherein the inner ring end cover 10 is connected to the bearing inner sleeve 14, and the outer ring end cover 9 is connected to the bearing sleeve 14, forming inner and outer rings that can rotate relatively. In addition, a first oil seal block 19 and a second oil seal block 20 arranged in an alternating manner are provided between the angular contact ball bearing 11 and the inner ring end cover 10 and the outer ring end cover 9. The two groups of oil seal blocks can prevent the loss of bearing lubricating oil and keep the bearing lubricated.

[0024] Since the present invention uses two sets of angular contact ball bearings 11, it can withstand a large lateral force and transmit the lateral force to the base 23 through the bearing inner sleeve 8 and the bearing sleeve 14. At the same time, since the base 23 is rigidly connected to the moving parts to be driven, the lateral force is finally applied to the moving parts, and will not cause any external force influence on the screw pair and other parts, thereby achieving the unloading effect of the screw pair.

[0025] The left and right ends of the lead screw 5 are supported by the left support seat 1 and the right support seat 16 respectively. Bearings are respectively arranged between the lead screw 5 and the left and right support seats to reduce the friction when the lead screw 5 rotates. The left end of the lead screw 5 is connected to the left locking nut 2, and the right end is connected to the right locking nut 17. The locking nut restricts the lead screw 5 on the support seat. At the same time, a disc spring 4 is arranged between one of the locking nuts and the corresponding support seat. Here, the disc spring 4 is arranged between the left locking nut 2 and the left support seat 1. Similarly, it can also be arranged between the right locking nut 17 and the right support seat 16. A spring pad 3 is arranged between the outer side of the disc spring 4 and the left locking nut 2.

[0026] The butterfly spring 4 plays two key roles in the screw pair: one is the pre-stretching effect: the screw 5 is pre-stretched to offset the thermal expansion and contraction effect of the material caused by temperature changes, so that the transmission accuracy of the screw pair can be maintained even under a small range of temperature changes. The second is to overcome the deformation of the screw caused by gravity: in large-scale CNC vertical grinders, due to the long stroke of the screw pair lever, its own weight will cause a natural drooping force tendency. The elastic force of the butterfly spring can overcome this natural drooping gravity, thereby maintaining the straightness and transmission accuracy of the screw pair, and improving the reliability and durability of the entire transmission mechanism.

[0027] During the operation of the machine tool, when the moving parts of the machine tool need to move, the servo motor 21 is started, and the motor output shaft drives the bearing inner sleeve 8 to rotate through the motor pulley 24, the synchronous belt 6, and the screw pulley 7 in sequence. Since the bearing inner sleeve 8 is fixed to the screw nut 15, the screw nut 15 is also driven to rotate. The screw nut 15 rotates and moves left and right along the screw 5, further driving the servo motor 21, the base 23 and the moving parts connected to the base to move along the screw 5, thereby realizing the left and right movement of the moving parts of the machine tool.

[0028] In this process, the synchronous belt 6 is used for transmission, which can not only transmit power, but also avoid the influence of vibration on the screw pair during the transmission process to a limited extent, thereby ensuring the stability and accuracy of the transmission. A rigid connection is adopted between the screw pulley 7 and the bearing inner sleeve 8. This connection method ensures lossless transmission of power. The bearing inner sleeve 8 is also rigidly connected to the screw nut 15, so that the screw pulley 7 can eventually drive the screw nut 15 to rotate. This rotational motion is converted into the linear motion of the screw pair, thereby driving the required moving parts to move.

[0029] The present invention adopts a servo motor to drive the lead screw nut mechanism. In the servo motor driven lead screw nut mechanism, in order to achieve the fixation of the lead screw lever and prevent it from rotating, two bearing seats are used to fix the lead screw, ensuring that the lead screw remains stable and does not rotate during the transmission process. This fixing method effectively solves the centrifugal force problem that may be generated during the rotation of a longer lead screw, avoids the centrifugal force from affecting the feed speed, and reduces the generation of noise. The present invention converts the rotational motion of the servo motor into the linear motion of the lead screw nut. During this process, the lead screw nut moves along the axis of the lead screw, achieving stable transmission of power. At the same time, this design eliminates the force effect of the torque on the lever during the driving of the lead screw lever, because the torque is mainly converted into the linear motion force of the nut, rather than acting on the lead screw lever, thereby effectively improving the service life of the lead screw pair. In addition, the lead screw nut mechanism has the characteristics of high precision, high efficiency and high responsiveness, ensuring that there is no invalid stroke in the rotation direction of the ball spline.

[0030] At the same time, in order to cope with the lateral force that may be generated during the transmission of the synchronous belt, four angular contact ball bearings are installed on the inner sleeve of the bearing. These bearings can not only withstand large lateral forces, but also transmit the lateral forces to the base through the inner sleeve and the bearing sleeve. The base is also rigidly connected to the moving parts to be driven, so that the lateral force is ultimately applied to the moving parts without any external force on the screw assembly parts, thereby achieving the unloading effect of the screw pair.

[0031] In addition, the butterfly spring plays the role of pre-stretching and overcoming the deformation of the screw caused by gravity in the screw pair, thereby offsetting the thermal expansion and contraction effects of the material caused by temperature changes, keeping the transmission accuracy of the screw pair unaffected, and overcoming the natural droop of the screw caused by its own weight to the greatest extent, thereby maintaining the straightness and transmission accuracy of the screw pair, and improving the reliability and durability of the entire transmission mechanism.

[0032] In summary, the machine achieves efficient and stable power transmission and effectively removes lateral force through the coordinated work of components such as servo motor, synchronous belt, screw pulley, bearing inner sleeve, screw pair nut and angular contact ball bearing. At the same time, a disc spring is installed at one end of the screw to ensure the transmission accuracy and stability of the screw pair.

[0033] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A load-releasing screw transmission mechanism for use in a CNC vertical grinding machine, comprising a screw (5), the screw (5) being externally connected to a screw nut (15), characterized in that: It also includes a servo motor (21), the output shaft of the servo motor (21) is connected to the bearing inner sleeve (8) through a synchronous belt (6), and the bearing inner sleeve (8) and the lead screw nut (15) are fixed by screws; the left and right ends of the lead screw (5) are supported by a left support seat (1) and a right support seat (16) respectively, and the left end of the lead screw (5) is connected to a left locking nut (2), and the right end is connected to a right locking nut (17), and a disc spring (4) is provided between the left locking nut (2) and the left support seat (1).

2. The unloading screw transmission mechanism for a CNC vertical grinder according to claim 1 is characterized in that: The output shaft of the servo motor (21) is connected to a motor pulley (24), the outer side of the end of the bearing inner sleeve (8) is connected to a screw pulley (7), and the motor pulley (24) and the screw pulley (7) are connected via a synchronous belt (6).

3. The unloading screw transmission mechanism for a CNC vertical grinder according to claim 2 is characterized in that: A motor flange (25) is fixed on the output shaft of the servo motor (21), and the motor pulley (24) is connected to the motor flange (25).

4. The unloading screw transmission mechanism for a CNC vertical grinder according to claim 2 is characterized in that: An angular contact ball bearing (11) is arranged outside the bearing inner sleeve (8), and a bearing sleeve (14) is arranged outside the angular contact ball bearing (11); the servo motor (21) is fixed on a base (23), and the bearing sleeve (14) is connected to the base (23) by bolts.

5. The unloading screw transmission mechanism for a CNC vertical grinder according to claim 4 is characterized in that: The left end of the angular contact ball bearing (11) is provided with an inner ring end cover (10) and an outer ring end cover (9), wherein the inner ring end cover (10) is connected to the bearing inner sleeve (14), and the outer ring end cover (9) is connected to the bearing sleeve (14); and a first oil seal block (19) and a second oil seal block (20) arranged alternately are provided between the angular contact ball bearing (11) and the inner ring end cover (10) and the outer ring end cover (9).

6. The unloading screw transmission mechanism for a CNC vertical grinder according to claim 5 is characterized in that: There are four angular contact ball bearings (11), which are divided into two groups. Each group of angular contact ball bearings (11) is located at two ends of the bearing inner sleeve (8), and the two groups of angular contact ball bearings (11) are separated by a bearing inner ring (12) and a bearing outer ring (13).

7. The unloading screw transmission mechanism for a CNC vertical grinder according to claim 6 is characterized in that: The right end of the bearing sleeve (14) is connected to the rear end cover (18); the outer ring of the angular contact ball bearing (11) is limited by the rear end cover (18); and the inner ring is limited by the bearing inner sleeve (8).

8. The unloading screw transmission mechanism for a CNC vertical grinder according to claim 1 is characterized in that: A spring washer (3) is provided between the disc spring (4) and the left locking nut (2).

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