High-precision grinder A-axis mechanism

Abstract

This utility model relates to the field of A-axis mechanism technology and discloses a high-precision grinding machine A-axis mechanism, including a cylindrical base, a DD motor installed on the inner wall, the rotor of which is connected to the outer ring of a turntable bearing through a connecting disc with an annular unloading groove, and the inner ring is interference-fitted with the spindle; a pneumatic tool holder is provided at the front end of the spindle, and a workpiece is clamped by an elastic chuck; a pneumatic tie rod is inserted into the shaft hole of the DD motor, the front end of which is in contact with the tapered surface of the tool holder, and the rear end of which is fixed with a pair of angular contact bearing assemblies, the outer ring of which is interference-fitted with the cylinder shaft and axially positioned by the bearing seat; the rear end of the cylinder shaft is threadedly connected to a piston, and an air inlet pipe connector is provided at the bottom of the cylinder seat; a waterproof cover is provided around the spindle, and a double-lip seal ring is installed on the inner wall, which, combined with the annular waterproof groove between the spindle and the waterproof cover, forms a double seal; this mechanism absorbs the thermal expansion of the DD motor through the unloading groove, isolates the rotational motion of the paired bearing assembly, and blocks the grinding fluid through the double seal, significantly improving thermal stability, reducing wear, and extending the service life of components.

Description

Technical Field

[0001] This utility model relates to the field of A-axis mechanism technology, and in particular to a high-precision grinding machine A-axis mechanism. Background Technology

[0002] The A-axis mechanism of a high-precision grinding machine is the core component for achieving workpiece rotation and positioning, and its performance directly affects the machining accuracy. Currently, the mainstream solution usually adopts a structure of direct drive by a DD motor combined with a rotary table bearing. For example, some CNC grinding machines use a DD motor to achieve full closed-loop control of the A-axis and use a rotary table bearing to support the spindle to improve rigidity. In terms of bearing selection, crossed roller bearings and precision angular contact ball bearings are widely used in rotary tables due to their high rigidity and anti-overturning ability. In addition, to solve the problem of thermal deformation, some technologies use temperature sensors to monitor and combine model predictions to perform thermal error compensation.

[0003] Although existing technologies have made some progress in precision control, they still suffer from insufficient thermal stability. The axial thermal expansion generated by the long-term operation of the DD motor can easily lead to a decrease in the spindle positioning accuracy. Traditional thermal compensation methods rely on complex temperature monitoring systems, which are costly and have a slow response. In view of this, we propose a high-precision grinding machine A-axis mechanism. Utility Model Content

[0004] The main objective of this invention is to provide a high-precision grinding machine A-axis mechanism that can effectively solve the problems in the background art.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] A high-precision grinding machine A-axis mechanism includes a cylindrical A-axis base, a DD motor installed on the inner wall of the A-axis base, and the rotor of the DD motor connected to a connecting disc by bolts. An annular unloading groove is provided on the outer ring of the connecting disc.

[0007] The connecting plate is fixedly connected to a turntable bearing by bolts. The inner ring of the turntable bearing is interference-fitted with a main shaft, and a pneumatic tool holder is installed at the front end of the main shaft.

[0008] A pneumatic pull rod is inserted through the shaft hole of the DD motor. The front end of the pneumatic pull rod is engaged with the tapered rear end of the pneumatic tool holder. A pair of angular contact bearings are fixedly installed on the outer ring of the rear end of the pneumatic pull rod.

[0009] A cylinder shaft is provided on one side of the paired angular contact bearing assembly, and a bearing housing is sleeved around the cylinder shaft. The bearing housing is axially positioned on the inner wall of one end facing the workpiece and the outer ring of the paired angular contact bearing assembly.

[0010] A cylinder seat is provided around the cylinder shaft, and a piston that is threadedly connected to the rear end of the cylinder shaft is provided inside the cylinder seat. An air intake pipe connector is provided at the bottom of the cylinder seat.

[0011] Preferably, a waterproof cover is provided on the periphery of the spindle. The outer ring of the waterproof cover is fixedly connected to the outer ring of the A-axis base by bolts. A double-lip seal is installed on the inner wall of the waterproof cover, and the inner lip of the double-lip seal is interference-fitted with the outer circular surface of the spindle.

[0012] Preferably, the unloading groove is provided with at least three stress relief grooves in the radial direction.

[0013] Preferably, the paired angular contact bearing assembly consists of at least two angular contact ball bearings mounted back-to-back.

[0014] Preferably, an annular waterproof groove is formed on the mating surface between the main shaft and the waterproof cover.

[0015] Preferably, the pneumatic tool holder contains a workpiece that can be detachably mounted via an elastic chuck.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. This utility model, through the annular unloading groove and radial stress relief groove on the connecting plate, can elastically absorb the axial thermal expansion of the DD motor, improve thermal stability, avoid thermal stress transmission to the spindle, and ensure positioning accuracy during long-term processing.

[0018] 2. This utility model isolates the rotational motion of the pneumatic tie rod from the cylinder shaft by using a pair of angular contact bearing assemblies, so that the cylinder system does not participate in the rotation, greatly reducing the wear of the seal ring and extending the cylinder life.

[0019] 3. This utility model forms a double sealing barrier by combining a double-lip seal ring between the spindle and the waterproof cover with an annular waterproof groove, effectively preventing the intrusion of grinding fluid and protecting the bearing system from corrosion.

[0020] 4. This utility model simplifies the transmission chain and reduces vibration transmission through the integrated design of the turntable bearing and DD motor. At the same time, the coordinated action of the pneumatic tie rod and the cylinder enables fast and accurate workpiece clamping, thereby improving processing efficiency. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0022] Figure 2 This is a cross-sectional view of the present invention;

[0023] Figure 3 This is a utility model Figure 2 A magnified view of circle A in the middle.

[0024] In the diagram: 1. A-axis base; 2. DD motor; 3. Connecting disc; 4. Turntable bearing; 5. Waterproof cover; 6. Double-lip seal ring; 7. Spindle; 8. Workpiece; 9. Pneumatic tool holder; 10. Pneumatic tie rod; 11. Paired angular contact bearing assembly; 12. Bearing housing; 13. Air inlet pipe connector; 14. Cylinder housing; 15. Cylinder shaft; 16. Piston; 17. Unloading groove; 18. Stress relief groove. Detailed Implementation

[0025] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0026] like Figures 1-3 As shown, a high-precision grinding machine A-axis mechanism includes a cylindrical A-axis base 1. A DD motor 2 is installed on the inner wall of the A-axis base 1. The rotor of the DD motor 2 is connected to a connecting disc 3 by bolts. An annular unloading groove 17 is opened on the outer ring of the connecting disc 3. At least three stress relief grooves 18 are arranged radially in the unloading groove 17 to absorb the axial thermal expansion of the DD motor 2.

[0027] refer to Figure 2 As shown, the connecting plate 3 is fixedly connected to the outer ring of the turntable bearing 4 by bolts, and the inner ring of the turntable bearing 4 is connected to the spindle 7 by interference fit. A pneumatic tool holder 9 is installed at the front end of the spindle 7, and the workpiece 8 can be detachably installed in the pneumatic tool holder 9 by means of an elastic chuck.

[0028] refer to Figure 2 As shown, a pneumatic pull rod 10 is inserted into the shaft hole of the DD motor 2. The front end of the pneumatic pull rod 10 is engaged with the rear tapered surface of the pneumatic tool holder 9. A pairing angular contact bearing assembly 11 is fixedly installed on the outer ring of the rear end. The pairing angular contact bearing assembly 11 consists of at least two angular contact ball bearings installed back to back, which are used to isolate the rotational movement of the pneumatic pull rod 10.

[0029] refer to Figure 2 As shown, a cylinder shaft 15 is provided on one side of the paired angular contact bearing assembly 11, and a bearing seat 12 is sleeved around the cylinder shaft 15. The inner wall of the bearing seat 12 facing the workpiece 8 is axially positioned with the outer ring of the paired angular contact bearing assembly 11.

[0030] refer to Figure 2 As shown, a cylinder seat 14 is provided around the cylinder shaft 15, and a piston 16 is provided inside the cylinder seat 14 and threadedly connected to the rear end of the cylinder shaft 15. An intake pipe connector 13 is provided at the bottom of the cylinder seat 14.

[0031] refer to Figure 2As shown, a waterproof cover 5 is provided on the outer periphery of the spindle 7. The outer ring of the waterproof cover 5 is fixedly connected to the outer ring of the A-axis base 1 by bolts. A double-lip seal ring 6 is installed on the inner wall of the waterproof cover 5. The inner lip of the double-lip seal ring 6 is press-fitted with the outer circular surface of the spindle 7. An annular waterproof groove is provided on the mating surface of the spindle 7 and the waterproof cover 5 to prevent coolant from seeping into the bearing system.

[0032] In practical applications, the working process of the A-axis mechanism of this high-precision grinding machine is as follows:

[0033] I. Power Transmission: DD motor 2 drives connecting plate 3 to rotate, which drives main shaft 7 to rotate synchronously through turntable bearing 4, realizing high-precision rotational motion of A-axis.

[0034] II. Thermal Compensation: When the DD motor 2 undergoes axial thermal expansion due to long-term operation, the annular unloading groove 17 and its radial stress relief groove 18 on the connecting plate 3 undergo elastic deformation to absorb the thermal expansion, prevent thermal stress from being transmitted to the spindle 7, and ensure the axial positioning accuracy of the spindle 7.

[0035] 3. Workpiece 8 clamping: High-pressure gas is introduced into the cylinder seat 14 through the air inlet pipe joint 13, which pushes the piston 16 and cylinder shaft 15 to move axially. The pneumatic pull rod 10 is pulled by the paired angular contact bearing group 11, which causes the elastic chuck in the pneumatic tool holder 9 to retract, thereby clamping the workpiece 8.

[0036] When the pressure is released, the elastic clamp resets and the workpiece is released.

[0037] IV. Rotational Isolation: The inner ring of the paired angular contact bearing assembly 11 rotates with the pneumatic tie rod 10, while the outer ring is fixed to the bearing housing 12, so that the cylinder shaft 15 and piston 16 do not participate in the rotation, which greatly reduces the wear of the seal ring and extends the life of the cylinder system.

[0038] V. Waterproof sealing: The annular waterproof groove between the spindle 7 and the waterproof cover 5 and the double-lip seal ring 6 form a double sealing structure, which effectively prevents grinding fluid from seeping in and protects the bearing system from corrosion.

[0039] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A high-precision grinding machine A-axis mechanism, comprising a cylindrical A-axis base (1), characterized in that: The inner wall of the A-axis base (1) is equipped with a DD motor (2), and the rotor of the DD motor (2) is connected to a connecting plate (3) by bolts. An annular unloading groove (17) is opened on the outer ring of the connecting plate (3). The connecting plate (3) is fixedly connected to the turntable bearing (4) by bolts. The inner ring of the turntable bearing (4) is interference-fitted with the spindle (7). The front end of the spindle (7) is equipped with a pneumatic tool holder (9). A pneumatic pull rod (10) is inserted through the shaft hole of the DD motor (2). The front end of the pneumatic pull rod (10) is engaged with the rear tapered surface of the pneumatic knife handle (9). A pair of angular contact bearings (11) are fixedly installed on the outer ring of the rear end of the pneumatic pull rod (10). A cylinder shaft (15) is provided on one side of the paired angular contact bearing assembly (11), and a bearing seat (12) is sleeved around the cylinder shaft (15). The bearing seat (12) is axially positioned on the inner wall of one end facing the workpiece (8) and the outer ring of the paired angular contact bearing assembly (11). A cylinder seat (14) is provided around the cylinder shaft (15). A piston (16) is provided inside the cylinder seat (14) and is threadedly connected to the rear end of the cylinder shaft (15). An air intake pipe connector (13) is provided at the bottom of the cylinder seat (14).

2. The high-precision grinding machine A-axis mechanism according to claim 1, characterized in that: A waterproof cover (5) is provided on the periphery of the main shaft (7). The outer ring of the waterproof cover (5) is fixedly connected to the outer ring of the A-axis base (1) by bolts. A double-lip seal (6) is installed on the inner wall of the waterproof cover (5). The inner lip of the double-lip seal (6) is press-fitted with the outer surface of the main shaft (7).

3. The high-precision grinding machine A-axis mechanism according to claim 1, characterized in that: The unloading groove (17) is provided with at least three stress relief grooves (18) in the radial direction.

4. The high-precision grinding machine A-axis mechanism according to claim 1, characterized in that: The paired angular contact bearing assembly (11) consists of at least two angular contact ball bearings mounted back to back.

5. The high-precision grinding machine A-axis mechanism according to claim 2, characterized in that: An annular waterproof groove is provided on the mating surface of the main shaft (7) and the waterproof cover (5).

6. The high-precision grinding machine A-axis mechanism according to claim 1, characterized in that: The workpiece (8) is detachably mounted inside the pneumatic tool holder (9) via an elastic chuck.

Images