High-precision hobbing workpiece spindle structure

Abstract

The utility model provides a high-precision hobbing workpiece main shaft structure, which relates to the technical field of machine tool precision main shaft manufacturing and comprises a shaft core, a front bearing assembly, a torque motor, a rear bearing assembly and a circular grating encoder. The front bearing assembly is composed of a front end cover, a front angular contact ball bearing, a front bearing seat and a front locking nut and arranged at the front end of the shaft core in a sleeving mode. The rear bearing assembly consists of a rear bearing seat, a rear angular contact ball bearing, a rear locking nut and an encoder mounting cover, and is sleeved at the rear end of the shaft core; the torque motor is composed of a torque motor stator and a torque motor rotor. The torque motor is arranged in the middle of the shaft core in a sleeving mode. According to the scheme, a coupler is omitted, a built-in motor direct drive scheme is adopted, and the transmission precision and the response speed are improved; according to the scheme, the torque permanent magnet motor is adopted for driving, the circular grating absolute value encoder is used for replacing a traditional servo motor and gear encoder scheme, the positioning precision of the main shaft is higher, the speed stability is higher, and the speed synchronism is also higher.

Description

Technical Field

[0001] This utility model relates to the field of precision spindle manufacturing technology for machine tools, and in particular to a high-precision gear hobbing workpiece spindle structure. Background Technology

[0002] In the field of gear processing, gear hobbing machines are widely used in the manufacture of high-precision gears;

[0003] Traditional gear hobbing machine spindle drive schemes typically employ a coupling plus a servo motor. While this scheme improves the power transmission efficiency between the motor and the spindle to some extent, it suffers from problems such as low transmission accuracy, slow response speed, and poor speed synchronization in practical applications. These defects directly affect the machining quality of high-precision gears and limit the machining accuracy and efficiency of gear hobbing machines. Therefore, we propose a high-precision gear hobbing workpiece spindle structure. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology and propose a new drive structure that can maintain transmission accuracy while improving response speed and speed synchronization.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A high-precision gear hobbing workpiece spindle structure includes a spindle core, a front bearing assembly, a torque motor, a rear bearing assembly, and a circular grating encoder;

[0007] The front bearing assembly consists of a front end cover, a front angular contact ball bearing, a front bearing housing, and a front lock nut, and is fitted onto the front end of the shaft core.

[0008] The rear bearing assembly consists of a rear bearing housing, a rear angular contact ball bearing, a rear lock nut, and an encoder mounting cover, and is fitted onto the rear end of the shaft core.

[0009] The torque motor consists of a torque motor stator and a torque motor rotor, and the torque motor is sleeved in the middle of the shaft core;

[0010] The circular grating encoder comprises a fixed stator and a rotating rotor;

[0011] The front bearing housing and the rear bearing housing are fastened together by screws, and the encoder mounting cover is fastened together with the rear bearing housing by screws. The front bearing housing and the rear bearing housing together form the motor mounting cavity.

[0012] Furthermore, the inner ring of the front angular contact ball bearing is interference-fitted with the shaft core, and the outer ring is clearance-fitted with the front bearing housing. The front lock nut is threadedly connected to the shaft core to press the inner ring of the front angular contact ball bearing, and the front end cover is locked to the front bearing housing by screws to press the outer ring of the front angular contact ball bearing.

[0013] Furthermore, the inner ring of the rear angular contact ball bearing is interference-fitted with the shaft core, the outer ring is clearance-fitted with the rear bearing housing, and the rear lock nut is threadedly connected to the shaft core to press the inner ring of the rear angular contact ball bearing, while the outer ring is in a floating state.

[0014] Furthermore, the stator end face of the torque motor is screwed to the rear bearing housing end face, the outer circle of the stator of the torque motor is clearance-fitted with the front bearing housing, and the rotor of the torque motor is interference-fitted with the shaft core.

[0015] Furthermore, the fixed stator of the circular grating encoder is locked to the encoder mounting cover screws, and the rotating rotor is fixed to the shaft core by the side set screws. The resolution of the circular grating encoder is 25 bits.

[0016] Furthermore, the front bearing assembly includes four front angular contact ball bearings arranged in series and back-to-back with a positioning preload structure, and the rear bearing assembly includes two rear angular contact ball bearings arranged back-to-back.

[0017] Furthermore, the four front angular contact ball bearings constitute the main support structure for bearing axial and radial forces, and the two rear angular contact ball bearings constitute the auxiliary support structure.

[0018] Compared with the prior art, the beneficial effects of this utility model are:

[0019] 1. This solution eliminates the coupling and uses a built-in motor direct drive, improving transmission accuracy and response speed;

[0020] 2. This solution uses a torque permanent magnet motor drive and a circular grating absolute encoder to replace the traditional servo motor + gear encoder solution, resulting in higher spindle positioning accuracy, higher speed stability, and higher speed synchronization. Attached Figure Description

[0021] Figure 1 A schematic diagram of a high-precision gear hobbing workpiece spindle structure provided by this utility model. Figure 1 ;

[0022] Figure 2 A schematic diagram of a high-precision gear hobbing workpiece spindle structure provided by this utility model. Figure 2 .

[0023] Legend: 1. Shaft core; 2. Front bearing assembly; 3. Torque motor; 4. Rear bearing assembly; 5. Circular grating encoder; 6. Front cover; 7. Front angular contact ball bearing; 8. Front bearing housing; 9. Front lock nut; 10. Torque motor stator; 11. Torque motor rotor; 12. Rear bearing housing; 13. Rear angular contact ball bearing; 14. Rear lock nut; 15. Encoder mounting cover. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0025] To facilitate understanding of this utility model, a more comprehensive description of this utility model will be provided below with reference to relevant embodiments, and several embodiments of this utility model will be given. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of this utility model more thorough and complete.

[0026] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0028] Example 1

[0029] like Figure 1-2 As shown, this utility model provides a technical solution: a high-precision gear hobbing workpiece spindle structure. The spindle as a whole includes a spindle core 1, a front bearing assembly 2, a torque motor 3, a rear bearing assembly 4, and a circular grating encoder 5 as its basic structure. During the operation of the spindle, the front end of the spindle can withstand axial and radial forces. During the operation of the spindle, the 3 is used as the direct drive, which ensures stable speed, high transmission efficiency, and large transmission torque. During the operation of the spindle, the 5 detects the position of the rotating shaft in real time and feeds it back to the drive system, which provides fast feedback speed, high resolution, and high positioning accuracy.

[0030] The front bearing assembly 2 consists of a front cover 6, a front angular contact ball bearing 7, a front bearing housing 8, and a front locking nut 9. It is fitted onto the front end of the shaft core 1. The front cover 6 protects the front bearing assembly and prevents dust and foreign objects from entering. The front angular contact ball bearing 7 provides the main support and bears axial and radial forces. The front bearing housing 8 supports the front angular contact ball bearing and together with the rear bearing housing, forms the motor mounting cavity.

[0031] The rear bearing assembly 4 consists of a rear bearing housing 12, a rear angular contact ball bearing 13, a rear lock nut 14, and an encoder mounting cover 15, and is fitted onto the rear end of the shaft core 1.

[0032] The torque motor 3 consists of a torque motor stator 10 and a torque motor rotor 11, and the torque motor 3 is sleeved in the middle of the shaft core 1;

[0033] The circular grating encoder 5 includes a fixed stator and a rotating rotor;

[0034] The front bearing housing 8 and the rear bearing housing 12 are fastened together by screws, and the encoder mounting cover 15 is fastened together with the rear bearing housing 12 by screws. The front bearing housing 8 and the rear bearing housing 12 together form the motor mounting cavity.

[0035] Example 2

[0036] like Figure 1-2 As shown, the inner ring of the front angular contact ball bearing 7 is interference-fitted with the shaft core 1, and the outer ring is clearance-fitted with the front bearing housing 8. The front lock nut 9 is threadedly connected to the shaft core 1 to press the inner ring of the front angular contact ball bearing 7, ensuring the bearing is securely installed. The front cover 6 is locked to the front bearing housing 8 with screws to press the outer ring of the front angular contact ball bearing 7.

[0037] The inner ring of the rear angular contact ball bearing 13 is interference-fitted with the shaft core 1, and the outer ring is clearance-fitted with the rear bearing housing 12. The rear lock nut 14 is threadedly connected to the shaft core 1 to press the inner ring of the rear angular contact ball bearing 13, and the outer ring is in a floating state.

[0038] The end face of the torque motor stator 10 is screwed to the end face of the rear bearing housing 12 and fixed on the rear bearing housing to provide a magnetic field. The outer circle of the torque motor stator 10 is clearance-fitted with the front bearing housing 8. The torque motor rotor 11 is interference-fitted with the shaft core 1 and directly drives the shaft core to rotate.

[0039] The fixed stator of the circular grating encoder 5 is secured to the encoder mounting cover with 15 screws, and the rotating rotor is fixed to the shaft core 1 by the side set screw. The resolution of the circular grating encoder 5 is 25 bits.

[0040] The front bearing assembly 2 includes four front angular contact ball bearings 7, which are arranged in series back-to-back with a positioning preload structure. The rear bearing assembly 4 includes two rear angular contact ball bearings 13 arranged back-to-back.

[0041] Four front angular contact ball bearings 7 form the main support structure that bears axial and radial forces, while two rear angular contact ball bearings 13 form the auxiliary support structure.

[0042] The working principle of this utility model is as follows: In this spindle structure, the front bearing assembly has four front angular contact ball bearings 13, which are paired in series and back-to-back, and are positioned and pre-tightened as fixed support ends.

[0043] The rear bearing consists of two rear angular contact ball bearings 13 placed back-to-back as an auxiliary support end, with a built-in torque motor 3 in the middle for driving, and a rear circular grating (absolute value) encoder 5 for detection and feedback.

[0044] The front end of the spindle can withstand axial and radial forces. The spindle is driven to rotate by a torque motor 3. The circular grating (absolute value) encoder 5 monitors and detects the position of the rotating shaft in real time during the spindle rotation and feeds it back to the drive system. With this solution, the spindle speed has strong stability and high positioning accuracy.

[0045] Based on the above working principle, the overall spindle structure can meet the requirements of high-precision gear hobbing workpiece shafts.

[0046] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-precision gear hobbing workpiece spindle structure, characterized in that, It includes a shaft core (1), a front bearing assembly (2), a torque motor (3), a rear bearing assembly (4), and a circular grating encoder (5); The front bearing assembly (2) consists of a front end cover (6), a front angular contact ball bearing (7), a front bearing seat (8), and a front locking nut (9), and is sleeved on the front end of the shaft core (1); The rear bearing assembly (4) consists of a rear bearing housing (12), a rear angular contact ball bearing (13), a rear locking nut (14), and an encoder mounting cover (15), and is fitted onto the rear end of the shaft core (1). The torque motor (3) consists of a torque motor stator (10) and a torque motor rotor (11), and the torque motor (3) is sleeved in the middle of the shaft core (1); The circular grating encoder (5) comprises a fixed stator and a rotating rotor; The front bearing housing (8) and the rear bearing housing (12) are fastened together by screws, and the encoder mounting cover (15) is fastened together with the rear bearing housing (12) by screws. The front bearing housing (8) and the rear bearing housing (12) together form the motor mounting cavity.

2. The spindle structure according to claim 1, characterized in that The inner ring of the front angular contact ball bearing (7) is interference-fitted with the shaft core (1), and the outer ring is clearance-fitted with the front bearing housing (8). The front locking nut (9) is threadedly connected to the shaft core (1) to press the inner ring of the front angular contact ball bearing (7). The front end cover (6) and the front bearing housing (8) are locked together by screws to press the outer ring of the front angular contact ball bearing (7).

3. The spindle structure of claim 1, wherein The inner ring of the rear angular contact ball bearing (13) is interference-fitted with the shaft core (1), and the outer ring is clearance-fitted with the rear bearing housing (12). The rear locking nut (14) is threadedly connected to the shaft core (1) to press the inner ring of the rear angular contact ball bearing (13), and the outer ring is in a floating state.

4. The spindle structure of claim 1, wherein The end face of the torque motor stator (10) is screwed to the end face of the rear bearing housing (12), the outer circle of the torque motor stator (10) is clearance-fitted with the front bearing housing (8), and the torque motor rotor (11) is interference-fitted with the shaft core (1).

5. The spindle structure of claim 1, wherein The fixed stator of the circular grating encoder (5) is locked to the encoder mounting cover (15) with screws, and the rotating rotor is fixed to the shaft core (1) by the side set screw. The resolution of the circular grating encoder (5) is 25 bits.

6. The spindle structure according to claim 1, characterized in that, The front bearing assembly (2) includes four front angular contact ball bearings (7) arranged in series back-to-back with a positioning preload structure, and the rear bearing assembly (4) includes two rear angular contact ball bearings (13) arranged back-to-back.

7. The spindle structure of claim 6, wherein, The four front angular contact ball bearings (7) constitute the main support structure for bearing axial and radial forces, and the two rear angular contact ball bearings (13) constitute the auxiliary support structure.

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