A high-rigidity electric spindle for deep hole internal grinding

Abstract

This utility model discloses a high-rigidity electric spindle for deep hole internal grinding. The spindle structure includes: a spindle housing, a motor shaft section, a motor stator, a motor rotor, and bearing retaining rings for supporting the spindle, including a front support bearing, a middle support bearing, a tail support bearing, and a middle support bearing. A connecting spindle and a front grinding wheel spindle are also present. The front end of the spindle extends out of the machine body to mount the grinding wheel. Driven by the motor, the spindle provides power to the grinding wheel spindle via the connecting spindle. This high-rigidity electric spindle for deep hole internal grinding has a large length-to-diameter ratio, allowing it to penetrate deep into the hole and drive the grinding wheel mounted at the front end to grind the inner wall and end face of the hole. The spindle has high rigidity and is not prone to displacement, thus ensuring machining accuracy and stability during the grinding process.

Description

Technical Field

[0001] This utility model relates to the field of machining equipment technology, specifically to a high-rigidity electric spindle for deep hole internal grinding. Background Technology

[0002] High-rigidity deep-hole internal grinding electric spindles utilize cutting tools to penetrate deep into the workpiece's inner hole for internal grinding. Because the cutting tool needs to extend into the hole, these spindles typically employ a cantilevered single-support structure with a large length-to-diameter ratio, resulting in a large cantilever length and insufficient rigidity at the spindle end. Under cutting forces, this makes them prone to bending deformation, leading to significant deflection and affecting machining accuracy. Furthermore, the spindle diameter is limited by the workpiece's hole diameter, and the need to accommodate an internal motor results in an excessively slender spindle structure. This slender structure not only makes it difficult to meet high-precision machining requirements for the spindle itself but also leads to a complex and cumbersome assembly process, making bearing replacement in the middle position difficult and significantly shortening the spindle bearing's lifespan under alternating loads. Summary of the Invention

[0003] To address the shortcomings of the existing technology, the purpose of this invention is to provide a high-rigidity electric spindle structure for deep hole internal grinding with a large length-to-diameter ratio and a three-segment spindle design. This spindle has high rigidity, is not prone to misalignment, and can extend into deeper holes to drive the grinding wheel mounted at the front end of the spindle to grind the inner wall and end face of the hole, thereby ensuring machining accuracy and stability during the grinding process. This invention also solves the problem of extending the spindle's service life (i.e., extending the fatigue life of the spindle bearings) due to difficulties in spindle assembly. It improves the assembly accuracy of the spindle while maintaining the machining rotation accuracy of the spindle structure.

[0004] The technical solution of this utility model is described in detail below.

[0005] A high-rigidity electric spindle for deep hole internal grinding has a spindle core structure divided into three sections: a grinding wheel spindle, a connecting spindle, and a motor spindle. The connecting spindle is connected to the grinding wheel spindle at the front end and the motor spindle at the rear end via connecting bolts, forming a three-section spindle. The motor spindle, driven by a motor, provides power to the grinding wheel spindle through the connecting spindle. The front end of the grinding wheel spindle extends out of the machine body for mounting the grinding wheel.

[0006] This utility model includes a spindle housing, a spindle end cap at the front end of the spindle housing, and a grinding wheel spindle, a connecting spindle, and a motor spindle arranged on the axis of the spindle housing.

[0007] In this utility model, the motor spindle is located on the inner axis of the motor housing, and the inner axis of the motor housing and the axis of the spindle housing are on the same straight line. The motor rotor is interference-fitted in the middle of the motor spindle. The motor spindle is supported by the front support bearing and the rear support bearing installed at both ends of the motor spindle. The front support bearing is fixed and constrained by the front end of the motor housing, and the rear support bearing is fixed and constrained by the rear end of the motor housing.

[0008] In this invention, a motor cooling water channel is provided between the motor stator and the spindle housing; a temperature measuring channel is provided on the spindle housing located outside the connecting spindle.

[0009] In this utility model, the grinding wheel shaft is supported by a front support bearing and a rear support bearing installed at both ends of the grinding wheel shaft. The two sides of the front support bearing are constrained by the spindle end cap and the middle retaining ring of the front support bearing, respectively. The two sides of the rear support bearing are constrained by the middle retaining ring of the front support bearing and the front grinding wheel shaft shoulder.

[0010] In this utility model, the connecting spindle is supported by a front support bearing and a rear support bearing. Both the front and rear support bearings are supported by a bearing retainer assembly consisting of a middle bearing support retainer and a support rubber ring, which is connected to the spindle housing.

[0011] In this invention, the cross-section of the main shaft housing corresponding to the position of the grinding wheel shaft is a concentric ring.

[0012] In this utility model, the front support bearing of the grinding wheel shaft, the rear support bearing of the grinding wheel shaft, the front support bearing of the motor shaft, the rear support bearing of the motor shaft, the front support bearing of the central shaft, and the rear support bearing of the central shaft are all 15° high-speed angular contact ball bearings.

[0013] Compared with the prior art, the beneficial effects obtained by adopting the technical solution of this utility model are reflected in several aspects: 1) The three-axis connection design can effectively shorten the length of each spindle unit, significantly reduce the manufacturing difficulty of a single spindle, and thus better ensure the realization of its machining accuracy; 2) The three spindles are fastened together with bolts. This mechanical connection structure is easy to process and manufacture, and is more convenient and efficient in the assembly process. At the same time, it can achieve high assembly positioning accuracy, and the overall structure formed after connection has excellent mechanical rigidity, which directly enhances the rigidity performance of the spindle shaft in the working state. 3) Each spindle segment is supported by a double-row bearing, and the bearing span is calculated and designed with rigor to ensure that each spindle segment can obtain the optimal support stiffness, thereby improving the stiffness of the support system formed by the spindle and the housing. 4) The one-piece molded shell structure design eliminates the weak links in the connection caused by the split structure and effectively enhances the overall rigidity of the shell; 5) The spindle cross section adopts a concentric structure layout. This design not only simplifies the processing and manufacturing difficulty of the integrated housing, but more importantly, considering that the spindle is essentially a cantilever beam structure, the concentric design can effectively suppress the vibration during the operation of the spindle, allowing its working speed range to avoid the resonant frequency region, optimizing the dynamic characteristics of the spindle system, and ultimately comprehensively improving the overall rigidity and machining accuracy of the spindle. Attached Figure Description

[0014] Figure 1 This is a structural cross-sectional view of the present invention.

[0015] Figure 2 yes Figure 1 AA section view of the front end of the grinding wheel housing shaft.

[0016] Figure 3 yes Figure 1 Enlarged view of the bolt connection at point B.

[0017] In the diagram: 1-Spindle end cover, 2-Grinding wheel shaft front support bearing, 3-Front end grinding wheel shaft, 4-Front end support bearing intermediate retaining ring, 5-Connecting bolt, 6-Middle section bearing support retaining ring, 7-Central shaft front support bearing, 8-Supporting rubber ring, 9-Connecting spindle, 10-Motor housing, 11-Motor cooling water channel, 12-Motor stator, 13-Motor rotor, 14-Fixing flange, 15-Motor shaft rear support bearing, 16-Motor spindle, 17-Temperature measuring channel, 18-Grinding wheel shaft rear support bearing, 19-Central shaft rear support bearing, 20-Motor shaft front support bearing, 21-Spindle housing. Detailed Implementation

[0018] The technical solution of this utility model will be described in detail below with reference to the accompanying drawings and embodiments.

[0019] Example 1

[0020] See Figure 1 , Figure 2 and Figure 3 In this embodiment, a high-rigidity deep-hole internal grinding electric spindle is provided, including a spindle end cover 1, a front support bearing for the grinding wheel spindle 2, a grinding wheel spindle 3, a middle retaining ring for the front support bearing 4, a connecting bolt 5, a middle section bearing support retaining ring 6, a front support bearing for the central spindle 7, a support rubber ring 8, a connecting spindle 9, a motor housing 10, a motor cooling water channel 11, a motor stator 12, a motor rotor 13, a fixed flange 14, a rear support bearing for the motor 15, a motor spindle 16, a temperature measuring channel 17, a rear support bearing for the grinding wheel spindle 18, a rear support bearing for the central spindle 19, a front support bearing for the motor spindle 20, and a spindle housing 21.

[0021] The spindle core structure is divided into three sections: grinding wheel spindle 3, connecting spindle 9, and motor spindle 16. The connecting spindle 9 is connected to the front grinding wheel spindle 3 and motor spindle 16 respectively by connecting bolts, forming a three-section spindle. The front end of the grinding wheel spindle 3 extends out of the machine body for mounting the grinding wheel. The motor spindle 16 provides power to the grinding wheel spindle 3 through the connecting spindle 9 under the drive of the motor.

[0022] The motor housing 10 houses the motor stator 12. A grinding wheel shaft 3 is mounted on the axial position inside the motor housing 10, connecting the spindle 9 and the motor spindle 16. The motor rotor 13 is interference-fitted into the middle of the motor spindle 16. The motor spindle 16 is supported by a front support bearing 20 and a rear support bearing 15 mounted at both ends. The front support bearing 20 is fixed and constrained by the front end of the motor housing 10, and the rear support bearing 15 is fixed and constrained by the rear end of the motor housing 10. A fixing flange 14 is located 50mm from the rear end of the spindle and is mainly used for fixing and constraining the entire spindle; it is integrated with the housing. A temperature measuring channel 17 is located next to the front bearing in the spindle housing and is formed by an opening; it is mainly used to test the internal temperature rise of the spindle. A motor cooling water channel 11 is located outside the motor stator and is used to cool the motor.

[0023] The grinding wheel spindle 3 is mounted at the front end of the high-rigidity deep-hole internal grinding electric spindle core, and is also mounted on the axial position. The grinding wheel spindle 3 is supported by a front support bearing 2 and a rear support bearing 18 mounted at both ends. The left side of the front support bearing 2 is constrained by the spindle end cap 1, and the right side is constrained by the intermediate retaining ring 4 of the front support bearing. The left side of the rear support bearing 18 is constrained by the intermediate retaining ring 4 of the front support bearing, and the right side is constrained by the shoulder of the grinding wheel spindle 3. Both the front support bearing 2 and the rear support bearing 18 are installed inside the spindle housing 21.

[0024] The connecting spindle 9 is installed on the axis position. Its front end is connected to the grinding wheel spindle 3 by connecting bolt 5, and its rear end is connected to the motor spindle 16 by connecting bolt 5. It is supported by the front support bearing 7 and the rear support bearing 19 of the central shaft. The support of the front support bearing 7 and the rear support bearing 19 of the central shaft is connected to the spindle housing 21 by a bearing retaining ring combination consisting of the middle bearing support retaining ring 6 and the support rubber ring 8.

[0025] The outer shell at position 3 of the grinding wheel shaft has a concentric circular cross-section.

[0026] The front support bearing 2 of the grinding wheel shaft, the rear support bearing 18 of the grinding wheel shaft, the front support bearing 20 of the motor shaft, the rear support bearing 15 of the motor shaft, the front support bearing 7 of the center shaft, and the rear support bearing 19 of the center shaft are all 15° high-speed angular contact ball bearings.

[0027] The high-rigidity deep hole internal grinding electric spindle of this invention has a large length-to-diameter ratio, which allows it to extend into a deeper hole and drive the grinding wheel mounted at the front end of the spindle to grind the inner wall and end face of the hole. The spindle has high rigidity and is not prone to deviation, thereby ensuring the machining accuracy and stability during the grinding process.

[0028] The above description is only a preferred embodiment of the present utility model. The protection scope of the present utility model is not limited to the above embodiments. Any equivalent modifications or changes made by those skilled in the art based on the content disclosed in the present utility model should be included in the protection scope recorded in the claims.

Claims

1. A high-rigidity deep-hole internal cylindrical grinding electric spindle, characterized by, The spindle core structure is divided into three sections: grinding wheel spindle (3), connecting spindle (9) and motor spindle (16); among them, the connecting spindle (9) is connected to the front grinding wheel spindle (3) and the rear motor spindle (16) respectively by connecting bolts (5), forming a three-section spindle; the motor spindle (16) provides power to the grinding wheel spindle (3) through the connecting spindle (9) under the drive of the motor, and the front end of the grinding wheel spindle (3) extends out of the machine body for mounting the grinding wheel.

2. The high-rigidity deep-hole internal grinding electric spindle according to claim 1, characterized in that, Includes a spindle housing (21), with a spindle end cap (1) at the front end of the spindle housing (21), and a grinding wheel spindle (3), a connecting spindle (9) and a motor spindle (16) arranged on the axis of the spindle housing (21).

3. The high-rigidity deep-hole internal grinding electric spindle according to claim 1, characterized in that, The motor spindle (16) is located on the internal axis of the motor housing (10). The internal axis of the motor housing (10) and the axis of the spindle housing (21) are on the same straight line. The motor rotor (13) is interference-fitted in the middle of the motor spindle (16). The motor spindle (16) is supported by the front support bearing (20) and the rear support bearing (15) of the motor shaft installed at both ends. The front support bearing (20) of the motor shaft is fixedly constrained by the front end of the motor housing (10), and the rear support bearing (15) of the motor shaft is fixedly constrained by the rear end of the motor housing (10).

4. The high-rigidity deep-hole internal grinding electric spindle according to claim 3, characterized in that, A motor cooling water channel (11) is provided between the motor stator and the spindle housing (21); a temperature measuring channel (17) is provided on the spindle housing (21) located outside the connecting spindle (9).

5. The high-rigidity deep-hole internal grinding electric spindle according to claim 1, characterized in that, The grinding wheel shaft (3) is supported by the front support bearing (2) and the rear support bearing (18) of the grinding wheel shaft installed at both ends. The front support bearing (2) of the grinding wheel shaft is constrained on both sides by the spindle end cover (1) and the intermediate retaining ring (4) of the front support bearing, respectively. The rear support bearing (18) of the grinding wheel shaft is constrained on both sides by the intermediate retaining ring (4) of the front support bearing and the shoulder of the front grinding wheel shaft (3).

6. The high-rigidity deep-hole internal grinding electric spindle according to claim 1, characterized in that, The connecting spindle (9) is supported by the front support bearing (7) and the rear support bearing (19) of the central spindle. The support of the front support bearing (7) and the rear support bearing (19) of the central spindle is connected to the spindle housing (21) by a bearing retainer combination consisting of a middle section bearing retainer ring (6) and a support rubber ring (8).

7. The high-rigidity deep-hole internal grinding electric spindle according to claim 1, characterized in that, The cross section of the main shaft housing (21) corresponding to the position of the grinding wheel shaft (3) is a concentric ring.

8. The high-rigidity deep-hole internal grinding electric spindle according to claim 1, characterized in that, The front support bearing (2) of the grinding wheel shaft, the rear support bearing (18) of the grinding wheel shaft, the front support bearing (20) of the motor shaft, the rear support bearing (15) of the motor shaft, the front support bearing (7) of the center shaft, and the rear support bearing (19) of the center shaft are all 15° high-speed angular contact ball bearings.

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