Electric spindle and numerical control machine tool

Abstract

The utility model relates to the field of working spindles, in particular to an electric spindle and a numerical control machine tool. The motorized spindle and the numerical control machine tool are used for solving the problem that a motor lead in a motorized spindle in the prior art is damaged due to the fact that the motor lead scrapes a rotating part of the motorized spindle. The electric spindle comprises a shell, a spindle and a rear cover, a stator and a bearing seat are mounted in the shell, a bearing is mounted in the bearing seat, a rotary transformer is arranged in the rear cover, a fixed part of the rotary transformer is fixedly mounted on the rear cover, a radial interval is formed between the fixed part and the inner wall of the rear cover, and an axial interval is formed between the bearing seat and the fixed part. The bearing seat is provided with a lead channel, a motor lead passes through the lead channel and penetrates out of the rear cover at the radial interval, and the axial interval is provided with a separation structure which shields the motor lead outside so as to prevent the motor lead from being in contact with a rotating component in the axial interval. Damage to the motor lead due to the fact that the motor lead scrapes a rotating component when the electric spindle runs is avoided, and running safety of the electric spindle is guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of spindles, specifically to an electric spindle and a CNC machine tool. Background Technology

[0002] As a key component of modern CNC machine tools, the performance and reliability of electric spindles are crucial to the efficiency and product quality of the entire production line.

[0003] An existing electric spindle structure such as Figure 1 As shown, the device includes a housing, within which a stator is fixedly mounted. Bearing seats are mounted on both axial sides of the stator within the housing, and bearings are installed in the bearing seats. The main shaft is rotatably mounted within the housing via the bearings. A rotary transformer is mounted at the tail end of the main shaft. The fixed part of the rotary transformer is fixedly connected to a rear cover connected to the tail end of the housing, while the rotating part is fixedly connected to the main shaft. The bearing seats have axially penetrating lead-in channels. Stator leads are led out through these channels, passing through the radial space between the fixed part of the rotary transformer and the rear cover, and through a through-hole on the rear cover, before connecting to connectors. To facilitate welding of the stator leads to the connectors, a certain length is often reserved so that the stator leads have some length remaining after passing through the through-hole. Thus, when welding is completed and the connectors are installed on the rear cover, the stator leads will bend inside the rear cover, behind the bearing seats. A rear nut is fixed on the main shaft between the bearings and the rotary transformer to position and stop the bearings. Due to the presence of the rear nut, there is a certain axial gap between the bearing seats and the rotary transformer. If the stator leads bend and extend into the axial gap, the rear nut, which rotates at high speed with the spindle, will scrape against the stator leads during operation, thereby damaging the insulation layer of the motor leads and increasing the risk of spindle open circuit. Utility Model Content

[0004] The purpose of this invention is to provide an electric spindle to solve the problem of motor leads in existing electric spindles rubbing against the rotating parts of the spindle, causing damage to the motor leads. Another purpose of this invention is to provide a CNC machine tool to solve the problem of motor leads in existing CNC machine tools rubbing against the rotating parts of the spindle, causing damage to the motor leads.

[0005] To solve the above-mentioned technical problems, the electric spindle of this utility model adopts the following technical solution:

[0006] An electric spindle includes a housing and a spindle. A rear cover is fixedly installed at the rear end of the housing. A stator is installed inside the housing, and a bearing housing is installed at the rear side of the stator. A bearing for rotatably supporting the spindle is installed inside the bearing housing. A rotary transformer is provided inside the rear cover. A fixed part of the rotary transformer is fixedly installed on the rear cover, and there is a radial gap between the fixed part and the inner wall of the rear cover. There is an axial gap between the bearing housing and the fixed part. An axially penetrating lead wire channel is provided on the bearing housing. The motor lead wire passes through the lead wire channel and the radial gap and exits the rear cover. A partition structure is provided at the axial gap to shield the motor lead wire from contact with the rotating parts within the axial gap.

[0007] Furthermore, the partition structure is a cylindrical protective cover, and the protective cover is provided with a connection structure for connecting with the bearing seat.

[0008] Furthermore, the connection structure is a connecting flange, and the connecting flange is provided with a wire-passing structure for the motor leads to pass through.

[0009] Furthermore, the through-line structure is a D-shaped cut notch formed by cutting along the chord on the connecting flange.

[0010] Furthermore, the edges of the cut surfaces of the connecting flange are chamfered.

[0011] Furthermore, the axial length of the protective cover is not less than the distance between the bearing and the rotary transformer.

[0012] Furthermore, the inner diameter of the protective cover is not less than the outer diameter of the rotary transformer and has a portion that fits over the rotary transformer. The outer diameter of the protective cover is consistent with the inner diameter of the bearing housing and has a portion that extends into the bearing housing.

[0013] Furthermore, the side of the protective cover facing the motor leads and the cut surface on the connecting flange are both smooth surfaces.

[0014] This invention proposes an improved technical solution by providing a partition structure at the axial interval to shield the motor leads and prevent them from contacting rotating components within the axial interval. This partition structure prevents the motor leads from being damaged by scraping against rotating components during spindle operation, ensuring the safety of spindle operation and extending its service life.

[0015] Another aspect of this utility model provides a CNC machine tool, which includes an electric spindle. The electric spindle includes a housing and a spindle. A rear cover is fixedly installed at the rear end of the housing. A stator is installed inside the housing, and a bearing seat is installed at the rear side of the stator. A bearing for rotating and supporting the spindle is installed inside the bearing seat. A rotary transformer is provided inside the rear cover. The fixed part of the rotary transformer is fixedly installed on the rear cover, and there is a radial gap between the fixed part and the inner wall of the rear cover. There is an axial gap between the bearing seat and the fixed part. An axially penetrating lead wire channel is provided on the bearing seat. The motor lead wire passes through the lead wire channel and the radial gap and exits the rear cover. A partition structure is provided at the axial gap to shield the motor lead wire from contact with the rotating parts within the axial gap.

[0016] Furthermore, the partition structure is a cylindrical protective cover, and the protective cover is provided with a connection structure for connecting with the bearing seat.

[0017] Furthermore, the connection structure is a connecting flange, and the connecting flange is provided with a wire-passing structure for the motor leads to pass through.

[0018] Furthermore, the through-line structure is a D-shaped cut notch formed by cutting along the chord on the connecting flange.

[0019] Furthermore, the edges of the cut surfaces of the connecting flange are chamfered.

[0020] Furthermore, the axial length of the protective cover is not less than the distance between the bearing and the rotary transformer.

[0021] Furthermore, the inner diameter of the protective cover is not less than the outer diameter of the rotary transformer and has a portion that fits over the rotary transformer. The outer diameter of the protective cover is consistent with the inner diameter of the bearing housing and has a portion that extends into the bearing housing.

[0022] Furthermore, the side of the protective cover facing the motor leads and the cut surface on the connecting flange are both smooth surfaces.

[0023] This invention proposes an improved technical solution by providing a partition structure at the axial interval to shield the motor leads and prevent them from contacting rotating components within the axial interval. This partition structure prevents the motor leads from being damaged by scraping against rotating components during spindle operation, ensuring the safety of spindle operation and extending its service life. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of an existing electric spindle;

[0025] Figure 2 This is a cross-sectional view of an electric spindle according to the present invention;

[0026] Figure 3 for Figure 2 A magnified view of a portion of point A;

[0027] Figure 4 A 3D view of the protective shield;

[0028] Figure 5 for Figure 4 The front view;

[0029] Figure 6 for Figure 4 A cross-sectional view of plane AA.

[0030] In the diagram: 1. Stator; 2. Rotor; 3. Spring washer; 4. Spring; 5. Spring seat; 6. Bearing seat; 7. Rear cover; 8. Motor lead wire; 9. Handle; 10. Connector; 11. Rear pressure cap; 12. Rotary transformer; 13. Protective cover; 131. Connecting flange; 132. Cut surface; 14. Rear nut; 15. Bearing; 16. Main shaft; 17. Water jacket; 18. Housing. Detailed Implementation

[0031] This utility model proposes an improved technical solution to address the problems existing in the above-mentioned technical solutions. The core concept of this utility model is to provide a separation structure at the axial interval to shield the motor leads from contact between the motor leads and rotating parts within the axial interval. This separation structure prevents the motor leads from being damaged by scraping against rotating parts during the operation of the electric spindle, ensuring the safety of the electric spindle operation and improving its service life.

[0032] In view of the above-mentioned inventive concept, the electric spindle of this utility model includes as follows: Figure 2The diagram shows a housing 18 and a main shaft 16. A rotor 2 is mounted on the front of the main shaft 16. A rear cover 7 is fixedly mounted on the rear end of the housing 18. A stator 1 is installed inside the housing 18, and a bearing housing 6 is mounted on the rear side of the stator 1. A bearing 15, which rotatably supports the main shaft 16, is installed inside the bearing housing 6. A rotary transformer 12 is housed inside the rear cover 7. The fixed part of the rotary transformer 12 is fixedly mounted on the rear cover 7, and there is a radial gap between the fixed part and the inner wall of the rear cover 7. The main shaft 16 is mounted on the rotating part of the rotary transformer 12, and the main shaft 16 is rotatably mounted to the rear cover 7 via a rear pressure cap 11. There is an axial gap between the bearing housing 6 and the fixed part. A rear nut 14 is mounted on the main shaft 16 within the axial gap. The rear nut 14 can position the bearing 15 on the rear side of the bearing 15. A spring seat 5 is provided in front of bearing 15, and a spring washer 3 is provided at the front end of bearing housing 6. A spring 4 is installed between spring washer 3 and spring seat 5. The spring 4 can press bearing 15 on the front side of bearing 15, thus achieving bearing positioning. Bearing housing 6 has an axially through-through lead wire channel. Motor lead wire 8 passes through the lead wire channel and radially spaced out of rear cover 7. Motor lead wire 8 may bend within the radial space and may enter the axial space, scraping against rotating parts within the axial space (such as rear nut 14 on the shaft, inner ring of bearing 15, or rotor part of rotary transformer 12). Therefore, a partition structure is provided at the axial space to shield motor lead wire 8 from contact with rotating parts within the axial space. The partition structure prevents motor lead wire 8 from scraping against rotating parts during the operation of the electric spindle, thus ensuring the safety of electric spindle operation and improving the service life of electric spindle.

[0033] In this embodiment, the partition structure is as follows: Figure 4 , Figure 6 The cylindrical protective cover 13 shown is provided with a connection structure for connecting to the bearing housing 6. The cylindrical protective cover 13 circumferentially separates the rotating component and the motor lead 8, ensuring the separation effect of the protective cover 13. In other embodiments, the separation structure can also be an arc-shaped plate, installed between the motor lead 8 and the rotating component, as long as it can be used to separate the rotating component and the motor lead 8 within the axial interval. In this embodiment, the protective cover 13 is 4mm thick and made of 40Cr alloy steel. This material has high strength and good toughness, and can withstand various mechanical loads such as centrifugal force, axial force, radial force, and vibration that may be generated when the electric spindle rotates at high speed. The motor lead 8 protective cover 13 made of 40Cr alloy steel not only meets the requirement of physically isolating the motor lead 8 from the rotating component, but also helps to improve the reliability and durability of the entire electric spindle system. At the same time, the economic benefits of 40Cr alloy steel also ensure the economic efficiency of the motor lead 8 protective device.

[0034] In this embodiment, the connection structure is as follows: Figure 4 The connecting flange 131 shown has a wire-passing structure for the motor lead 8 to pass through. The thickness A4 of the connecting flange 131 is 5mm, and the connecting flange has the following... Figure 5 The connecting holes shown have diameters A1 (5mm) and A2 (110mm). The connecting flange 131 is connected to the bearing housing 6 using screws, thus ensuring a reliable connection between the protective cover 13 and the bearing housing 6. Alternatively, in other embodiments, the connecting structure can be a connecting lug extending radially outward from the protective cover, connecting to the bearing housing. In another embodiment, the connecting structure can be a threaded structure on the outer circumference of the protective cover; in this case, a threaded structure can also be provided in the inner ring of the bearing housing, connecting the two via the threaded structure. In yet another embodiment, the protective cover can be mounted on the rotary transformer via a connecting flange or connecting lug, as long as the reliability of the protective cover installation is ensured.

[0035] In this embodiment, the through-line structure is a D-shaped cut notch formed by cutting along the chord on the connecting flange 131. For example... Figure 5 As shown, the positioning dimension A3 of the chord (the straight-line distance from the center of the connecting flange 131 to the chord) is 52mm. When the protective cover 13 is installed on the bearing seat 6, a wire passage is formed between the cut notch and the inner wall of the rear cover 7. The cut notch is easy to manufacture and provides a certain space for the motor lead 8 to pass through. In addition, in other embodiments, the wire passage structure can also be a wire passage hole on the connecting flange.

[0036] In this embodiment, the edges of the cut surface 132 of the connecting flange 131 are chamfered. The connecting flange 131 in this embodiment has a 45° chamfered edge on the cut surface 132, and the chamfer radius is set to 1mm. This treatment ensures that the cut edge forms a smooth bevel, effectively reducing the scraping and squeezing of the motor lead 8 by the cut edge, and ensuring the smooth and safe installation and operation of the motor lead 8.

[0037] In this embodiment, the axial length of the protective cover 13 is not less than the distance between the bearing 15 and the rotary transformer 12. This ensures the reliability of the protective cover 13. Furthermore, in other embodiments, the axial length of the protective cover 13 may also be less than the distance between the bearing and the rotary transformer, but it is necessary to ensure that after the protective cover is installed, the motor lead 8 will not enter the axial gap from the gap between the protective cover and the bearing or between the protective cover and the rotary transformer.

[0038] In this embodiment, the inner diameter of the protective cover 13 is not less than the outer diameter of the rotary transformer 12 and has a portion that fits over the rotary transformer 12. The outer diameter of the protective cover is the same as the inner diameter of the bearing housing 6 and has a portion that extends into the bearing housing. Figure 6 As shown, in this embodiment, the axial length A5 of the protective cover 13 is 19.5 mm, which is greater than the distance between the bearing 15 and the rotary transformer 12. The inner diameter A6 of the protective cover 13 is 92 mm, slightly larger than the outer diameter of the rotary transformer 12, so that the protective cover 13 can be fitted over the rotary transformer 12. The outer diameter A7 of the protective cover 13 is 100 mm, which is the same as the inner diameter of the bearing housing 6, so that the protective cover 13 can extend into the bearing housing 6. The distance A8 from the connecting flange 131 to the front end of the protective cover 13 is 2.5 mm, which is the same as the distance from the end of the bearing 15 to the end of the bearing housing 6. Figure 3 As shown, when the protective cover 13 is installed, its end can abut against the outer ring of the bearing 15. This arrangement not only positions the protective cover 13 but also ensures that the protective cover 13 circumferentially and thoroughly separates the motor leads 8 and the rotating parts, guaranteeing the separation effect of the protective cover 13. Furthermore, in other embodiments, the inner diameter of the protective cover can be smaller than the inner diameter of the rotary transformer, but it must be ensured that the inner ring of the protective cover does not extend into the inner ring of the bearing. It is readily apparent that the inner diameter of the protective cover can also be greater than or equal to the inner diameter of the bearing housing; in this case, the outer diameter of the protective cover is also greater than the inner diameter of the bearing housing, as long as the protective cover can separate the motor leads and the rotating parts.

[0039] In this embodiment, the side of the protective cover 13 facing the motor lead 8 and the cut surface 132 of the connecting flange are both smooth surfaces. The smooth surface makes it easier for the motor lead 8 to pass through the protective cover 13, avoiding difficulties caused by the rough surface of the protective cover 13. During manufacturing, the side of the protective cover 13 facing the motor lead 8 and the cut surface of the connecting flange need to be mechanically polished. The specific steps are as follows: First, thoroughly clean the surface of the protective cover 13 with a cleaning agent to remove all impurities. Next, select suitable polishing equipment and polishing materials, such as a cloth wheel and fine-grained polishing paste. Then, evenly apply the polishing agent to the polishing pad and polish at a moderate speed and pressure to ensure that each area is uniformly treated. During the polishing process, periodically check the smoothness of the protective cover 13 surface and adjust the operating parameters to avoid over-polishing or uneven surface. After polishing, remove any residual polishing agent from the surface and perform a final inspection of the treated surface to ensure that the surface meets the smoothness requirements. Alternatively, in other embodiments, the side of the protective cover facing the motor lead and the cut surface of the connecting flange may also be rough surfaces.

[0040] Another aspect of this utility model provides a CNC machine tool, which includes an electric spindle. Since the electric spindle is the same as the embodiment of the electric spindle described above, it will not be described again here.

[0041] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. The patent protection scope of the present utility model shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present utility model shall also be included within the protection scope of the present utility model.

Claims

1. An electric spindle, comprising a housing and a spindle, a rear cover fixedly mounted on the rear end of the housing, a stator installed inside the housing and a bearing housing mounted on the rear side of the stator, a bearing for rotatably supporting the spindle installed inside the bearing housing, a rotary transformer housed inside the rear cover, a fixed portion of the rotary transformer fixedly mounted on the rear cover with a radial gap between the fixed portion and the inner wall of the rear cover, an axial gap between the bearing housing and the fixed portion, and an axially penetrating lead wire channel on the bearing housing, through which motor leads pass through the lead wire channel and radially spaced out of the rear cover, characterized in that: A partition structure is provided at the axial interval to shield the motor leads from contact with rotating parts within the axial interval.

2. The electric spindle according to claim 1, characterized in that: The partition structure is a cylindrical protective cover, and the protective cover is provided with a connection structure for connecting with the bearing housing.

3. The electric spindle according to claim 2, characterized in that: The connection structure is a connecting flange, and the connecting flange is provided with a wire guide structure for the motor leads to pass through.

4. The electric spindle according to claim 3, characterized in that: The through-line structure is a D-shaped cut notch formed by cutting along the chord on the connecting flange.

5. The electric spindle according to claim 4, characterized in that: The cut edges of the connecting flange are chamfered.

6. The electric spindle according to any one of claims 2-5, characterized in that: The axial length of the protective cover is not less than the distance between the bearing and the rotary transformer.

7. The electric spindle according to claim 6, characterized in that: The inner diameter of the protective cover is not less than the outer diameter of the rotary transformer and has a portion that fits over the rotary transformer. The outer diameter of the protective cover is the same as the inner diameter of the bearing housing and has a portion that extends into the bearing housing.

8. The electric spindle according to any one of claims 2-5, characterized in that: The side of the protective cover facing the motor leads and the cut surface on the connecting flange are both smooth surfaces.

9. A CNC machine tool, comprising an electric spindle, characterized in that: The electric spindle includes the electric spindle according to any one of claims 1-8.

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