High-speed nut rotation feed lead screw device

Abstract

The present invention discloses a high-speed nut rotating feed lead screw device including a lead screw, a lead screw nut, a bearing unit and a driving unit, the lead screw is fixed to a machine tool through a lead screw base, the bearing unit includes a bearing inner fixed sleeve, a bearing outer fixed sleeve and a bearing assembly mounted therebetween, one end of the bearing inner fixed sleeve is fixedly connected to one end of the lead screw nut and the other end is fixedly connected to the driving unit. The lead screw nut is installed on the lead screw, the driving unit includes a first pulley, a second pulley, a timing belt and a driving motor, the first pulley is connected to the driving motor, the second pulley is fitted on the lead screw and connected to the bearing inner fixed sleeve, and the first pulley and the second pulley are connected by a timing belt. The high-speed nut rotating feed lead screw device disclosed in the present invention has the advantages of simple structure, small volume, easy heat dissipation, fast operating speed, etc.

Description

[Technical Field]

[0001] The present invention relates to the technical field of feed drive for numerically controlled machine tools, and in particular to a high-speed nut rotation feed lead screw device. [Background technology]

[0002] In the field of numerically controlled machine tools, lead screw drives are a commonly adopted design structure, especially for the feed motion of the machine tool's slide table or spindle. However, conventional lead screw drives generally use a drive motor connected to the lead screw, which drives the lead screw to rotate, and a lead screw nut is fixedly connected to the moving member. As the lead screw rotates, the lead screw nut is driven to move along a straight line, thereby driving the moving member. However, conventional lead screw drives have the following drawbacks: The lead screw has a large volume and mass, and therefore a large inertia. To drive and rotate the lead screw, a high-power drive motor is required, which increases the volume and cost of the entire drive. At the same time, conventional lead screw drives require a bearing unit to be mounted outside the lead screw nut, which increases the radial dimension of the lead screw nut assembly and the volume of the entire lead screw drive. At the same time, because the bearing unit is mounted outside the lead screw nut, it is difficult to dissipate the heat generated between the lead screw nut and the lead screw, which affects the performance and service life of the lead screw nut. Summary of the Invention

[0003] SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a high-speed nut rotation feed lead screw device.

[0004] The technical solutions adopted by the present invention are as follows:

[0005] A high-speed nut rotation feed lead screw device including a lead screw, a lead screw nut, a bearing unit and a drive unit, the lead screw is fixed to a machine tool via a lead screw base; the bearing unit includes an inner bearing fixed sleeve, an outer bearing fixed sleeve, and a bearing assembly, the outer bearing fixed sleeve is fitted into the inner bearing fixed sleeve, a bearing mounting space is formed between the outer bearing fixed sleeve and the inner bearing fixed sleeve, the bearing assembly is mounted in the bearing mounting space, one end of the inner bearing fixed sleeve is a lead screw nut connecting end for fixedly connecting to one end of a lead screw nut, and the other end is a drive unit connecting end for fixedly connecting to a drive unit, The lead screw nut is installed on the lead screw, and one end is fixedly connected to the lead screw nut connecting end of the bearing inner fixed sleeve; The drive unit includes a first pulley, a second pulley, a timing belt, and a drive motor, the first pulley is connected to the drive motor, the second pulley is fitted to the lead screw and is fixedly connected to the drive unit connection end of the bearing inner fixed sleeve, and the first pulley and the second pulley are connected via a timing belt.

[0006] Furthermore, a bearing seal ring is provided at one end adjacent to the lead screw nut connection end between the bearing inner fixed sleeve and the bearing outer fixed sleeve.

[0007] Furthermore, the bearing outer fixed sleeve is further provided with an oil injection passage communicating with the bearing seal ring.

[0008] Furthermore, a torque limiter is further provided between the drive motor and the first pulley.

[0009] Furthermore, the bearing assembly includes two sets of symmetrically installed angular contact ball bearings, each set of angular contact ball bearings including at least one angular contact ball bearing.

[0010] Furthermore, the bearing-internal fixed sleeve has a stepped shaft sleeve structure, and one end of the bearing-internal fixed sleeve adjacent to the drive unit connection end is provided with a male thread, and the bearing assembly is fixed to the bearing-internal fixed sleeve with a lock nut.

[0011] The device further includes a retaining cover, which is fixedly connected by screws to one end of the slide table adjacent to the drive unit connecting end and one end of the bearing outer fixed sleeve adjacent to the drive unit connecting end.

[0012] Furthermore, the lead screw is further provided with a cooling passage arranged along the axial direction of the lead screw.

[0013] Compared with the prior art, the high-speed nut rotation feed lead screw device disclosed in the present invention has the following advantageous effects: In the lead screw device disclosed in the present invention, the drive unit directly drives and rotates the lead screw nut, which in turn drives and moves the slide table. Therefore, the lead screw nut has a small volume, light weight, and low inertia. This allows for the adoption of a low-power drive motor, thereby reducing the volume and cost of the device. At the same time, the small motion inertia of the entire device allows for high-speed rotation feed of the lead screw nut. Furthermore, because the lead screw nut and bearing unit are arranged along the axial direction of the lead screw, the overall outer diameter of the lead screw nut and bearing unit is small, thereby reducing the volume of the lead screw device. At the same time, because the lead screw nut and bearing unit are arranged along the axial direction of the lead screw, heat dissipation is facilitated, improving the performance and service life of the lead screw. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a structural diagram of a high-speed nut rotation feed lead screw device disclosed in the present invention; [Figure 2] FIG. 2 is an enlarged schematic view of a portion enclosed by a dashed line in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] 1 and 2 show a high-speed nut rotation feed lead screw device including a lead screw 1, a lead screw nut 2, a bearing unit 3 and a drive unit 4 disclosed in the present invention, Both ends of the lead screw 1 are fixed to a machine tool via a lead screw base 10. The bearing unit 3 includes a bearing-interior fixed sleeve 30, a bearing-exterior fixed sleeve 31, and a bearing assembly 32, the bearing-exterior fixed sleeve 31 is fitted into the bearing-interior fixed sleeve 30, a bearing mounting space 33 is formed between the bearing-exterior fixed sleeve 31 and the bearing-interior fixed sleeve 30, the bearing assembly 32 is mounted in the bearing mounting space 33, one end of the bearing-interior fixed sleeve 30 is a lead screw nut connecting end 34 for fixed connection to one end of the lead screw nut 2, and the other end is a drive unit connecting end 35 for fixed connection to the drive unit 4, The lead screw nut 2 is installed on the lead screw 1, and one end is fixedly connected to the lead screw nut connecting end 34 of the bearing inner fixing sleeve 30. Preferably, the lead screw and the lead screw nut are of a standard lead screw structure for ease of purchase, thereby reducing the cost of designing and manufacturing the machine tool. The drive unit 4 includes a first pulley 40, a second pulley 41, a timing belt 42, and a drive motor 43. The first pulley 40 is connected to the drive motor 43. The second pulley 41 is fitted to the lead screw 1 and fixedly connected to the drive unit connecting end 35 of the bearing-inside fixed sleeve 30. The first pulley 40 and the second pulley 41 are connected via a timing belt 42. In this embodiment, a servo motor is used as the drive motor.

[0016] Specifically, a lead screw nut connection flange 20 is provided at one end of the lead screw nut 2 facing the bearing unit 3, the bearing-mounted sleeve 30 has a stepped shaft sleeve structure, and a male thread is provided at one end of the bearing-mounted sleeve 30 close to the drive unit connecting end 35, the bearing assembly 32 is fixed to the bearing-mounted sleeve 30 by a lock nut 39, i.e., the lock nut abuts against the inner ring of the bearing, thereby limiting the bearing to the bearing-mounted sleeve, and a bearing-mounted sleeve connection flange 300 is provided at one end of the bearing-mounted sleeve 30 facing the lead screw nut 2, and the lead screw nut connection flange The flange 20 and the bearing inner fixed sleeve connecting flange 300 are fixedly connected by screws, and a retaining cover 38 is further provided at one end where a lock nut is provided, and the retaining cover 38 is fixedly connected by screws to one end adjacent to the drive unit connecting end of the slide table and one end adjacent to the drive unit connecting end of the bearing outer fixed sleeve 31, respectively. The retaining cover abuts against one end of the bearing outer ring, thereby restricting the bearing inner ring to the bearing outer fixed sleeve. A through hole is formed in the middle of the second pulley 41, and the second pulley is fitted onto a lead screw through the through hole and fixedly connected to the bearing inner fixed sleeve by screws.

[0017] In the lead screw device disclosed in the present invention, the drive unit directly drives and rotates the lead screw nut, which in turn drives and moves the slide table, so that the lead screw nut has a small volume, light weight, and small inertia, allowing it to be driven by a drive motor with a small output, reducing the volume and cost of the device, and at the same time, the small motion inertia of the entire device allows the lead screw nut to be rotated at a high speed. Furthermore, because the lead screw nut and bearing unit are arranged along the axial direction of the lead screw, the overall outer diameter of the lead screw nut and bearing unit is reduced, allowing the use of bearings with particularly small diameters, further reducing the moment of inertia and thereby reducing the volume of the lead screw device. At the same time, because the lead screw nut and bearing unit are arranged along the axial direction of the lead screw, the lead screw nut is fully exposed, facilitating heat dissipation from the lead screw nut and improving the performance and service life of the lead screw. Furthermore, because the lead screw nut is connected via the bearing unit and both ends of the lead screw are fixed, the lead screw is equivalent to having three support points, and the driving force applied by the drive unit is close to the lead screw nut. This improves the rigidity of the lead screw and allows the lead screw nut to rotate at high speeds. This significantly increases the safe rotation speed between the lead screw and the lead screw nut, further improving the operating performance of the machine tool.

[0018] Furthermore, a bearing seal ring 36 is provided at one end adjacent to the lead screw nut connecting end 34 between the bearing inner fixed sleeve 30 and the bearing outer fixed sleeve 31, and an oil injection passage 37 communicating with the bearing seal ring 36 is further provided on the bearing outer fixed sleeve 31. The bearing seal ring structure and the oil injection passage are provided to achieve sealing for the bearing assembly, thereby ensuring the performance of the bearing and the performance of the entire lead screw device and extending its service life.

[0019] Furthermore, a torque limiter 44 is further provided between the drive motor 43 and the first pulley 40, and by installing the torque limiter, if an overload occurs on the machine tool due to a collision or other cause, the torque limiter is activated to protect the drive unit from damage.

[0020] Furthermore, the bearing assembly 32 includes two sets of symmetrically installed angular contact ball bearings, each set of which includes at least one angular contact ball bearing. In this embodiment, each set has two angular contact ball bearings, with a spacer separating the two sets of angular contact ball bearings. The use of angular contact ball bearings not only allows them to withstand the axial force generated between the lead screw and lead screw nut, but also the radial force generated by the drive motor via the timing belt, thereby ensuring the performance between the lead screw nut and lead screw and improving service life. Preferably, an angular contact ball bearing with a contact angle of 60 degrees is used.

[0021] Furthermore, the lead screw 1 is further provided with a cooling channel 11 arranged along the axial direction of the lead screw. Specifically, a cooling channel is machined in the center of the lead screw along the axial direction, passing through both ends of the lead screw. By injecting coolant into the cooling channel, the arrows in the figure indicate the flow direction of the coolant, which can further cool the lead screw and lead screw nut, ensuring the performance and service life of the lead screw and lead screw nut.

[0022] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited thereto. Any equivalent replacements or modifications made by those skilled in the art based on the technical solutions and inventive concepts of the present invention within the technical scope disclosed in the present invention should be included in the protection scope of the present invention. [Explanation of symbols]

[0023] 1 lead screw 10 Lead screw base 11 Cooling channel 2 lead screw nuts 20 Lead screw nut connection flange 3 Bearing Unit 30 Bearing inner fixed sleeve 300 Bearing inner fixed sleeve connection flange 31 Bearing outer fixed sleeve 32 Bearing Assembly 33 Bearing installation space 34 Lead screw nut connection end 35 Drive unit connection end 36 Bearing seal ring 37 Oil injection channel 38 Presser foot cover 39 Lock nut 4 Drive Unit 40 No. 1 pulley 41 No. 2 pulley 42 Timing belt 43 Drive motor 44 Torque limiter

Claims

1. A high-speed nut rotation feed lead screw device including a lead screw, a lead screw nut, a bearing unit and a drive unit, the lead screw is fixed to a machine tool via a lead screw base; the bearing unit includes a bearing-inner fixed sleeve, a bearing-outer fixed sleeve, and a bearing assembly, the bearing-outer fixed sleeve is fitted into the bearing-inner fixed sleeve, a bearing mounting space is formed between the bearing-outer fixed sleeve and the bearing-inner fixed sleeve, the bearing assembly is mounted in the bearing mounting space, one end of the bearing-inner fixed sleeve is a lead screw nut connecting end for fixedly connecting to one end of a lead screw nut, and the other end of the bearing-inner fixed sleeve is a drive unit connecting end for fixedly connecting to a drive unit, the lead screw nut and the bearing unit are arranged along the axial direction of the lead screw, the lead screw nut is installed on the lead screw, and one end of the lead screw nut is fixedly connected to the lead screw nut connecting end of the bearing inner fixing sleeve, and the other end of the lead screw nut is separated from the bearing unit, and the lead screw nut is located outside the bearing unit; a timing belt and a drive motor; the first pulley is connected to the drive motor; the second pulley is fitted to the lead screw and is fixedly connected to the drive unit connecting end of the bearing-inside fixed sleeve; and the first pulley and the second pulley are connected via a timing belt.

2. 2. The high-speed nut rotating feed lead screw device according to claim 1, wherein a bearing seal ring is provided at one end adjacent to the lead screw nut connecting end between the bearing inner fixed sleeve and the bearing outer fixed sleeve.

3. 3. The high-speed nut rotating feed lead screw device according to claim 2, wherein the bearing outer fixed sleeve is further provided with an oil injection passage communicating with the bearing seal ring.

4. 4. The high-speed nut rotation feed lead screw device according to claim 1, further comprising a torque limiter provided between the drive motor and the first pulley.

5. 5. The high-speed nut rotating feed lead screw device according to claim 4, wherein the bearing assembly includes two sets of symmetrically installed angular contact ball bearings, and each set of angular contact ball bearings includes at least one angular contact ball bearing.

6. 2. The high-speed nut rotating feed lead screw device according to claim 1, wherein the fixed sleeve in the bearing has a stepped shaft sleeve structure, and one end of the fixed sleeve in the bearing adjacent to the drive unit connection end is provided with a male thread, and the bearing assembly is fixed to the fixed sleeve in the bearing by a lock nut.

7. 7. The high-speed nut rotation feed lead screw device according to claim 6, further comprising a retaining cover, the retaining cover being fixedly connected by screws to one end of the slide table adjacent to the drive unit connection end and one end of the bearing outer fixed sleeve adjacent to the drive unit connection end.

8. The high-speed nut rotation feed lead screw device according to any one of claims 1 to 3, characterized in that the lead screw is further provided with a cooling channel installed along the axial direction of the lead screw.

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