Lead screw supporting structure

Abstract

The utility model provides a lead screw supporting structure which comprises a ball screw and a tail end seat, the tail end seat is provided with a through installation hole, one end of the ball screw is installed in the installation hole through a bearing, a limiting ring is arranged on the ball screw on the axial outer side of the bearing in a sleeved mode, and the limiting ring is arranged on the tail end seat. A locking nut is mounted on the lead screw on the axial outer side of the limiting ring; the ball screw on the axial inner side of the bearing is sleeved with a spacer ring, and a compressed elastic piece is arranged between the axial inner side of the spacer ring and the tail end base. The installation mode of the tail end of the ball screw is changed into a supporting mode from a fixing mode, continuous axial supporting force is provided for the tail end of the ball screw through the action of the elastic piece and the distance ring, axial movement of the ball screw is restrained, and the displacement precision of the ball screw is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of numerically controlled machine tools, in particular to a screw support structure. Background Art

[0002] The lead screw is one of the core components of CNC machine tools. It carries the transmission system of each axis of the entire machine tool and is the main carrier for realizing the movement of the machine tool. Ball screw pairs are widely used in CNC machine tools due to their high transmission efficiency, good precision, and strong precision retention.

[0003] Existing ball screws generally adopt an installation structure with both ends fixed or one end fixed and the other end free. If both ends are fixed, in order to prevent the thermal expansion of the screw, the tail end of the screw generally adopts a pre-tensioning structure to pre-stretch the screw to offset the thermal expansion of the screw. However, the pre-tensioning effect is not good for large-diameter and long-stroke screws. On the one hand, the force required for pre-tensioning of large-diameter screws is too large, which seriously affects the life of the screw bearings; on the other hand, the thermal expansion of long-stroke screws is large and cannot be offset by pre-tensioning. If one end is fixed and the other end is free, the screw at the free end is not subject to axial force, causing the screw to move axially, resulting in displacement error. Utility Model Content

[0004] In view of the shortcomings of the prior art mentioned above, the purpose of the utility model is to provide a screw support structure, which changes the installation method of the tail end of the screw from fixed to supported, and provides continuous axial support force to the tail end of the screw, so as to solve the problem that the screw fixing structure in the prior art cannot solve the thermal expansion of the screw.

[0005] To achieve the above-mentioned purpose and other related purposes, the utility model provides a screw support structure, including a ball screw and a tail end seat, the tail end seat is provided with a through mounting hole, one end of the ball screw is installed in the mounting hole through a bearing, a limit ring is provided on the ball screw on the axial outside of the bearing, and a locking nut is installed on the screw on the axial outside of the limit ring; a spacer ring is provided on the ball screw on the axial inside of the bearing, and a compressed elastic member is provided between the axial inside of the spacer ring and the tail end seat.

[0006] In one embodiment of the present invention, a protrusion extending inward is provided on the axial front side of the tail end seat, the front side of the elastic member abuts against the protrusion, and the rear side of the elastic member abuts against the spacer ring.

[0007] In an embodiment of the present invention, the outer diameter of the spacer ring is slightly smaller than the inner diameter of the tail end seat.

[0008] In one embodiment of the present invention, a dust cover cooperating with a limiting ring is installed at the outer end of the tail end seat.

[0009] In one embodiment of the utility model, the limiting ring includes an annular portion and a limiting portion, the limiting portion is located on the annular portion and extends radially along the annular portion, and the axial outer side of the dust cover is matched and abutted against the axial inner side of the limiting portion.

[0010] In an embodiment of the present invention, the inner diameter of the dust cover is slightly larger than the outer diameter of the annular portion.

[0011] In an embodiment of the present invention, the distance from the axial inner side of the limiting portion to the axial inner side of the annular portion is greater than the thickness of the dust cover.

[0012] In one embodiment of the present invention, the end of the ball screw has a step portion, and the inner wall of the bearing and the limiting ring are in contact with the step portion.

[0013] As described above, the screw support structure of the utility model has the following beneficial effects:

[0014] 1. The utility model changes the installation mode of the tail end of the ball screw from fixed to supported, and provides continuous axial support force to the tail end of the ball screw through the action of elastic parts and spacer rings, thereby restraining the axial movement of the ball screw and improving the displacement accuracy of the screw.

[0015] 2. The utility model has a dust cover matched with a limit ring installed at the outer end of the tail end seat, and the dust cover can effectively protect the bearing from the entry of cutting fluid and impurities. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The utility model discloses a structural schematic diagram of a screw support structure.

[0017] Component number description

[0018] 1. Ball screw; 2. Tail end seat; 3. Elastic part; 4. Spacer ring; 5. Bearing; 6. Limiting ring; 61. Ring part; 62. Limiting part; 7. Locking nut; 8. Dust cover. DETAILED DESCRIPTION

[0019] The following specific embodiments illustrate the implementation of the present invention, and those familiar with the technology can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0020] See also Figure 1The utility model provides a screw support structure, including a ball screw 1 and a tail end seat 2, the tail end seat 2 is provided with a through mounting hole, one end of the ball screw 1 is installed in the mounting hole through a bearing 5, a limiting ring 6 is sleeved on the ball screw 1 on the axial outside of the bearing 5, and a locking nut 7 is installed on the screw on the axial outside of the limiting ring 6. The utility model realizes axial support of the ball screw 1 through the cooperation of the bearing 5, the limiting ring 6 and the locking nut 7; it is worth noting that a spacer ring 4 is sleeved on the ball screw 1 on the axial inside of the bearing 5, and a compressed elastic member 3 is provided between the axial inside of the spacer ring 4 and the tail end seat 2.

[0021] Specifically, the axial front side of the tail end seat 2 is provided with a protrusion extending inward, the front side of the elastic member 3 abuts against the protrusion, and the rear side of the elastic member 3 abuts against the spacer ring 4. The elastic member 3 is preferably a spring.

[0022] When the ball screw 1 has not yet been thermally expanded, the elastic member 3 is compressed, so the elastic member 3 applies axial pressure to the spacer ring 4, thereby applying axial force to the tail end of the ball screw 1 through the spacer ring 4. When the ball screw 1 is thermally expanded, the compressed elastic member 3 will push the spacer ring 4 to move backward, maintain the axial support force on the tail end of the ball screw 1, and effectively restrain the axial movement of the ball screw 1.

[0023] Furthermore, the outer diameter of the spacer ring 4 is slightly smaller than the inner diameter of the tail end seat 2 , thereby ensuring that the spacer ring 4 can move smoothly in the mounting hole of the tail end seat 2 without tilting.

[0024] Furthermore, the inner diameter of the spacer ring 4 is slightly larger than the outer diameter of the ball screw 1 , so as to prevent the spacer ring 4 from blocking the thermal expansion of the ball screw 1 .

[0025] In one embodiment of the utility model, a dust cover 8 cooperating with a limit ring 6 is installed at the outer end of the tail end seat 2. The dust cover 8 can effectively protect the bearing 5 from the entry of cutting fluid and impurities.

[0026] Furthermore, the limiting ring 6 includes an annular portion 61 and a limiting portion 62, the limiting portion 62 is located on the annular portion 61 and extends radially along the annular portion, and the axial outer side of the dust cover 8 cooperates with the axial inner side of the limiting portion to prevent impurities from entering.

[0027] Furthermore, the inner diameter of the dust cover 8 is slightly larger than the outer diameter of the annular portion, thereby ensuring that the limiting ring 6 can be displaced relative to the tail end seat 2 .

[0028] Furthermore, the distance from the axial inner side of the limiting portion 62 to the axial inner side of the annular portion is greater than the thickness of the dust cover 8, so that in the initial state, a gap is left between the axial outer side of the bearing 5 and the dust cover 8, thereby leaving space for the thermal expansion of the ball screw 1.

[0029] In one embodiment of the present invention, the end of the ball screw 1 has a step portion, and the inner walls of the bearing 5 and the limiting ring 6 are in contact with the step portion.

[0030] Furthermore, four bearings 5 ​​are arranged in the mounting hole, and the stability of the ball screw 1 is ensured by the four bearings 5 ​​.

[0031] The utility model changes the installation mode of the tail end of the ball screw from fixed to supported, and provides continuous axial support force to the tail end of the ball screw through the action of the elastic member and the spacer ring, restricts the axial movement of the ball screw, and improves the displacement accuracy of the screw. Therefore, the utility model effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0032] Among them, the terms such as "upper", "lower", "left", "right", "front", "back", "middle" and "one" cited in this specification are only for the convenience of description and are not used to limit the scope of implementation of the present utility model. Changes or adjustments to their relative relationships should be regarded as the scope of implementation of the present utility model without substantially changing the technical content.

[0033] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. All equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas disclosed in the present invention shall still be covered by the claims of the present invention.

Claims

1. A screw support structure, characterized in that: It includes a ball screw and a tail end seat, the tail end seat is provided with a through mounting hole, one end of the ball screw is installed in the mounting hole through a bearing, a limit ring is sleeved on the ball screw on the axial outside of the bearing, and a locking nut is installed on the screw on the axial outside of the limit ring; a spacer ring is sleeved on the ball screw on the axial inside of the bearing, and a compressed elastic member is provided between the axial inside of the spacer ring and the tail end seat.

2. A screw support structure according to claim 1, characterized in that: The axial front side of the tail end seat is provided with a protrusion extending inwardly, the front side of the elastic member abuts against the protrusion, and the rear side of the elastic member abuts against the spacer ring.

3. A screw support structure according to claim 1, characterized in that: The outer diameter of the spacer ring is slightly smaller than the inner diameter of the tail end seat.

4. A screw support structure according to any one of claims 1 to 3, characterized in that: The outer end of the tail end seat is provided with a dust cover matched with a limiting ring.

5. A screw support structure according to claim 4, characterized in that: The limiting ring comprises an annular portion and a limiting portion, wherein the limiting portion is located on the annular portion and extends radially along the annular portion, and the axial outer side of the dust cover is matched and abutted against the axial inner side of the limiting portion.

6. A screw support structure according to claim 5, characterized in that: The inner diameter of the dust cover is slightly larger than the outer diameter of the annular portion.

7. A screw support structure according to claim 5, characterized in that: The distance from the axial inner side of the limiting portion to the axial inner side of the annular portion is greater than the thickness of the dust cover.

8. A screw support structure according to claim 1, characterized in that: The end of the ball screw has a step portion, and the inner wall of the bearing and the limiting ring contacts the step portion.

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