Nut structure of ball screw

Abstract

The utility model provides a nut structure of a ball screw, and belongs to the technical field of ball screws. The problems of few contact points, stress concentration, accelerated damage and the like caused by errors between the screw pitch and the nut pitch in the prior art are solved. The device comprises a nut assembly, the nut assembly comprises two mutually independent nuts, the two nuts are sequentially arranged in the axial direction of a lead screw, the opposite sides of the two nuts are each provided with a mounting part, and the two nuts are fixedly connected through the mounting parts; the nut is in a spiral shape, has elasticity in the axial direction and can deform along with the lead screw, and the nut is provided with a spiral face or a spiral groove used for making contact with the roller. The screw nut has the advantages that the two independent screw nuts are combined to form a novel screw nut structure, the problem that a circle of rollers in the middle of a single screw nut are not stressed is solved, the screw nut is designed into a spiral shape, axial elastic deformation force can be generated by the screw nut after assembly to press the rollers, pretightening force of the rollers on each section of screw pitch is consistent, and the service life of the screw nut is prolonged. And the roller is in uniform contact with the lead screw nut.

Description

Technical Field

[0001] The utility model belongs to the technical field of ball screws and relates to a nut structure of a ball screw. Background Art

[0002] The ball screw has a low friction coefficient and wide applications. However, its inherent problem is the existence of backlash, which needs to be adjusted manually.

[0003] When applied to a numerically controlled machine tool, the numerical control system will have backlash compensation. After being applied for a period of time, the screw will wear. When the friction on each section of a screw is uneven, the adjustment and system compensation methods will fail, and a new screw needs to be replaced. At the same time, due to the errors between the screw pitch and the nut pitch, and the raceways of the screw and the nut do not contact all the rollers, this will result in fewer contact points and stress concentration, accelerating damage and other problems. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a nut structure with uniform contact between rollers and a screw nut for the above problems existing in the existing nut of a ball screw.

[0005] The purpose of the utility model can be achieved by the following technical solutions:

[0006] A nut structure of a ball screw, characterized in that it includes a nut assembly. The nut assembly includes two independent nuts, which are arranged in sequence along the axial direction of the screw. One installation part is provided on each of the two opposite sides of the two nuts, and the two nuts are fixedly connected through the installation parts; the nut is spiral and axially elastic, and can deform with the screw. A spiral surface or a spiral groove for contacting the roller is provided on the nut.

[0007] In the above-mentioned nut structure of a ball screw, the nut assembly further includes a gasket, which is located between the two nuts, and the two installation parts and the gasket are fixedly connected together.

[0008] In the above-mentioned nut structure of a ball screw, the opposite side surfaces of the two installation parts are mutually attached and fixed.

[0009] In the above-mentioned nut structure of a ball screw, a plurality of installation holes are formed in the installation part, and the two installation parts are connected through fasteners.

[0010] In the above-mentioned nut structure of a ball screw, the nut and the installation part are integrally processed.

[0011] In the above-mentioned nut structure of a ball screw, when the cross-sectional shape of the nut for contacting the rollers on both sides is a concave arc, the two sets of helical surfaces on the nut are used to contact the rollers, and the cross-section of the helical surface is an arc line; the rollers contact the generatrix of the helical surface on the nut.

[0012] In the above-mentioned nut structure of a ball screw, when the cross-sectional shape of the nut for contacting the rollers on both sides is a straight line, the two sets of helical lines on the nut are used to contact the rollers; the rollers are in point contact with the helical lines on the nut.

[0013] In the above-mentioned nut structure of a ball screw, when the lead of the screw is the same as the lead of the nut, move or rotate the nut to misalign the two nuts, and the two nuts apply an axial pressing force to the rollers.

[0014] In the above-mentioned nut structure of a ball screw, when the lead of the screw is not the same as the lead of the nut and the phases of the two nuts are the same, the two nuts apply an axial pressing force to the rollers.

[0015] In the above-mentioned nut structure of a ball screw, when the lead of the screw is not the same as the lead of the nut, move or rotate the nut to misalign the two nuts, and the two nuts apply an axial pressing force to the rollers.

[0016] Compared with the prior art, the nut of the present utility model is designed in a spiral shape. After assembly, the nut will generate an axial elastic deformation force, which can be used as the preloading force for pressing the rollers, and the preloading force of the rollers on each pitch is the same, making the contact between the rollers and the screw nut uniform, reducing the accelerated wear caused by uneven roller contact, and automatically compensating for the wear of the screw and the rollers.

[0017] Compared with two independent nut structures, there will be a problem that one circle of rollers in the middle of a single spiral nut is not stressed. Therefore, the present utility model combines two independent nuts to form a new nut structure, and there are no rollers on the spiral groove between the two nuts, solving the problem that one circle of rollers in the middle of a single nut is not stressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic diagram of the overall structure of the ball screw of the present utility model;

[0019] Figure 2 is a schematic diagram of the structure of the nut assembly of the present utility model;

[0020] Figure 3 is an enlarged cross-sectional view of the nut assembly on the ball screw of the present utility model;

[0021] Figure 4 is an enlarged cross-sectional view of the overall ball screw of the present utility model;

[0022] Figure 5 It is a schematic diagram of another nut structure of the present utility model;

[0023] Figure 6 It is a schematic diagram of the contact surface between the nut and the roller of the present utility model being a straight line;

[0024] Figure 7 It is a schematic diagram of the cross-sectional shape of the nut of the present utility model being circular;

[0025] Figure 8 It is a schematic diagram of the cross-sectional shape of the nut of the present utility model being rectangular.

[0026] In the figure, 1, nut; 2, lead screw; 3, roller; 4, concave arc; 5, mounting part; 6, gasket; 7, mounting hole. Specific embodiments

[0027] The following are specific embodiments of the present utility model and in conjunction with the accompanying drawings, the technical solutions of the present utility model are further described, but the present utility model is not limited to these embodiments.

[0028] Embodiment 1

[0029] As Figures 1 to 3 shown, a nut 1 structure of a ball screw 2 according to the present utility model includes a nut assembly. The nut assembly includes two independent nuts 1. The two nuts 1 are arranged in sequence along the axial direction of the lead screw 2. A mounting part 5 is provided on each side of the two nuts 1 facing each other, and the two nuts 1 are fixedly connected through the mounting parts 5.

[0030] The nut 1 of the present utility model is spiral and has elasticity in the axial direction and can deform with the lead screw 2. A spiral surface or spiral groove for contacting the roller 3 is provided on the nut 1.

[0031] The nut assembly in this embodiment further includes a gasket 6. The gasket 6 is located between the two nuts 1, and the two mounting parts 5 and the gasket 6 are fixedly connected. A plurality of mounting holes 7 are provided on the mounting part 5, and the two mounting parts 5 are connected through fasteners. As Figure 2 shown, the nut 1 and the mounting part 5 are integrally processed. The mounting part 5 is a sheet-like structure integral with the nut 1.

[0032] When the cross-sectional shape of the nut 1 for contacting the rollers 3 on both sides is a concave arc 4, two spiral surfaces are provided on the nut 1 for contacting the roller 3, and the cross-section of the spiral surface is an arc line; the roller 3 contacts the generatrix of the spiral surface on the nut 1.

[0033] In the present utility model, the nut 1 is designed in a spiral shape. After assembly, the nut 1 will generate an axial elastic deformation force, and this elastic deformation force can be used as the pre-tightening force for pressing the roller 3. There are three ways for the nut 1 of the present utility model to apply pressure to the roller 3: ① When the pitch of the screw rod 2 is the same as the pitch of the nut 1, move or rotate the nut 1 to misalign the two nuts 1, and the two nuts 1 apply an axial pressing force to the roller 3. ② When the pitch of the screw rod 2 is different from the pitch of the nut 1 and the phases of the two nuts 1 are the same, the two nuts 1 apply an axial pressing force to the roller 3. ③ When the pitch of the screw rod 2 is different from the pitch of the nut 1, move or rotate the nut 1 to misalign the two nuts 1, and the two nuts 1 apply an axial pressing force to the roller 3.

[0034] There are two methods to misalign the two nuts 1: The first method is to rotate one of the nuts 1; the second method is to move the position of the nut 1 by increasing or decreasing the thickness of the installation part, or by increasing or decreasing the thickness of the gasket.

[0035] When the pitch of the screw rod is different from the pitch of the nut, the processing method of the nut is as follows:

[0036] The first processing method: Use a forming device to form a nut 1 with a spiral structure and a specific cross-sectional shape, and the pitch of the nut 1 is the same as the pitch of the screw rod 2. The specific cross-sectional shape is the shape of the contact positions of the nut 1 with the two side rollers 3; Stretch or compress the nut 1 and fix the pitch of the nut 1, and perform quenching heat treatment on the stretched or compressed nut 1; Make the pitch of the formed nut 1 different from the pitch of the screw rod 2.

[0037] The second processing method: Use a forming device 1 to process a nut 1 with a spiral structure, and the pitch of the nut 1 is different from the pitch of the screw rod 2; Perform quenching heat treatment on the nut 1; Stretch or compress the nut 1 and fix the pitch of the nut 1 to make the pitch of the nut 1 the same as the pitch of the screw rod 2; Use a forming device 2 to process the nut 1 after fixing the pitch, and process a spiral groove on the nut 1, and the pitch of the spiral groove is the same as the pitch of the screw rod 2.

[0038] Embodiment 2

[0039] As Figure 5 shown, different from Embodiment 1, in this embodiment, the installation part 5 is in a spiral shape, and the outermost circle of the installation part 5 forms a plane for installation and fixation after being wound.

[0040] Embodiment 3

[0041] Different from Embodiment 1, in this embodiment, as Figure 6 shown, the cross-sectional shape of the nut 1 for contacting the two side rollers 3 is a straight line; as Figure 7 shown, the cross-sectional shape of the nut 1 is a circle; as Figure 8As shown, the cross-sectional shape of the nut 1 is rectangular. Figures 6 to 8 On the nut 1 in Figures 6 to 8 , there are two sets of helical lines for contacting the roller 3. The roller 3 is in point contact with the helical lines on the nut 1. Compared with the structure of the nut 1 in Embodiment 1, the structure of the nut 1 in this embodiment is simpler and the processing cost is lower.

[0042] Embodiment 4

[0043] Different from Embodiment 1, there is no gasket 6 in the nut assembly of this embodiment. The two nuts 1 are directly fixed, and the opposite side surfaces of the two mounting portions 5 are mutually attached and fixed.

[0044] It should be understood that in the claims and the description of the present invention, all "including..." should be understood in an open sense, that is, its meaning is equivalent to "at least containing...", and should not be understood in a closed sense, that is, its meaning should not be understood as "only containing...".

[0045] The specific embodiments described herein are only illustrative of the spirit of the present invention. Those skilled in the art to which the present invention pertains can make various modifications or supplements to the described specific embodiments or use similar ways to replace them, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A nut structure of a ball screw, characterized in that: The invention comprises a nut assembly, wherein the nut assembly comprises two mutually independent nuts (1), the two nuts (1) are arranged in sequence along the axial direction of a screw rod (2), the two nuts (1) are each provided with a mounting portion (5) on the opposite side, and the two nuts (1) are fixedly connected via the mounting portion (5); the nut (1) is spirally shaped and axially elastic and can be deformed along with the screw rod (2), and the nut (1) is provided with a spiral surface or a spiral groove for contacting a roller (3).

2. A nut structure of a ball screw according to claim 1, characterized in that: The nut assembly further comprises a gasket (6), which is located between the two nuts (1), and the two mounting parts (5) and the gasket (6) are fixedly connected.

3. The nut structure of a ball screw according to claim 1, characterized in that: The opposite side surfaces of the two mounting parts (5) are fitted and fixed to each other.

4. The nut structure of a ball screw according to claim 1, characterized in that: The mounting portion (5) is provided with a plurality of mounting holes (7), and the two mounting portions (5) are connected via fasteners.

5. The nut structure of a ball screw according to claim 1, characterized in that: The nut (1) and the mounting portion (5) are integrally formed.

6. The nut structure of a ball screw according to claim 1, characterized in that: When the cross-sectional shape of the nut (1) for contacting the rollers (3) on both sides is a concave arc (4), the nut (1) for contacting the rollers (3) is two sets of spiral surfaces, and the cross-sections of the spiral surfaces are circular arc lines; the rollers (3) and the generatrix of the spiral surfaces on the nut (1) are in contact.

7. The nut structure of a ball screw according to claim 1, characterized in that: When the cross-sectional shape of the nut (1) for contacting the rollers (3) on both sides is a straight line, the nut (1) for contacting the rollers (3) is two groups of spiral lines; the rollers (3) and the spiral lines on the nut (1) are in point contact.

8. The nut structure of a ball screw according to claim 1, characterized in that: When the pitch of the screw rod (2) is consistent with the pitch of the nut (1), the nut (1) is moved or rotated to cause the two nuts (1) to be misaligned, and the two nuts (1) apply axial pressing force to the roller (3).

9. The nut structure of a ball screw according to claim 1, characterized in that: When the pitch of the screw rod (2) is inconsistent with the pitch of the nut (1), and the two nuts (1) are in the same phase, the two nuts (1) apply axial pressing force to the roller (3).

10. The nut structure of a ball screw according to claim 1, characterized in that: When the pitch of the screw rod (2) is inconsistent with the pitch of the nut (1), the nut (1) is moved or rotated to cause the two nuts (1) to be misaligned, and the two nuts (1) apply axial pressing force to the roller (3).

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