CN111981022B

CN111981022B - Lock nut

Info

Publication number: CN111981022B
Application number: CN201910435122.6A
Authority: CN
Inventors: 戴兵; 马求山
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2019-05-23
Filing date: 2019-05-23
Publication date: 2024-03-08
Anticipated expiration: 2039-05-23
Also published as: CN111981022A

Abstract

The invention provides a locknut, which is used for being screwed on the periphery of a shaft (200), and comprises a nut main body (110) and a stop piece (130), wherein the nut main body (110) is provided with a lockcavity (111), the lockcavity (111) comprises a stop groove (111G), the stop groove (111G) comprises a first surface (F1) positioned in front of the screwing direction (TD) of the locknut (100) and a second surface (F2) positioned behind the screwing direction (TD), when the stop piece (130) simultaneously abuts against the first surface (F1) and a curved surface coplanar with the peripheral surface of the shaft (200), the stop piece (130) is contacted with the first surface (F1) at a point T, the cross section of the stop piece (130) is in a circle with a point C1 as a center, and the point C1, the point T and the center point D1 of the cross section circle of the shaft (200) in the first plane are obtuse angles. The locknut of the present invention is not easily loosened during, for example, following the long-time forward rotation and reverse rotation of the shaft member.

Description

Lock nut

Technical Field

The invention relates to the field of fasteners, in particular to a locknut.

Background

Locknuts are widely used in various applications, and in fields such as machine tools, motors, and electric vehicles, a spindle bearing for high-speed operation is generally required to be provided with a locking force in an axial direction by the locknut. Prior art locknuts typically have a threaded through hole in the radial direction into which a screw can be screwed and contact the spindle, preventing the locknut from rotating in the reverse direction of the locking direction.

In order to meet the stiffness requirements of the spindle bearing, the locking torque that the locknut is required to provide is typically not very large (and may be much smaller than the maximum locking torque of the locknut). Since the spindle may undergo forward rotation and reverse rotation for a long time, the locknut in the above prior art is easily loosened during this process, so that the normal operation of the machine cannot be ensured.

Disclosure of Invention

The invention aims to overcome or at least alleviate the defects in the prior art and provide the locknut with good locking effect.

The invention provides a locknut for screwing connection on the periphery of a shaft, which comprises a nut main body and a stop piece,

the nut body has at least one anti-loosening cavity including a stop slot, the stop being receivable in the stop slot,

the stop groove comprises a first surface positioned at the front in the screwing direction of the locknut and a second surface positioned at the rear in the screwing direction of the locknut,

when the stopper is simultaneously abutted against the first face and a curved face coplanar with the outer peripheral face of the shaft, the stopper is in contact with the first face at a point T, and in a first plane perpendicular to the axial direction of the nut body and passing through the point T, the stopper has a circular cross section with a center of a circle being a point C1,

and connecting the point C1, the point T and a center point D1 of a cross-sectional circle of the shaft piece in the first plane to obtain an angle TC1D1, wherein the angle TC1D1 is an obtuse angle.

In at least one embodiment, when the stopper is simultaneously abutted against the second face and a curved face coplanar with the outer peripheral face of the shaft, the stopper is in contact with the second face at a point Q, in a second plane perpendicular to the axial direction of the nut body and passing through the point Q, the stopper has a circular cross section with a center of a circle being a point C2,

and connecting the point C2, the point Q and a center point D2 of a cross-sectional circle of the shaft piece in the second plane to obtain an angle QC2D2, wherein the angle QC2D2 is an acute angle or a right angle.

In at least one embodiment, the stopper can only contact both of the first face, the second face, and a curved face coplanar with an outer peripheral face of the shaft at the same time in a plane perpendicular to an axial direction of the nut body.

In at least one embodiment, the stopper groove has a stopper notch at an inner circumferential surface of the nut body, and the stopper accommodated in the stopper groove is capable of contacting the shaft at the stopper notch.

In at least one embodiment, the anti-loose cavity further comprises a limit hole, the limit hole is communicated with the stop groove, an opening at one end of the limit hole is positioned on the axial end face of the nut main body, the stop piece can enter and exit the stop groove through the limit hole,

the locknut further comprises a limiting piece, wherein the limiting piece can be fixed in the limiting hole, so that the limiting piece is limited in the axial direction to prevent the limiting piece from falling out of the limiting hole.

In at least one embodiment, the stopper has a space movable in an axial direction within the stopper groove when the stopper is fixed to the stopper hole.

In at least one embodiment, the stop screw of the stop member, the stop hole has internal threads that threadably engage threads of the stop screw.

In at least one embodiment, the plurality of the anti-loosening cavities are uniformly distributed in the circumferential direction of the nut body.

In at least one embodiment, the stop is a sphere.

In at least one embodiment, the stop is made of a material that includes a magnetically permeable material.

According to the locknut of the present invention, the locknut is not easily loosened during, for example, following the long-time forward rotation and reverse rotation of the shaft member.

Drawings

Fig. 1 is a schematic view of a locknut according to an embodiment of the invention mounted to a shaft.

Fig. 2 is a cross-sectional view of fig. 1 in the axial direction.

Fig. 3 is a radial cross-sectional view (taken along two non-collinear radial directions) of the locknut of fig. 1.

Fig. 4 is a cross-sectional view taken along a-a of fig. 2.

Fig. 5 and 6 are schematic views of a first embodiment of a stop groove according to the invention.

Fig. 7 is a schematic view of a second embodiment of a stop groove according to the invention.

Fig. 8 is a schematic view of a third embodiment of a stop groove according to the invention.

Description of the reference numerals

100 locknuts;

110 a nut body; a 111 locking cavity; 111H limiting holes; a 111G stop groove; f1 first side; f2 second side;

120 stop screws;

130 stops;

200 shaft members;

a TD screwing direction; LD release direction; the RD shaft element rotation direction;

aaxial direction; r is radial.

Detailed Description

Exemplary embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that these specific illustrations are for the purpose of illustrating how one skilled in the art may practice the invention, and are not intended to be exhaustive of all of the possible ways of practicing the invention, nor to limit the scope of the invention.

Hereinafter, unless otherwise specified, referring to fig. 2, a denotes an axial direction of the nut body 110, which coincides with an axial direction of the shaft member 200; r represents a radial direction of the nut body 110, which coincides with a radial direction of the shaft member 200; the circumferential direction of the nut body 110 corresponds to the circumferential direction of the nut body.

Referring to fig. 1 to 4, the locknut 100 according to the present invention is used to lock on the outer circumference of the shaft member 200, wherein the shaft member 200 particularly includes a rotating member that rotates in the forward and reverse directions in the operating state.

The locknut 100 includes a nut body 110, a stop screw 120, and a stop 130. The stopper screw 120 and the stopper 130 are accommodated in the locking cavity 111 inside the nut body 110.

The nut body 110 has an internal thread (not shown), and the internal thread of the nut body 110 can be screwed with an external thread (not shown) of the shaft member 200. After the nut body 110 is loaded with a certain locking torque, the nut body 110 is not easily loosened by reverse rotation in the locking direction during rotation of the shaft member 200.

The specific structure and operation of the locknut 100 according to the present invention will be described with reference to fig. 2 to 8.

In the present embodiment, the stopper 130 has a spherical shape. And preferably the stopper 130 is made of a material having magnetic permeability (the stopper 130 has magnetic permeability such that it can be easily disassembled, as will be further described below).

The nut body 110 has two anti-loosening cavities 111 spaced 180 degrees apart in the circumferential direction. Each of the lock chambers 111 includes a stopper hole 111H and a stopper groove 111G, and the stopper hole 111H and the stopper groove 111G are communicated with each other.

The axial direction of the limiting hole 111H is parallel to the axial direction a of the nut body 110, an opening at one end of the limiting hole 111H is located at the end face of the nut body 110, and the other end of the limiting hole 111H is communicated to the stop groove 111G. The inner diameter of the stopper hole 111H is larger than the outer diameter of the stopper 130 so that the stopper 130 can enter and exit the stopper groove 111G through the stopper hole 111H (the function of this structure will be more easily understood in the process of assembling and disassembling a locknut described later). The limit hole 111H has an internal thread capable of being screwed with an external thread of the limit screw 120, and when the limit screw 120 is screwed into the limit hole 111H, an opening of one end of the limit hole 111H is blocked by the limit screw 120.

An opening (stop notch) of the stop groove 111G at the surface of the nut body 110 is located at the inner peripheral surface of the nut body 110. The stopper groove 111G has a substantially wedge-shaped cross section perpendicular to the axial direction a (see fig. 4). The stopper 130 can be accommodated in the stopper groove 111G, and the stopper 130 has a space movable in the circumferential direction in the stopper groove 111G. The walls of the wedge-shaped stopper groove 111G include a first face F1 and a second face F2, and the stopper 130 may move circumferentially within the stopper groove 111G and contact the first face F1 or the second face F2 during rotation of the nut body 110 relative to the shaft 200. When the stopper 130 contacts the first surface F1 during movement and there is a tendency for the two to move relative to each other, the stopper 130 is engaged between the shaft 200 and the nut body 110 to prevent the shaft 200 and the nut body 110 from rotating in opposite directions.

In the assembly of the locknut 100, for example, the nut body 110 is first screwed into the shaft 200, and the locking torque, which can be screwed into the nut body 110, for example, is slightly less than the required locking torque; then, the stopper 130 is put into the stopper groove 111G through the stopper hole 111H; after which the stop screw 120 is screwed in and the locking torque of the nut body 110 is adjusted to the desired locking torque.

The working principle of the stopper groove 111G in preventing the nut body 110 from being released, and three different structures of the stopper groove 111G are described below with reference to fig. 5 to 7.

(first embodiment of stopper groove 111G)

First, a first structure of the stopper groove 111G will be described with reference to fig. 5 and 6. Fig. 5 is an enlarged schematic view of one of the stopper grooves 111G in fig. 4. Assuming that the screwing direction of the nut body 110 is clockwise, that is, the nut body 110 is screwed into the shaft member 200 by clockwise rotation, an arrow TD in fig. 5 indicates the screwing direction of the nut body 110 (nut screwing direction TD). The first surface F1 is located forward of the tightening direction TD, and the second surface F2 is located rearward of the tightening direction TD. In the prior art, when the shaft member 200 is rotated in the counterclockwise direction (i.e., the shaft member rotation direction indicated by arrow RD in fig. 5), the nut body 110 is easily gradually released from the shaft member 200, and the broken line arrow LD in fig. 5 shows the releasing direction of the nut body 110. Particularly, during the long-time high-speed forward rotation and reverse rotation switching of the shaft member 200, the nut body 110 is easily loosened by the relative rotation in the loosening direction LD.

In the present embodiment, the first surface F1 and the second surface F2 of the stopper groove 111G are each planar. In a plane perpendicular to the axial direction of the nut body 110, when the stopper 130 moves to contact with the first surface F1, an angle α in the stopper groove 111G between the first surface F1 and a straight line perpendicular to a line connecting a center point C of a cross-sectional circle of the stopper 130 and a center point D of a cross-sectional circle of the shaft 200 (only a position of the point D is schematically shown in the drawing) is acute (refer to fig. 5); when the stopper 130 moves to contact with the second face F2, an angle β between the second face F2 and a straight line perpendicular to a line connecting the center point C of the cross-sectional circle of the stopper 130 and the center point D of the cross-sectional circle of the shaft 200 forms a right angle or an obtuse angle within the stopper groove 111G (refer to fig. 6). In addition, it is also possible to say that the angle between the first surface F1 and the outer peripheral surface of the shaft 200 facing the stopper groove 111G is an acute angle, and the angle between the second surface F2 and the outer peripheral surface of the shaft 200 facing the stopper groove 111G is a right angle or an obtuse angle.

The advantage of the stop groove 111G having the above-described shape feature is that when the nut body 110 has a tendency to come loose from the shaft member 200, the first surface F1 will come into contact with the stop 130 and generate a force and a reaction force therebetween, and at this time, the force generated by the stop 130 against the first surface F1 has a force component in the screwing direction TD, so that the nut body 110 can be prevented from coming loose from the shaft member 200.

In addition, when the stopper 130 moves radially outward under the centrifugal force or upon vibration, the stopper 130 collides against the first surface F1 and applies a force having a force component in the screwing direction TD to the first surface F1, thereby tending to screw the nut body 110.

When the operator needs to adjust the tightening torque of the nut body 110, for example, during the process of assembling the nut body 110, when the nut body 110 needs to be further screwed in the screwing direction TD, the stopper 130 will contact the second surface F2, and the force generated by the stopper 130 on the second surface F2 will not significantly prevent the further screwing of the nut body 110 due to the obtuse angle β, in other words, the stopper 130 will not be jammed between the second surface F2 and the shaft 200.

It should be understood that when the stopper 130 is accommodated in the stopper groove 111G, the stopper 130 has a space within the stopper groove 111G that is movable in the circumferential direction, i.e., the stopper 130 can only contact two of the shaft member 200, the first face F1 and the second face F2 at the same time, not all of them at the same time, which is also to ensure that the stopper 130 is not caught between the second face F2 and the shaft member 200 when adjusting the tightening torque of the nut body 110, particularly when increasing the tightening torque of the nut body 110.

When the nut body 110 is required to be released or detached from the shaft member 200, the stopper screw 120 may be removed first, and then the stopper 130 may be taken out of the stopper hole 111H communicating with the stopper groove 111G. Alternatively, a magnetically-bearing tool may be used to remove the magnetically-permeable stopper 130 from within the retention aperture 111H.

It should be appreciated that the effect of the stop screw 120 within the limiting aperture 111H is to merely prevent the stop 130 from falling out of the anti-lock cavity 111 in the axial direction A, and that the stop screw 120 need not provide additional force to the stop 130 in the axial direction A. And preferably, when the stopper screw 120 is screwed into the limit hole 111H, the stopper 130 can have a space to move in the axial direction without being jammed, and the stopper 130 is not jammed in the axial direction so that the stopper 130 can play a role of preventing the nut body 110 from being loosened in the circumferential direction.

In fact, the contact area of the stopper 130 with the first face F1 and the second face F2 is very small, for example, the spherical stopper 130 is in point contact with both the first face F1 and the second face F2, so the first face F1 and the second face F2 do not have to be planar. A second embodiment of the stopper groove 111G in which the first surface F1 is curved and a third embodiment of the stopper groove 111G in which the second surface F2 is curved are described below.

(second embodiment of stopper groove 111G)

Referring to fig. 7, this embodiment is a modification of the first embodiment of the stopper groove 111G. The stopper groove 111G includes a first surface F1 located forward of the screwing direction TD, and the first surface F1 is a curved surface. When the stopper 130 moves in the stopper groove 111G, in a plane perpendicular to the axial direction of the nut body 110, the stopper 130 intersects (i.e., is tangent to) the first surface F1 at a point T, which is an angle TCD, which is an obtuse angle, a center point C of a cross-sectional circle of the stopper 130 and a center point D of a cross-sectional circle of the shaft 200.

It should be understood that the above-described prescribed angular relationship (angle TCD is an obtuse angle) also applies in the first embodiment of the stopper groove 111G.

(third embodiment of stopper groove 111G)

Referring to fig. 8, this embodiment is a modification of the first embodiment of the stopper groove 111G. The stopper groove 111G includes a second surface F2 located rearward of the screwing direction TD, and the second surface F2 is curved. When the stopper 130 moves in the stopper groove 111G, in a plane perpendicular to the axial direction of the nut body 110, the stopper 130 intersects (i.e., is tangent to) the second face F2 at a point Q, which is an acute angle or a right angle, a point Q, a center point C of a cross-sectional circle of the stopper 130, and a center point D of a cross-sectional circle of the shaft 200.

It should be understood that the above-specified angular relationship (the angle QCD is an acute angle or a right angle) also applies in the first embodiment of the stopper groove 111G.

It should be appreciated that the three embodiment partial aspects or features of the stop groove 111G described above may be combined as appropriate.

The present invention has at least one of the following advantages:

(i) The locknut 100 according to the present invention is not easily loosened from the shaft member 200 even when the shaft member 200 undergoes forward rotation and reverse rotation for a long time. In particular, the stopper 130 in the stopper groove 111G can prevent the nut body 110 from reversely loosening when the shaft rotation direction RD is opposite to the screwing direction TD of the locknut 100.

(ii) The locknut 100 according to the present invention has a lockstructure or a lockmember inside the nut body 110, and the original design of other parts is not changed by using the locknut 100.

Of course, the present invention is not limited to the above-described embodiments, and various modifications may be made to the above-described embodiments of the present invention by those skilled in the art in light of the present teachings without departing from the scope of the present invention. For example:

(i) Although the stopper 130 is preferably spherical, the present invention is not limited thereto, and for example, the stopper 130 may be cylindrical or ellipsoidal, and a cross section of the cylindrical or ellipsoidal stopper perpendicular to the axial direction of the nut body 110 is circular when placed in the stopper groove 111G.

(ii) The stop screw 120 and the limiting hole 111H may be replaced by other removable limiting members and limiting holes, for example, a buckle is used to replace the stop screw 120, a slot is used to replace the limiting hole 111H, and the buckle and the slot cooperate to limit the stop member 130 in the axial direction.

(iii) The locknut 100 according to the present invention is provided with at least one locknut cavity 111 and corresponding stopper 130, and when the locknut 100 is provided with a plurality of locknut cavities 111, it is preferable that the locknut cavities 111 are uniformly distributed in the circumferential direction of the nut body 110, thereby balancing the stress of the locknut 100 in the circumferential direction.

(iv) In order to facilitate the assembly and disassembly of the locknut 100, particularly to prevent the stopper 130 from falling from the opening of the stopper groove 111G located at the inner circumferential surface of the nut body 110 during the assembly and disassembly, an easily deformable spacer member, such as a thin copper sheet, may be provided at the opening of the stopper groove 111G located at the inner circumferential side of the nut body 110. When the stopper 130 exerts a stopping action, that is, when the stopper 130 moves into contact with the first surface F1 and a force is generated between the stopper 130 and the first surface F1, the spacer member is capable of deforming to the radially inner side to contact the shaft member 200, at which time the stopper 130 is not in direct contact with the shaft member 200, but the stopper 130 abuts against a virtual curved surface coplanar with the outer peripheral surface of the shaft member 200, and transmits the force between the stopper 130 and the first surface F1 to the shaft member 200 through the deformed spacer member.

Claims

1. A locknut (100) for screwing on an outer periphery of a shaft member (200), the locknut (100) comprising a nut body (110) and a stopper (130),

the nut body (110) has at least one anti-loosening cavity (111), the anti-loosening cavity (111) comprising a stop groove (111G), the stop (130) being receivable within the stop groove (111G),

the stop groove (111G) comprises a first surface (F1) located at the front in the screwing direction (TD) of the locknut (100) and a second surface (F2) located at the rear in the screwing direction (TD) of the locknut (100),

when the stopper (130) is simultaneously abutted against the first face (F1) and a curved face coplanar with the outer peripheral face of the shaft (200), the stopper (130) contacts with the first face (F1) at a point T, and in a first plane perpendicular to the axial direction of the nut body (110) and passing through the point T, the stopper (130) has a circular cross section with a center of a circle being a point C1,

connecting said point C1, said point T and a centre point D1 of a cross-sectional circle of said shaft (200) in said first plane, obtaining an angle TC1D1, said angle TC1D1 being an obtuse angle,

the anti-loose cavity (111) further comprises a limit hole (111H), the limit hole (111H) is communicated with the stop groove (111G), an opening at one end of the limit hole (111H) is positioned on the axial end face of the nut main body (110), the stop piece (130) can enter and exit the stop groove (111G) through the limit hole (111H),

the locknut (100) further comprises a limiting piece which can be fixed to the limiting hole (111H) so as to limit the stop piece (130) in the axial direction to prevent the stop piece (130) from falling out of the limiting hole (111H).

2. The locknut (100) according to claim 1, wherein when the stopper (130) is simultaneously abutted to the second face (F2) and a curved face coplanar with the outer peripheral face of the shaft member (200), the stopper (130) contacts with the second face (F2) at a point Q, and in a second plane perpendicular to the axial direction of the nut body (110) and passing through the point Q, the stopper (130) has a circular cross section with a center of a circle being a point C2,

and connecting the point C2, the point Q and a center point D2 of a cross-sectional circle of the shaft (200) in the second plane to obtain an angle QC2D2, wherein the angle QC2D2 is an acute angle or a right angle.

3. The locknut (100) of claim 1, wherein the stop (130) can only contact both of the first face (F1), the second face (F2), and a curved face coplanar with an outer peripheral surface of the shaft (200) at the same time in a plane perpendicular to an axial direction of the nut body (110).

4. A locknut (100) according to any one of claims 1-3, wherein the stop groove (111G) has a stop notch located at an inner peripheral surface of the nut body (110), at which the stop member (130) accommodated in the stop groove (111G) is capable of contacting the shaft member (200).

5. A locknut (100) according to any one of claims 1-3, wherein the stop (130) has a space within the stop groove (111G) that is movable in an axial direction when the stop is fixed to the stop hole (111H).

6. The locknut (100) of claim 5, wherein the stop screw (120) has an internal thread that threads with the thread of the stop screw (120).

7. A locknut (100) as claimed in any one of claims 1-3, wherein there are a plurality of the lockcavities (111), the plurality of lockcavities (111) being evenly distributed in the circumferential direction of the nut body (110).

8. A locknut (100) as claimed in any one of claims 1-3, wherein the stop (130) is a sphere.

9. The locknut (100) of claim 1, wherein the stop (130) is made of a material comprising a magnetically permeable material.