JP5169770B2 - Ring shaped lock nut - Google Patents

Description

  The present invention relates to a ring-shaped lock nut having a screw portion that is screwed onto an object on an outer surface or an inner surface.

  In the present application, the “lock nut” means a nut configured not to loosen due to vibration or the like. Conventionally, a lock nut is used for a part that is subjected to severe vibration during use, such as a part of a jet engine, in order to prevent the part from loosening during use.

  Conventionally, various lock nuts have been proposed as such lock nuts (for example, Patent Documents 1 and 2).

Patent document 1 aims at being able to be used with an optimal locking ability any number of times by a replaceable insert.
Therefore, as shown in FIG. 4, the self-locking nut is formed so as to open in the radial direction in the nut body 51 and the annular nut body 51 used by being screwed to the threaded member 50. It comprises a groove 52 and a compressible flexible elongated insert 53 having both ends and detachably mounted in the groove 52.
The insert 53 is made of resin, and has no thread, so that the threaded portion of the threaded member 50 bites into the insert 53 to generate a friction torque and exert a locking ability. Further, the insert 53 can be easily attached to and detached from the groove with a rod or the like after the lock nut is removed.

Patent document 2 aims to improve the force of fastening between a fastening nut and a lock nut.
Therefore, as shown in FIG. 5, the lock nut 61 includes a groove 70 formed concentrically continuously from the periphery of the screw hole 64 of one seat surface 63, and a plurality of protrusions 65 formed in the groove 70. The nut main body 62 is provided. Each protrusion 65 is made of the same material as the nut body 62, and has an inclined outer surface 71 extending from the boundary between the seat surface 63 of the nut body 62 and the groove 70 toward the center of the nut body 62, and a screw hole. 64 and an inner side surface 72 formed to be an extension of the inner surface. The depth of the groove 70 is such that when the lock nut 61 is screwed onto the bolt 66 and fastened to the fastening nut 67, a part of the projection 65 crushed between the seating surfaces of both nuts 61, 67 is 67, the screw hole 64 of the bolt 66 and the threaded portion 69 of the bolt 66 are wound, and the remaining part of the crushed protrusion 65 is the seat surface 68 of the fastening nut 67 and the seat surface 63 of the nut body 62. The dimension is set so as not to enter between.

Japanese Patent Laid-Open No. 62-4912, “Self-locking nut” Japanese Patent No. 3914975, “Lock Nut”

  FIG. 6 is a schematic diagram showing a rotor portion of a jet engine targeted by the present invention. A rotor 81 constituting a compressor or turbine of a jet engine has a plurality of disks 83 that can withstand a large centrifugal force applied to the blades 82, and the disks 83 are coupled to each other to form an integral rotating body.

Conventionally, as a lock nut for constituting such an integral rotating body, a hollow cylindrical nut having a screw portion on the outer surface or the inner surface is used, and a part of the nut is deformed to be required for screwing of the screw portion. The tightening torque is set larger than the loosening torque received during use, thereby constituting a loosening prevention.
For partial deformation of the nut, for example, a circumferential groove is provided on the outer surface or inner surface of the hollow cylindrical nut, and the outer portion of the nut is plastically deformed into an elliptical or polygonal shape on the screw portion side. The tightening torque required for screwing of the screw portion is set by the sliding resistance of the portion.

However, such a conventional lock nut has a problem that it is difficult to accurately set the tightening torque required for screwing of the threaded portion, and the tightening torque is lowered after two or three times of use, and cannot be reused. There was a point.
In addition, since the conventional lock nut that can no longer be reused is difficult to repair, it is necessary to replace the entire lock nut, resulting in a high cost of replacement parts and a high maintenance cost.

  The present invention has been developed to solve the above-described problems. That is, the object of the present invention is to have a threaded portion on the outer surface or the inner surface, the tightening torque required for screwing the threaded portion can be accurately and easily set to a predetermined torque larger than the loosening torque received during use, and replacement An object of the present invention is to provide a ring-shaped lock nut that is low in cost of parts and can be repeatedly reused by replacing parts even when the tightening torque is reduced.

According to the present invention, a hollow cylindrical nut body having a plurality of through-holes passing through a threaded portion for threaded engagement with the cylindrical threaded portion of the object has an outer surface, and radially,
Fitting into the plurality of through holes, the screw portion side surface is composed of a plurality of insert members located between the crest and trough of the screw portion,
The plurality of through holes are provided at symmetrical positions with respect to the rotation axis of the nut body,
The through hole is composed of a large-diameter cylindrical hole on the screw part side, and a small-diameter cylindrical hole communicating with the small-diameter,
The large-diameter cylindrical hole is a cylindrical hollow hole, and its bottom surface is flat.
The insert member is a flexible cylindrical resin that fits into the large-diameter cylindrical hole with an interference fit, and a lower surface thereof abuts on a step between the large-diameter cylindrical hole and a small-diameter cylindrical hole, and an upper surface thereof is the screw. Located between the mountain and valley
Support the compressive force acting on the insert member at the step ,
A ring-shaped lock nut is provided , wherein the nut body has a torque transmission portion at its end face for rotating the entire nut about the axis of the screw portion .

Moreover, it is preferable that the outer diameter of the insert member is smaller than the maximum diameter of the threaded portion and larger than the minimum diameter after the nut body is assembled.

According to the configuration of the present invention, the hollow cylindrical nut body has a plurality of through holes that penetrate in the radial direction, the plurality of insert members are fitted into the respective through holes, and the surface of the screw portion side is the inner surface or Located between the crests and troughs of the external thread. When the ring-shaped lock nut is screwed with the cylindrical threaded portion of the object in this state, the threaded portion side surface of the insert member is fitted and elastically deformed with the cylindrical threaded portion of the object, and the object and the nut main body are The screw is fitted into the gap between the screw portions, pressure is applied to both of them, and the tightening torque required for screwing the screw portions is increased.
This tightening torque usually coincides with the torque resisting the torque acting in the direction of loosening during use.

  In addition, since the increase in the tightening torque due to a single insert member is substantially constant, the tightening torque required for screwing of the screw portion (that is, torque that resists loosening) is used depending on the number of insert members used. It can be accurately and easily set to a predetermined torque larger than the loosening torque received inside.

  Furthermore, when the insert member deteriorates due to repeated reuse and the tightening torque does not reach the predetermined torque, the reuse can be repeated by simply replacing the insert member of the ring-shaped lock nut.

  In addition, since the insert member is a simple part with a small shape, its manufacturing cost is lower than that of the entire ring-shaped lock nut, and the cost of the replacement part can be greatly reduced.

  In particular, the through-hole is composed of a large-diameter cylindrical hole on the screw side and a small-diameter cylindrical hole that communicates with the small-diameter cylindrical hole, and the insert member fits into the large-diameter cylindrical hole with an interference fit. The bottom surface is in contact with the step between the large-diameter cylindrical hole and the small-diameter cylindrical hole, and the upper surface is inserted between the threaded portion and the valley of the screw portion by pushing out from the small-diameter cylindrical hole side. Since the members can be easily exchanged and the shape is simple, it can be manufactured at low cost.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

FIG. 1 is a partial cross-sectional view of a jet engine provided with ring-shaped lock nuts 10A and 10B of the present invention.
In this figure, 1 is a rotating shaft of a jet engine, 2 is a rotor part of a low-pressure turbine, 3 is a carbon seal runner, 4 is a labyrinth seal runner, 5 is a bearing inner race, 6 is a carbon seal on the stator side, and 7 is a stator side. Labyrinth.

In this example, the left end portion of the carbon seal runner 3 is fixed to the inner surface of the end portion of the rotor component 2 by a ring-shaped lock nut 10A. Further, the right end portion of the labyrinth seal runner 4 and the bearing inner race 5 are fixed to the outer surface of the end portion of the rotor component 2 by a ring-shaped lock nut 10B.
With this configuration, the rotor component 2 of the low-pressure turbine, the carbon seal runner 3, the labyrinth seal runner 4, the bearing inner race 5, and the ring-shaped lock nuts 10A and 10B can be firmly connected to each other. 1 can be rotated around the center.
In addition, this example is an example of the usage form of ring-shaped lock nut 10A, 10B, and this invention is not limited to this structure, Other structures may be sufficient.

In FIG. 1, the ring-shaped lock nut 10 </ b> A has a screw portion that is screwed with a cylindrical screw portion 2 a of an object (in this example, the rotor part 2) on the outer surface. On the inside. That is, the ring-shaped lock nuts 10A and 10B are different in that the threaded portion is on the outer surface or the inner surface, and the other configurations are the same.
Therefore, only the ring-shaped lock nut 10A will be described below.

FIG. 2 is an overall perspective view of the ring-shaped lock nut 10A of FIG.
In this figure, a ring-shaped lock nut 10A of the present invention comprises a hollow cylindrical nut body 12 and a plurality of insert members 14.

The hollow cylindrical nut body 12 has a screw portion 12a that is screwed with a cylindrical screw portion of an object (in this example, the rotor part 2) on the outer surface, and a plurality of (four in this example) that penetrate in the radial direction. ) Through-holes 12b. The plurality of through holes 12 b are preferably provided at symmetrical positions with respect to the rotation axis 1.
The inner diameter and the outer diameter of the nut main body 12 can be arbitrarily set as long as the screw portion 12a and the through hole 12b can be formed. For example, when the screw portion 12a is provided on the outer surface, the inner diameter can be reduced to about 10 mm. On the other hand, when the screw portion 12a is provided on the inner surface, the inner diameter is preferably increased to about 100 mm due to the workability of the through hole 12b.

  A plurality (four in this example) of the insert members 14 are fitted in the through holes 12b of the nut main body 12, and the screw portion side surface is positioned between the crests and troughs of the screw portion 12a.

In this figure, the nut body 12 further has a torque transmission portion 15. In this example, the torque transmitting portion 15 is a slot 15a and a tab 15b provided at the end of the nut body 12, and a nut that fits them rotates the nut body 12 about the axis of the screw portion 12a. A predetermined torque can be transmitted to the nut body 12.
The torque transmission portion 15 is not limited to this configuration, and may be a spline or slit provided on the end surface, the inner surface, or the outer surface of the nut main body 12, or a chamfer.

  FIG. 3 is a partially enlarged view of the ring-shaped lock nut of FIG. In this figure, (A) is a view showing the outer surface of the ring-shaped lock nut 10A, (B) is a sectional view taken along line BB of (A), and (C) is a detailed view of the screw portion 12a.

In FIG. 3A, the circumferential positions of the through hole 12b and the slot 15a coincide. However, this configuration is not essential and may be shifted from each other.
As shown in FIG. 3 (B), the through hole 12b of the nut body 12 includes a large diameter cylindrical hole 13a and a small diameter cylindrical hole 13b. The large-diameter cylindrical hole 13a is a cylindrical recess provided on the screw portion 12a side, and its bottom surface is flat. The small-diameter cylindrical hole 13b is concentric with the large-diameter cylindrical hole 13a and communicates therewith and has a smaller diameter.

The diameter of the large-diameter cylindrical hole 13a is set so that the screw part 12a acts effectively at a circumferential position where the large-diameter cylindrical hole 13a is shorter than the axial length of the screw part 12a. The diameter of the large diameter cylindrical hole 13a is, for example, 6.4 mm.
Further, the depth of the large-diameter cylindrical hole 13a is such that the insert member 14 fitted to the large-diameter cylindrical hole 13 is fitted into the cylindrical screw portion 2a of the object and elastically deformed. It is preferable to set so that a sufficient pressure can be applied to the screw portion 2a of the object when fitting into the gap of the screw portion.

Further, the diameter of the small diameter cylindrical hole 13b can support the compressive force acting on the insert member 14 with the step 13c in a state where the insert member 14 is in contact with the step 13c between the large diameter cylindrical hole 13a and the small diameter cylindrical hole 13b. And it is set so that the insert member 14 can be easily taken out with a rod-shaped jig through which the small-diameter cylindrical hole 13b passes. The diameter of the small diameter cylindrical hole 13b is, for example, 3.5 mm.
The insert member 14 is a flexible cylindrical resin that fits into the large-diameter cylindrical hole 13a with a “fitting fit”. This resin should be a resin that can withstand the operating temperature of the nut body and has good machinability, such as a polyimide resin.
In addition, after assembling to the nut body, the outer diameter of the insert member is preferably smaller than the maximum diameter of the screw portion and larger than the minimum diameter.

The lower surface 14a of the insert member 14 abuts on a step 13c between the large-diameter cylindrical hole 13a and the small-diameter cylindrical hole 13b, and the upper surface 14b is located between the peaks and valleys of the screw portion 12a.
For example, if the upper surface 14b is set at the position of the pitch diameter of the screw portion 12a, the variation of the increase in the tightening torque can be reduced. Further, if the position is lower than the pitch diameter position, the increase in the tightening torque can be reduced, and if the position is higher than the reverse pitch diameter position, the increase in the tightening torque can be increased.

Further, a taper surface 14c is provided on the outer edge of the lower surface of the insert member 14 to facilitate insertion into the large diameter cylindrical hole 13a.
Furthermore, a tapered surface 14d is also provided on the outer edge portion of the upper surface of the insert member 14, and when the nut body 12 is screwed into the cylindrical screw portion 2a of the object, the contact with the thread of the other screw portion is made smooth. Thus, the insert member 14 is easily deformed.

As shown in FIG. 3C, there is a slight gap between the cylindrical screw portion 2a of the object and the screw portion 12a of the nut body 12 in order to facilitate mutual screwing.
Although most of the insert member 14 is plastically deformed, the upper surface 14b of the insert member 14 is located between the crest and trough of the screw portion 12a, and as shown by the oblique lines in this figure, the screw portion side surface 14b is the target object. The cylindrical threaded portion 2a is fitted and elastically deformed, and the threaded portion 2a of the object bites into the insert member 14.

According to the configuration of the present invention described above, the hollow cylindrical nut body 12 has a plurality of through holes 12b through which the hollow cylindrical nut body 12 penetrates in the radial direction, and the plurality of insert members 14 are fitted into the respective through holes 12b. The side surface 14b is located between the peaks and valleys of the screw portion 12a. In this state, when the ring-shaped lock nut 10A is screwed with the cylindrical screw portion 2a of the object, the screw portion side surface 14b of the insert member 14 is engaged with the cylindrical screw portion 2a of the object and elastically deformed, It fits into the gap between the object and the screw part of the nut body 12, and pressure is applied to both of them to increase the tightening torque required for screwing of the screw part.
This tightening torque usually coincides with the torque resisting the torque acting in the direction of loosening during use.

  Further, since the amount of increase in the tightening torque by the single insert member 14 is substantially constant, the tightening torque required for screwing of the screw portion (that is, torque that resists loosening) depends on the number of insert members 14 used. It can be accurately and easily set to a predetermined torque larger than the loosening torque received during use.

  Furthermore, when the insert member 14 deteriorates due to repeated reuse and the tightening torque becomes less than the predetermined torque, the reuse can be repeated by simply replacing the insert member 14 in the ring-shaped lock nut 10A.

  Further, since the insert member 14 is a simple part with a small shape, its manufacturing cost is lower than that of the entire ring-shaped locknut, and the cost of the replacement part can be greatly reduced.

  In particular, the through-hole 12b comprises a large-diameter cylindrical hole 13a on the screw portion side and a small-diameter cylindrical hole 13b that communicates with the large-diameter cylindrical hole 13b, and the insert member 14 fits into the large-diameter cylindrical hole 13a with an interference fit. It is a flexible cylindrical resin, and its lower surface 14a is in contact with a step 13c between the large diameter cylindrical hole and the small diameter cylindrical hole, and its upper surface 14b is positioned between the crest and trough of the screw portion 12a. By extruding from the cylindrical hole side, it is easy to replace the insert member and the shape is simple, so that it can be manufactured at low cost.

  In addition, this invention is not limited to embodiment mentioned above, Of course, a various change can be added in the range which does not deviate from the summary of this invention.

It is a fragmentary sectional view of the jet engine provided with the ring-shaped lock nut of the present invention. It is a whole perspective view of the ring-shaped lock nut of FIG. It is the elements on larger scale of the ring-shaped lock nut of FIG. It is a block diagram of the lock nut of patent document 1. FIG. It is a block diagram of the lock nut of patent document 2. FIG. It is a schematic diagram which shows the rotor part of a jet engine.

Explanation of symbols

10A, 10B Ring-shaped lock nut,
12 Nut body, 12a Screw part, 12b Through hole,
13a Large diameter cylindrical hole, 13b Small diameter cylindrical hole, 13c Step,
14 insert member, 14a lower surface, 14b upper surface,
14c taper surface, 14d taper surface,
15 Torque transmission part, 15a slot, 15b tab

Claims (2)

Has a cylindrical threaded portion screwed to the threaded portion of the object to the outer surface, and a hollow cylindrical nut body having a plurality of through holes penetrating in the radial direction,
Fitting into the plurality of through holes, the screw portion side surface is composed of a plurality of insert members located between the crest and trough of the screw portion,
The plurality of through holes are provided at symmetrical positions with respect to the rotation axis of the nut body,
The through hole is composed of a large-diameter cylindrical hole on the screw part side, and a small-diameter cylindrical hole communicating with the small-diameter,
The large-diameter cylindrical hole is a cylindrical hollow hole, and its bottom surface is flat.
The insert member is a flexible cylindrical resin that fits into the large-diameter cylindrical hole with an interference fit, and a lower surface thereof abuts on a step between the large-diameter cylindrical hole and a small-diameter cylindrical hole, and an upper surface thereof is the screw. Located between the mountain and valley
Support the compressive force acting on the insert member at the step ,
The said nut main body has the torque transmission part for rotating the whole centering on the axial center of the thread part in the end surface, The ring-shaped lock nut characterized by the above-mentioned. The ring-shaped lock nut according to claim 1, wherein the outer diameter of the insert member is smaller than the maximum diameter of the threaded portion and larger than the minimum diameter after assembling to the nut body.

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