GB2238592A - Self-aligning nut - Google Patents

Self-aligning nut Download PDF

Info

Publication number
GB2238592A
GB2238592A GB8926826A GB8926826A GB2238592A GB 2238592 A GB2238592 A GB 2238592A GB 8926826 A GB8926826 A GB 8926826A GB 8926826 A GB8926826 A GB 8926826A GB 2238592 A GB2238592 A GB 2238592A
Authority
GB
United Kingdom
Prior art keywords
nut
bearing
self
collar
precision
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB8926826A
Other versions
GB8926826D0 (en
Inventor
Lawrence Luk
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
CHINA BEARING CO Ltd
Original Assignee
CHINA BEARING CO Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by CHINA BEARING CO Ltd filed Critical CHINA BEARING CO Ltd
Priority to GB8926826A priority Critical patent/GB2238592A/en
Publication of GB8926826D0 publication Critical patent/GB8926826D0/en
Publication of GB2238592A publication Critical patent/GB2238592A/en
Application status is Withdrawn legal-status Critical

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16CSHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C35/00Rigid support of bearing units; Housings, e.g. caps, covers
    • F16C35/04Rigid support of bearing units; Housings, e.g. caps, covers in the case of ball or roller bearings
    • F16C35/06Mounting or dismounting of ball or roller bearings; Fixing them onto shaft or in housing
    • F16C35/063Fixing them on the shaft
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16BDEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS, WEDGES, JOINTS OR JOINTING
    • F16B37/00Nuts or like thread-engaging members
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16BDEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS, WEDGES, JOINTS OR JOINTING
    • F16B43/00Washers or equivalent devices; Other devices for supporting bolt-heads or nuts
    • F16B43/02Washers or equivalent devices; Other devices for supporting bolt-heads or nuts with special provisions for engaging surfaces which are not perpendicular to a bolt axis or do not surround the bolt
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16CSHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C35/00Rigid support of bearing units; Housings, e.g. caps, covers
    • F16C35/04Rigid support of bearing units; Housings, e.g. caps, covers in the case of ball or roller bearings
    • F16C35/06Mounting or dismounting of ball or roller bearings; Fixing them onto shaft or in housing
    • F16C35/067Fixing them in a housing

Abstract

A self-aligning nut assembly, comprises a nut (6) and a washer (5) provided with part-spherical engaging surfaces (62) and (52) to allow self-aligning of a rotating shaft into perpendicular relation with the bearing face 31 of a bearing 3. Such automatic self-adjustment of the nut (6) reduces the error to within 1 mu at the rim of the bearing. <IMAGE>

Description

HIGH PRECISION SELF-ALIGNMENT NUT High precision self-alignment nut of a type for application as a bolting nut positioned between the rolling bearing and the main shaft, such that the perpendicularity of the main shaft relative to the rim edge of the bearing is maintained to a toleration of error of less than 1 p.

The trend to go for development in precision industry nowadays has rendered the demand more and more rigorous for the precision level of parts and components serving various kinds of machines in the domain of precision processing. Since all the means of control applied in various power-driven machineries depend largely upon main shaft for transmision, the level of precision of the main shaft in rotation, then, is directly answerable for the precision of the machine's operation.In where processing machinery is concerned the main shaft functions virtually as does the heart of a human being to the human being, the precision of the rotation of the main shaft is a direct function of the precision of the object being processed, in more cases than often, failure to promote the precision of the main shaft has resulted in the impossibility to promote the quality feature of the object being processed therewith, this is a truth acknowledge by all the interested parties, here in this country and elsewhere beyond enumeration.

Experience tells us that apart from the cylindricality of the main shaft per se and tolerance for the concentricity, the main shaft bearing and other associated parts, accessories are closely correlated with the rotational precision of a main shaft. That is why bearings for use with the main shaft of a precision processing machine are selected out of extremely accuracy-assured bearings so as to meet the afore-mentioned precision requirements.

Still, even in cases where high precision bearings have already been employed, one has to procure other associated high precision accessories and components, like bolting nuts, etc., to see that the precision requirement is maintained in all events. In common practice up to the present time, high precision main shaft accessories are screened one by one so as to ensure the high level of precision once they are put to work, such a procedure is both time and labor consuming and has, to all purposes and intents, ruled out the possibility for mass production, with this understanding, the inventor has set as its motive for invention, the design of bolt-type nuts intended for use on or with main shafts and which are possible for mass production without any sacrifice on precision requirements.

Processing precision requirements specified for bolt-nut for use in machine tool rolling bearings classified under #3090, category MCS, Chinese National Standards, can hardly meet the challenging requirement for precision which has become more and more rigorous, facing the industrial societies in this country and elsewhere. That in speaking of the precision nut (referring to Fig. 1, Fig. 2) for use on the main shaft and with the bearing, very high level of precision. is in demand on the true flatness of the rim edge 11 and om the middle threaded face 12, is explained by the necessity to have its main screwing shaft 2 in contact with the rim edge on the inner ring 31 of the bearing 3, as illustrated in Fig. 3.At present the local industries are still unable to produce extremely high precision nuts which can be considered match, for example, for the Kuso high precision nuts of Switzerland, those which the local industries presently import from the country of origin, while such high precision nuts can meet the precision requirements they cost exorbitantly high, furthermore, the real performance of such extremely high precision nuts can hardly be expected if the processing of the screwing teeth on the part of the main shaft is not up to the standard in the first place.

In common practice the inner ring of the bearing is clamped tight to the body in the axial direction by means of a bolt-nut, but then the error of the processing precision regarding the nut edge can be sensed immediately on the rotative axis of the main shaft; an inclination of the nut edge, for instance, or warping of the rather thin main shaft, as resulting from twist-tightening efforts, as illustrated in Fig. 3-A, or inclination of the inner ring of the bearing thereby caused, as illustrated in Fig. 3-B, can bring about slipping of the ball, and subsequently a rise in temperature, noises and wearing effects. Or alternatively these effects can give rise to concentrated loading in the form of torque bearing upon the inner ring of the bearing to deformation, like what is shown in Fig. 3-C, with negative effects brought upon the precision of processing.

According to the invention, there is provided a self-aligning nut assembly comprising an internally threaded nut adapted to engage a threaded component and a collar to space the nut from a further component, the nut and collar having mutually engaging, part spherical; respectively convex and concave surfaces to allow adjustment of the relative angular alignment between the nut and the collar.

In view of the many shortcomings and problems found with the use of conventional bolt-nuts as they were fixed to the assembly, as rectified in the foregoing, the inventor has betaken himself to years of researching for improvements by taking into accounts many years of experience accumulated in the making, and eventually come out with the present invention which embodies a nut and a mounting therefor as improved structure of bolt-nut mounted to the main shaft and to the bearing, with one rim edge of the mounting precision processed to yield a flat plane while the lateral side that is in contact with the nut is ground into spherical cavities, and the face in contact with the nut ground to yield a spherical protrusion both sharing the same radius of curvature, the nut screw-bound to the main shaft, with spheroidal contacts utilised to maintain the centre line of the main shaft perpendicular; to the effect that the main shaft permits automatic adjustment to secure absolute perpendicularity with respect to the rim edge of the bearing, thereby realising an extremely high rotational precision even though an inclination of the main shaft takes place because of the inaccuracy of the screwing teeth thereto.

There now follows a description of a specific embodiment of the invention, by way of example, with reference being made to the accompanying drawings in which: Fg. 1 is an overview of the conventional fixation type nut; Fig. 2 is a perspective view of the conventional fixation type nut; Fig. 3 is an analytical view of the assemblage of a conventional fixation type nut; Fig. 3-A, 3-B, and 3-C illustrate altogether the manly problems associated with the use of conventional fixation type nuts; Fig. 4 is an analytical view of the invention; Fig. 5 is a perspective illustration of the invention in use; Fig. 6 and Fig. 7 represent other embodiments structured according to the invention.

Fig. 4 shows that the invention consists essentially of a nut 6 and a mounting 5 therefor, the exposed face 51 where the mounting 5 intersects the inner ring 31 of the bearing is processed flat, while the other lateral side is processed by means of a spheroidal front to yield a spheroidal cavity 52; moreover, the inner wall of the nut 6 is tapped with threads 61 which are screwed to the main shaft, whilst that part of the nut 6 in contact with the mounting 5 is likewise processed with a spheroidal front to yield a symmetrically configured spheroidal cavity 62, to the effect that by setting the edge 51 on the nut 5 into contact with the inner ring 31 of the bearing, and the teeth 21 of the main shaft 2 interscrewed with threads 61 on the inner wall of the nut, also the spheroidal protrusion 62 on the nut into contacts with spheroidal cavity 52 on the mounting the assemblage is accomplished.

When the main shaft 2 is transmitted to rotation by causing the spheroidal devices one provided on the nut 6 and the other on the mounting 5 to come into contact with each other, the main shaft 2 can be adjusted automatically to the effect that it can always maintain perpendicular relative to the edge. As the bearing 3 on the main shaft is set to rotation the equilibrium prevailing on the spheroidal sub-structure will function such that an emerging inclination occurring on the bearing of the main shaft 3 will bring the nut 6 to slide relative to the mounting 6, till even and equal force is applied to where the main shaft 2 is screwed to the nut 6, that is a position where the centre line of the main shaft 2 rests in total perpendicularity to the bearing's edge.The inventor has run experiments which have proven that with the threads set as a norm for comparison, the standard error of the bearing's edge can be controlled within 1 , this figure is much more by far a proof of precision than the ranging of 30--4- S where conventional nut standards are employed, or in the case of precedent precision level for wnich the tolerance lies in the range of 2 , this is because error in precision is simply inevitable in dealing with conventional fixed nuts where the screwing teeth of the main shaft is not accurate enough, by contrast the present invention provides for self-alignment features by utilising the equilibrium of a spheroidal couplet sub-structure to ensure permanent perpendicularity of the shaft core in relation to the bearings edge.

The present invention for application is by no means restricted by the emdodiments descried hereinbefore, for example, the one shown in Fig. 6, a fixation nut assembly to serve shafts, is one prepared for use with the inner ring of a fixed bearing; also, the fixation nut assembly shown in Fig. 7, for application in a bearing box, is one proposed for use with the outer ring of a fixation bearing; so to be concise and comprehensive, all nuts which are designed to self-alignment by means of spheroidal contacts, should be deemed structured according to, and therefore, covered under, the present invention.Further, with reference to the direction in which the line indicative of the stress bearing upon the bearing rollers as illustrated in Fig. 6, Fig. 7 goes, it will be appreciated that the invention device will not have any extruding effects against the inner ring of the bearing, this means substantial reduction of noises as well as extension of the serviceable term of the bearing, all these are obvious proof of the advantage of the present invention over previous, prior arts, severally or collectively.A tabulation is prepared below to facilitate comparison of the subject high precision self-alignment nut with standard nuts (Precision Grade and Regular Grade): Features Standard Fixation Type High Precision Nuts (Precision Grade Self-Alignment Nut and Regular Grade) As per 1SO2982 1972 Not yet available Standard DIN 981 1977 JIS B1554 CNS B2257 MCS 3090 Standard Standard 40--60 p Adjustable within 1 p Range of (depending upon size) error Precision Grade 2 p with respect to the threads Effects (1) Standard:May be adjusted possible Inclination on the automatically using upon Nut's edge, tighten- spheroidal setting to Precision will result in the maintain the contact Bearings warping of the edge perpendicular with relatively thinner respect to the centre Main Shaft, as well line of the shaft, even as deviation of the though the teeth on the inner ring. part of the shaft per se (2) Precision Grade: is not sufficiently Notwithstanding that precise.

the edge precision is as high as 2 , lack of precision with the screwing teeth of the shaft can defeat such a precision.

Production Simple, Low-cost The only processing-intensive aspect is the spheroid processing, but which can be accomplished using presently available skill with the cost kept reasonable.

============================================================ Size & Standardized Different design has to design be considered to comply with different applications, can be a labyrinthic device for sealing.

============================================================ Usage and Standardized As in the case of a Packing regular standard nut.

Restrictions Failing to meet No restrictions in requirements to application, can reach more rigorous extremely high level of precision levels. accuracy.

Claims (6)

1. A self-aligning nut assembly comprising an internally threaded nut adapted to engage a threaded component and a collar to space the nut from a further component, the nut and collar having mutually engaging, part spherical; respectively convex and concave surfaces to allow adjustment of the relative angular alignment between the nut and the collar.
2. A self-aligning nut assembly according to Claim 1 wherein the inner diameter of the collar is greater than the diameter of the threaded component to allow relative radial movement between the collar and the threaded component.
3. A bearing assembly on a shaft including a self-aligning nut assembly according to Claim 1 or Claim 2; a shoulder; and a bearing having first and second place faces, the shaft being supported in the bearing, wherein the collar of the nut assembly engages the first plane face of the bearing to hold the bearing in place on the shaft with the second plane face of the bearing engaging the shoulder.
4. High precision self-alignment nut, composed essentially of a nut body and a mounting therefor; the inner wall of the nut tappet with threads for screw-coupling with the teeth on the main shaft while one edge of the mounting is maintained in constant contact with the bearing's edge, characterised in that the two halves making up a spheroid each of a same radius of curvature, completing each other in a contexo-concave configuration is formed where the nut and the mounting therefor comes into contact, so that the centre line of the main shaft can effect timely self-adjustment with respect and therefore maintain perpendicular to the exposed contact edge of the bearing.
5. A self-aligning nut assembly generally as herein described, with reference to and as illustrated in Figures 4 to 7 of the accompanying drawings.
6. A bearing assembly generally as herein described, with reference to and as illustrated in Figures 5 to 7 of the accompanying drawings.
GB8926826A 1989-11-28 1989-11-28 Self-aligning nut Withdrawn GB2238592A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB8926826A GB2238592A (en) 1989-11-28 1989-11-28 Self-aligning nut

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB8926826A GB2238592A (en) 1989-11-28 1989-11-28 Self-aligning nut

Publications (2)

Publication Number Publication Date
GB8926826D0 GB8926826D0 (en) 1990-01-17
GB2238592A true GB2238592A (en) 1991-06-05

Family

ID=10667015

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8926826A Withdrawn GB2238592A (en) 1989-11-28 1989-11-28 Self-aligning nut

Country Status (1)

Country Link
GB (1) GB2238592A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6086479A (en) * 1998-01-30 2000-07-11 Bayside Controls, Inc. Alignment device
DE102007003487A1 (en) * 2007-01-24 2008-07-31 Schaeffler Kg Grooved screw for use in screw connection, has screw head with circular bearing surface formed at lower side of screw head, and screw shaft with self-grooved thread, where circular bearing surface of screw head is curved to be convex
WO2013020680A1 (en) * 2011-08-08 2013-02-14 Festo Ag & Co. Kg Annular anchoring element and fluid engineering assembly equipped therewith

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB798734A (en) * 1956-08-23 1958-07-23 Charles Eric Schutte Improvements in and relating to washers for bolts or like fastening means
GB1223846A (en) * 1967-06-21 1971-03-03 Divcon Internat U K Ltd Seal
GB2051285A (en) * 1979-06-21 1981-01-14 Forest Fasteners Ltd Wheel Nuts
GB2065818A (en) * 1979-11-30 1981-07-01 Mac Lean Fogg Lock Nut Co Fastener assembly
GB2138529A (en) * 1983-04-20 1984-10-24 Oteco S R L Wheel Hub Nut
US4830557A (en) * 1988-01-26 1989-05-16 General Electric Company Self-aligning floating nut fastener

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB798734A (en) * 1956-08-23 1958-07-23 Charles Eric Schutte Improvements in and relating to washers for bolts or like fastening means
GB1223846A (en) * 1967-06-21 1971-03-03 Divcon Internat U K Ltd Seal
GB2051285A (en) * 1979-06-21 1981-01-14 Forest Fasteners Ltd Wheel Nuts
GB2065818A (en) * 1979-11-30 1981-07-01 Mac Lean Fogg Lock Nut Co Fastener assembly
GB2138529A (en) * 1983-04-20 1984-10-24 Oteco S R L Wheel Hub Nut
US4830557A (en) * 1988-01-26 1989-05-16 General Electric Company Self-aligning floating nut fastener

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
J.Soled,"fasteners handbook",published 1957 Reinhold publishing corp., page 205. *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6086479A (en) * 1998-01-30 2000-07-11 Bayside Controls, Inc. Alignment device
DE102007003487A1 (en) * 2007-01-24 2008-07-31 Schaeffler Kg Grooved screw for use in screw connection, has screw head with circular bearing surface formed at lower side of screw head, and screw shaft with self-grooved thread, where circular bearing surface of screw head is curved to be convex
WO2013020680A1 (en) * 2011-08-08 2013-02-14 Festo Ag & Co. Kg Annular anchoring element and fluid engineering assembly equipped therewith
CN103717919A (en) * 2011-08-08 2014-04-09 费斯托股份有限两合公司 Annular Anchoring Element And Fluid Engineering Assembly Equipped Therewith
CN103717919B (en) * 2011-08-08 2016-10-19 费斯托股份有限两合公司 Ring-type anchoring element and the fluid technique assembly equipped with this

Also Published As

Publication number Publication date
GB8926826D0 (en) 1990-01-17

Similar Documents

Publication Publication Date Title
US3209606A (en) Friction type continuous speed variation device
US3469897A (en) Lock plate for fixed motor rotor bearing
US9200672B2 (en) Method, apparatus, and nut for preloading a bearing
US4369387A (en) Electric drive unit
JP2875781B2 (en) Zero clearance bearing
US3463520A (en) Combination collar-clamp and shaft coupling
US3726576A (en) Rolling bearing
DE69535255T2 (en) Hydraulic nut for mounting conical objects
US5884980A (en) Vehicle brake and hub attachment system and method
US4096766A (en) Self-contained modular joint, notably for robots
US6325180B1 (en) Electric actuator and calliper brake comprising such actuator
JP3386337B2 (en) Method for producing a low-friction ball joint and a low-friction ball joint
US4765688A (en) Anti-friction bearing for wheels of automotive vehicles
US7559135B2 (en) Method and apparatus for preloading a bearing
US3903754A (en) Bicycle crank hub assembly
US5662445A (en) Locking nut
US4369011A (en) Preloaded ball screw assembly
EP0174903B1 (en) Shaft locking device for bearing assemblies
US6769809B2 (en) Asymmetric double row angular contact ball bearing, and cantilever mounting of gears on such a bearing
US6460423B1 (en) Method of measuring preload in a multirow bearing assembly
US4225263A (en) Locking device
GB2286231A (en) Method and apparatus for measuring clearance in double row rolling bearing
CA2576337C (en) Method, apparatus and nut for preloading a bearing
EP2248679B1 (en) Wheel bearing joint unit
US3736010A (en) Pitch link assembly and locking device therewith

Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)