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GB2131341A - Plastics components of or for bearings - Google Patents

Plastics components of or for bearings Download PDF

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Publication number
GB2131341A
GB2131341A GB08328268A GB8328268A GB2131341A GB 2131341 A GB2131341 A GB 2131341A GB 08328268 A GB08328268 A GB 08328268A GB 8328268 A GB8328268 A GB 8328268A GB 2131341 A GB2131341 A GB 2131341A
Authority
GB
United Kingdom
Prior art keywords
plastics
parts
expanding agent
bearing
sleeve
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Withdrawn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
GB08328268A
Other versions
GB8328268D0 (en
Inventor
Hans Meining
Manfred Brandenstein
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.)
SKF GmbH
Original Assignee
SKF Kugellagerfabriken GmbH
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
Priority claimed from DE19823239335 external-priority patent/DE3239335A1/en
Priority claimed from DE19823239334 external-priority patent/DE3239334A1/en
Application filed by SKF Kugellagerfabriken GmbH filed Critical SKF Kugellagerfabriken GmbH
Publication of GB8328268D0 publication Critical patent/GB8328268D0/en
Publication of GB2131341A publication Critical patent/GB2131341A/en
Withdrawn legal-status Critical Current

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
    • F16C35/07Fixing them on the shaft or housing with interposition of an element
    • F16C35/073Fixing them on the shaft or housing with interposition of an element between shaft and inner race ring
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C44/00Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles
    • B29C44/02Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles for articles of definite length, i.e. discrete articles
    • B29C44/12Incorporating or moulding on preformed parts, e.g. inserts or reinforcements
    • B29C44/1228Joining preformed parts by the expanding material
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08JWORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J9/00Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/04Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08KUse of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K7/00Use of ingredients characterised by shape
    • C08K7/02Fibres or whiskers
    • C08K7/04Fibres or whiskers inorganic
    • 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
    • F16C33/00Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30Parts of ball or roller bearings
    • F16C33/38Ball cages
    • F16C33/44Selection of substances
    • 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
    • F16C33/00Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30Parts of ball or roller bearings
    • F16C33/58Raceways; Race rings
    • F16C33/60Raceways; Race rings divided or split, e.g. comprising two juxtaposed rings
    • 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
    • F16C33/00Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30Parts of ball or roller bearings
    • F16C33/58Raceways; Race rings
    • F16C33/62Selection of substances
    • 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
    • F16C33/00Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30Parts of ball or roller bearings
    • F16C33/58Raceways; Race rings
    • F16C33/64Special methods of manufacture
    • 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
    • F16C19/00Bearings with rolling contact, for exclusively rotary movement
    • F16C19/02Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows
    • F16C19/04Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for radial load mainly
    • F16C19/06Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for radial load mainly with a single row or balls
    • 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
    • F16C2220/00Shaping
    • F16C2220/02Shaping by casting
    • F16C2220/04Shaping by casting by injection-moulding

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Medicinal Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Injection Moulding Of Plastics Or The Like (AREA)
  • Sliding-Contact Bearings (AREA)

Abstract

A material for the production of dynamically stressed precision parts for bearings is disclosed. In order to prevent shrinkage of the material during the processing in a mould, after cooling or curing, an expanding agent is added. When the basic material is a thermoplastics, preferably 0.2 to 2% of an expanding agent is added. In order to prevent a bearing, which is secured on a shaft (11) by means of an insert-moulded plastics sleeve (12,14), from becoming loose as a result of shrinkage of the sleeve material, an expanding agent is added to the moulding compound. Accordingly, the plastics sleeve is seated under preloading between the bearing and the shaft, in which case the inner wall thickness resulting from the shrinkage is compensated for. A preferred working material is 100 parts polyamide, 10 parts glass fibre and 0.8 parts expanding agent. <IMAGE>

Description

SPECIFICATION Plastics components of or for bearings The invention relates to a material for use in the production of dynamically stressed precision parts for bearings comprising an injection mouldable or castable plastics material, and to the installation of a bearing using a plastic sleeve.
Precision plastics parts for bearings, for example cages for rolling bearings, bearing rings around which plastics material has been injection-moulded etc., are usually required to have close-tolerance dimensions.
In accordance with series production, a manufacturing process is desirable having as few as possible work steps and, as far as possible, no second or finishing operations. Accordingly, these precision parts are mostly produced using injection-moulding or casting technology, in which after removal of the mould a finished product is obtained requiring no further machining. Although a large choice of basic materials is available, and they can be provided with a very wide variety of fillers (for example glass fibres or carbon fibres) and other additives and can thus be extensively adapted to the particular requirements, in nearly all known embodiments a serious disadvantage is present: after processing, the plastics material shrinks in the course of cooling or curing. This means that the dimensions become slightly smaller in relation to the original size of the mould.In the case of certain simple mouldings, for example with the same material thickness throughout, it is possible to overcome this drawback by increasing the dimensions of the mould by the amount of the expected shrinkage. However, this solution is not possible if the moulding is complicated, has different wall thicknesses merging into one another or has portions disposed angularly with respect to one another.In these cases even an amount of shrinkage individually calculated or determined at each point of the moulding, a correspondingly designed mould would be unsuccessful in series production, because slight dimensional variations between mouldings always occur as a result of conditions which vary during production, such as temperature gradients in the mould, temperature of the plastics material, pressure, for example, during the injection-moulding process, mix ratio of the plastics material etc.
Particularly in bearing technology, dimensional variations of this type, even though slight, can considerably affect the smooth running and service life of the whole bearing, for example in the case of a rolling-bearing cage. In this example, the affected areas are the cage pockets, the side faces of which act as abutment surfaces for the rolling body. The shrinkage of the plastics material may thus cause the following defects: - deviation from the geometrical shape of the cage pocket; - side faces inclined in relation to the corresponding abutment surfaces of the rolling body: - uneven side faces; - to large or too small dimensions of the cage pockets.
Even though these defects are extremely small from a dimensional aspect, in addition to the usual production tolerances they contribute considerably to the fact that the quality of a series of rolling bearings fluctuates substantially. With the plastics materials used hithertoforthe production of precision parts, the quality of the mouldings can be improved only by expensive finishing work.
The invention in one aspect provides a material for use in the production of dynamically stressed precision parts for bearings, comprising an injection mouldable or castable plastics material wherein an expanding agent is added to the basic material.
A material of this type can be processed in conventional manner using a mould in injection moulding technology. As a result of the expanding agent, expansion forces arise during processing which, upon cooling or curing of the plastics material, counteract the shrinkage. In this way, the moulding advantageously retains the desired dimensions, whereby in particular accurate surfaces are produced conforming to the mould; moreover, these surfaces retain the position and alignment pre-determined by the mould.
This advantage is particularly noticeable in cages for roller bearings. The side faces of the cage pockets form an accurate abutment surface which is of large area or, if desired, is linear, and which effects low-friction, uniform and smooth guidance or support of the rolling bodies. The accurate and uniform alignment of all cage pockets also brought about by the method according to the invention results in accurate rolling motion of all rolling bodies, whereby the operating noise of the rolling bearing is substantially reduced.
Preferably, when the plastics is thermoplastic the expanding agent is in the amount of 0.2 to 2 parts per 100 parts of plastics.
In practical tests this percentage has given particularly satisfactory results, it being necessary to determine by tests the actual percentage within the indicated range, depending on the moulding to be manufactured. Example 1.
Acagefor a rolling bearing was produced using the following moulding composition: polyamide - 100 parts glass fibre - 25 parts expanding agent - 1 part The polyamide was type PA66, available from BASF, Federal Republic of Germany and the expanding agent was type EF-A (an azo-dicarbonate) available from Lehmann and Voss, Federal Republic of Germany.
The individual description for the use of the plastics according to the invention in the production of cages for rolling bearings is to be taken merely by way of example. Of course, similar precision parts can also be produced therewith.
In the installation of a bearing, a plastics sleeve-shaped insert is provided between the seating faces of a bearing ring and a shaft, axle or a housing.
Patent Specification DE 1253960 discloses a method of installation of this type. In this case, the seating face of a bearing has a broad annular groove in which is accommodated a prefabricated elastic insert comprising a plastics material, which insert is deformed upon insertion of the bearing into the bore of a housing. As a result of subsequent curing of the material of the insert, a sufficiently accurate adaption to the bore in the housing is achieved. However, this installation is provided specially for producing a loose bearing fit and necessitates plastics sleeves and washers or spacers adapted to the respective application and bearing size.
Patent Specification DD 73682 discloses another method in which the accurate alignment of a number of bearings is achieved by filling a space between the bearing rings and accommodaring bores with, for example, epoxy resin. However, as a result of the ageing of the material and as a result of loading it is possible for the bearing rings to become loosened from the plastics filling, whereby damage may occur.
In the case of all the materials used hitherto for the installation of the type indicated, their volume diminishes slightly as a result of ageing, i.e. they shrink in the course of their service life. Accordingly, in the case of bearings initially installed with an accurate fit, a gap is formed as a result of which precise mounting is no longer present.
The invention provides in another aspect a method of installing a bearing, in which a plastics sleeve-shaped insert is provided between the seating faces of a bearing and a shaft, axle or a housing, by casting, injection-moulding or the like, wherein an expanding agent is added to the material for the sleeve-shaped insert.
In the material with added expanding agent, which can be processed or worked in the usual manner using an injection-moulding die, after curing there occur expansion forces which retain the relevant bearing ring under pre-loading, for example on the shaft. Accordingly, any shrinkage caused by ageing of the material is advantageously compensated for, so that the fitting of the bearing without play is maintained.
Preferably, when the plastics is a thermoplastic 0.2 to 2 parts of an expanding agent is added to 100 parts of the plastics.
According to the percentage of added expanding agent, it is possible for inter alia the preloading force and thus shrinkage compensation to be adapted to the particular application. The composition according to the invention has proven to be advantageous, for example, for the installation of rolling bearings and for the tolerances occurring therein. The installation according to the invention can be effected wherever tolerances are to be expected in the dimensions and wherever it is possible for alignment errors to occur, for example, in bores for the reception of bearings of a shaft. In all these cases it is possible for errors to be individually compensated for by the sleeve-shaped insert according to the invention. Of course, it is also possible to provide force-locked connections in addition to form-locked connections.
In the accompanying drawings, Figure 1 illustrates, in longitudinal section, a conventional installation and Figure 2 an installation according to the invention.
Referring to Figure 1', the inner ring 10 of a ball-bearing is mounted on a shaft 11 via a plastics sleeve 12.
The plastics sleeve 12 is inserted directly between the inner ring 10 and the shaft 11 using an injection-moulding process, the mould die components not being shown. A gap 13 is evident between the circumferential surface of the plastics sleeve 12 and the bore surface of the inner ring 10, whish gap results from shrinkage of the material caused by ageing, when a hitherto conventional material is used for the plastics sleeve 2. A gap of this type does not arise when, as shown in Figure 2, the material for the plastics sleeve 14 is provided with an expanding agent and the expanding agent causes an expansion ofthe plastics sleeve.
Example 2: A plastics sleeve 14 was produced using the following moulding composition: polyamide - 100 parts glass fibre - 10 parts expanding agent - 0.8 parts The polyamide was type PA66, available from BASF, Federal Republic of Germany, and the expanding agent was type Geniton AF100 (an inorganic carbonate) available from Lehmann and Voss, Federal Republic of Germany.

Claims (9)

1. A material for use in the production of dynamically stressed precision parts for bearings, comprising an injection mouldable or castable plastics material wherein an expanding agent is added to the basic material.
2. A material according to Claim 1, wherein when the basic material is a thermoplastic the expanding agent is in the amount of 0.2 to 2 parts per 100 parts of plastics.
3. A method of installing a bearing, in which a plastics sleeve-shaped insert is provided between the seating faces of a bearing and a shaft, axle or a housing, by casting, injection-moulding or the like, wherein an expanding agent is added to the material for the sleeve-shaped insert.
4. A method according to Claim 3, wherein when the plastics is a thermoplastic 0.2 to 2 parts of an expanding agent is added to 100 parts of plastics.
5. A method of producing a component of or for a bearing assembly, which component is made of plastics, the method including injection moulding or casting the component from a compound including an expanding agent.
6. A method as claimed in Claim 5, in which the assembly comprises a bearing mounted in a bore of a housing or mounted on a shaft, and in which the component is a plastics sleeve positioned between the seating surfaces of the bearing and the bore or the shaft, wherein the sleeve is injection moulded or cast between the seating surfaces.
7. A method as claimed in Claim 5 or 6, wherein, when the plastics is a thermoplastic, the expanding agent is in the amount of 0.2 to 2 parts for every 100 parts of plastics.
8. A method of producing a component of or for a bearing assembly substantially as herein described with reference to the Examples and Figure 2 of the accompanying drawings.
9. A component of or for a bearing assembly when produced by a method as claimed in any one of Claims 5 to 8.
GB08328268A 1982-10-23 1983-10-21 Plastics components of or for bearings Withdrawn GB2131341A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19823239335 DE3239335A1 (en) 1982-10-23 1982-10-23 Material for the production of dynamically stressed precision components for bearings
DE19823239334 DE3239334A1 (en) 1982-10-23 1982-10-23 Installation of bearings

Publications (2)

Publication Number Publication Date
GB8328268D0 GB8328268D0 (en) 1983-11-23
GB2131341A true GB2131341A (en) 1984-06-20

Family

ID=25805311

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08328268A Withdrawn GB2131341A (en) 1982-10-23 1983-10-21 Plastics components of or for bearings

Country Status (1)

Country Link
GB (1) GB2131341A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2352779B (en) * 1999-07-29 2004-04-21 Munster Simms Eng Ltd Diaphragm pumps
WO2008092654A1 (en) * 2007-01-30 2008-08-07 Dsm Ip Assets B.V. Construction comprising a bearing mounted on a plastic body
EP4667761A1 (en) * 2024-06-20 2025-12-24 Marelli Europe S.p.A. Actuator for automotive applications and the manufacturing method thereof

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB853934A (en) * 1956-01-24 1960-11-09 Roehm & Haas Gmbh Improvements in or relating to casts and moulds
GB944611A (en) * 1959-07-30 1963-12-18 Monsanto Chemicals Moulding compositions
GB1382207A (en) * 1972-06-17 1975-01-29 Akontz E Process for making a symbol carrier element for a demonstration or educational aid device
GB1393680A (en) * 1971-11-23 1975-05-07 Atomic Energy Authority Uk Porous plastics materials
GB1427670A (en) * 1974-03-28 1976-03-10 Rotoplas Ltd Rotational moulding

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB853934A (en) * 1956-01-24 1960-11-09 Roehm & Haas Gmbh Improvements in or relating to casts and moulds
GB944611A (en) * 1959-07-30 1963-12-18 Monsanto Chemicals Moulding compositions
GB1393680A (en) * 1971-11-23 1975-05-07 Atomic Energy Authority Uk Porous plastics materials
GB1382207A (en) * 1972-06-17 1975-01-29 Akontz E Process for making a symbol carrier element for a demonstration or educational aid device
GB1427670A (en) * 1974-03-28 1976-03-10 Rotoplas Ltd Rotational moulding

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2352779B (en) * 1999-07-29 2004-04-21 Munster Simms Eng Ltd Diaphragm pumps
WO2008092654A1 (en) * 2007-01-30 2008-08-07 Dsm Ip Assets B.V. Construction comprising a bearing mounted on a plastic body
EP4667761A1 (en) * 2024-06-20 2025-12-24 Marelli Europe S.p.A. Actuator for automotive applications and the manufacturing method thereof

Also Published As

Publication number Publication date
GB8328268D0 (en) 1983-11-23

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