A90 Series Correspondence Lessons PART E. Miniature and Thrust Bearings

Transcription

1 A90 Series Correspondence Lessons PART E Miniature and Thrust Bearings Lesson A9013 Miniature Bearings Lesson A9014 Thrust and Clutch Thrust Bearings

2 PART E Miniature and Thrust Bearings Series 90 Training

3 PART E Miniature and Thrust Bearings Lessons A9013 to A9014 Correspondence Course LESSON A9013 Miniature Bearings Table of Contents Angular Contact 4 Numbering System 7 Cage Design 5 - Metric Series 7 Flanged Type 3 - Special series Metric 8 Expanded Type 4 - Inch Series 9 Extended Inner Ring 4 Pressed Crown Cage 5 Introduction 3 Pressed Ribbon Cage 5 Machined Cage 5 Standard Type 3 Miniature Bearings 3 Thin Section 4 Structured Training Plan This lesson is the thirteenth of a series of Correspondence lessons in the BSC Structured Training Plan. Objectives The objective of this lesson is to acquaint students with the range of miniature bearings supplied by BSC. Pre-requisites Completion of Correspondence Lessons A A9012. Methods Achievement of the objectives is by presentation of lessons in an 'On-Line' or Correspondence Course format. The lessons in a Correspondence Course style are conducted for internal students in a lecture situation. Assessment A formal test is provided with this lesson. LESSON A9013 Series 90 Training

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5 Miniature Bearings Since the last lesson on needle rollers was rather heavy, we will make this one a little lighter. Smaller bearings are usually referred to as miniature or instrument bearings. All bearings in the range have an outside diameter less than 10 mm. There is also a range referred to as extra small bearings. These have an OD equal to or greater than 10 mm and up to 16mm. The range includes several new types of bearing which we have not covered before in these lessons. Dimensions, like the one shown in the photo to the right, go right down to 1 mm although you are unlikely to find anything less than 3 mm in stock, even in a state warehouse. They are available in open type or with steel shields and some of the larger sizes are available with rubber shields. Click to enlarge There are 6 main types: Standard type Flanged outer ring Extended inner ring< Expanded type< Thin section type Angular Contact Ball Bearings Let's begin by examining each of these types in turn. Click to enlarge Click to enlarge Standard type Standard type miniature bearings are like a miniature version of their bigger cousins. As such, they have all the inherent advantages of their larger counterparts. This includes ability to handle some thrust loading as well as radial loads. The low friction associated with ball bearings means low noise and vibration levels. Several different cage styles are available. Flanged Type This type of miniature bearing corresponds to ordinary ball bearings with snap rings. The flange extends round the entire circumference of the bearing and is flush with one side. When fitting in a housing, it is not necessary to machine an area for the flange as the bearing can be mounted with the flange outside the housing as shown to the left. This reduces machining time. LESSON A9013 Miniature Bearings Series 90 Training page 3

6 Extended inner ring These are inch series bearings and have their inner ring extended on both sided by 1/64 inch (0.375mm). This makes the inner ring slightly larger than the outer ring which simplifies things when designing parts directly surrounding the bearing. Expanded type. These bearings are inch series and have an extended outer ring. This makes the OD quite large relative to the ID. These bearings are used mainly in synchros but are convenient in some other applications. Thin section These bearings have a small radial cross sectional thickness which makes them useful where extreme compactness is required. They are available with a bore size of 10 mm to 16mm which makes them slightly outside the usual range if miniature bearings. Angular Contact Ball Bearings Angular contact bearings can sustain thrust loads in one direction only, as well as radial loads. The usual configuration is to have an extended shoulder on the outer ring only although they are available with extended shoulders on both rings which makes then suitable for extremely high speeds. they are usually used in pairs and require an appropriate preload. Single shoulder bearings are still suitable for high speed applications. LESSON A9013 Miniature Bearings Series 90 Training page 4

7 Cage design Miniature bearings are usually crown type (smaller sizes) or ribbon type (larger bearings). The older machined cage types are rarely seen these days although you may come across one which needs replacing. The table below shows the various types of cages and the corresponding symbols: J, JH Pressed ribbon cage (JH cages have lower torque) W Pressed crown cage T Machined cage LESSON A9013 Miniature Bearings Series 90 Training page 5

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9 Numbering system - Metric series, Deep groove Ball Bearings 60 1X W MC3 P4 L UC3 AF2 F 62 5 h J ZZ MC2 P5 B32 Bearing type symbol Lubricant Type Blank: Standard Oil F: Flanged AF2: Aeroshell Fluid 12 Bearing Series Number A4D: Anderol-401D 68, 69, 60, 62 and 63 Grease Bore Diameter Number B32: Beacon to 9: Bore diameter in mm PS2 Multemp PS2 X indicates bore diameter (Others available on request) 1X, 2X: contains a fraction Bore or OD Sorting Symbol Material symbol UC1: Bearings are sorted into 2 groups Blank: Bearing steel depending on bore tolerance h: Stainless steel UC2: Bearings are sorted into 2 groups Cage Symbol depending on OD tolerance J: Ribbon cage UC3: Bearings are sorted into 4 groups JL: Ribbon cage (light clinching) depending on ID/OD tolerance W: Crown Cage Torque Symbol T: Non Metallic Machined cage Blank: No torque number (Cage symbols are occasionally omitted) L: Low torque Seals and shields Tolerance class symbol ZS, ZZS: Z, ZZ: V, VV: D, DD One shield, two shields (snap ring type) One shield, two shields (Pressed type) One Seal, two seals (noncontact type) One Seal, two seals (contact type) Blank: Tolerance class 0 P6: Tolerance class 6 P5: Tolerance class 5 P4: Tolerance class 4 One Seal, two seals Clearance Symbol TS, TTS (Synthetic resin, contact type) MC1,MC2,MC3.MC4,MC5, and MC6 BSC carries these bearings under the basic part number eg 681ZZ, 605ZZMC3. The other indicators may appear on the supplier packaging. LESSON A9013 Miniature Bearings Series 90 Training page 7

10 Numbering system - Specific Dimension Series, Special Metric Series, Deep Groove Ball Bearings S ML 8014 W ZZ MC3 P5 UC1 B32 MLF 148 J MC4 Material symbol Lubricant Type Blank : Bearing Steel (SUJ2) Oil S: Stainless Steel AF2: Aeroshell Fluid 12 Bearing Type Number A4D: Anderol-401D ML: Standard type Grease MLF: Standard type with flange B32: Beacon 325 MR: Special Metric Series PS2: Multemp PS2 MF: Special metric series with flange (Others available on request) Size Number Bore or OD sorting symbol Number indicates OD and bore size where bore is multiplied by 10 eg ML8014 is 8mm ID x 14mm OD LESSON A9013 Miniature Bearings Series 90 Training page 8 UC1: Bearings are sorted into 2 groups depending on ID tolerance Cage Symbol UC2: Bearings are sorted into 2 groups J: Ribbon cage depending on OD tolerance JL: Ribbon cage (light clinching) UC3: Bearings are sorted into 4 groups W: Crown Cage depending on ID/OD tolerance T: Non Metallic Machined cage Torque Symbol (Cage symbols are occasionally omitted) Blank: No torque number Seals and shields L: Low torque ZS, ZZS: One shield, two shields (snap ring type) Tolerance class symbol Z, ZZ: One shield, two shields (Pressed type) Blank: Tolerance class 0 TS, TTS:One Seal, two seals (Synthetic resin, contact type) P6: Tolerance class 6 P5: Tolerance class 5 P4: Tolerance class 4 Clearance Symbol MC1,MC2,MC3.MC4,MC5, and MC6 BSC carries these bearings under the basic part number eg 681ZZ, 605ZZMC3. The other indicators may appear on the supplier packaging.

11 Numbering system - Inch Series, Deep groove Ball Bearings S FR 133 X3 W ZZS MC3 7P L UC1 AF2 R 2 J ZZ MC4 B32 Material symbol Lubricant Type Blank: Bearing Steel (SUJ2) Oil S: Stainless Steel AF2: Aeroshell Fluid 12 Bearing Type Number A4D: Anderol-401D OB: Inch series standard type Grease OBF: Inch series standard type with flange B32: Beacon 325 R: Inch series deep groove ball bearing PS2 Multemp PS2 FR: RW: Inch Series deep groove ball bearing with flange Inch Series deep groove ball bearing with extended inner ring (Others available on request) Bore or OD sorting symbol Size Number UC1: Bearings are sorted into Number indicates OD and bore size (but is not a calculated number). 2 groups depending on ID tolerance Special design symbol UC2: Bearings are sorted into 2 groups depending on OD tolerance Cage Symbol UC3: Bearings are sorted into J: Ribbon cage 4 groups depending on JL: Ribbon cage (light clinching) ID/OD tolerance W: Crown Cage T: Non Metallic Machined cage Torque Symbol (Cage symbols are occasionally omitted) Blank: No torque number Seals and shields L: Low torque ZS, ZZS: One shield, two shields (snap ring type) Tolerance class symbol Z, ZZ: One shield, two shields (Pressed type) Blank: ABEC 1 TS, TTS: One Seal, two seals (Synthetic resin, contact type) 3: ABEC3 5P: ABEC 5P 7P: ABEC 7P Clearance Symbol MC1,MC2,MC3.MC4,MC5, and MC6 LESSON A9013 Miniature Bearings Series 90 Training page 9

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13 A9013- Questionnaire Name: Employee No (from Payslip): Branch (eg QAA) Date: Miniature Bearings Questions Q1. What is the 0D size range for miniature ball bearings? Answers A. 5 mm to 15 mm B. 3 mm to 12 mm C. 1 mm to 9 mm Q2. Which of the 6 types of miniature bearing would you recommend for applications where there is a moderate to heavy thrust load present? A. Standard type B. Flanged outer ring C. Extended inner ring D. Expanded type E. Thin section type F. Angular Contact type Q3. With Inch series extended inner ring type bearings, how much is the inner ring extended on each side? A. 1/64 inch B. 1/32 inch C. 1/16 inch Q4. When fitting a flange type bearing, is it necessary to machine out a recess for the flange? Q5. Which type of miniature ball bearing has an extended outer ring? A. Yes B. No A. Standard type B. Flanged outer ring C. Extended inner ring D. Expanded type E. Thin section type F. Angular Contact type LESSON A9013 Miniature Bearings Series 90 Training page 11

14 A9013- Questionnaire (cont.) Name: Employee No (from Payslip): Branch (eg QAA) Date: Miniature Bearings Q6. What type of cage is indicated by the letter J? A. Ribbon type - light duty B. Ribbon type - normal duty C. Crown type Q7. What is the ID and OD of a ML6010 Bearing? A. 60 x 100 B. 60 x 10 C. 6 x 10 Q8. Select the attributes of a F605 Bearing. A. Flanged Unflanged B. Light Series Medium Series C. 5mm ID 25mm ID LESSON A9013 Miniature Bearings Series 90 Training page 12

15 PART E Miniature and Thrust Bearings Lessons A9013 to A9014 Correspondence Course LESSON A9014 Thrust Bearings and Clutch Thrust Bearings Table of Contents Ball Thrust Bearings 3 Needle Roller Thrust 6 Ball Thrust Bearing Series: 4 Single Direction Thrust 3-6 XLT 4 Spherical Roller Thrust & Supplement A Tapered Roller Thrust & Tapered Thrust Bearings & TTC series & TTHD Heavy Duty 9 - FT series 4 - TTHDFL Heavy Duty 9 - LT series 4 - TTSC series 9 - Metric 4 TMP series 6 - MT 4 Washer Plates 7 Clutch Thrust Bearings 10 - AS type 7 Cylindrical Roller Thrust 5 - TWA type 7 Double Direction Thrust 3 - GS type 7 K811( cage and roller assembly) 6 - WS type 7 Lazy Susan Bearings 12 - LS type 7 Structured Training Plan This lesson is the fourteenth of a series of Correspondence lessons in the BSC Structured Training Plan. Objectives The objective of this lesson is to teach the principals of thrust bearing types, construction and numbering systems. Both Ball thrust and roller thrust bearings will be covered. The second section of the lesson deals with Clutch Thrust bearings and here we attempt to teach the basic principals of clutch operation and bearing applications which use standard clutches. Pre-requisites Completion of Correspondence Lessons A A9013. Methods Achievement of the objectives is by presentation of lessons in an 'On-Line' or Correspondence Course format. The lessons in a Correspondence Course style are conducted for internal students in a lecture situation. Assessment A formal test is provided with this lesson. LESSON A9014 Series 90 Training

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17 BALL THRUST BEARINGS Thrust bearings are made in both imperial and metric dimensions with either ball, roller or tapered roller elements. Thrust bearings are designed to take axial or thrust loads along the axis of the shaft only. Unlike Angular Contact Bearings, thrust bearings have absolutely no radial load carrying capacity and consequently, no radial load should be applied to them. In this lesson we will discuss four types of thrust bearing Ball thrust bearings Roller thrust bearings Needle thrust bearings Spherical roller thrust bearings. Ball thrust bearings will not function correctly unless some thrust load is continuously applied. This is because the thrust load is required to hold the bearing together, as we shall see in a moment. There are basically two types of ball thrust bearings: SINGLE DIRECTION THRUST BALL BEARINGS DOUBLE DIRECTION THRUST BALL BEARINGS SINGLE DIRECTION THRUST BALL BEARINGS The construction of a single acting thrust ball bearing is a three piece unit. It has two thrust washer plates and a cage fitted with balls and is illustrated in the diagrams to the right. They are available with either a flat seat or with a spherically ground aligning seat in which case a matching aligning washer would be required, thus giving the bearing a self aligning capability. DOUBLE DIRECTION THRUST BALL BEARINGS The bores of the two washer plates are not the same dimension and one is ground to the nominal shaft size and is for mounting on the shaft seating. The other washer plate, of the pair, is ground oversize on the bore by a dimension shown in the catalogues so that it will have a clearance over the shaft diameter. This ensures that with a rotating shaft application, the bore of the stationary washer will not rub on the shaft. With larger sizes of thrust ball bearings, the outside diameter of the rotating washer is ground undersized so that it will not rub on the bore of the housing. As previously stated, they are available in both imperial and metric dimensions. LESSON A9014 Thrust Bearings and Clutch Thrust Bearings Series 90 Training page 3

18 Our principal source of both single and double direction metric ball thrust bearings is NSK who use the IS0 numbering system. As you can see from the diagrams above, both the single and double type ball thrust bearings are available with either a flat seat or an aligning seat. Ball thrust bearings with aligning seal rings can be fitted either directly into a housing or with an aligning washer. Metric Numbering systems As previously stated, we use the IS0 numbering system for these bearings. There are four series as shown in the chart to the right:- The code for the bore (the last two numbers of the part number) is the same as used for Deep Groove ball bearings e.g. Part number is a medium series ball thrust bearing with an alignjng seat and a bore size of 65mm (13x5). The suffix 'U' is used when aligning seat bearing is supplied with an aligning seat washer (two in the case of Double Direction bearings). The suffix X' is used when the outside diameter of the shaft washer (ring) is smaller than that of the housing washer (ring). Extra Light Metric numbering system for Ball Thrust Bearings Single Direction Flat Seat Aligning Seat Double Direction Flat Seat Light Medium Heavy Imperial Numbering system Imperial numbering system for ball thrust bearings Series Number Extra light series Flat Raceway Grooved Raceway Prefix Exampl e FT FT 3/4 XLT XLT 2-1/2 Light Series LT LT 5E Medium Series MT MT 3-3/8 We source imperial ball thrust bearings from NSK-RHP and therefore use their numbering system These are single direction bearings only and there are three series as shown below. The bearings are similar to the metric series except for the W series which has flat raceways. The Part Number consists of an identifying prefix followed by the shaft seating diameter in inches and fraction E.G LT 1-1/4. You will frequently find that bearings of 4 inches or greater ID in whole inch sizes have a letter E (for English - imperial) added to the part number. This suffix was introduced to avoid confusion with the old R & M numbering for metric bearings but is now being phased out. LESSON A9014 Thrust Bearings and Clutch Thrust Bearings Series 90 Training page 4

19 Other Suffixes RHP uses various suffixes to indicate nonstandard configurations The most common are as shown B M MB CN C3 One ring is bored oversize on the ID to give shaft clearance. Machined Brass cage located on the rolling elements Machined brass cage located on the inner ring outer diameter Normal clearance - not usually marked Clearance greater than normal indicator Cylindrical Roller Thrust Bearings Timken These bearings are similar to the Ball thrust bearings except that the rolling elements are rollers instead of balls and the rings are flat - not grooved. Whilst this type of bearing is available from NSK and INA, Timken has become the usual supplier for Cylindrical Roller Thrust Bearings. These were originally Torrington brand bearings and were transferred to the Timken range whet Timken took over Torrington. CRT bearings are designed to operate under heavy loads at moderate speeds. Timken TP range has 2 flat hardened and ground steel washers with a cage holding one or more steel rollers. Where the bearing size calls for more than one roller, the rollers are manufactured to different lengths and placed in alternative positions in adjacent pockets in the cage. This prevents grooving of the washers so extending the bearing life. Timken Part Numbers have the following format: 50 TP 190 Bore size x 10 so 50 = 5mm bore Bearing type - Thrust cylindrical roller bearing Index number (not calculated from dimensions). You need to check the catalogue to find the index number for a particular sized bearing. LESSON A9014 Thrust Bearings and Clutch Thrust Bearings Series 90 Training page 5

20 NSK Metric numbering system for cylindrical roller thrust bearings (NSK) Part Number Extra Light - - TMP 11 Light - - TMP 12 Medium - - TMP 93 Heavy - - TMP 94 NSK make a metric series, single direction, double roller thrust bearing as illustrated above: The seating shaft diameter size ranges from 40mm to 200mm and four series are manufactured as shown in the chart below: The shaft seating diameter is added as the first numbers of the part numbers EG 120 TMP 93 = 12Omm shaft seating diameter, double roller thrust bearing, medium series. INA INA refer to their thrust bearings as Axial cylindrical roller and Axial needle roller bearings. They make a wide range of metric cylindrical roller thrust bearings in several configurations (single roller, double roller similar to NSK, and one that has alternating two and three rollers - see the diagrams below). Centre washers are available for their K811 series of single roller thrust cage and roller assemblies, which enable this series to be used as a double direction thrust bearing. Care must be taken, as INA have separate part numbers for the cage and needle assemblies and the thrust washers. Supplements 1 and 2 are taken from the INA catalogue and explain the Ina Bearings in more detail. Needle Roller Thrust Bearings These bearings are made to both imperial and metric dimensions and are sourced from INA. They are similar to single roller cylindrical thrust bearings except that the roller is at least three times longer than its diameter. Whilst this type of bearing is usually installed as a complete unit - consisting of 2 washers and a cage and roller assembly, it is also possible to utilise just the cage and roller assembly on its own and to run this directly on to the surface of the shaft and housing. In this case special; attention needs to be given to the surfaces, which must be hardened and ground. Alternatively, load ratings must be reduced. LESSON A9014 Thrust Bearings and Clutch Thrust Bearings Series 90 Training page 6

21 Metric Numbering System The metric needle roller thrust bearings also have separate part numbers for the cage and roller assemblies and the thrust washers. There are three types of thrust washer which differ from each other in thickness. Cage and roller assembly - the letters "AXK" are identifying prefix letters, followed by the shaft diameter and the overall diameter of the cage assembly. E.g. AXK shaft diameter 10 mm, overall diameter of cage assembly 24mm. There are four types of washers available: AS type - thin thrust washers, thickness 1 mm LS type - thicker thrust washer, thickness increases with size of washer. GS811- housing locating washer, same thickness as LS type. WS811 - shaft locating washer, same thickness as LS type. AXK AS LS GS 811 WS 811 The AS and LS washer have the same numbering system 'as the cage and roller. The GS811 and WS811 have a separate numbering system and the INA catalogue should be referred to at all times when supplying these bearings. A centre washer ZS' is available for this series so that double direction bearings can be made up. Imperial Numbering Systems The cage and roller assembly has a separate part number from the thrust washers. There are three types of thrust washers which differ from each other in their thickness. Cage and roller assembly - the letters 'TC' are identifying prefix letters. The rest of the part number is made up of the shaft diameter and the minimum housing bore diameter expressed as 16th inch e.g. TC shaft diameter 1/2" (8/16), min. hsg. bore dia of 15/16". There are three types of thrust washers as follows: TWA " thick TWB " thick TWC " thick TWD " thick The thrust washers use exactly the same numbering system as the cage and roller assemblies. Thus if the customer wanted a TC 815 cage and roller assembly he would have the choice of either TWA 815 thrust washers or TWC 815 thrust washers to suit. You can access a copy of some pages from the INA catalogue here - Supplement A. There are some questions in the test relating to these pages so you may wish to print them out. You could also refer to the Ina Catalogue 307, from which these pages were taken. LESSON A9014 Thrust Bearings and Clutch Thrust Bearings Series 90 Training page 7

22 Spherical Roller Thrust Bearings These bearings, as their names suggests, have a single row of spherical rollers between two thrust plates. We source these bearings from NSK and they made to suit shaft sizes from 120mm to 500mm. These bearings not only take heavy thrust loads but will take some radial load, because the rollers are steeply aligned. Their self-aligning design means that they automatically adjust for mounting errors or shaft deflection. Because of the difficulty of lubricating this type of bearing, they are not suitable for high speeds. NUMBERING SYSTEM Spherical roller thrust bearings are identified by a five digit part number that always has the first two digits as '29'. There are three series:- LIGHT series MEDIUM series HEAVY series The Last two numbers, up to and including 48- bore, are the bore code which is the same as that used for Deep Groove ball bearings. Example: Part number Spherical roller bearing (29), medium series (3), with a 180mm bore. At 500 mm the part number changes so that instead of a bore code the actual bore size is shown thus: Light series 292/500 etc. LESSON A9014 Thrust Bearings and Clutch Thrust Bearings Series 90 Training page 8

23 Tapered Roller Thrust Bearings The Timken thrust bearings consist of two tapered thrust races, rollers and an outside retainer and are cage less. The outside retainer is of pressed metal construction and holds the assembly together for shipping and installation. The TTC (Taper Thrust Cageless type) has a retainer which extends over the face of one race. The retainer on the TTSC (Taper Thrust Cageless Short retainer) type covers the outer surface of the rings only (see diagram). Heavy Duty Series Timken manufacture two series of heavy duty Tapered Roller Thrust Bearings The TTHD series and the TTHDFL >series. The TTHD (Tapered Thrust Heavy Duty) type consists of two thrust races, rollers and cage. All components are separable. The TTHDFL (Tapered Thrust Heavy Duty Fiat Race) type is different in that one of the raceways is a flat thrust race. This bearing is used extensively in various applications including oil well swivels, pulp refiners, extruders and piercing mill thrust block. TTC TTCS TTHD TTHDFL LESSON A9014 Thrust Bearings and Clutch Thrust Bearings Series 90 Training page 9

24 Numbering Systems Part numbers for Timken thrust tapered roller bearings are not related to size but are merely a catalogue number so to check the dimensions you need to refer to the Timken bearing manual. However the addition of a W suffix indicates the presence of an oil hole in the retainer. Some examples of the type of number you may expect to encounter: TTC TTCS TTHD TTHDFL T127. T138W, T152 T128, T136, T189W T311, T451 T15500 Clutch Thrust Bearings The action of joining the power from the motor to the gearbox and the transmission drive to the rear wheels, is generally through a plate clutch in cars, trucks, tractors, earthmoving equipment etc (see diagram above). The exceptions are when a fluid drive or automatic transmission is used to connect the engine to the rear axle drive. A clutch thrust bearing (also called a clutch throwout or release bearing) is used to disengage the clutch minimising friction (and therefore wear) between the clutch pressure plate assembly and the release lever mechanism (refer diagram next page). The bearings are most commonly ball thrust bearings, fitted inside a stamped steel housing, with a clearance allowing the large bore race to rotate freely. Occasionally angular contact type ball thrust bearings may be used, where it is desired that the bearing support a combination of both thrust and radial load. LESSON A9014 Thrust Bearings and Clutch Thrust Bearings Series 90 Training page 10

25 The clutch thrust bearings however, should not be confused with the clutch pilot bearing (refer to the diagram on the left), which is the free end bearing on the transmission main drive shaft, onto which the clutch is mounted. Our main sources for these bearings are NSK and RHP. We also stock a range of bearings under the NICE numbering system. Nice used to be the principal suppliers of this type of bearing. The bearings stocked under the Nice numbering system now come from CBC and are Aetna brand. We can also purchase NICE bearings from Rolling Bearings or Bearing Distributors. Nice bearings are manufactured by RBC in the USA. This company does not have any direct connection with RBC (Rolling Bearings) in Australia. Rolling Bearings in Australia is a member of the Inenco group of companies. Most of the NSK clutch thrust bearings have two numbers followed by two or three letters and then two or three numbers with suffixes after. EG.24TK308 V2U3, 40TMK20B1 etc. R H P part numbers are made up of one or two numbers followed by a "/", then a W and then the bore size. EG. 1/W3, 7/W 5/8, 14/W1-1/2 etc. NICE use the prefix 'N' followed by a number that is a drawing number and bears no relationship to the bearings dimensions at all. EG. N856, N1086 etc. INA manufacture a range of clutch release bearings as well as complete clutch release systems. Details are available in the INA Technical Product Information sheet. LESSON A9014 Thrust Bearings and Clutch Thrust Bearings Series 90 Training page 11

26 Lazy Susan Bearings These bearings are referred to in the price list as Triangles but this is a reference to the manufacturer's name. They are simple pressed metal plates in either a square pattern or circular pattern as shown m the diagrams on this page. The balls are located in the pressed grooved of the raceways during the manufacturing process which also locks the two outer raceways together. The manufacturers claim many uses for these bearings including turntables and fixtures of all kinds. Some examples are computer display units, rotating tables, jeweller s display units and rotating corner cupboard shelves. Only 4 sizes are available as follows 3C 3' Square pattern Capacity 90kg 4C 4' Square Pattern Capacity 136kg 6C 6' Square Pattern Capacity 225kg 12C 12' Round Pattern Capacity 450kg LESSON A9014 Thrust Bearings and Clutch Thrust Bearings Series 90 Training page 12

27 SUPPLEMENT A. Pages from INA Catalogue LESSON A9014 Thrust Bearings and Clutch Thrust Bearings Series 90 Training page 13

28 SUPPLEMENT A. Pages from INA Catalogue (cont.) LESSON A9014 Thrust Bearings and Clutch Thrust Bearings Series 90 Training page 14

29 A Questionnaire Name: Employee No (from Payslip): Branch (eg QAA) Date: Thrust Bearings and Clutch Thrust Bearings Questions Q1. Thrust bearings do not function properly unless a thrust load is applied. Q2. Why is the bore of one washer plate on a ball thrust bearing ground oversize? Answers A. True B. False A. To make it easier to fit. B. To ensure clearance over the shaft diameter C. Manufacturing requirements Q3. Why is the washer plate of some ball thrust bearings ground spherically? A. To allow it to seat in an aligning washer B. To make it easier to fit. C. Can take a higher load Q4. What is the ISO part number for a ball thrust bearing, medium series, single direction with an aligning seat to suit a 50mm shaft, supplied complete with the matching aligning washer? Q5. Describe an LT 5 E. A B U C U A. Series: Light Medium Heavy B. Genre: Imperial Metric C. Type: Ball Thrust Roller Thrust Needle Roller Thrust D. Bore size: 4 inch 5 inch 25 mm LESSON A9014 Thrust Bearings and Clutch Thrust Bearings Series 90 Training page 15

30 A9014 Questionnaire (cont.) Name: Employee No (from Payslip): Branch (eg QAA) Date: Thrust Bearings and Clutch Thrust Bearings Q6. Referring to Supplement A, describe how the INA series K812 differ from the K894 series. A. K812 is Single row, K894 is double row B. K812 is Double row, K894 is Single row C. K812 is Cylindrical Roller, K894 is Needle roller Q7. Supplement A details the separate components of an INA thrust needle roller bearing. Referring to this chart, write down the numbers for the 3 parts required to make up a bearing to suit a 20mm shaft if only 6MM max depth were available. The application requires one washer to be shaft located. Q8. What is the part number for a 80mm heavy series spherical roller thrust bearing? A. Shaft Locating Washer B. Roller Assembly C. Axial Washer A B C Q9. What do the initials TTC in tapered thrust bearings stand for? A. Tapered thrust cageless B. Tapered thrust with cage C. Tapered thrust cylindrical Q10. How does the TTHD series taper thrust bearings differ from the TTHDFL series? A. TTHDFL has a flange B. TTHDFL has a flat race C. TTHDFL has a ground fillet on the outside edge Q11. 3/W 2½ 24TK308B2U3 N1080 The above are all types of Bearings A. Needle Thrust bearing B. Clutch pilot Bearing C. Clutch thrust Bearing A9014 Questionnaire (cont.) LESSON A9014 Thrust Bearings and Clutch Thrust Bearings Series 90 Training page 16

31 Name: Employee No (from Payslip): Branch (eg QAA) Date: Thrust Bearings and Clutch Thrust Bearings Q12. Check alongside the part numbers, the manufacturer to which the numbering system is attributed. A. 3/W 2½ B. 24TK308B2U3 Timken NSK Nice C. N1080 Q13. What is the difference between a clutch thro - out bearing and a clutch pilot bearing? A. Used to disengage the clutch between the clutch pressure plate and the flywheel. Clutch Throw-out Bearing Clutch Pilot Bearing B. Carrier bearing on which the onto which the clutch is mounted Clutch Throw-out Bearing Clutch Pilot Bearing Q14. What is the largest size of Lazy Susan bearing normally carried in stock? A. 6 inch B. 8 inch C. 12 inch LESSON A9014 Thrust Bearings and Clutch Thrust Bearings Series 90 Training page 17

32 LESSON A9014 Thrust Bearings and Clutch Thrust Bearings Series 90 Training page 18