GB2236362A

GB2236362A - Shaft support

Info

Publication number: GB2236362A
Application number: GB9018121A
Authority: GB
Inventors: Gye Hwan Bae
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-08-17
Filing date: 1990-08-17
Publication date: 1991-04-03
Also published as: KR910004981A; DE4025913A1; JPH0396739A; GB9018121D0; KR910009539B1

Abstract

A high speed rotating shaft supporting apparatus comprises a plurality of rotating bodies 2 having larger radiuses than that of the shaft 1 to support the shaft from at least two points. The contact may be plain (Fig 1) or gear-mesh (Fig 6), and the rotating bodies may drive the shaft or be driven by it. The apparatus allows the shaft to be rotated at above 100,000 r.p.m. <IMAGE>

Description

A HIGH SPEED ROTATING SHAFT SUPPORTING APPARATUS

FIELD OF THE INVENTION

The present invention relates to a high speed rotating shaft a) supporting apparatus, and more specifically to a novel high speed rotating shaft supporting apparatus i..Iiit--h can effectively support a high speed rotating shaft of revolutions of 100,000 RPM or more with usual mechanical components. 10 Prior Art

In various machines or mechanisms, a shaft which generates a rotational force is, in general, stably installed and supported by fixing and maintaining the position of the shaft with a plurality of bearing members and with shaft supports surrounding and supporting the bearing members, and the higher the revolutions of the shaft becomes, the larger resisting force and higher accurac... the shaft supporting apparatus requires, and in particualr, it is extremely difficult to support the support with the 20 usual shaft supporting means due to the enormous mechanical friction and frictional heat denerated in lhe shaft supports in case of the high speed rotating shafl of 30,000 RPM biizi more.

(2) In the case where such super high speed rotating shaft is needed, there is a problem of requiring the high technology and a large amount of expense because the shaft is supported with bearing elements which is super-precision fabricated from a material which is given a high strength and a high resisting 'force through the high technology alloy treatment a C nd heat treatment, and because the shaft is installed through a extremely complicated shaft support assembly and a lubricating mechanism related with the shaft and furthermijre, when the revolutions of the shaft exceeds a limit it is very dif f icul 11 Lo obtain the intended. super high" speed rotat -inz-,y -0 shaft because -1t is almost impossible to support the shaft.

The prior arts related with the present inverition are the arts disclosed in the United States Patent No.3,747,998, No.4,514,099 and No.4,521,121.

LS The Patent No.3,747,998 which was issued on July 24, 19713 relates to a high speed magnetic shaft bearing having a preferred wear-resistance and a dampink capability applicable to a high speed shaft, such as in electric motors and centrifuges. The patent No.4,514,099 which was issued on April 30 1985 relates to hydrodynamic bearing assembly utilizing a li,,.,drauli-c The Patent No-12,5211,121 which was 'Issued on June 4, 1985 relates pressure. 1 to an air bearing which retains a shaft without the shaft being contacted with a housing which support the shaft utilizing a compressed air. However, all the arts disclosed in the above mentioned Patents require expensive and complicated apparatus and related facilities for supply of the ma- 1dnetic force the hydraulic pressure or the air pressure necessary f..-)r supporting a a shaft.

3 The present invention is based. on the above described background, and provides for a super high speed rotating shaft to be supported effectively at low expense. This super high speed bearing is superior to the prior art and exceeds the limit of the rotational speed of the shaft which was obtainable previously.

Accordingly, the invention proposes a high speed bearing characterized in that a rotating shaft, especially a high speed rotating shaft, is supported by a plurality of rotating bodies having a larger radius than that of said shaft and driven in a direction such as to reduce the friction between the shaft and the rotating bodies.

is The enbodiments of the present invention with which the above described object can be accomplished effectively will be described in detail with reference to the accompanying drawings.

Fig. 1 illustrates the basic principle of the apparatus according to the present invention.

Fig. 2 shows an exploded perspective view of the shaft supporting apparatus of an embodiment of the present invention and a shaft supported by the apparatus.

(4) Fig. 3 shows a section view of the apparatus of Fig.2 in combined condition.

Fig. 4 shows a section view taken along the line A-A of Fig. 3.

Fig. 5 shows a section view of a possible revision of the above said embodiment.

Fig. 6 shows a partial perspective view of the shaft supporting apparatus of another embodiment of the present invention and a shaft supported by the apparatus.

Fig. 7 shows a section view of the apparatus of Fig. 6 installed condition.

Fig. 8 shows a section view taken along the line B-B of Fig.7.

Fig. 9 shows a section view of a possible revision of the embodiment of Fig. 6 to Fir.8.

Above all, the basic principle of supporting the shaft in the shaft supporting apparatus of the present invention is, as shown in Fi. 1, to support a rotating shaft (1), especially a high speed rotaltincr shaft, between a plurality of rotating bodies (2) each of which has a lar-rer.

m radius than that of the shaft (1) and is operated in the direction of decrease in the friction at the contact portion with the shaft(l). The ideal operating condition of the rotating bodies (2) according to the shaft supporting principle is the condition in.which the circumferential speed of. the bodies (2) is same as that of the shaft- (1), whereby the shaft (1) (5) can be rotated with high speed ideally almost without causing the mechanical friction with the rotating bodies (2) supporting the shaft (1).

However, in actual application a certain amount of slips in rotation can be' :caused between the shaft (1) and the rotating bodies (2), and in any case including such case the frictional coefficient of the contact portion between the high speed rotating shaft (1) and the rotating bodies (2) supporting the shaft (1) becomes lower than the allowable frictional coefficient. Herein the terminology " the allowable frictional coefficient" refers to the maximum frictional coefficient within the range in which the rotating bodies (2) mounted as above to support the shaft (1) are not destroyed during the rotation of the shaft (1).

When the shaft (1) is rotated, the rotating bodies (2) having the larger radius than the shaft (1) rotate with substantially low speed ( for example, corresponding to the 1/10 of the rotational speed of the shaft (1) compared with that of the shaft (1), therefore, the support of the rotating bodies (2) can be effected with the usual bearing supports. Consequently, the h.igh speed rotating shaft (1) can be supported suitably almost without the mechanical friction by the rotational bodies (2) which can be mounted easily and cheaply with the usual means, whereby the shaft (1) can be rotated smoothly with high speed.

The rotating bodies (2) described above may have various forms such as a circular disk, a cylinder or a sphere, in actual application the circular disk type is preferable in consideration of all the installation conditions.

The type of the contact between the rotating bodies (2) and the shaft may be a simple contact or a gear-mesh type.

(6) The rotation of the rotating bodies (2) is effected by the rotational force of the shaft (1) supported by the rotating bodies (2), and when considering the decrease of the rotational load, it is preferable to rotate the rotating bodies (2) in a way described above with a separate power source.

Optionally, the contact portion of the rotating bodies (2) in contact the shaft 111) may be suitably reinforced. Also optionally, either any one or all of the rotating bodies (2) may be composed of a construction of a belt type or of a chain type.

0 The Fi.;.2 which shows an exploded view and the Fid.' which shows m ', U a section view of the apparatus of the Fig.2 in combined condition show a preferred embodiment of the shaft supporting apparatus well suited to the object of the present invention, in which embodiment the shaft supporting -apparatus is constructed so as that a certain rotating shaft is to be supported at three points by three suitable rotating bodies.

Describing the embodiment in more detail, a rotating shaf t (100) is supported at two places along its axis, at one place the shaft 0 (100) being supported between three identical rotating bodies (201, 202, 203) and at the other place the shaft (100) beind. supported between another three identical rotating bodies (201', 202', 203% where the respective rotating body is mounted on a shaft (5, 6, 7) between two frames (3, 4) in a such way that the circumferential surface of the respective rotating body is in surface contact with the rotating shaft (100) so as not to slipabout (7) the rotating shaft (100) and to rotate simultaneously together with the shaft (100). It is to be noted that the rotating bodies have the identical sized circular disk forms. Among the shafts (5, 6, 7), the shaft (7) having the rotating bodies (203, 203') is a driving shaft supported by the conventional bearing means between the frames (3,4) and the other shafts (5, 6) each of which having. the rotating bodies (201, 201') or the rotating bodies (202, 202') are the fixed shaft where the respective rotatin.a bodies are supported by the bearing means to be rotated freely on their shafts respectively.

In some cases, the rotating bodies (201, 201',202, 202') may be fixed on the shafts (5,6) which, in turn, may be supported by the bearing means to be rotated freely between the frames (3, 4). On the driving shaft (7) two gears (83 9) in addition to the rotating bodies (203, 203') are mounted to rotate in a body with the shaft (7). The gear (8) on the shaft (7) is is engaged with -the gear(10) on the rotating shaft (100). And the other gear.0) on the same shaft (7) is, on one hand, mounted so as to rotate a gear (12),..being mounted so as to rotate in a body with the rotating bodies (201, 201') on the shaft (5), in the same direction as the gear (9) through an idle gear (11) engaged with one side of the gear (9), and on the other hand, the above gear (9) is mounted so as to rotate the gear (14), being, mounted a so as to rotate in a body with the rotating bodies (202, 202') on the shaft (6), also in the same direction as the gear (9) through another idle gear (13) engaged with the other side of the gear (9).

In this installation condition in the above embodiment, when the driving shaft (7) rotates on its axis, the gears (8,9) and the rotating bodies (203, 203') aounted on the shaft (7) rotate together in a body then the gear (8) rotates the shaft (100) at a certain speed through the gear (10 on the rotating shaft (100) which gear (10) is engaged with the gear (8 and at the same time the other gear (9) rotates the gears (12, 14) in the same direction as the gears (9) through the idle gears (11, 13) engaged with the gears (9), then the rotating bodies (201, 20V) and the rotating bodies (202, 202') rotating in a body respectively with the gears (12, 14) rotate at the same speed and in the same direction as the rotating bodies (203, 20V) on the driving shaft (7), and consequently the rotating shaft (100) is maintained stably at two places respectively by the rotating bodies (201, 202, 2033) and the rotating bodies (201', 202', 9-03' rotating at the same speed and in the same direction as described above and rotates with high speed at its place.

Therefore, the rotating shaft (100) is supported between the plurality of the rotating bodies((201, 202, 203) and (202', 202' 203')) rotating at the same speed and in the same direction to rotate without slip together with the rotating bodies (201, 202, 203, 20V,202', 203% whereby the shaft (100) is supported fir"mly and optimally without the mechanical friction which can be seen in the conventional shaft supporting means, and by this shaft supporting apparatus according to the present invention, the rotat-Ing shaft (100) can rotate without difficulty with a exceedingly high speed going beyond the limit of the rotational speed of the shaft that can be obtained throueh the conventional shaft supporting means.

(9) Fig. 4 is the section view taken through the line A-A of the Fig. 3, and it illustrates wore clearly that the shaft supporting apparatus of the above embodiment conforms well to the principle of the present invention. On the other hand, in the above described embodiment, the axial movement of the rotating shaft (100) is effectively prevented by the means of a recess (15) provided to a place of the shaft (100) and a circular plate shaped stopper (16) provided to the corresponding place of the driving shaft (7), with the edge of the stopper '16) being inserted into the recess 1115), this means of the preventing the axial movement of the shaft (100) can take other convention forms according to the necessity in the design.

For example, the stopper can take the form of a stopper projected from a casing or a protecting wall surrounding the above described shaft supporting apparatus. A conventional starting pulley (17) is mounted on the extension of the driving shaft (7) outside of the frame (3), and this pulley (17) may have a proper buffer construction for relievin,g the shock at the starting or the stopping, this buffer construction being of conventional type having no necessity of description. If necessary in the design, the shaft (5,6) can be the driving shaft.

The Fig. 5 shows a possible modified embodiment of the shaft supporting apparatus of the above described embodiment, this being the case where the rotating shaft is the shaft of the various motor. Describing this in more detail, the cas-ings (20, 21) are provided to the outsides of the frame's (18, 19) to surround and seal the both outer extensions of the (10) rotor shaft (110) being extended to the outsides of those frames (18, 19), and the extensions of the rotator shaft (110) are respectively supported in the each casings (20, 21) by three rotating bodies (211, 212, 213) an d three rotating bodies (211', 212', 213') of freely rotating circular disk.

The above rotating bodies are bearing bodies are bearing supported each in idle condition on the fixed shaft (22, 23, 24) and the f ixed shaft (22', 2V, 24') which are mounted between the frames (18, 19) and the casing (20, 21) at the each rotation center of the rotating bodies, and the crear (25, 26, 27) and the gear (25', 26', 27' 11 are mounted on the f ixed shaf ts, each gears being rotating in a body with the rotating bodies on the same shaft, 0 and the gear (25, 26, 27) in one casing (20) is engaged with the gear (28 0 0 on the one extension of the rotor shaft (110), and at the same time the gear (25', 26', 27') in the other casing (21) is engaged with the gear (28') on the other extension of the rotor shaft (110). A circular plate is shapped stopper (29) is attached on one side of the gear (27') on one fixed -shaft (here the fixed shaft (24'))amon.,, the above fixed shafts, and the edge.,.of the stopper (29) is inserted in a circular groove (30) provided to one place of the rotor shaft (110) so as to prevent the axial movement of the rotor shaft (110). If necessafy, the inner space surrounded with the said frames (18) (19) and the casings (20) (21) may be filled with preferable lubricating oil and ring grooves (31) (32) or bushing (33) with such ring grooves may be formed at the penetrating parts of said rotor shaft (110) to the frames (18, 19) and the casings (20), (21) b e i ng provided with, ordinary seal ring to prevent the leakade of the lubricating oil. The reference number 34 in the drawings shows an conventional rotor fixed on said rotor shaft (110). According to the condition of installation in the above modified embodiment, the gears (25) (26) (27) and the gears (25') (26) (27') encraged respectively with the gears (28) (28) on said rotor shaft (110) rotate simultaneously in the same direction as the rotor shaft (110) rotates, and then the rotating bodies (211) (212) 0 (213) and the rotating bodies (211') (212') (213') which are concentric and in a body respective.ly with these gears rotate in the same direction likewise, therefore as Lhe rotor shaft (110) rotates simultaneously without any slip together with those rotating bodies being holded firmly from three directions by the rotating bodies (211) (212) (213) and (211') (212') (213% the shaft (110) can be supported to rotate stably with almost no mechanical friction and so it can get an extremely high speed of rotation which may not be available so far by the conventional shaft supporting means. In this specification, although said rotating bodies (211) (212) (213) (211') (212') (213') are set up under condition that they rotate by means o f the transmitted rotational force of the rotor shaft(110) through the engaged relations among gears (25') (26') (27') and gear (28'), said rotating bodies can be installed, if desired, so as to rotate with a cetain predetermined speed and direction of rotation through another power source, and the latter is more preferable from a point of view according to the invention.

3 Meanwhile, if the rotor shaft (110) said above is in vertical, a support cap (35) can be set up properly to the outside of the easing (21) in bottom part considering the weights of said rotor shaft (110) in axial direction so that lower end of the rotor shaf t ( 110) can be held up properly in the (12) support cap (35). Preferably, in the center part of said support cap (35) a support device (36) having the hole (36a) and the flow path (36b) may be provided, and a- plurality of washer (37) having the hole (37a) at it's center may be inserted being overlapped together in the hole (36a) of said support device (36), these washers (37) being constructed so as to support the lower end of said vertical rotor shaft (110) properly, and if necessary, the inside of the support cap (35) being filled with some lubricating oil.

All the embodiments described above show that a rotatin,.- shaft to be supported is held by three identical rotatin,g bodies from three direction in shaft support.

F i g. 6 and Fig. 7 show another selective embodiment of said shaft supporting apparatus according to the present invention, and these figures show that a rotating shaft (120) to be supported is supported at two places by two preferable rotating bodies (221) (222) and rotating (221') (222') at each place. The rotating bodies (221) (222) and the rotating bodies (221') MV) in this example consist of spur gear type and each of these rotating bodies is engaged with that of gear (or gear part) (38) (38') on the rotating shaft (120) simultaneously and the idle gears (39) (39,) are engaged respectively with the rotating bodies (221) (222) and the rotating bodies (29-1') (222 in each shaf t supporting po-int.

Respectively, the rotating , body (221) and (221') and the rotating body (222) and (222% and idle gear (39) and (39') rotate concentrically with each other and these gears are mounted on the installed shafts (42) (431) (44) supported the frames (40), (41) located on both sides olir that rotating (13) shaft (120).

In the illustrated embodiment, one shaft among said shafts (42) (43) (44 for example, shaft (43) having rot4ting bodies (222) (222') is a driving shaft which is installed through the ordinary bearing members between frames (40) (41), and the shafts (42) (44) which have the other rotating bodies (221) (221') and idle gear (39) (399 respectively are fixed shafts supporting the rotating bodies (221,221') and the idle gears (39, 39') with the ordinary bearing members.

If desired, each of the rotating bodies (221) (221') and the idle gears (39) (39') may be fixed on the shafts (42) (44), and in this case in these shafts may be mounted on the frames (40), (41) rotatably.

The driving shaft (43) may be provided with an ordinary starting pulle (45).

In operation of said embodiment, as the driving shaft -(43) rotates, rotating (222) (222') fixed on this' shaft rotate at the speed of the shaft (43), and rotation force of these rotating bodies (222) (222') is transmitted to the rotating bodies (221) (221') of opposite side through the idle gears (39) (39') making these rotating bodies (221) (221') rotate at same speed and in the same direction with said rotating body (222) (222% and 6onsequently the rotating shaft (120) is ideally supported to rotate with high speed through the rotating bodies (221) (222) and rotating bodies (221') (222') which rotate at same speed and in the same direction simultaneously, and such mechanical friction as can be seen in ordinary shaft supporting means is hardly incorporated.

(14) Fig. 8, the cross sectional view taken along the line B-B of Fig. 7, shows well that this embodiment also corresponds with the principle of theshaft support of the present invention.

Meanwhile, in said embodiment, axial movement of the rotating shaft (120) is prevented by means of a recess (46) provided on a place of said shaft (120) and by a circular plate shaped stopper (47) provided on said driving shaft (43) with the edge of the stopper (47) being inserted into the recess(46), in a similar way as the embodiment shown in Fig. 2 to Fig. 5 the shaft (42) or the shaft (44) can be the driving shaft according to the necessity of design.

Fig.9 shows another possible embodiment modified from the embodiment shown in Fig.6 to Fid. 8, and in this embodiment, the present shaft supporting z 0 apparatus is applied to installation of the rotor shaft of the various motor similar to the case of Fig. 5.

Describing in more detail, a motor (48) is installed and supported so as to be lotated at the center of the inside of the casing (49), and both extension of said motor shaft (130) in the casing '149) is supported between two rotating bodie's (231) (232) and two rotating bodies (231') (232') respectively which are installed to be free "ctat-iti-,,r on the shaft 1, 50) (51) mounted across the inner part of easing (49). All the said rotating bodies (231) (232) and rotating bodies (231') (23.2') are contacted with said motor shaf.l 0J.30) in gear engagement, and the crear (52) is endaded to the rotatin-r budies '93M232) and the other ear. (52') is encraded to the rotatind =5 Z (15) bodies (231') (232.' and these gears (52) (52'.) are installed on 4-he same shaf t (53) set up traversely in the casing (49). Any one of said shafts (50) (51) (53) may be driving shaft driven by other separate power source', and in such a case rotating bodies (231) (2311') or rotating bodies(232) (232' or gears (52) (52') are installed on the shaft so as to rotatR in a body with the shaft.

The groove (54) is formed at one point on the motor shaft (130) aad the 1 circular plate shaped stopper (55) is installed at one side of rotating bodies (232) (232') in such a way that the edge, of the stopper (35) being inserted in said groove (54), and these groove (54) and stopper (5,5) mears prevent properly the axial movement of said motor shaft (1RO) as seen in above-mentioned embodiments. in operation, for example, if said rotating bodies (231) (232) (231') (232') are installed so as to be rotated is preferably in the rotation spmed and direction established by some external power sourcel all the rotating bodies (231) (232) and rotating bodies (231') (232') rotate simultaneously in the same speed and direction due to the.' engaged relation with gears (52) (52'1 as seen in operation of aforesaid embodiments, furthermore, rot ating under the condition that circumferential speed of every rotating body (231) (232) (231') (232') and motor shaft (130) coincide idntically, the motor shaft (130) can be rotated with high speed hardly with incorporation of mechanical friction between the rotating bodies (231) (232) and (231') (232% and without any difficulty at super high speed of rotation which can not be seen so far.

Meanwhile, as seen in the embodiments shown in Fig6-9, when the shaftsupport rotating bodies are particularly made up in the type of gear and (16) these rotation bodies are contacted with the shaft in the gear engagement the grooves (46) (54) and the stopper (47) (55) means said above can be eliminated provided that gear part of shaft engaging with said gear-type rotating bodies in recessed from the other surface of the shaft, because this can prevent the axial movement of the shaft.

As illustrated above in detail, the present invention is a novel and very useful shaft supporting apparatus that provides an excellent advantage of being able to support the super high speed rotating slia.Ft 0 effectively with low expense and with the usual mechanical components which can be mounted and provided with ease.

Although this invention has been described in its preferred forms, it must be understood that another changes and modifications can be made without departing from the spirit and the scope of the present invention by those of skilled in this art.

M 17

Claims

1. A high speed bearing characterized in that a rotating shaft. especially a high speed rotating shaft, is supported by a plurality of rotating bodies having a larger radius than that of said shaft and driven in a direction such as to reduce the friction between the shaft and the rotating bodies.

io

2. A bearing according to Claim 1 comprising three rotating bodies which are disc-shaped and which support the shaft in three radial directions in a common plane.

3. A bearing according to Claim 1 comprising two rotating bodies which are gear-like and which contact with the shaft in gear engagement in two directions in a common plane.

4. A bearing according to Claim 1, 2 or 3 characterized in that said rotating bodies are rotated by the rotational force of said rotating shaft.

5. A bearing according to Claim 1, 2 or 3 characterized in that said rotating bodies are rotated by an external power source.

6. A bearing according to Claim 1, characterized in that one or more of said rotating bodies has the form of a moving belt.

7. A bearing according to Claim 1, characterized by provision of means which prevent axial movement of the shaft.

18

8. A bearing according to Claim 7, characterized in that said means for preventing the axial movement of said shaft consists of a circumferential recess on said shaft and of a a stopper which engages in the recess.

9. A bearing according to Claim 7 characterized in that said means for preventing the axial movement of said shaft consists of a circumferential on said shaft with which said rotating bodies engage.

10. A high speed bearing substantially as herein described with reference to Figs. 1 to 4, or Fig 5, or Figs 6 to 8, or Fig 9 of the accompanying drawings.

Published 1991 atme patent ofrwe. State House. 66171 High Holborn Undon WC1R 41P. Further copies rnay be obtained from Sales Branch. Unit Q Nine Mile Point CIinfach. Cross K". Newport. N PI 7HZ, Printed by Multiplex techniques lid. St Mary Cray. Kent.