DE2502793A1 - GEAR MACHINE (PUMP OR MOTOR) - Google Patents

Description

R, ^{2 5} 29 '

8th*. January 1975 Wd / We

Attachment to

Patent and

Utility model registration

ROBERT BOSCH GIvIBH, S ¹ I ¹ U ¹ X ¹ TU-ARO! Gear machine (Punrae or motor)

The invention "relates to a gear machine (pump or motor) with shaft journals mounted in bores of bearing bodies on which By utilizing a negative pressure, a forced lubrication and cooling starting from the 4-way suction side is achieved:

In such a "known gear machine" the suction pressure the opening tooth gaps "used a forced circulation lubrication to create. This is done via recesses on both bearing body end faces, holes in the bearing bodies and Ring grooves on the shaft bores a steady flow of liquid the suction side along the shaft journal back to the suction side.

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It has now been shown that the negative pressure created in the tooth gaps is insufficient for effective lubrication and cooling to generate the shaft journal.

It is an object of the invention to provide a gear machine as described in the opening paragraph mentioned type, whose shaft journals are particularly well cooled and lubricated.

This is achieved according to the invention in that on each bearing body end face facing the gear wheels and the suction chamber adjacent in the area of the tooth gaps a self-contained recess is formed, from which a channel to the rear The end of the bore leads and that a channel is also formed in or near each bearing body end face facing the gears which leads from the suction chamber to the bore and opens into it.

In this way, the centrifugal pressure that occurs when rotating adjusts the tooth gaps in the liquid filling and its size to the square of the angular velocity and the respective BAhnhalbmec-ser dee gear is proportional, as a pressure gradient used to flush the bearings lengthways.

Particularly expedient refinements of the invention result from the subclaims, the description and the drawing.

An embodiment of the invention is shown in the drawing. This shows in

1 shows a cross section through a gear pump; FIG. 2 shows a section along II-II according to FIG. 1.

The gear pump (it can also be a gear motor) has a Housing 10, in which two intersecting longitudinal bores 11 and 12 are formed. This results in a housing interior

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the cross-sectional shape of a figure eight. The housing 10 is on both sides closed by cover 13, H ".

In the bore 12 two bearing bushes 15, 16 are pressed in Bushings 15 ', 16' arranged, the one side a flat have and in the bores 18, 19, the shaft 20 of a gear is arranged. The gear is practically free of backlash between the "both sockets 15, 16.

In the bore 11 two sockets 22, 23 are also pressed in Bushings 22 ', 23' arranged, in their bores 24, 25, the shaft 26 of a gear (not shown) is arranged. This is also practically free of play between the sockets. These also have flats 27 which bear against the flats 17 of the sockets 15, 16.

In the intersection of the longitudinal bores 11, 12 penetrates from a bore 28 on one side of the housing, and on the opposite side Side axis =; slightly to this one hole 29. The latter is referred to below as the suction chamber. These holes open into Height of the gears in the housing interior. ;

On the side facing the side surface of the gear 21 Plaehseite the bush 15 and the bore 29 is adjacent in the diameter range the tooth gaps, i.e. close to the diameter of the root circle D a self-contained recess 30 is formed, which has approximately the shape of a longitudinal slot. As can be seen from FIG. 1 is, the inner edge of this recess is still a small distance from the root diameter D. From the recess 30 extends a bushing 15 penetrating bore 31 to cover-side end of the bore 24 and opens into an "annular groove 32, which is formed by the recessed bearing bushing and the bevel 33 at the 3 end of the shaft journal. Also on the gear wheel side An annular groove 34 is formed at the end of the shaft journal, and by the fact that the bushing 15 'does not go all the way to the gear' ' enough, so / ie by a slight rounding at the transition from the shaft journal 20 to gear 21. The two annular grooves 32, 34 are through a groove 35 connected to one another in the liner. ''

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Exactly the same arrangements, i. H. slot-like recess, Longitudinal bore and annular grooves are on the other bearing bodies or running book f .; en and shaft journals so that these arrangements are no longer referred to as Bind.

In the flat side of the bearing body 22 facing the gear wheel side surface, a relatively deep hat 36 is also formed, which extends from the bore 29 to the annular groove 34 and opens into the bore 29. Such grooves are also formed on the other bearing bodies and are not designated any further.

If the gears are driven in the direction of the arrow, so fill they are at the suction chamber, d. H. at the bore 29, with hydraulic fluid and convey it along the longitudinal bores 11, 12 to the bore 28, which forms the high-pressure side of the pump.

In the tooth gaps passing by the bore 29 at high speed, a negative pressure, the so-called centrifugal pressure, is created by the effect of the force of the force - whereby a lower pressure is created in the recess 30 than is prevailing in the bore 29, as a result of the bore 29 via the groove 36 " Liquid into the annular groove 32 and then via the bore 31 to the recess 36 ″. promoted. The pressure gradient between the bore 29 and the recess 30 is proportional to the square of the angular velocity and the respective radius of the gears, and this pressure gradient is used for longitudinal flushing, ie cooling and lubrication of the bearing.

The pressure difference between the bore 29 and the recess 30 results in

^p _z = ^(r k ² '- v> - ^ ² -4-

where r _fc = tip circle 0, τ ^ = mean radius of recess 30, Co = angular velocity and S = density of the liquid. If the flow resistances are kept small, it arises

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a sufficiently strong flow of liquid. The flow device can also be reversed by changing the

Bore 29 with the backs of the sockets 15, 16 * and the recess 30 is connected to the front of these sockets. Instead of the hat 36 can also be a radial. .Bore provided.

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Claims (5)

- ft - -G. Ansürüch-e 2 5 2 a / Ί .J Gear machine (pump or motor) with in bores of bearing bodies mounted shaft journals, on which, by taking advantage of an underpressure, a force emanating from the suction side is forced Lubrication and cooling is achieved, characterized in that on each of the bearing body end face facing the gear wheels (21) (15, 16; 22, 23) and the suction chamber 29 adjacent in the diameter range of the tooth gaps a self-contained Recess (30) is formed, from which a channel (31) leads to the rear end of the bore (19) and that in or a channel (36) is also formed near each of the bearing body end faces facing the gears, which from the suction chamber (29) leads to the bore (19) and opens into this. 2. Machine according to claim 1, characterized in that the self-contained recess (30) closer to the root diameter (D) than the tip diameter of the gears. 3. Machine according to claim 1 and / or 2, characterized in that the recess (30) is designed as an elongated hat and that the channel (36) proceeding from this is a bore that penetrates the bearing body (15). 4. Machine according to one of claims 1 to 3, characterized in that annular grooves (32, 34-) are formed at both ends of the bores, which are connected to one another via a groove (35) formed in the bore, and that the at the gear side 609 83 1/0105 250279J _ 7 _. ·. ■ ".. ^{2 ί> 2α} Ring groove (34) bordering the surface with the one leading to the suction chamber (29) Recess (36) is connected. 5. Machine according to one of claims T to 4, characterized in that dai? the channel (36) is closer to the: i-atrium (29) than the self-contained recess (30). / 609831/0105 Blank page