DE1914444A1 - Gear pump - Google Patents

Description

19U444

ZAHffRADFABRIK FRESDRICHSHAFEN Aktiengesellschaft
Friedrichshafen

Gear pump

The invention relates to a gear pump with pairs intermeshing gears.

Known pumps of this type are particularly useful at high speeds Affected with strong hydraulic noises, the main cause of which is insufficient filling of the suction-side delivery chambers and cavitation could be determined.

The invention provides a means of reducing such Noises.

The invention is' that in the inlet channel between the inflow opening and the suction-side conveyor chambers formed from tooth gaps and housing wall at least one guide surface is arranged, which the funding to externally toothed Deflects the wheels in a direction opposite to the direction of the centrifugal force.

A preferred embodiment of the invention relates to Gear pumps with an internally toothed ring gear, an externally toothed one Inner rotor and a housing with a sickle-shaped filler piece. According to the invention, the suction end of the FUllstückes provided with a guide surface facing the inner rotor. .

At high speed of the pump rotors with self-priming pumps, the filling of the tooth gaps of the externally toothed one is particularly important Puapenrades so difficult, since the filling against the

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19U444

force must be done. Furthermore, the eddy formation is greater with increasing speed. The result of incomplete filling The negative pressure prevailing in these chambers for the chambers of the inner rotor favors the occurrence of cavitation, which is known to lead to high levels of noise.

Gear pumps according to the invention allow operation at significantly higher maximum speeds compared to previous designs and are characterized in the upper speed range due to better volumetric efficiency and a considerable reduced noise level.

Further details of the invention can be found in the following description and the drawing, which shows two embodiments of the invention.

fig. 1 is a top plan view of one having an internal gear Ring gear provided gear pump according to the invention;

fig. 2 shows a top view of a sickle-shaped filler piece in a further embodiment.

In fig. 1, 3 is the housing of a gear pump, which is open on one side. · An internally toothed ring gear is with 1 and that with This meshing pinion gear is designated by 2. In the assembled state, the housing 3 is closed by a cover, not shown, which is on a collar 8 of the housing centered and connected to this by means of screws 7 · The Axis "0" of the pinion gear is also the central longitudinal axis of the Housing 3 and a drive shaft 12 of the Ritael gear, which « is rotatably mounted in the pump housing. The assumed direction of rotation is indicated by the arrow

In the cavity between the teeth of both pump wheels lies a sickle-shaped filler piece 4, which is old

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19UAA4

housing 3 is firmly connected. A suction chamber 5 I and a pressure chamber 6 I adjoin both ends of the filler piece in the circumferential direction. Hit 5 II is the suction kidney and 6 II is the pressure kidney, which can be cast into the housing 3. The two kidneys 5 II and 611 are facing blind kidneys of the same outline shape in the housing cover. An intake channel 5 opens into the suction chamber 5 I. An outlet channel 6 opens into the pressure chamber 6 I.

The pressure-side end 9 of the filler piece 4 can be flattened or rounded as desired, as shown. The suction side The end of the filler piece is formed by an inclined guide surface 10 facing the teeth of the inner rotor 2. These the conveying means entering through the channel 5 into the suction chamber 5 I directs the gaps between the teeth of the inner rotor against the centrifugal force closed, so that the delivery chambers 2 I formed by the filler piece and the tooth gaps of the rotor 2 are better filled. Sufficient filling of the outer delivery chambers 1 I is through the effect of centrifugal force secured.

The guide surface 10 is parallel to the longitudinal axis "0". the Guide surface is flat or curved. In special cases, the guide surface can be inclined to the pump axis "0", as in FIG 2 indicated by * the area 11. This can be the filling of the chambers 2 I favorably if the U1 sucked into the space 5 I does not flow exactly in the circumferential direction.

The end surface 10 1 is expediently the suction duct 5 II as well as the corresponding surface of the associated blind kidney ia housing cover in alignment with the guide surface 10 executed.

19 · 3.1969

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009841/0616

Claims (1)

19H4U fr Patent claims: Γ \\ Gear pump with gearwheels engaged in pairs, characterized in that at least one guide surface is arranged in the inlet channel between the inflow opening and the suction-side pumping chambers formed from tooth gaps and housing wall, which deflects the conveying means to externally toothed gears in a direction opposite to the centrifugal force and so that the filling of the externally toothed wheel or the externally toothed wheels favors. 2. Gear pump with an internally toothed ring gear, an externally toothed inner rotor and a housing with a sickle-shaped Filler piece, characterized in that the filler piece (4) has an end facing the inner rotor (2) at its suction-side end Has guide surface (10). 3. Gear pump according to claim 1, characterized in that a guide surface (11) is present which is to the axis of the Inner rotor runs inclined. 4. Gear pump according to claim 1 to 3 »characterized in that the end surface (10 I) of the suction kidney (5 II) and the corresponding end surface of the associated blind kidney arranged in correspondence with the guide surface (10) are. 19.3.1969
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