CN2050097U - Gear hydraulic pump - Google Patents

Abstract

The utility model relates to a positive displacement hydraulic pump, in particular to a gear hydraulic pump. The utility model comprises a pump body, a couple of meshed gears in the pump body, a propeller shaft and a shaft bearing, end covers installed on the both ends of the couple of the meshed gears and a compensating groove on the end covers. Because the shape, the dimension and the position of the compensating groove are newly designed, the gear hydraulic pump of the utility model has the characteristics of easy processing, low cost, long lifetime, high ability to solve or eliminate the oil phenomenon, etc. At the same time, the gear hydraulic pump can move in both directions, so that the gear hydraulic pump can be generally used with an oil motor. The utility model is a gear hydraulic pump with multiple functions.

Description

Gear hydraulic pump

The utility model belongs to volume-type hydraulic pump, especially the gear hydraulic pump.

At present, in various types of volume-type hydraulic pumps, therefore the gear hydraulic pump extensively is used in pressure not high (25 * 10 because it is simple in structure, in light weight, cost is low, reliable operation, easy to maintenance ⁵Below) hydraulic system in, as science tech publishing house in " metal-cutting machine tool hydraulic transmission " book of publishing in 1985 the 61st page the gear hydraulic pump has been done introduction, it is by the pump housing and be installed in a pair of gear and transmission shaft thereof in the pump housing, bearing, and the end cap that is installed in the gear both ends of the surface is formed, though this gear hydraulic pump has above-mentioned advantage, but since the gear hydraulic pump require can continuous oil supply, therefore require the overlap coefficient (ε) of gear engagement greater than 1, that is to say that requirement is before a pair of teeth are about to throw off, the engagement that is about to begin of a pair of teeth of back, in this short time, engagement just has two pairs of teeth simultaneously, at this moment the fluid of staying between cog is just because of in the enclosed cavity that forms two pairs of teeth, when gear continues rotation, this cavity volume reduces gradually, trapped fluid is subjected to push by force, pressure sharply rises, make gear and bearing be subjected to very big radial force, so-called entrap phenomenon that Here it is, it directly influences the stable working and the life-span of gear hydraulic pump, the way that present stage solves is that gear hydraulic pump two side ends covers the compensating grooves that mill two elimination entrap phenomena, size between compensating groove should guarantee that the pocketed oil space is communicated with pumping cavity before arriving minimum position, be communicated with oil sucting cavity after having crossed minimum position, but this size can not be too small,, pumping cavity and oil sucting cavity cause leakage otherwise being communicated with, volumetric efficiency is reduced, therefore this size is difficult for accurately control, and then makes entrap phenomenon can not get thorough solution.The compensating groove of this gear hydraulic pump is asymmetric layout in addition, and gear can only directed (promptly unidirectional) move, so usability is relatively low.

The utility model has been done improvement at the problem that prior art exists, the gear hydraulic pump that provide a kind of easy manufacturing, cost is low, the life-span is long, can two-way (positive and negative both direction) moves.

The utility model is realized by following manner: a kind of gear hydraulic pump, comprise the pump housing and be installed in gear and the transmission shaft and the bearing of pair of meshing in the pump housing, and be installed in respectively one meshed gears both ends of the surface end cap and on compensating groove, the utility model is that above-mentioned said compensating groove is arranged in the gear of pair of meshing on any gear, soon be arranged on originally on the flank of tooth of any gear in the gear that compensating groove on the end cap is arranged on pair of meshing, corresponding compensating groove is made up of full-depth tooth full-depth tooth face compensating groove and addendum surface compensating groove, and wherein the gear of pair of meshing is meant gear I and gear II.

Said full-depth tooth face compensating groove and addendum surface compensating groove can be arranged on the different flank of tooth of same gear and be staggered along the top circle surface, and said here same gear can be the gear I, also gear II; Another kind of situation is, full-depth tooth face compensating groove and addendum surface compensating groove also can be arranged on the corresponding flanks on the different gears, be that full-depth tooth face compensating groove is when being arranged on the gear I, the addendum surface compensating groove then is arranged on the gear II, perhaps the two opposite setting, but the two must be arranged on the flank of tooth of the same side in the different gears in the gear sectional view of pair of meshing, wherein full-depth tooth face compensating groove is to offer tooth top from tooth root, the addendum surface compensating groove is to offer tooth top at the first half of the flank of tooth, and two groove depth maximums must not surpass half of addendum width size.The said flank of tooth first half of this fruit is meant the radius size of starting point of addendum surface compensating groove in the segment distance of tooth top, and the radius of the starting point of addendum surface compensating groove or the root that deserves to be called flank of tooth compensating groove are through (r ¹) then obtain (with reference to Fig. 4) promptly through digital calculation by Principles of Gear Connection:

r ¹＝O ₂B ₂

＝ $\sqrt{\mathrm{(N}{}_{2}B{}_2){}^2{\mathrm{+(N}}_{2}O{}_2){}^2}$

＝ $\sqrt{\mathrm{(rb}{}_2\mathrm{·tg\alpha +rb}{}_1\mathrm{·tg\alpha -rb}{}_1\mathrm{·tg\alpha }{}_{\mathrm{a1}}\mathrm{+pb)}{}^2{\mathrm{+rb}}_2{}^2}$

In the formula: the reference radius of rb2-gear II;

The reference radius of rb1-gear I;

α-pressure angle of graduated circle;

The top circle pressure angle of α a1-gear I;

The Pb-circular pitch.

Said full-depth tooth face compensating groove and addendum surface compensating groove, its channel section can be triangles, also can be semicircle or rectangle, see that from the situation of strength of gear with semicircle or circular arc be the best.

Its working procedure is: the flank of tooth of the gear of the pump housing and interior pair of meshing thereof and end cap form the working space of sealing, when the gear worker rotates or gear II when rotating in the counterclockwise direction along clockwise direction, the teeth on right side are separated gradually, form partial vacuum, and oil suction outside pump; The teeth in left side mesh gradually, and working space reduces gradually, and the cavity of between cog reduces gradually, fluid is extruded the pump housing, will produce entrap phenomenon usually in this process, because the utility model has compensating groove on the flank of tooth of gear, thereby entrap phenomenon is solved, and the concrete practice is; The flank engagement line that the setting of full-depth tooth face compensating groove and addendum surface compensating groove should make two pairs of engagement teeth form in the envelope chamber has only one to be continuous, when pair of engaged gears turned to a certain position (as the position of Fig. 2), original two enclosed cavities were linked up by oil sucting cavity, the pumping cavity offering full-depth tooth face compensating groove and make itself and pump; When pair of engaged gears continued rotation another location (as the position of individual Fig. 3), two enclosed cavities communicated by the full-depth tooth face compensating groove of offering, and linked up by the pumping cavity (or oil sucting cavity) of offering addendum surface compensating groove and pump simultaneously; And when having only the engagement of teeth, full-depth tooth face compensating groove will make enclosed cavity or pumping cavity link up.The situation of the communication of above-mentioned several enclosed cavity and pumping cavity (or oil sucting cavity) all will make enclosed cavity because the fluid that variation had more of volume obtains discharging, and the fluid that can go out is compensated, and has therefore solved entrap phenomenon well.

The utility model compared with prior art has easy processing, and cost is low, and the life-span is long, solves or eliminate the characteristics such as degree height of entrap phenomenon, and this gear liquid formula pump can two-way (positive and negative both direction) move simultaneously, like this can be general with oil motor.

Fig. 1 is an overall erection drawing of the present utility model.

Fig. 2 is the work schematic representation of pair of engaged gears of the present utility model when turning to a certain position.

Fig. 3 is the work schematic representation of pair of engaged gears of the present utility model when turning to the another location.

Fig. 4 be the root of addendum surface compensating groove of the present utility model when directly calculating the various sizes parameter concern schematic representation.

Fig. 5, Fig. 6 are first kind of section configuration schematic representation of full-depth tooth face compensating groove of the present utility model, addendum surface compensating groove.

Fig. 7, Fig. 8 are second kind of section configuration schematic representation of the utility model full-depth tooth face compensating groove, addendum surface compensating groove.

Fig. 9, Figure 10 are the third cross-sectional configuration schematic representation of the utility model full-depth tooth face compensating groove, addendum surface compensating groove.

Among the figure: 1 left end cap, 2 bearings, 3 pump housings, 4 right end caps, 5 transmission shafts, 6 gear I, 7 gear II, 8 full-depth tooth face compensating grooves, 9 addendum surface compensating grooves.

Most preferred embodiment of the present utility model is shown in Fig. 1-10.A kind of gear liquid formula pump, comprise the pump housing (3) and be installed in the gear (6 of the interior pair of meshing of the pump housing (3), 7) and transmission shaft (5) and bearing (2), and the gear (6 that is installed in pair of meshing, 7) end cap (1 of both ends of the surface, 4) and on compensating groove, the utility model is the gear (6 that above-mentioned said compensating groove is arranged on pair of meshing, 7) on any gear in (6 or 7), soon be arranged on end cap (1 originally, 4) compensating groove on is arranged on the gear (6 of pair of meshing, on the flank of tooth of any gear 7) (6 or 7), corresponding compensating groove is made up of full-depth tooth face compensating groove (8) and addendum surface compensating groove (9), and its a pair of meshed gears is meant gear I (6) and gear II (7).

Said full-depth tooth face compensating groove (8) and addendum surface compensating groove (9) can be arranged on the different flank of tooth of same gear (6 or 7) and be staggered along the top circle surface, here said same gear can be gear I (6), also can be gear II (7); Another kind of situation is, full-depth tooth face compensating groove (8) also can be separately positioned on the corresponding flanks of different gears with addendum surface compensating groove (9), be that full-depth tooth face compensating groove (8) is when being arranged on gear I (6) and going up, addendum surface compensating groove (9) then is arranged on the gear II (7), perhaps the two opposite setting, but in pair of engaged gears (6,7) the two must be arranged on the flank of tooth of the same side in the different gears in the sectional view, wherein full-depth tooth face compensating groove (8) is to offer tooth top from tooth root, addendum surface compensating groove (9) is to offer tooth top at the first half of the flank of tooth, above-mentioned two grooves (8,9) degree of depth maximum must not surpass half of addendum width size, here the said flank of tooth first half is meant the radius size of starting point of addendum surface compensating groove (9) in the segment distance of tooth top, and addendum surface compensating groove or deserve to be called the root footpath (r of flank of tooth compensating groove ¹) then obtain (with reference to Fig. 4) through mathematical computations by Principles of Gear Connection, that is:

r ¹＝O ₂B ₂

＝ $\sqrt{\mathrm{(N}{}_{2}B{}_2){}^2{\mathrm{+(N}}_{2}O{}_2){}^2}$

＝ $\sqrt{\mathrm{(rb}{}_2\mathrm{·tg\alpha +rb}{}_1\mathrm{·tg\alpha -rb}{}_1\mathrm{·tg\alpha }{}_{\mathrm{a1}}\mathrm{+pb)}{}^2{\mathrm{+rb}}_2{}^2}$

In the formula: the reference radius of rb2-gear II (7);

The reference radius of rb1-gear I (6);

α-pressure angle of graduated circle;

The top circle pressure angle of α a1-gear I (6);

The Pb-circular pitch.

Said full-depth tooth face compensating groove (8) and addendum surface compensating groove (9), its channel section can be triangle (as Fig. 5,6), also can be semicircle (as Fig. 7,8) or rectangle (as Fig. 9,10), see that from the stressed situation of gear (6,7) with semicircle or circular arc be the best.

Claims (5)

1, a kind of gear hydraulic pump, comprise the pump housing and be installed in gear and the transmission shaft and the bearing of pair of meshing in the pump housing and be installed in respectively pair of meshing the gear both ends of the surface end cap and on compensating groove, feature of the present utility model is that said compensating groove is arranged in the pair of engaged gears on any gear, soon be arranged on originally on the flank of tooth of any gear in the gear that compensating groove on the end cap is arranged on pair of meshing, corresponding compensating groove is made up of full-depth tooth face compensating groove and addendum surface compensating groove.

2, gear hydraulic pump as claimed in claim 1, it is characterized in that said full-depth tooth face compensating groove and addendum surface compensating groove can be arranged on the different flank of tooth of same gear and staggered along the top circle surface, wherein full-depth tooth face compensating groove is to offer tooth top from tooth root, and the addendum surface compensating groove is to open at the first half of the flank of tooth to throw into tooth top.The face compensating groove is to open at the first half of the flank of tooth to throw into tooth top.

3, gear hydraulic pump as claimed in claim 1, it is characterized in that said full-depth tooth face compensating groove and addendum surface compensating groove also can be arranged on the corresponding flanks on the different gears, wherein full-depth tooth face compensating groove is to offer tooth top from tooth root, and the addendum surface compensating groove is to open at the first half of the flank of tooth to throw into tooth top.

4, as the described gear hydraulic pump of claim 1-3, it is characterized in that said full-depth tooth face compensating groove and addendum surface compensating groove, its transverse section can be a triangle.

5, as the described gear hydraulic pump of claim 1-3, it is characterized in that said full-depth tooth face compensating groove and addendum surface compensating groove, its transverse section also can be semicircle or rectangle.

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