DE102009040431A1 - transmission pump - Google Patents

Abstract

A gear pump includes a drive shaft, a rotatable pump element mounted on the drive shaft, a side wall member disposed on one side of the pump element and formed with a through hole through which the drive shaft extends, and a side plate on the other Side of the pump element is arranged. The transmission pump further includes a connecting portion connecting the drive shaft to the pump member in a manner to prevent relative rotation and to permit relative axial movement between the drive shaft and the pump member. The connecting portion includes a drive recess formed in the pump member and a drive projection projecting radially outward from the drive shaft and engaging with the drive recess to prevent the relative rotation. The drive projection is arranged to limit the axial movement of the drive shaft with respect to the pump element with the side wall member or the side plate.

Description

The The present invention relates to gear pumps.

The published Japanese Patent Application No. 2007-278085 shows a gear pump in which a bearing for supporting a drive shaft is arranged to restrict an axial movement of the drive shaft. This bearing comprises an inner race, an outer race and rolling elements, which are inserted between the inner and outer race. The axial movement of the drive shaft is limited by the arrangement in which the drive shaft is attached to the inner race by means of press-fitting and the outer race is mounted in a housing such that the axial movement is prevented.

The Press fit of the inner race via the drive shaft in the above-mentioned gear pump leads to difficulties during installation. Besides, the usage leads the bearing as a means for limiting the axial movement thereto, the size of the pump at an increase in the Increase stock.

Therefore It is an object of the present invention to provide a transmission pump to provide, which is well suited for mounting and in the size is reduced.

The This object is achieved by the features of the claims 1, 12, 22 and 23 respectively. The respective subclaims disclose preferred developments of the invention.

According to one Aspect of the present invention is the axial movement of a Drive shaft with at least one drive projection, that of the drive shaft projects radially outward and with one on the drive shaft attached gearing engaged, limited.

Further Details, features and advantages of the invention will become apparent the following description of exemplary embodiments of the drawings:

1 FIG. 15 is a perspective view showing a front side of a transmission pump according to a first embodiment of the present invention. FIG.

2 is a perspective view, the rear of the gear pump of 1 shows.

3 is a front view of the gear pump of 1 ,

4 is a sectional view taken along a line A4-A4 3 ,

5 is a sectional view taken along a line A5-A5 of 3 ,

6 is an enlarged view showing a pump assembly in section of 4 shows.

7 is an enlarged view showing a pump assembly in section of 5 shows.

8th is a perspective view showing the front of an in 6 and 7 shown intermediate element shows.

9 FIG. 15 is a perspective view showing the back of the intermediate member (or sealing member). FIG.

10 is a front view of the intermediate element.

11 is a rear view of the intermediate element.

12 is a sectional view taken along a line A12-A12 in FIG 11 ,

13 is a perspective view showing the front of a first, in 6 and 7 shown, side plate element shows.

14 Fig. 16 is a perspective view showing the front side of the first side plate.

15 is a front view showing the first side plate.

16 is a rear view of the first side panel.

17 is a plan view of the first side plate.

18 is a view showing the arrangement of a first toothing and the first side plate, which in 6 and 7 are shown to explain the functions of the transmission pump according to the first embodiment.

19 FIG. 12 is a view showing the arrangement of the first teeth, the first side plate, the intermediate member (indicated by a two-dot broken line), and a holding member (indicated by a broken line). FIG.

20 is a sectional view taken along a line A20-A20 in FIG 19 ,

21 is a perspective view showing the back of a second, in 6 and 7 shown, side plate shows.

22 Fig. 16 is a perspective view showing the back side of the second side plate.

23 is a front view of the second side plate.

24 is a rear view of the second side plate.

25 is a plan view of the second side plate.

26A . 26B and 26C are schematic views for explaining the dimensions of a connecting portion about a drive shaft in the in 1 to 7 shown gear pump and to explain the relative positioning with drive pins of the connecting portion.

27 is a sectional view showing a gear pump according to a second embodiment.

28 FIG. 10 is a sectional view showing a gear pump according to a third embodiment. FIG.

29 FIG. 10 is a sectional view showing a gear pump according to a fourth embodiment. FIG.

30 is a view for explaining the functions of the gear pump of 29 ,

31 is a sectional view similar to 6 but showing a transmission pump according to another embodiment of the present invention.

1 to 26 show a gear pump according to a first embodiment of the present invention. As in 1 to 5 shown is the gear pump 1 of the first embodiment, to be used as an actuator for a brake pressure control system of a motor vehicle. The gear pump 1 in the example shown is a tandem gear pump. The gear pump 1 comprises as main components a housing 2 and a pump assembly 3 in the housing 2 is housed.

The housing 2 includes a pump chamber 4 for receiving the pump assembly 3 , In this example, the case is 2 , as in 3 shown, rectangular and has, as in 1 and 2 shown the shape of a rectangular measuring cube. Exterior surfaces of the housing 2 are with several mounting holes 2a provided to attach switching valves and sensors (not shown). The pump chamber 4 is approximately at the center of the front of the case 2 open. The pump chamber 4 is cylindrical and has approximately the shape of a stepped, circular cylinder extending backwards from an open end, which is in the front surface of the housing 2 is formed, to a bottom of the pump chamber 4 extends on the back and an annular shoulder surface 4b pointing towards the open end and an annular step in the pump chamber 4 shaped.

The pump arrangement 3 extends from a front side connected to a drive source, which in this example is an electric motor (not shown), to a back side, at which a first pump 8th lies. As in 6 and 7 shown includes the pump assembly 3 a cover element 6 , an intermediate element 7 (which may be referred to as a sealing element or separator), the first pump 8th , a second pump 9 etc. It is possible that the pump assembly 3 further a plug element 5 The pump assembly may also include a drive shaft 10 include.) The plug element 5 is a circular, plate-like element that has a central hexagonal through-hole 5a is formed, which extends from a front surface to a rear surface 5d the plug element 5 extends. The back surface 5d is a contact surface on the cover 6 is applied. The plug element 6 includes an annular axial projection 5b that the rear contact surface 5d surrounds and projects axially to the rear. The plug element 5 further comprises a male threaded portion 5c formed in the outer peripheral surface. With the external thread area 5c becomes the plug element 5 in an internally threaded area 4a in the pump housing 4 of the housing 2 screwed.

The cover element 6 is a circular, plate-like element with a front surface 6e , one against the plug element 5 fitting contact surface is, and an annular recess 6f holding the front bearing surface 6e surrounds and forms a step. When the plug element 5 in the pump chamber 4 is screwed in, lies the rear bearing surface 5d the plug element 5 against the front bearing surface 6e of the cover 6 on and the annular projection 5b the plug element 5 fits over a front end portion of the cover 6 in the annular recess 6f of the cover 6 ,

The cover element 6 further includes a radial circumferential projection 6g which protrudes radially outward and has an outer diameter which is approximately equal to the inner diameter of pump chamber 4 and the outer diameter of the annular projection 5b the plug element 5 is, so the lead 6g and the lead 5b in the inner cylinder surface of the pump chamber 4 are fitted. The cover element 6 further comprises an annular sealing groove 6h on the back of the projection 6g lies. A first annular seal S1 is axially between the annular axial projection 5b the plug element 5 and the radial projection 6g of the cover 6 arranged to form a radial gap between the outer surface of the cover 6 and the inner surface of the pump chamber 4 seal. A second annular seal S2 is in the seal groove 6h arranged to a gap between the cover and the inner surface of the pump chamber 4 seal. The first and second seals S1 and S2 are disposed at two separate positions axially spaced in the forward and rearward directions (axially).

A stepped through hole 6b is at an eccentric position of the cover 6 educated. The stepped through hole 6b includes a larger diameter (front) portion and a smaller diameter (rear) portion having an inner diameter smaller than the inner diameter of the large diameter portion. A drive shaft 10 is with a gap 6a in the area of smaller diameter in this stepped through hole 6b used. Annular seal members S3 are respectively in the larger diameter portion and the smaller diameter portion of the stepped through hole 6b arranged to leave a void around the drive shaft 10 seal. The cover element 6 further includes a cylindrical recessed area 6d coming from the rear end of the cover 6 is recessed toward the front end, and an annular axial projection 6c , the recessed area 6d surrounds and projects axially to the rear. In the annular axial projection 6c is an annular stepped area 6i formed, which is defined by an annular shoulder surface which faces backwards.

The intermediate element (or sealing element) 7 is a circular, plate-like element, as in 8th to 12 shown. The intermediate element 7 includes a passage shaft hole 7a and two insertion holes 7b and 7c , The insertion holes 7b and 7c are on the lower side of the through hole 7a arranged as in 7 to 12 and aligned in a line parallel to a centerline of the through shaft hole 7a extends as best in 7 you can see. The passage shaft hole 7a is a circular hole having a circular cross section and extending axially in the forward and backward direction through the sealing member 7 , The insertion holes 7b and 7c are also circular holes with a circular cross-section. The insertion holes 7b and 7c are respectively from the front and rear side surface of the intermediate element 7 open and extend to each other in the direction of the thickness up to a bottom wall, which the insertion holes 7b and 7c separates, as in 12 and 7 shown. On the front as well as the rear side includes the intermediate element 7 a side seal area 7d that's the through hole 7a and the insertion holes 7b or 7c surrounds and axially projects around the corresponding holes so as to seam the holes. Each of the side sealing areas 7d includes a pair of engagement projections 7e that project to one side.

The side seal area 7d on the front and back comprises an annular ring receiving recess 7f , which is recessed in the direction of the thickness, coaxially around the through hole 7a , as in 8th and 9 shown. Furthermore, on the back of an annular ring receiving area 7g formed with a smaller diameter, the lower throughout in the direction of the thickness of the annular recess 7f the back coaxially around the through hole 7a is omitted, as in 9 is shown. In addition, the intermediate element comprises 7 an annular sealing groove 7h extending from the outer peripheral surface of the intermediate element 7 is recessed radially inwardly, and a front annular axial projection 7i projecting radially forward from the front.

The intermediate element 7 is from the cover 6 by the axial force from the plug element 5 is generated when this in the pump chamber 4 is screwed in (see 6 and 7 ), pushed backwards. This will cause the annular front projection 7i in the step area 6i located on the radial inside of the annular rear projection 6c of the cover 6 is formed, fitted, and an outer region of the rear side surface of the intermediate element 7 lies on the forward facing, annular shoulder surface 4b in the pump chamber 4 is formed, on, so that the sealing element 7 is reliably arranged at a predetermined position. The drive shaft 10 is received and rotatable in the through-shaft hole 7a of the intermediate element 7 stored. bearing shafts 11a and 11b are each in insertion holes 7b and 7c pressed in and fixed.

An annular rotary sealing element (or shaft sealing element or shaft sealing element) 12 (like an X-ring) is in the rear annular seal receiving area 7g arranged to seal around the drive shaft 10 to provide a later-described first pump chamber P1 seal. In addition, a first sealing ring 13a in the annular seal receptacle mevertiefung 7f arranged on the back such that the annular recess 7g of the rotary sealing element 12 closed is. A second sealing ring 13b is in the annular recess 7f arranged on the front. The sealing rings 13a and 13b are made of a material that is harder and more durable than the sealing element 7 is. The first and second sealing ring 13a and 13b can serve as the first and second stop element. In this example, the sealing rings 13a and 13b Metal elements, such as a sintered metal element or a hard metal element or a superhard alloy element. An annular seal S4 is in the annular seal groove 7h of the intermediate element 7 arranged to be in close contact with the inner peripheral surface of the pump chamber 4 stand to secure a sealing separation between the first pump chamber P1 and the second pump chamber P2.

The first pump chamber P1 is defined as a closed space between the intermediate element 7 and the bottom of the pump chamber 4 in a recessed area 4c which extends axially backwards from the shoulder surface 4b of the housing 2 is omitted, defined. A first pump 8th is provided in the first pump chamber P1. The second pump chamber P2 is defined as a closed space between the bottom of the recessed area 6d of the cover 6 and the intermediate element 7 Are defined. A second pump 9 is provided in the second pump chamber P2.

A first gearing 15 is in the first pump chamber P1 between the intermediate element 7 and a first side plate 14 arranged so that the front and back sides and the tooth tips are sealed by these elements. As in 13 to 17 shown is the first side plate 14 an element of resin and shaped like a (rounded) triangle, as seen in the front view. The first side plate 14 includes three through holes 14a . 14b and 14c , each in three corners of the triangular first side plate 14 are formed. The first side plate 14 further includes a side seal area 14d that the through holes 14a and 14b surrounds on the front and protrudes axially forward.

A seal block 14e is in the first side plate 14 educated. The seal block 14e is shaped like a triangle and projects axially from the front surface of the first side plate 14 forward. The seal block 14e the first side plate 14 includes: a passageway area 14f for forming an open area continuous from the through hole 14c towards the middle of the first side panel 14 extends; a pair of tooth tip sealing areas 14g on both sides of the passage area 14f are formed, which are continuous with a part of the side seal area 14d are and which have the shape of a curved surface; and intervention areas 14h placed on the front of the respective tooth tip sealing areas 14g lie. The seal block 14e further includes a curved groove 14i which is recessed to the rear and around the through hole 14c and the tooth tip sealing areas 14g extends. On the back is the first side plate 14 , as in 16 shown with a sealing groove 14j formed, which extends curved and thus describes a triangle and the three through holes 14a . 14b and 14c surrounds.

As in 7 shown is the drive shaft 10 rotatable at a predetermined radial distance in the through hole 14a the first side plate 14 taken up and the rear bearing shaft 11a is in the through hole 14b taken with a predetermined radial distance. A gasket S5 is in the rear gasket groove 14j received and thus arranged to seal the first pump chamber P1 against a low pressure region.

The first gearing 15 consists of a drive gear (or gear that serves as a pump element) 15a that on the drive shaft 10 is fixed, and a driven gear (or a gear, which serves as another pump element) 15b that on the bearing shaft 11a is attached. The teeth 15c and 15d of the drive gear 15a and the driven gear 15b are together in an intervention area 15e engaged, as best in 18 you can see. As in 6 and 18 shown is the drive shaft 10 with a radial hole or recessed area 10d formed radially inward at the position that the drive gear 15a stored, is omitted. A radially extending drive pin 10a (serving as a first or second drive projection) is in this radial hole 10d used. In this example is the drive pin 10a cylindrical. The drive pin 10a can be fixed by press fitting or can easily into the radial hole 10d be used.

The drive pin 10a engages in a recess (drive recess) 15f (which serves as a first or second recess), which in the inner periphery of the drive gear 15a in the form of a cutout that extends through the drive gear 15a in the direction of the width of the drive gear 15a extends, is formed. The drive shaft 10 includes a front end portion 10b , which is adapted to be connected to the drive source, which in this example is an electric motor (not shown) 7 ). This front end area 10b is formed so that it has a non-circular cross-section, such. B. is a rectangular cross-section, and is arranged to serve as an area with the rotary shaft of the engine to be connected. Thus, the drive shaft 10 designed to be driven by the rotation of the motor.

Thus, the drive pin 10a arranged to the rotation of the drive gear 15a in relation to the drive shaft 10 to prevent and to cause the drive gear 15a as a unit with the drive shaft 10 rotates. When the drive shaft 10 is driven, the drive gear rotates 15a in the same direction as the drive shaft 10 and the driven gear 15b is through the drive gear 15a turned in the opposite direction.

As in 18 shown are the tips of the teeth 15c and 15d of the drive gear 15a and the driven gear 15b shaped and designed so that they are liquid-tight and lubricated with corresponding tooth tip sealing areas 14g of the sealing block 14e the first side plate 14 are in contact. As in 19 are shown, the first and second engaging projection 7e on the back of the intermediate element 7 each with the intervention areas 14h of the sealing block 14 engaged in such a tight manner that the curved concave surfaces of the engaging portions 14h with the curved convex surfaces of the corresponding engagement projections 7e are in contact. By this arrangement are the tips of the teeth 15c and 15d of the drive gear 15a and the driven gear 15b with the side seal area 14d the first side plate 14 sealed. Furthermore, a holding element 16 which extends so as to describe a triangle in the groove 14i on the outer circumference of the seal block 14e and on the corresponding side seal area 7d of the sealing element 7 fitted in (as in 7 shown).

The pump chamber 4 of the housing 2 is with an inlet port (not shown) connected to the through hole 14c the first side plate 14 and an outlet port (not shown) communicating with the first pump chamber P1.

The second pump 9 is on the front of the intermediate element 7 so arranged that the first pump 8th and the second pump 9 with respect to a cross section of the intermediate element 7 in the middle between the pumps 8th and 9 are symmetrical. A second gearing 18 the second pump 9 is between the intermediate element 7 on the back and a second side plate 17 sealed on the front. As in 21 to 25 is shown comprises the second side plate 17 , analogous to the first side plate 14 , Through holes 17a . 17b and 17c , a side seal area 17d , a seal block 17e , a passageway 17f Tooth tip sealing areas 17g , Intervention areas 17h , a groove 17i and a sealing groove 17j , Furthermore, a holding element 16 which extends so as to describe a triangle in the groove 17i on the outer circumference of the seal block 17e and on the corresponding side seal area 7d of the sealing element 7 fitted in (as in 7 shown).

As in 7 shown is the drive shaft 10 rotatable at a predetermined radial distance in the through hole 17a the second side plate 17 received, and the front bearing shaft 11b is in the through hole 17b taken with a predetermined radial distance. A gasket S6 is in the front side seal groove 17j received and thus arranged to seal the second pump chamber P2.

The second gearing 18 exists, similar to the first gearing 15 of a drive gear (a gear serving as a pump element) 18a that on the drive shaft 10 is fixed, and a driven gear (a gear, which serves as another pump element) 18b that on the bearing shaft 11b is attached. The teeth 18c and 18d of the drive gear 18a and the driven gear 18b are together in an intervention area 18e engaged.

As in 6 shown is the drive shaft 10 with a radial hole or a depression 10e formed radially inward at the position that the drive gear 18a stored, is omitted. A radially extending drive pin 10c is in this radial hole 10e used. In this example is the drive pin 10c a cylindrical pin extending from the central axis of the drive shaft 10 projecting radially outward in a radial direction. The drive pin 10c can be fixed by press fitting or can easily into the radial hole 10e be used. The drive pin 10c engages in a drive recess 18f a, in the inner circumference of the drive gear 18a is trained. The drive pin 10c can serve as a drive projection. In this example, the drive recess has 18f the shape of a cutout or notch extending through the drive gear 18a in the direction of the width of the drive gear 18a extends.

Thus, the drive pin 10c arranged to the rotation of the drive gear 18a in relation to the drive shaft 10 to prevent and to cause the drive gear 18a as a unit with the drive shaft 10 rotates. When the drive shaft 10 is driven, the drive gear rotates 18a in the same direction as the drive shaft 10 and the driven gear 18b is through the drive gear 18a turned in the opposite direction.

In the second pump 9 is the pump chamber 4 of the housing 2 with an inlet port (not shown) passing over one in the cover member 6 trained oil passage with the through hole 17c the second side plate 17 and an outlet port (not shown) via one in the cover member 6 formed oil passage is in communication with the second pump chamber P2. Otherwise, the second pump 9 constructed in the same way as the first pump 8th ,

• 1. Der Antriebsvorsprung (10a, 10c) ist so bemessen, dass der Antriebsvorsprung radial nach außen nicht über das Anschlagelement (13a, 13b) hinaus vorsteht, und das Anschlagelement erstreckt sich radial auswärts über den Antriebsvorsprung hinaus.
• 2. Das Anschlagelement (13a, 13b) hat einen größeren Querschnitt als das Drehdichtelement 12.
• 3. Das Drehdichtelement 12 erstreckt sich radial nach außen über den Antriebsvorsprung (10a, 10c) hinaus.

The dimensions near the drive shaft 10 are determined as follows (see 26A . 26B and 26C ): In 26A D1 is a (radial) distance from the center of the drive shaft 10 to the radial outer end of the drive pin 10a (or drive pin 10c ) extending radially outward, D2 is the radius of the annular rotary seal member 12 and D3 is the radius of the first seal ring 13a (or the second sealing ring 13b ). As in 26A is shown schematically, these dimensions D1, D2 and D3 are set so that D1 <D2 <D3 applies. In general, at least one of the following three conditions is met:

• 1. The drive projection ( 10a . 10c ) is dimensioned such that the drive projection does not extend radially outward beyond the stop element ( 13a . 13b ), and the stopper member extends radially outward beyond the drive projection.
• 2. The stop element ( 13a . 13b ) has a larger cross-section than the rotary sealing element 12 ,
• 3. The rotary sealing element 12 extends radially outwardly beyond the drive projection ( 10a . 10c ).

The diameter D4 of the drive pin 10a (or the drive pin 10c ) is less than or equal to the thickness D5 of the drive gear 15a (or the drive gear 18a ). In general, the drive projection ( 10a . 10c ) in its axial dimension thinner than the drive gear ( 15a . 18a ) so that the drive projection does not protrude laterally or axially beyond the drive gear.

The (axial) depth H1 of each ring receiving area 7f is substantially equal to the (axial) thickness H2 of the first seal ring 13a (or the second sealing ring 13b ).

The distance 12 between the drive pins 10a and 10c (Distance between the opposite nearer (or inner) sides of the drive pins 10a and 10c ) is greater than the distance L1 between the farther (or outer) sides of the seal rings 13a and 13b ,

The diameter of the through hole 14a or 17a each side plate 14 and 17 is greater than the diameter of the drive shaft 10 , The diameter of each through hole 14b and 17b is larger than the diameter of the bearing shaft 11a or 11b , The drive shaft 10 and the bearing shafts 11a and 11b are in the appropriate holes 14a . 17a . 14b and 17b the side plates 14 and 17 used with a small game.

The gear pump thus constructed 1 is assembled in the following way: First, the rotary seal element 12 in the seal receiving area 7g the intermediate element (or sealing element) 7 used, which was provided in advance with the seal S4, and thus provisionally attached.

Then the drive shaft 10 through the through hole 7a of the intermediate element 7 used and then the bearing shafts 11a and 11b each in the insertion holes 7b and 7c used. Thus, a subassembly of intermediate element 7 , Drive shaft 10 and bearing shafts 11a and 11b educated.

Then the sealing rings 13 and 13b each in the ring receiving areas 7f of the intermediate element 7 used. In this case, the rotary seal member 12 from the first sealing ring 13a pressed and thus becomes the rotary seal element 12 firmly on the drive shaft 10 pressed.

Then the drive pins 10a and 10c each in the radial holes or recessed areas 10d respectively. 10e introduced and fixed there. After that, the drive gears 15a and 18a on the drive shaft 10 fastened in the state in which the drive pins 10a and 10c in the wells 15f respectively. 18f the drive gears 15a respectively. 18a are engaged.

After that, the driven gears 15b and 18b on the bearing shafts 11a and 11b attached and get to the drive gears 15a respectively. 18a engaged.

Then the side plates 14 and 17 into the subassembly of the intermediate element 7 integrated by the drive shaft 10 and the bearing shafts 11a and 11b in the side plates 14 and 17 , in advance with the seals S5 or S6 and the retaining elements 16 respectively. 19 be introduced. In this case, the first side plate may be simple with respect to the intermediate element 7 be positioned by the engaging areas 14h the first side plate 14 with the engagement projections 7e of the intermediate element 7 be engaged, so that the assembly step is easier. It is also due to the retaining element 16 possible, the intermediate element 7 and the first side plate 14 temporarily together. The Halteele ment 16 can easily on the intermediate element 7 and the first side plate 14 be attached by the retaining element 16 first on the intermediate element 7 is attached and then the holding element 16 on the first side plate 14 is extended.

Similarly, the second side plate may be simple with respect to the intermediate element 7 be positioned by the engaging areas 17g the second side plate 17 with the engaging projections 7e of the intermediate element 7 be engaged, so that the assembly step is easier. It is also due to the retaining element 19 possible, the intermediate element 7 and the second side plate 17 temporarily together. The holding element 19 can easily on the intermediate element 7 and the second side plate 17 be attached by the retaining element 19 first on the intermediate element 7 is attached and then the holding element 19 on the first side plate 17 is extended.

Thereafter, the cover member 6 into the subassembly of the intermediate element 7 integrated by the drive shaft 10 in the through hole 6a of the cover 6 introduced and at the same time the annular projection 6c of the cover 6 in the intermediate element 7 is fitted. This is the pump arrangement 3 assembled.

The thus mounted pump assembly 3 gets into the pump chamber 4 of the housing 2 used. Then the plug element becomes 5 in the pump chamber 4 screwed in and thus in the housing 2 attached. In this case, the intermediate element 7 by the axial force generated by screwing in the plug element 5 is generated against the step area 4b in the pump chamber 4 and thus stably positioned so that the positions of the parts in the axial direction or the forward and backward directions can be accurately determined, and the gear pump can then prevent instability or uncertainty due to pressure fluctuations of the operating fluid, as described later. In addition, the plug element pushes 5 with the annular projection 5b on the seal S1 and thus improves the seal between cover 6 and pump chamber 4 of the housing 2 ,

In this way, the parts of the gear pump 1 first preassembled and in the form of a pump assembly 3 in the case 2 used. Thus, the transmission pump 1 simplify the assembly process according to the first embodiment.

The gear pump 1 is operated as follows: When the drive shaft 10 by the motor in one direction of rotation, in 18 indicated by an arrow is driven, then the driven gear 15b through the drive gear 15a rotated in the first pump P1. By this movement, the operating fluid with a lower pressure (or negative pressure) from the inlet port through the through hole 14c of the sealing block 14e the first side plate 14 sucked and the operating fluid with a higher pressure is discharged into the pump chamber P1. The higher pressure operating fluid is output through the corresponding outlet port.

In the second pump P2, the driven gear 18b over the drive gear 18a through the drive shaft 10 rotated, as in the first pump P1. By this movement, the operating fluid becomes less pressure through the through hole 17c of the sealing block 17e the second side plate 17 sucked and the operating fluid with a higher pressure is discharged into the second pump chamber P2. This higher pressure operating fluid is output through the corresponding output port.

Thus, the first pump 8th and the second pump 9 Inlet operations (intake of operating fluid) and exhaust operations (discharge of operating fluid under pressure) are performed in two separate hydraulic systems. The gear pump 1 in the illustrated example of the first embodiment may also serve as an external tandem gear pump.

In general, the first pump 8th and the second pump 9 respectively for first and second hydraulic systems, eg. B. first and second braking systems of a vehicle used. For example, one of the hydraulic systems is used for the front left wheel and the rear right wheel and the other system is used for the front right wheel and the rear left wheel.

The tooth tip sealing areas 14g and 17g are each in one piece in the side plates 14 respectively. 17 educated. Thus, this gear pump 1 reduce the number of components and thus the manufacturing cost and simplify the assembly process. The side panels made of resin 14 and 17 are beneficial for improving manufacturing accuracy and sealing performance.

The sealing ability is improved as follows: the teeth 15c and 15d the gears 15a and 15b in the first pump 8th are arranged to rotate while holding the tooth tip sealing areas 14g the first side plate 14 touch liquid-tight. As in 18 As shown, they are thus formed as a low-pressure fluid chamber B1 surrounded by the passage region 14f through gang lochs 14c connected to the inlet port, the drive gear 15a , the driven gear 15b and a part of the intermediate element 7 is communicated, and the pump chamber P1 becomes a high-pressure fluid chamber B2.

Accordingly, the seal block 14e by a pushing force from the second fluid chamber B2 toward the first fluid chamber B1 (toward the tooth tip sealing portions 14g ) and pushed sideways. This will push the engagement areas 14h of the sealing block 14e the engagement projections 7e of the intermediate element 7 to the close contact between the intermediate element 7 and the seal block 14e the first side plate 14 ensure and thus the sealing performance between the high pressure side and the low pressure side is ensured. In addition, the tooth tip sealing areas are located 14g by the above-mentioned pushing force exactly on the tips of the respective teeth 15c and 15d the gears 15a and 15b and thus improve the sealing performance between the high pressure side and the low pressure side.

In addition, the holding element offers 16 a holding force or connecting force acting to cause the tooth tip sealing portions 14g be forced exactly against the teeth 15c and 15d the gears 15a and 15b to touch and to improve the seal. Thus, the retaining element 16 the seal between the high and low pressure sides and the seal around the through hole 14c and the intermediate element 7 improve.

The second pump 9 works in the same way and has the same effects as the first pump 8th ,

The side surfaces of the gears are sealed as follows: the front and rear side surfaces of the gears 15a and 15b be through the appropriate side seal area 14d the first side plate 14 and the side seal area 7e of the intermediate element 7 sealed.

In this case, the axial dimension (or diameter) is D4 of the drive pin 10a (or the drive pin 10c ) is less than or equal to the axial dimension (or thickness) D5 of the drive gear 15a (or the drive gear 18a ). Thus, the drive pin 10a ( 10c ) within the thickness of the drive gear 15a ( 18a ), without projecting laterally from the drive gear, so that the sealing performance on both sides of the teeth 15 and 18 is ensured.

The depth H1 of each ring receiving area 7f is substantially equal to the thickness H2 of the first seal ring 13a (or second seal ring 13b ). Thus, the sealing rings 13a and 13b be kept stable and the sealing performance of the drive gear 15a ( 18a ) can be improved.

The diameter of the through hole 14a or 17a the side plate 14 or 17 is greater than the diameter of the drive shaft 10 , The diameter of the through hole 14b or 17b the side plate 14 or 17 is larger than the diameter of the bearing shaft 11a or 11b ,

This will cause the drive shaft 10 and the bearing shafts 11a and 11b loose with a slight gap in the corresponding through holes 14a . 17a . 14b and 17b the side plates 14 and 17 used. Thus, the side plates become 14 and 17 even if the drive shaft 10 or the bearing shaft 11a or 11b is inclined, not obstructed by the inclined wave, and no unwanted external force is exerted on this. Thus, the intermediate element 7 and the side plates 14 and 17 a stable system and a contact between them for the seal maintained, whereby the reliability of the gear pump is improved.

The drive shaft 10 and the gears 15 and 18 are arranged with respect to each other as follows: In the first embodiment, the drive pins move 10a and 10c axially together with the drive shaft 10 when the drive shaft 10 moves axially. This axial movement is through the sealing ring 13a or 13b on the rear side, against the front side of the drive pin 10a or 10c on the back of this movement, limited.

As in 26A shown is the distance 12 between the insides of the drive pins 10a and 10c greater than the distance L1 between the outer sides of the sealing rings 13a and 13b , When the drive shaft 10 moved to the left, as indicated by an arrow in 26B indicated, thus lies only the left side surface of the first drive pin 10a on the first sealing ring 13a on the rear side, which in the case of axial movement to the left is the right side, and the movement of the drive shaft 10 to the left is through this attachment between the first drive pin 10a and the first sealing ring 13a limited.

In case of movement of the drive shaft 10 to the right, as indicated by an arrow in 26C is displayed, only the right side surface of the second drive pin 10c on the second sealing ring 13b on the rear side, which in the case of axial movement to the right is the left side, and the movement of the drive shaft 10 to the right is through this attachment between the second drive pin 10b and the second sealing ring 13b limited.

The thicknesses are set so that when the drive pin 10a (or the drive pin 10c ) on one side against the first sealing ring 13a (or the second sealing ring 13b ), the drive pin 10c (or the drive pin 10a ) on the opposite side not with the side plate 17 (or the side plate 14 ) is in contact.

Thus, the gear pump of the first embodiment enables the axial position of the drive shaft 10 in relation to the first and second gearing 15 and 18 to determine the axial movement of the drive shaft 10 with respect to the first and second teeth within a predetermined range in the thickness of the first and second teeth 15 and 18 ( 15a . 18a ), and the axial movement in the first (backward) direction with the drive projection (FIG. 10c ) of the second (front) side and in the second (forward) direction with the drive projection ( 10a ) on the first (rear) side to prevent extraction in the axial direction.

The drive projections 10a and 10c are arranged so that they are against the respective sealing rings 13a and 13b only with the insides of the drive projections 10a and 10c abut each other axially over the intermediate element 7 opposite, so that at the time of investment each drive projection 10a or 10c an axial force experiences only in an axial direction. Thus, it is possible the durability of each drive pin 10a or 10c to improve.

In a comparative example, in which the first and second sealing ring 13a and 13b and the intermediate element 7 are a single integral element, it is necessary to use the intermediate element 7 made of hard metal to achieve durability. Thus, the comparative example increases the manufacturing cost and the weight of the transmission pump.

In contrast to the comparative example, the intermediate element 7 according to the first embodiment, an element separate from the sealing rings 13a and 13b , Thus, the intermediate element 7 be made of a resin or other material that is advantageous for the cost and weight reduction. Compared with another comparative example, in which the first and second sealing ring 13a and 13b in the corresponding side plates 14 and 17 (instead of the intermediate element 7 ) are provided, this embodiment also allows the axial position of the drive shaft 10 in terms of any gearing 15 or 18 accurate and easy to determine by only the dimension of the intermediate element 7 is checked.

The first sealing ring 13a is arranged around the seal receiving area 7g close. Thus, the first sealing ring prevents 13a a contact between the drive pin 10a and the rotary seal member 12 and thus protects the rotary seal member 12 from abrasion and damage.

This arrangement of the first seal ring 13a can improve the sealing separation between the pump chambers P1 and P2 and thus the reliability of the gear pump. It is optionally possible to have a similar seal receiving area 7g on the side of the second seal ring 13b form and a similar rotary sealing element 12 in this seal receiving area 7g in the same way as in the first pump to achieve the same effect.

It is possible to have a seal receiving area 7g in the middle of the through hole 7a by a first method of forming the intermediate element 7 of a metal by bonding two separate parts of the metal material, which can form the seal receiving area between the two separate parts, or a second method of forming the intermediate element of a resin using a slide mold inserted into the through hole. However, these methods deteriorate productivity and increase the arrangement. Besides, it is difficult to use the rotary seal 12 in the middle of the intermediate element 7 in the seal receiving area 7g use. In contrast, the seal receiving area 7g in the first embodiment on one side of the intermediate element 7 be formed, so that the transmission pump of the first embodiment is advantageous in terms of productivity and assembly process.

As in 16A is shown, the radial length D1 from the center line of the drive shaft 10 to the top of the drive pin 10a (or 10c ) smaller than the radius D2 of the seal ring 13a (or 13b ). Thus it is by reducing the projection length of the drive pin 10a ( 10c ) possible, the size or radius of the drive gear 15a ( 18a ) and thus the size of the gear pump 1 to reduce.

27 shows a gear pump 1 according to a second embodiment of the present invention in section. The following explanation refers only to portions in which the second embodiment is different from the first embodiment, and a repeated explanation of similar members bearing the same reference numerals will be omitted.

In the gear pump 1 of the 27 become the sealing rings 13a and 13b omitted, and the intermediate element 7 is a one-piece metal element formed by cold forging of a metal material.

An annular bearing element 21 made of resin or metal and an annular seal S7 are in a stepped recess area 20 arranged in the intermediate element 7 at the position in the case of 6 of the first embodiment, the rotary seal 12 is arranged, is formed. The stepped indentation area 20 includes a larger area with a larger diameter and a smaller area with a smaller diameter than that of the larger area formed continuously from the larger area on the front side or lower side of the larger area. The annular seal S7 is in the smaller area of the stepped recess area 20 fitted and the annular bearing element 21 is in the larger area axially between the annular seal S7 and the first toothing 15 arranged. The drive shaft 10 is in the shaft hole 7a of the intermediate element 7 loose with a radial gap 22 added. The drive shaft 10 is with pressure in the annular bearing element 21 fitted and attached. Thus, the drive shaft 10 over the bearing element 21 rotatable by the intermediate element 7 in the recessed area 20 stored. The seal S7 is arranged to be in close contact with the drive shaft 10 and sealingly separate the first pumping chamber P1 and the second pumping chamber P2. The bearing element 21 can be replaced by a bearing, as in metal ball bearings.

The bearing element 21 is arranged to control the axial movement of the drive shaft 10 by abutment against the inside of the drive pin 10a to limit, and the intermediate element 7 is arranged to control the axial movement of the drive shaft 10 by abutment against the inside of the drive pin 10c to limit. In this way, the transmission pump of the second embodiment can provide the same advantageous effects.

28 shows a transmission pump according to a third embodiment of the present invention in section. The following explanation refers only to portions in which the second embodiment is different from the first embodiment, and a repeated explanation of similar members bearing the same reference numerals will be omitted.

As in 28 is shown, unlike the gear pump of the 6 in the first embodiment, the first sealing ring 13a in the first side plate 14 provided and the second sealing ring 13b is in the second side plate 17 intended.

The first sealing ring 13a limits the axial movement of the drive shaft 10 by abutment against the outside of the drive pin 10a (which together with the drive shaft 10 in the direction away from the intermediate element 7 is moved), and the second sealing ring 13a limits the axial movement of the drive shaft 10 by abutment against the outside of the drive pin 10c (which together with the drive shaft 10 in the direction away from the intermediate element 7 is moved). In this way, the gear pump of the third embodiment can achieve the same advantageous effects.

29 shows a gear pump 1 according to a fourth embodiment of the present invention. In the 29 shown gear pump 1 includes many components that have substantially identical correspondences in the transmission pump of the first embodiment. Therefore, the components that are similar to the corresponding components of the gear pump 1 of the first embodiment, the same reference numerals, a repeated explanation will be omitted and the following explanation refers only to the differences from the first embodiment.

The gear pump 1 of the fourth embodiment, unlike the first embodiment, which describes an external gear pump, an internal gear pump. In the example of 29 is the gear pump 1 a tandem internal gear pump.

In the in 29 shown embodiment, the first and the second side plate 14 and 17 cup-shaped elements having the same shape. Instead of the sealing blocks 14e and 17e includes each side plate 14 or 17 an annular outer sealing area or a wall 40 or 41 that of a bottom wall or end wall axially to the intermediate element 7 protrudes and over one of the side sealing areas 7d of the intermediate element 7 is fitted.

In the space of the annular outer seal area 40 the first side plate 14 is surrounded and axially between the first side seal area 7d of the intermediate element 7 and the end wall of the first side plate 14 is arranged, is the first gearing 15 , which forms the first pump P1, provided. In the space of the annular outer seal area 41 the second side plate 17 is surrounded and axially between the second side seal area 7d of the intermediate element 7 and the end wall of the second side plate 17 is arranged, is the second toothing 18 , which forms the second pump P2, provided. An annular seal S8 encloses the annular outer seal area 40 and thus seals the first pump P1, and an annular seal S9 encloses the annular outer seal portion 41 and thus seals the second Pump P2 off.

These annular seals S8 and S9 are partially around the side plate 14 respectively. 17 expanded, although not shown, similar to the holding elements 16 and 19 , and thus arranged to the intermediate element 7 and the first and second side plates 14 and 17 to keep.

As in 30 shown, includes the first gearing 15 the first pump 8th an outer rotor 42 (serving as a pump element) with an internal tooth area 42a , which is formed in the inner circumference, and an inner rotor 43 (serving as a pump element) with an external tooth area 43a formed in the outer periphery. The inner rotor 43 is eccentric in the outer rotor 42 arranged and the external tooth area 43a is with the inner tooth area 42a in an intervention area 44 engaged, leaving a pump chamber 45 between the outer rotor 42 and the inner rotor 43 is trained.

A drive projection 46 is integral in the drive shaft 10 at each of the positions facing the inner rotor 43 the first pump 8th and the second pump 9 opposite, trained. Every drive projection 46 protrudes radially outward. In this example, each drive projection has 46 the shape of a rectangular column. The drive projections 46 are each in drive recesses 43b in the inner rotor 43 fitted. Each drive recess 43b has the shape of a cutout in the inner rotor 43 is trained. The axial dimension of each drive projection 46 is smaller than the thickness of the inner rotor 43 ,

Thus, the inner rotor 43 in the pump 8th or the pump 9 on the drive shaft 10 attached and with the drive shaft 10 connected so that a relative rotation is prevented. Thus, the inner rotor becomes 43 from the drive shaft 10 driven and the outer rotor 42 is through the inner rotor 43 rotated in the same direction. The outer rotor 42 is rotatable in the outer seal area 40 the side plate 14 or 17 fitted so that the outer circumference of the outer rotor 42 during its rotation in the outer seal area 40 in sliding contact with the inner periphery of the outer seal portion 40 is.

The first side plate 14 is at positions of the pump chamber 45 opposite, with through holes 47 and 48 trained as in 29 and 30 is shown. Every through hole 47 or 48 may be in the form of a groove shaped like a crescent. The through hole 47 is over a hollow area 49 that is between the first side plate 14 and the wall of the pump chamber 4 is formed with an inlet port 50 the pump chamber 4 connected. The through hole 48 is with an outlet port 51 the pump chamber 4 connected.

The second side plate 17 and the second gearing 18 the second pump 9 are constructed in the same way as the first side plate 14 and the first gearing 15 in the first pump 8th , The first side plate 17 is with through holes 52 and 53 educated.

The through hole 52 is via a fluid passage 54 which is in the cover element 6 is formed with an inlet port 55 the pump chamber 4 connected. The through hole 53 is over a gap 56 that is between the cover element 6 and the second side plate 17 is formed, and one in the cover 6 trained fluid passage 57 with an outlet port 58 the pump chamber 4 connected.

On the first (rear) side of the intermediate element 7 towards the first gearing 15 is a bearing element 21 provided, as in the transmission pump of the second embodiment. On the second (front) side of the intermediate element 7 towards the second gearing 18 is a rotary seal element 12 provided, as in the transmission pump of the first embodiment. A gasket S11 is around the through hole 48 the first side plate 14 provided and arranged to seal between the room 49 and the through hole 48 provide. A gasket S12 is around the through hole 52 the second side plate 17 provided and arranged to seal between the room 56 and the through hole 52 provide.

The gear pump 1 according to the fourth embodiment operates as follows: When the drive shaft 10 from an electric motor in the direction of rotation, indicated by an arrow in 30 is displayed, is driven, then the outer rotor 42 through the inner rotor 43 in the pump 8th or 9 driven. In this case, each pump generates a pumping action with the volume change of the pumping chamber 45 in the gears 15 and 18 , That is why in the first pump 8th the fluid at a lower pressure from the inlet port 50 through the through hole 47 the first side plate 14 initiated. The introduced fluid is pressurized and through the through hole 48 the first side plate 14 to the outlet port 51 output.

In the second pump 9 becomes a fluid at a lower pressure from the inlet port 55 through the through hole 52 the second side plate 17 initiated. The introduced fluid is pressurized and through the through hole 53 the second side plate 17 to the outlet Enough 58 output.

Thus, the first pump 8th as well as the second pump 9 Inlet operations (intake of operating fluid) and exhaust operations (discharge of operating fluid under pressure) are performed in two separate hydraulic systems. The gear pump 1 in the illustrated example of the fourth embodiment may serve as a tandem internal gear pump.

The outer sealing area 40 or 41 is in one piece in the first side plate 14 or second side plate 17 educated. The tooth tip sealing area 14g or 17g is in one piece in the first side plate 14 or the second side plate 17 educated. Thus, it is possible to reduce the number of required components and the manufacturing cost and to facilitate the assembly process. The use of the side plates 14 and 17 Resin-made resin is advantageous for improving manufacturing accuracy and sealing performance. In addition, the sealing performance with the intermediate element 7 through the retaining element 16 and 19 be ensured.

In the fourth embodiment, it is for the first gearing 15 and / or the second gearing 18 possible, instead of the integrally formed drive projection 46 , the drive pin ( 10a . 10c ) to be inserted into the radial hole ( 10d . 10e ) used in the drive shaft 10 is formed, and in the drive recess ( 43b ) intervenes.

The present invention is not limited to the examples shown. Various variations and modifications are possible within the scope of the present invention. For example, it is possible to change the materials and configurations of some components. As in 31 is shown, the sealing ring ( 13b ) on the side on which the rotary seal element 12 is not intended to be omitted.

According to the illustrated embodiments, a transmission pump has a basic structure comprising:
a drive shaft (to be connected to a drive source such as an electric motor); a rotatable pump element mounted on the drive shaft and configured to perform a pumping operation; a sidewall member (such as the intermediate member or separator 7 ), which is arranged on one side of the pump element and with a shaft hole ( 7a ) is formed, through which the drive shaft extends; a side plate disposed on the other side of the pump member so that the pump member is disposed axially between the side wall member and the side plate; and a connecting portion serving as means for connecting the drive shaft to the pump member in such a manner as to prevent relative rotation and allow relative axial movement between the drive shaft and the pump member. The connecting portion includes a drive recess formed in the pump member and a drive projection projecting radially outward from the drive shaft. The drive projection is arranged to engage the drive recess to prevent relative rotation to drive the pump element with the drive shaft and is arranged to limit the axial movement of the drive shaft with respect to the pump member with the side wall member or side plate. The drive recess may be shaped to allow the drive projection of the drive shaft to move axially through the pump element. The pump thus constructed can determine the axial position of the drive shaft with respect to the pump member with the drive projection for transmitting drive torque from the drive shaft to the pump element, simplify the mounting operation of the pump, and reduce the size of the pump.

The gear pump may further include a stopper member (such as 13a or 13b ) in addition to the above basic construction. The abutment member is disposed axially between the drive projection and a abutment member which is the side wall member or the side plate, is held in the abutment member, and is arranged to limit the axial movement of the drive shaft by abutment with the drive projection. The abutment material may be made of a material that is harder than the material of the abutment element. With this structure, it is possible to reduce the cost and weight of the abutment member.

The stopper member in the examples shown is an annular member having an outer circumference with a radius (such as D3) greater than a radial distance (such as D1) of the drive projection from the center of the drive shaft to the upper end of the drive projection. This structure allows the size of the pump element (such as the drive gear 15a or 18a or the inner rotor 43 ) and thus the gear pump 1 to downsize.

The stopper member is received in the examples shown in a recess formed in the abutment member which is the sidewall member or the side plate, and the depth (like H1) of the recess (FIG. 7f ) is substantially equal to the thickness (such as H2) of the stop member. Therefore, the stop element in a stabi len condition and improve the sealing performance.

The gear pump may further comprise a shaft seal area ( 12 ) which in a stepped depression ( 7f . 7g ) arranged around the shaft hole ( 7a ) in the sidewall element ( 7 ) is arranged, and is arranged to a circumferential gap between the drive shaft and the inner surface of the shaft hole ( 7a ) seal. The stop element ( 13a in 6 and 31 . 13b in 29 ) is also received in the stepped recess, so that the shaft seal element ( 12 ) is inserted or limited or pressed between the bottom of the stepped recess and the stop member, and the stopper member is arranged to abut on the drive projection to limit the axial movement of the drive shaft. Thus, the stop element, the shaft seal element ( 12 ), improve the durability of the shaft seal element and reduce the size of the sidewall element ( 7 ) contribute.

In the illustrated examples, the axial width (such as D4) of the drive projection (FIG. 10a . 10c . 46 ) smaller than the thickness (like D5) of the pump element ( 15a . 18a . 43 ). In this structure, the drive projection ( 10a . 10c . 46 ) not laterally (in the axial direction of the drive shaft) of one of the side surfaces of the pump element (FIG. 15a . 18a . 43 ), so that the sealing performance is ensured on both sides.

In the embodiments shown, the gear pump is a double pump, such as a tandem pump, and comprises: a drive shaft (FIG. 10 ); a first gearing ( 15 or 18 ) (including a rotatable pump element); a sidewall member disposed on one side of the first toothing to act as an intermediate member or separator (10); 7 ), and that with a shaft hole ( 7a ) is formed, which receives the drive shaft; a first side plate ( 14 or 17 ), which is arranged on the other side of the first toothing, so that the first toothing axially between the side wall element ( 7 ) and the first side plate is arranged. The gear pump further comprises a second toothing ( 18 or 15 ) (including a rotatable pump element) and a second side plate ( 17 or 14 ), which is arranged so that the second toothing lies axially between the second side plate and the side wall element, which the intermediate element ( 7 ), which is arranged between the first and the second toothing. The transmission pump further comprises a connection portion serving as means for connecting the drive shaft to each toothing ( 15 . 18 ) in such a way as to prevent relative rotation and allow relative axial movement between the drive shaft and the toothing. The connecting portion includes at least one drive recess formed in the first or second teeth, and at least one drive projection projecting radially outward from the drive shaft. The drive recess may be shaped to allow the drive projection of the drive shaft to move axially in the drive recess, and the drive projection is arranged to engage the drive recess to prevent relative rotation to drive the teeth with the drive shaft. and to limit the axial movement of the drive shaft with respect to the gearing with the side wall member or the first and second side plates. In the illustrated preferred embodiments, the connecting portion comprises first and second drive projections (FIG. 10a . 10c . 46 ) and first and second drive recesses ( 15f . 18f . 43b ) for the first and the second toothing. The pump thus constructed can determine the axial position of the drive shaft with the drive projections for transmitting drive torque from the drive shaft to the first and second teeth, simplify the assembly operation of the pump, and reduce the size of the pump.

According to the first embodiment ( 6 ), the second embodiment ( 27 ), the fourth embodiment ( 29 ) and the fifth embodiment ( 31 ), the drive projections are arranged to control the axial movement of the drive shaft with the intermediate element ( 7 ) to limit. This arrangement makes it possible to accurately and simply determine the relative axial position of the drive shaft and each gearing only by monitoring the dimensions of the intermediate element compared with the arrangement in which the drive projections are arranged to control the relative position of the drive shaft with the first one and second side plate ( 14 . 17 ).

The first and second drive projections may be arranged as follows: the first drive projection (FIG. 10a or 10c ; 46 ) is arranged to limit the relative axial movement of the drive shaft in a first (axial) direction, and the second drive projection ( 10c or 10a . 46 ) is arranged to limit the relative axial movement of the drive shaft in a second (axial) direction opposite to the first direction. With this arrangement, each drive projection experiences force from only one side, so that the durability is improved. Thus, the drive projection or drive projections (FIG. 10a . 10c . 46 ) as a limiting device for limiting the axial movement of the drive shaft ( 10 ), together with the intermediate element ( 7 ) or the side plate ( 14 . 17 ), serve.

According to the first embodiment ( 6 ), the second embodiment ( 27 ), the fourth embodiment ( 29 ) and the fifth embodiment ( 31 ) is the side wall or the intermediate wall element ( 7 ) axially between the first and second drive projections ( 10a . 10 ) and limits the axial movement of the drive shaft in both the first and second directions. The first drive projection is arranged to prevent the axial movement of the drive shaft in the second direction by abutment against the intermediate wall element (FIG. 7 ), directly or via an investment facility (such as 13a . 13b . 21 ) for limiting the axial movement, and the second drive projection is arranged to prevent the axial movement of the drive shaft in the first direction opposite to the second direction by abutment against the intermediate wall element (FIG. 7 ), directly or via an investment facility (such as 13b . 13a . 21 ), to limit. In the in 26A . 26B and 26C In the examples shown, the first drive projection ( 10a ) within the (axial) width of the first pump element ( 15a ) of the first gearing ( 15 ) and the second drive projection ( 10c ) lies within the (axial) width of the second pump element ( 18a ) of the second toothing ( 18 ), when the first drive projection ( 10a ) at the limit position limiting the axial movement of the drive shaft in the second direction (to the left) (as in FIG 26B ), so that an axial (narrower) gap, which a bearing of the second drive projection against the second side plate ( 17 ), and an axial (wider) gap, which a bearing of the second drive projection against the intermediate wall element ( 7 ) are present. If the second drive projection ( 10c ) at the limit position limiting the axial movement of the drive shaft in the first direction (to the right) is (as in 26C ), the drive projection ( 10c ) within the (axial) width of the second pump element ( 18a ) of the second toothing ( 18 ) and the first drive projection ( 10a ) is within the (axial) width of the first pump element ( 15a ) of the first gearing ( 15 ), so that an axial (narrower) gap, which a bearing of the first drive projection against the first side plate ( 14 ), and an axial (wider) gap, which a plant of the first drive projection against the intermediate wall element ( 7 ) are present.

• X1. Getriebepumpe, umfassend: eine Antriebswelle, die mit einer Antriebsquelle verbunden wird; eine erste Verzahnung, die von der Antriebswelle angetrieben wird und angeordnet ist, um eine erste Pumpe zu bilden; eine zweite Verzahnung, die von der Antriebswelle angetrieben wird und angeordnet ist, um eine zweite Pumpe zu bilden; ein Zwischenelement, das zwischen der ersten und zweiten Verzahnung angeordnet ist und mit einem Wellenloch ausgebildet ist, das sich durch das Zwischenelement erstreckt und die Antriebswelle aufnimmt; eine erste Seitenplatte, die so angeordnet ist, dass die erste Verzahnung zwischen der ersten Seitenplatte und dem Zwischenelement angeordnet ist; eine zweite Seitenplatte, die so angeordnet ist, dass die zweite Verzahnung zwischen der zweiten Seitenplatte und dem Zwischenelement angeordnet ist; und einen Verbindungsabschnitt, der die Antriebswelle mit der ersten und zweiten Verzahnung in einer Weise verbindet, dass eine relative Drehung verhindert und eine relative axiale Bewegung ermöglicht wird, wobei der Verbindungsabschnitt erste und zweite Antriebsvertiefungen, die jeweils in der ersten und zweiten Verzahnung ausgebildet sind, und erste und zweite Antriebsvorsprünge, die von der Antriebswelle radial nach außen vorstehen, mit der ersten bzw. zweiten Antriebsvertiefung in Eingriff gelangen und eine relative axiale Position der Antriebswelle in Bezug auf die erste und zweite Verzahnung zusammen mit dem Zwischenelement und/oder der ersten und zweiten Seitenplatte bestimmen, umfasst.
• X2. Getriebepumpe nach Anspruch X1, wobei der erste Antriebsvorsprung angeordnet ist, um die relative axiale Position der Antriebswelle in einer zweiten Richtung zu begrenzen, und der zweite Antriebsvorsprung angeordnet ist, um die relative axiale Bewegung der Antriebswelle in einer ersten Richtung entgegengesetzt zur zweiten Richtung zu begrenzen.
• X3. Getriebepumpe nach Anspruch X1 oder X2, wobei die erste Verzahnung ein drehbares erstes Pumpenelement umfasst, das in einer axialen Richtung gleitfähig auf der Antriebswelle befestigt ist und mit einer ersten Antriebsvertiefung in der Form eines Ausschnitts ausgebildet ist, der mit dem ersten Antriebsvorsprung der Antriebswelle in Eingriff gelangt, um die axiale Bewegung der Antriebswelle in Bezug auf die erste Verzahnung zu ermöglichen und die relative Drehung zu verhindern, so dass die Antriebswelle und das erste Pumpenelement als eine Einheit drehen, und die zweite Verzahnung ein drehbares zweites Pumpenelement umfasst, das in einer axialen Richtung gleitfähig auf der Antriebswelle befestigt ist und mit der zweiten Antriebsvertiefung in der Form eines Ausschnitts ausgebildet ist, der mit dem zweiten Antriebsvorsprung der Antriebswelle in Eingriff gelangt, um die axiale Bewegung der Antriebswelle in Bezug auf die zweite Verzahnung zu ermöglichen und die relative Drehung zu verhindern, so dass die Antriebswelle und das zweite Pumpenelement als eine Einheit drehen.
• X4. Getriebepumpe nach Anspruch X3, wobei eine axiale Breite des ersten Antriebsvorsprungs kleiner als eine Dicke des ersten Pumpenelements der ersten Verzahnung ist, und die axiale Breite des zweiten Antriebsvorsprungs kleiner als die Dicke des zweiten Pumpenelements der zweiten Verzahnung ist.
• X5. Getriebepumpe nach Anspruch X1, wobei zumindest der erste und/oder der zweite Antriebsvorsprung einen Antriebsstift umfasst, der feststehend in einem in der Antriebswelle ausgebildeten radialen Loch eingesetzt ist.
• X6. Getriebepumpe nach einem der Ansprüche X1 bis X5, wobei das Zwischenelement angeordnet ist, um die relative axiale Position der Antriebswelle in Bezug auf die erste und zweite Verzahnung zu bestimmen, indem die axiale Bewegung des ersten und zweiten Antriebsvorsprungs begrenzt wird.
• X7. Getriebepumpe nach einem der Ansprüche X1 bis X5, wobei die Getriebepumpe ferner ein erstes Anschlagelement, das axial zwischen dem Zwischenelement und der ersten Seitenplatte angeordnet ist und die axiale Bewegung der Antriebswelle in einer Richtung durch axiale Anlage gegen den ersten Antriebsvorsprung begrenzt, und ein zweites Anschlagelement, das axial zwischen dem Zwischenelement und der zweiten Seitenplatte angeordnet ist und die axiale Bewegung der Antriebwelle in der anderen Richtung durch axiale Anlage gegen den zweiten Antriebsvorsprung begrenzt, umfasst.
• X8. Getriebepumpe nach Anspruch X7, wobei das erste Anschlagelement zwischen dem Zwischenelement und dem ersten Antriebsvorsprung vorgesehen ist und das zweite Anschlagelement zwischen dem Zwischenelement und dem zweiten Antriebsvorsprung vorgesehen ist, und jedes der ersten und zweiten Anschlagelemente aus einem Material gefertigt ist, das härter als ein Material des Zwischenelements ist.
• X9. Getriebepumpe nach Anspruch X7, wobei sowohl das erste Anschlagelement als auch das zweite Anschlagelement ein ringförmiges Element ist, das sich radial nach außen über den ersten und zweiten Antriebsvorsprung hinaus erstreckt.
• X10. Getriebepumpe nach Anspruch X7, wobei sowohl das erste Anschlagelement als auch das zweite Anschlagelement in einen vertieften Bereich eingepasst ist, der in dem Zwischenelement oder den Seitenplatten ausgebildet ist.
• X11. Getriebepumpe nach einem der Ansprüche X1 bis X5, wobei das Zwischenelement einen Dichtungsaufnahmebereich umfasst, der sich in Richtung zur ersten oder zweiten Verzahnung öffnet, und die Getriebepumpe ferner ein Wellendichtungselement, das angeordnet ist, um einen Zwischenraum zwischen einem Außenumfang der Antriebswelle und dem Durchgangsloch des Zwischenelements abzudichten und in dem Dichtungsaufnahmebereich des Zwischenelements aufgenommen ist, und ein Anschlagelement, das den Dichtungsaufnahmebereich schließt, umfasst.
• X12. Getriebepumpe nach einem der Ansprüche X1 bis X5, wobei das Zwischenelement angeordnet ist, um direkt gegen den ersten oder zweiten Antriebsvorsprung anzuliegen und somit die axiale Bewegung der Antriebswelle zu begrenzen.
• X13. Getriebepumpe nach einem der Ansprüche X1 bis X5, wobei die erste und die zweite Seitenplatte angeordnet sind, um die relative axiale Position der Antriebswelle in Bezug auf die erste und zweite Verzahnung durch Begrenzen der axialen Bewegung des ersten und zweiten Antriebsvorsprungs zu bestimmen.
• X14. Getriebepumpe nach einem der Ansprüche X1 bis X5, wobei die Getriebepumpe ferner ein Gehäuse mit einem Innenhohlraum, der sich von einem offenen Ende zu einem Boden erstreckt und eine gestufte Schulterfläche aufweist, die in Richtung zum offenen Ende des Innenhohlraums gewandt ist, und ein Stopfenelement, welches das offene Ende des Innenhohlraums des Gehäuses schließt, umfasst, wobei das Zwischenelement axial in dem Innenhohlraum des Gehäuses durch Anlage gegen die gestufte Schulterfläche des Gehäuses positioniert ist, wobei die erste oder zweite Seitenplatte axial zwischen dem Boden des Innenhohlraums des Gehäuses und dem Zwischenelement eingeklemmt ist, und die jeweils andere Seitenplatte axial zwischen dem Zwischenelement und dem Stopfenelement eingeklemmt ist.
• X15. Getriebepumpe, umfassend: (i) eine Antriebswelle; (ii) ein drehbares Pumpenelement, das auf der Antriebswelle befestigt ist; (iii) ein Seitenwandelement, das auf einer Seite des Pumpenelements angeordnet ist und mit einem Wellenloch ausgebildet ist, durch welches sich die Antriebswelle erstreckt; (iv) eine Seitenplatte, die auf der anderen Seite des Pumpenelements angeordnet ist, so dass das Pumpenelement axial zwischen dem Seitenwandelement und der Seitenplatte angeordnet ist; und (v) einen Verbindungsabschnitt, der die Antriebswelle mit dem Pumpenelement in einer Weise verbindet, dass eine relative Drehung verhindert und eine relative axiale Bewegung zwischen der Antriebswelle und dem Pumpenelement ermöglicht wird, wobei der Verbindungsabschnitt eine Antriebsvertiefung, die im Pumpenelement ausgebildet ist, und einen Antriebsvorsprung, der von der Antriebswelle radial nach außen vorsteht, umfasst, wobei die Antriebsvertiefung so geformt ist, dass sie dem Antriebsvorsprung der Antriebswelle ermöglicht, sich axial in der Antriebsvertiefung zu bewegen, und wobei der Antriebsvorsprung so angeordnet ist, dass er in die Antriebsvertiefung eingreift, um die relative Drehung zu verhindern, um das Pumpenelement mit der Antriebswelle anzutreiben, und angeordnet ist, um die axiale Bewegung der Antriebswelle in Bezug auf das Pumpenelement mit dem Seitenwandelement oder der Seitenplatte zu begrenzen.
• X16. Getriebepumpe nach Anspruch X15, wobei die Antriebsvertiefung ein Ausschnitt ist, der so geformt ist, dass er dem Antriebsvorsprung der Antriebswelle ermöglicht, sich axial in der Antriebsvertiefung durch das Pumpenelement zu bewegen.

According to one possible interpretation of the illustrated embodiments according to the present invention, the following claims are possible:

• X1. A gear pump comprising: a drive shaft connected to a drive source; a first gear driven by the drive shaft and arranged to form a first pump; a second gear driven by the drive shaft and arranged to form a second pump; an intermediate member disposed between the first and second teeth and formed with a shaft hole extending through the intermediate member and receiving the drive shaft; a first side plate arranged so that the first toothing is disposed between the first side plate and the intermediate element; a second side plate arranged so that the second toothing is interposed between the second side plate and the intermediate member; and a connecting portion connecting the drive shaft to the first and second teeth in a manner to prevent relative rotation and allow relative axial movement, the connecting portion having first and second drive recesses formed in the first and second teeth, respectively; and first and second drive projections projecting radially outward from the drive shaft engage the first and second drive recesses, respectively, and a relative axial position of the drive shaft relative to the first and second teeth together with the intermediate member and / or the first and second teeth second side plate.
• X2. The transmission pump of claim X1, wherein the first drive projection is arranged to limit the relative axial position of the drive shaft in a second direction, and the second drive projection is arranged to limit the relative axial movement of the drive shaft in a first direction opposite to the second direction ,
• X3. A gear pump according to claim X1 or X2, wherein the first gear comprises a rotatable first pump member which is slidably mounted in an axial direction on the drive shaft and formed with a first drive recess in the form of a cutout, which engages with the first drive projection of the drive shaft in order to allow the axial movement of the drive shaft with respect to the first gearing and prevent the relative rotation, so that the drive shaft and the first pump element rotate as a unit, and the second gearing comprises a rotatable second pump element, which in an axial Direction is slidably mounted on the drive shaft and is formed with the second drive recess in the form of a cut which engages with the second drive projection of the drive shaft to allow the axial movement of the drive shaft with respect to the second gear and the relative rotation to verhin so that the drive shaft and the second pump element rotate as a unit.
• X4. A gear pump according to claim X3, wherein an axial width of the first drive projection is smaller than a thickness of the first pump element of the first gear, and the axial width of the second Drive projection is smaller than the thickness of the second pump element of the second toothing.
• X5. Transmission pump according to claim X1, wherein at least the first and / or the second drive projection comprises a drive pin which is fixedly inserted in a formed in the drive shaft radial hole.
• X6. Transmission pump according to one of claims X1 to X5, wherein the intermediate element is arranged to determine the relative axial position of the drive shaft with respect to the first and second teeth by the axial movement of the first and second drive projection is limited.
• X7. Transmission pump according to one of claims X1 to X5, wherein the gear pump further comprises a first stop member which is axially disposed between the intermediate member and the first side plate and limits the axial movement of the drive shaft in one direction by axial abutment against the first drive projection, and a second stop element axially disposed between the intermediate member and the second side plate and limiting the axial movement of the drive shaft in the other direction by axial abutment against the second drive projection includes.
• X8. A gear pump according to claim X7, wherein the first stopper member is provided between the intermediate member and the first drive projection and the second stopper member is provided between the intermediate member and the second drive projection, and each of the first and second stopper members is made of a material which is harder than a material of the intermediate element.
• X9. A gear pump according to claim X7, wherein both the first stopper member and the second stopper member is an annular member which extends radially outwardly beyond the first and second drive projection.
• X10. A gear pump according to claim X7, wherein each of the first stopper member and the second stopper member is fitted in a recessed portion formed in the intermediate member or the side plates.
• X11. A gear pump according to any one of claims X1 to X5, wherein the intermediate member includes a seal receiving portion which opens toward the first or second teeth, and the gear pump further comprises a shaft seal member arranged to form a clearance between an outer periphery of the drive shaft and the through hole of the drive shaft Seal intermediate member and is received in the seal receiving portion of the intermediate member, and a stopper member, which closes the seal receiving portion comprises.
• X12. Transmission pump according to one of claims X1 to X5, wherein the intermediate element is arranged to abut directly against the first or second drive projection and thus to limit the axial movement of the drive shaft.
• X13. Transmission pump according to one of claims X1 to X5, wherein the first and the second side plate are arranged to determine the relative axial position of the drive shaft with respect to the first and second teeth by limiting the axial movement of the first and second drive projection.
• X14. A gear pump according to any of claims X1 to X5, the gear pump further comprising a housing having an interior cavity extending from an open end to a bottom and having a stepped shoulder surface facing towards the open end of the interior cavity, and a plug member, which closes the open end of the inner cavity of the housing, wherein the intermediate member is positioned axially in the inner cavity of the housing by abutting against the stepped shoulder surface of the housing, the first or second side plate being clamped axially between the bottom of the inner cavity of the housing and the intermediate member is, and the other side plate is clamped axially between the intermediate member and the plug member.
• X15. A transmission pump comprising: (i) a drive shaft; (ii) a rotatable pump element mounted on the drive shaft; (iii) a sidewall member disposed on a side of the pump member and formed with a shaft hole through which the drive shaft extends; (iv) a side plate disposed on the other side of the pump element so that the pump element is disposed axially between the side wall element and the side plate; and (v) a connecting portion connecting the drive shaft to the pump member in a manner to prevent relative rotation and allow relative axial movement between the drive shaft and the pump member, the connecting portion having a drive recess formed in the pump member, and a drive projection projecting radially outwardly from the drive shaft, wherein the drive recess is shaped to allow the drive projection of the drive shaft to move axially in the drive recess, and wherein the drive projection is arranged to enter the drive recess engages to prevent the relative rotation to drive the pump element to the drive shaft, and arranged to limit the axial movement of the drive shaft with respect to the pump element with the side wall member or the side plate.
• X16. The gear pump according to claim X15, wherein the drive recess is a cutout shaped to allow the drive projection of the drive shaft to move axially in the drive recess through the pump member.

This application is based on an earlier Japanese Patent Application No. 2008-229191 , filed on September 8, 2008. The entire contents of this Japanese Patent Application are hereby incorporated by reference into this application.

Also when the invention above with reference to certain embodiments of the invention has been described, the invention is not limited to limited embodiments described above. Modifications and Modifications of the Embodiments Described Above will come to the expert in the light of the above teaching in mind. The scope of the invention is with reference to the following Claims defined.

Summarized For example, the present invention discloses a transmission pump incorporating a Drive shaft, a rotatable pump element that is on the drive shaft is fixed, a side wall member, which is on one side of the pump element is arranged and formed with a through hole through which extending the drive shaft, and a side plate on the other side of the pump element is arranged comprises. The Gear pump further includes a connecting portion, which the Drive shaft connects to the pump element in a way that prevents relative rotation and relative axial movement between the drive shaft and the pump element is made possible. The connecting portion comprises a drive recess, which in the pump element is formed, and a drive projection, which projects radially outwardly from the drive shaft and engages in the drive recess to the relative rotation to prevent. The drive projection is arranged around the axial Movement of the drive shaft with respect to the pump element Side wall element or the side plate to limit.

P1

first pump chamber

P2

second pump chamber

S1

first annular seal

S2

second annular seal

S3

annular sealing elements

S4

annular poetry

S5

poetry

S6

poetry

S7

annular poetry

S8

annular poetry

S9

annular poetry

S11

poetry

S12

poetry

1

transmission pump

2

casing

2a

mounting holes

3

pump assembly

4

pump chamber

4a

Female threaded portion

4b

annular shoulder surface

5

plug member

5a

Through Hole

5b

axial head Start

5c

threaded portion

5d

rear area

6

cover

6a

gap

6b

Through Hole

6c

axial head Start

6d

recessed Area

6e

front surface

6f

annular deepening

6g

radial head Start

6h

annular seal groove

6i

step region

7

intermediate element

7a

Through shaft hole

7b

insertion

7c

insertion

7d

Side seal area

7e

engagement projections

7f

Ring receiving recess

7g

Ring receiving recess with a smaller diameter

7h

annular seal groove

7i

axial head Start

8th

first pump

9

second pump

10

drive shaft

10a

drive pin

10b

front end

10c

drive pin

10d

radial Hole / recessed area

10e

radial Hole / well

11a

bearing shaft

11b

bearing shaft

12

Rotary sealing element

13a

first sealing ring

13b

second sealing ring

14

first side plate

14a, b, c

Through holes

14d

Side seal area

14e

seal block

14f

Passage area

14g

Tooth top sealing

14h

engagement area

14i

curved groove

14j

seal groove

15

first gearing

15a

drive gear

15b

powered gear

15c

teeth

15d

teeth

15e

engagement area

15f

deepening

16

retaining element

17

second side plate

17a, b, c

Through holes

17d

Side seal area

17e

seal block

17f

Passage area

17g

Tooth top sealing

17h

engagement area

17i

groove

17j

seal groove

18

second gearing

18a

drive gear

18b

powered gear

18c

teeth

18d

teeth

18e

engagement area

18f

drive recess

20

depression area

21

bearing element

22

gap

40

Outer sealing area / wall

41

Outer sealing area / wall

42

outer rotor

42a

Inside the posterior region

43

inner rotor

43a

Outside the posterior region

43b

drive recess

44

engagement area

45

pump chamber

46

driving projection

47

Through Hole

48

Through Hole

49

hollow area

50

inlet port

51

outlet

52

Through Hole

53

Through Hole

54

Fluid passage

55

inlet port

56

gap

57

Fluid passage

58

outlet

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - JP 2007-278085 [0002]
• - JP 2008-229191 [0141]

Claims (23)

Gear pump, comprising: a drive shaft, which is connected to a drive source; a first gearing, which is driven by the drive shaft and is arranged to to form a first pump; a second gearing made by the drive shaft is driven and arranged to a second pump to build; a sealing element between the first and second Toothing is arranged and formed with a shaft hole, which extends through the sealing element and the drive shaft receiving, wherein the sealing element is arranged to one of the Side surfaces of the first gearing and one of the side surfaces to seal the second toothing; a first side plate, which is arranged to the other of the side surfaces of the seal the first toothing; a second side plate, the is arranged to the other of the side surfaces of the second To seal the gearing; and a connecting section, the the drive shaft with the first and second teeth in one Way that prevents relative rotation and one relative axial movement is possible, wherein the connecting portion first and second drive recesses, each in the first and second teeth are formed, and first and second drive projections, projecting radially outwards from the drive shaft, with the first and second drive recess engage and a relative axial position of the drive shaft with respect to the first and second teeth together with the sealing element and / or the first and second side panels. Transmission pump according to claim 1, wherein the sealing element is arranged to the relative axial position of the drive shaft with respect to the first and second gearing with the first and second second drive projection to determine. Transmission pump according to claim 2, wherein the gear pump further comprises a stop element made of a material is harder than the material of the sealing element is, and that between one of the drive projections and the sealing element is arranged so that the relative axial Position of the drive shaft is determined by the stop element. Transmission pump according to claim 3, wherein the stop element is an annular member and a radial dimension from a central axis of the drive shaft to an outer end the drive projection adjacent to the stopper element is smaller as a radius of the stopper element. Transmission pump according to claim 1, wherein the gear pump further comprises a stop member axially between an adjacent Projection, which is one of the drive projections, and one adjacent side wall member, which is the sealing element or the is first and second side plate, is arranged, and the stop element is fitted in a recessed area, in the adjacent Sidewall element is formed and has a depth in the Is substantially equal to a thickness of the stop element. Transmission pump according to claim 1, wherein the first drive projection is arranged to the relative axial position of the drive shaft to determine on one side, and arranged the second drive projection is to determine the relative axial position on the other side. Transmission pump according to claim 6, wherein the first and second drive projection are arranged to the relative axial To determine the position of the drive shaft with the sealing element. Transmission pump according to claim 7, wherein the gear pump further comprises a stop element made of a material is harder than the material of the sealing element is, and that between one of the drive projections and the sealing element is arranged so that the relative axial Position of the drive shaft is determined by the stop element. Transmission pump according to claim 8, wherein the stop element is an annular member and a radial dimension from a central axis of the drive shaft to an outer end the drive projection adjacent to the stopper element is smaller as a radius of the stopper element. Transmission pump according to claim 1, wherein the sealing element a seal receiving area extending towards the first or second toothing opens, and the gear pump Further, a shaft seal member which is arranged to a Space between an outer periphery of the drive shaft and in the through hole of the sealing member, and in is received in the seal receiving area of the sealing element, and a stopper member closing the seal receiving area, comprising, wherein the sealing element and one of the drive projections are arranged to the relative axial position of the drive shaft to be determined by the stop element. The transmission pump according to claim 1, wherein an axial width of the first drive projection is smaller is a thickness of the first teeth, and the axial width of the second drive projection is smaller than the thickness of the second teeth. Gear pump, comprising: a drive shaft, which is connected to a drive source; a first gearing, which is driven by the drive shaft and is arranged to to form a first pump; a first pump chamber, in the the first gear is received; a second gearing, which is driven by the drive shaft and is arranged to to form a second pump; a second pump chamber, in the the second gearing is received; a separator that is arranged to separate the first and the second pump chamber, which is formed with a shaft hole, which extends through the Dividing element extends and receives the drive shaft, and the axial between one of the side surfaces of the first toothing and one of the side surfaces of the second toothing arranged is; a first side plate which is arranged around the other facing the side surfaces of the first toothing; a second side plate which is arranged around the other of the side surfaces to oppose the second gearing; and one Connecting portion of the drive shaft with the first and second Gearing in a way that connects a relative rotation prevents and allows relative axial movement is, wherein the connecting portion is a drive pin, the in the drive shaft is provided and away from the drive shaft extends radially outward, and a recess which in the first or second toothing is formed and with the drive pin engages, wherein the drive pin a limiting device for limiting the axial movement of the drive shaft together with forms the separating element or side plates. Transmission pump according to claim 12, wherein the limiting device is provided between the drive pin and the separating element. Transmission pump according to claim 13, wherein the gear pump further comprises a stop element made of a material is harder than a material of the separator, and which is arranged between the drive pin and the separating element. Transmission pump according to claim 14, wherein the stop element is an annular member and a radial dimension from a central axis of the drive shaft to an outer end the drive pin is smaller than a radius of the stop element. Transmission pump according to claim 15, wherein the separating element is formed with a recessed portion of the stopper element receives and has a depth that is substantially equal to a thickness the stop element is. Transmission pump according to claim 12, wherein the drive pin a first drive pin for driving the first toothing and a second drive pin for driving the second toothing includes, the first drive pin is arranged to the relative axial Limiting movement of the drive shaft in a second direction, and the second drive pin is disposed about the relative axial Movement of the drive shaft in a first direction opposite to limit to the second direction. Transmission pump according to claim 17, wherein the limiting device through the first and second drive pins and the separator is formed. Transmission pump according to claim 18, wherein the gear pump further comprises a stop element made of a material is harder than a material of the separator, and disposed between one of the drive pins and the separator is. Transmission pump according to claim 19, wherein a radial Dimension from a central axis of the drive shaft to an outer end the drive pin is smaller than a radius of the stop element. Transmission pump according to claim 12, wherein the separating element a seal receiving area extending towards the first or second toothing opens, and the gear pump Further, a shaft seal member which is arranged to a Space between an outer periphery of the drive shaft and to seal the through hole of the partition member, and in the Sealing receiving portion of the separating element is received, and a stopper member closing the seal receiving area, comprising, wherein the separating element and the drive pin arranged are the relative position of the drive shaft through the stopper to determine. A gear pump comprising: a drive shaft connected to a drive source; a first gear driven by the drive shaft and arranged to form a first pump; a first pumping chamber in which the first toothing is received; a second gear driven by the drive shaft and arranged to form a second pump; a second pump chamber in which the second Ver toothing is recorded; a separator arranged to separate the first and second pump chambers and disposed axially between one of the side surfaces of the first gear and one of the side surfaces of the second gear; a first side plate arranged to oppose the other of the side surfaces of the first gear; a second side plate arranged to oppose the other of the side surfaces of the second gear; and first and second drive pins projecting radially outwardly from the drive shaft and respectively engaging a first drive recess formed in the first gear and a second drive recess formed in the second gear, respectively, so that the first and second drive grooves engage second teeth are respectively driven via the first and second drive pins in a manner to permit relative axial movement, the first drive pin being arranged to permit axial movement of the drive shaft in a second direction with the first side plate or the separator limit, and the second drive pin is arranged to limit the axial movement of the drive shaft in a first direction opposite to the second direction with the second side plate or the separating element. Gear pump, comprising: a drive shaft; a Toothing, which is driven by the drive shaft; one Sidewall element arranged on one side of the toothing is; a side plate on the other side of the gearing is arranged so that the teeth between the side wall element and the side plate lies and is sealed to escape to prevent a working fluid; and a connecting section, which connects the drive shaft with the toothing in a manner that prevents relative rotation and relative axial movement between the drive shaft and the toothing allows is, wherein the connecting portion has a drive projection, the is provided in the drive shaft and radially from the drive shaft protrudes outward, and a drive recess, which in the toothing is formed and with the drive projection in Engaged, wherein an axial dimension of the drive projection is less than or equal to a width of the toothing, wherein the drive projection is arranged to relate to the axial movement of the drive shaft on the teeth with the side wall element or the side plate to limit.