FR2705740A1 - Adjustable gear pump. - Google Patents

Abstract

a) Adjustable gear pump comprising at least two pairs of juxtaposed toothed wheels in a housing, one of the pairs of toothed wheels comprising a driving toothed wheel integrally coupled in rotation to the motor shaft while the other pair or pairs of wheels toothed wheels comprise a toothed wheel which can be alternately driven or decoupled from the motor shaft. b) Gear pump characterized in that the toothed wheel (4) which can alternatively be driven or decoupled from the motor shaft (2) can be connected to the motor shaft (2) by a friction connection or can be fixed against the housing (1) by a friction connection or a shaped connection, known per se.

Description

"Adjustable gear pump"

  The present invention relates to a gear pump

  Adjustable treads comprising at least two pairs of toothed wheels juxtaposed in a housing and having the following structure: - pairs of parallel axis gear wheels are preferably associated with a common suction channel, but the corresponding pressure channels are directly connected or indirectly;

  - one of the pairs of toothed wheels comprises a wheel den-

  driving shaft integrally coupled in rotation to the

  while the other gear pair or pairs comprise a gear wheel which can alternatively be driven or decoupled from the drive shaft,

  - the toothed wheel which is alternately driven or de-

  coupled is fixed in the decoupled state.

  The invention also relates to a gear pump

  Adjustable treads comprising at least two pairs of toothed wheels juxtaposed in a housing and having the following structure: - pairs of toothed wheels mounted with

  parallel axes in separate chambers and having in common

  a suction channel and each time a pressure channel

  one of the pairs of toothed wheels comprises a driving gear coupled integrally in rotation with a driving shaft while the one or more pairs of wheels

  have a toothed wheel which can be alternatively

  driven by or disengaged from the drive shaft,

  in general, the invention relates to a gear pump

  with a pair of gears or preferably at

  minus two pairs of gears juxtaposed in a box.

  Such gear pumps are already known.

  US-A-1 796 814. These pumps are equipped with several pairs of gears, juxtaposed in a housing

  and among which one or more of the pairs of

  have, to regulate the flow, a pinion which can alternatively

  be driven by the motor shaft, this gear being

  fixed relative to the housing when decoupled. This pi

  toothed gear that is alternately driven or decoupled, is coupled by a shape connection at a time when in its coupled state to the drive shaft and in its decoupled state of the drive shaft and in this case it is coupled by

  a form connection with the housing via

of a ratchet lock.

  This embodiment is not suitable for

  appropriate coupling or decoupling of the drive shaft

  as well as an attachment to the housing for a pair of gear wheels, in the operating state, and

mechanically without problem.

  The present invention aims to develop

  a gear pump corresponding to the type defined above.

  above, allowing coupling or decoupling with respect to the drive shaft and attachment to the housing for at least one pair of gears regardless of the operating conditions, in a safe manner, and which

  can be operated preferably hydraulically.

  For this purpose the invention relates to a pump for

  graining corresponding to the type defined above characterized

  in that the toothed wheel which can alternatively be

  trailed or uncoupled from the motor shaft can be connected to the motor shaft by a friction connection or can be fixed against the housing by a friction connection or

  a form connection, known per se.

  The coupling of the toothed wheel which is alterna-

  driven or fixed and belongs to a pair of gears can, by a friction connection on the drive shaft, passenger of the state coupled to the decoupled state

  whatever the operating conditions.

  Advantageously, the friction connection with the motor shaft is provided by the force of a spring while for fixing on the housing, the friction force is maintained hydraulically or a form connection is made by a hydraulic way and we

keep it.

  According to another advantageous characteristic of

  the invention, the pressure channel of the wheel pair den-

  which attaches to the housing is connected or can be unloaded directly with a valve

  stop working at nominal pressure or a distribution

  2/3 way scorer connected to the common pressure channel

of the pair of gears.

  According to another advantageous characteristic of the invention, the toothed wheel which can alternatively be driven or decoupled from the drive shaft is connected to the drive shaft by a frictional connection, between the pairs of gear wheels there is each axially slide, In the above cases, for the pair of gears and decoupled, a hydraulic discharge is

  makes any fixing on the housing unnecessary.

  According to other advantageous features of the invention: the pump comprises a toothed wheel which can be alternately driven or decoupled from the motor shaft and can be coupled to the motor shaft by a device

  of coupling by a friction link commanded by

  on the promoter tree, and the pressure channel of the

  pair of gears can be connected directly with

  a stop valve operating at nominal pressure or a 2/3 way distributor to the accumulator

  pressure and the outlet pressure channel or be de-

loaded in the coupled state.

  The present invention will be described hereinafter in more detail by means of exemplary embodiments of the invention shown in the drawings in which: FIG. 1 is a longitudinal section of a

  gear pump according to the invention.

  FIG. 2 is a diagram of the hydraulic control

  of the gear pump according to the invention with directly connected pressure channels for the two pairs

gear wheels.

  FIG. 3 is a diagram of a hydraulic control

  1 of a gear pump according to the invention, the pair of gear wheels which can be coupled or decoupled having a common pressure channel, which can be cut and

  a pressure channel connected indirectly.

  Figure 4 shows a diagram of a hy-

  a gear pump according to the invention, the pair of gear wheels being couplable and uncoupled having a common pressure channel which can be cut

  and a pressure channel, dischargeable, connected in a

direct.

  The gear pump according to the invention,

  shown in Figure 1, includes a housing 1 containing a

  driving shaft 2 driven by an engine M and driving

  two pairs of toothed wheels 3; 3A and 4; 4A. Both

  toothed wheels 3A; 4A not directly driven are

  rotationally on an axis 5 secured to the housing 1.

  The toothed wheel 3 is permanently connected to the

  2. The gear pair 3, 3A de-

  cock so permanently when the motor shaft 2 rotates.

  The toothed wheel 4 turns freely on the axis of

  dragging 2; however, alternatively it can be driven indirectly from the drive shaft 2 by a frictional connection by means of the friction members 6,

  7 or be fixed with respect to the housing 1.

  The toothed wheel 4 comprises a bearing element provided with a coupling ring 8. This coupling ring 8, a transmission ring 9 and piston scraper rings 10, 11 are axially sliding relative to one another. other thanks to appropriate sliding profiles

  while being solidary in rotation.

  The transition ring 9 is mounted on the drive shaft 2, freely between the friction members 6,

7 integral with the motor shaft 2.

  The piston scraper segments 10, 11 are

  guided in a chamber 15 of the housing 1, so that

  che, in rotation and sliding and can be applied against the friction members 6, 7 associated on both sides, on the drive shaft 2, with the aid of a spring

spreader 12.

  The piston scraper segments 10, 11 can

  thus be put in frictional connection or in connection

  sound of form by an attachment pin 14, by the force of the

  spring spacer 12 and friction members 6, 7 solid-

  motor shaft 2 or by biasing the chamber halves 15A and 15B in the opposite direction to the

  spring spacer 12, to be connected with a link

  friction lug 13 integral in rotation with the housing 1.

  The hooking rods 14 pass through the chamber in the manner of a sheet; the attachment teeth of the axial surfaces of the piston scraper rings 10, 11 creating when applied, a form connection not shown. To accentuate the frictional connection, for the driving of pairs of toothed wheels 4; 4A by the motor shaft 2, it is possible to provide the friction members 6, 7 and the piston scraper rings 10, 11 with complementary cones or interior cones.

  The corresponding control scheme is repre-

  Figure 2. This figure shows the pairs of toothed wheels 3, 3A; 4; 4A as the independent pump units shown schematically. These pairs of toothed wheels 3; 3A and 4; 4A directly feed a pressure channel

common 19.

  The coupling device 20 is composed as de-

  Ia described, parts bearing the references 6 to 12. The chamber halves 15A and 15B corresponding to the housing 1, are fed by the channels A and B (see Figure 1) by a valve or valve distributor 21 to 2/3 channels controlled

  by the pressure in the pressure channel 19.

  The feeding and the evacuation is done by the pressure channel 19. The pair of toothed wheels 4; 4A also remains

  stressed by the pressure in the pressure channel

  sion 19 even when decoupled and immobile.

  Advantageously, between the pairs of wheels

  toothed 3; 3A; 4, 4A, one can predict each time a clo-

  its sealing 16, preferably axially sliding.

  This partition prevents the pair of toothed wheels 4; 4A from

  movable does not undergo a hydraulic influence, for example by the marginal vortex of the gear pair

3; 3A that runs continuously.

  In the embodiment thus described, to reduce the retaining torque and to prevent leakage losses at the pair of toothed wheels 4;

  housing 1 it is provided for the separate pressure channel 19A.

  re of this pair of gears the interposition of a stop valve 17 controlled by the pressure in the pressure channel 19 and connected to the common pressure channel

7 2705740

  19 pairs of toothed wheels 3; 3A; 4; 4A (see Figure 3).

  This stop valve 17 advantageously forms with the

  21, a combined distribution unit, commissioned in

pressure in a common way.

  In another embodiment of the invention according to claim 10, with pairs of toothed wheels 3; 3A; 4; 4A (see also Fig. 4) which are spatially separated by a sliding partition 16, a hydraulic discharge is effected on the pressure side of the toothed wheel 4,4A, in the decoupled state, via a

  18/2-way drawer distributor controlled by the press

  sion in the pressure channel 19. As a result,

  There is no need to secure the attachment to the casing 1. The

  corresponding control min appears in Figure 3; the

  representation mode corresponds to Figure 4. The distribution

  drawer scorer 18 to 2/3 ways and the distributor 21 are combined in the form of a set controlled jointly by

  pressure. The construction described above gives us

  also because of the sliding wall 16, pressurized, of the chamber of the pair of gears 3; 3A, and which continuously delivers, an additional braking torque for the pair of decoupled wheels 4; 4A. The braking torque is created by tightening the pair of

  toothed wheels 4, 4A between the partition 16 and the housing 1.

  A pressure limiting valve 23 is provided

  view in all the embodiments of the hy-

  hydraulics between the pressure channel 19 and the channel

  common suction of the pair of gears.

  One could also consider a pump

  switchable graining described with only one pair of switchable gears and with a pressure accumulator; depending on its pressure or its degree of filling, the gear pair is coupled or uncoupled and the pressure is released in the decoupled state. This

  embodiment is not shown separately.

8 2705740

  List of part numbers 1 Housing 2 Motor shaft 3 Drive gear 3A Drive gear 4 Gear wheel which is alternately driven or which is fixed relative to the gearbox 4A Driven gear wheel Gear wheel axle 3A; 4A 6 Friction element integral with the drive shaft 2 7 Friction element integral with the drive shaft 3 8 Coupling ring 9 Transmission ring Piston scraper segment 1il Piston scraper segment 12 Spreader spring 13 Friction ring, jointly guided rotating in the housing 1 14 Friction rod Chamber 15A: 15B Chamber halves 16 Partition 17 Shut-off valve 18 2/3 way distributor 19 Pressure channel 19A Pressure channel of gear pair 4; 4A Device coupling 21 2/3 way spool valve 23 Pressure limiting valve

M Engine.

Claims (10)

R E V E N D I C A T IONS   1) Adjustable gear pump with   at least two pairs of toothed wheels juxtaposed in a box   and having the following structure: - pairs of parallel-axis gear wheels are preferably associated with a common suction channel,   However, the corresponding pressure is directly indirectly or indirectly;   - one of the pairs of toothed wheels comprises a wheel den-   driving shaft coupled integrally in rotation to the motor shaft while the one or more other pairs of toothed wheels comprise a toothed wheel which can alternatively be driven or decoupled from the drive shaft,   - the toothed wheel which is alternately driven or de-   coupled is set in the decoupled state, gear pump characterized in that the gear wheel (4) which can alternatively be driven   decoupled from the driving shaft (2) can be connected to the   motor (2) by a friction connection or can be fixed against the housing (1) by a friction connection   or a form connection, known per se.   2) Gear pump, adjustable according to the   cation 1, characterized in that piston scraper segments (10; 11) are integrally connected in rotation but axially movable in opposite directions to the toothed wheel (4) which can alternatively be driven or decoupled, and can be friction connection alternately with friction members (6; 7) integral in rotation   motor shaft (2) or with friction surfaces   lidar rotation of the housing (1).   3) Gear pump according to Claim 1, characterized in that the axially movable piston scraper rings (10, 11) are held in a friction connection with friction members (6; 7) integral in rotation with each other. engine shaft (2) by the force of a spring.   4) Gear pump according to claim 3,   characterized in that the friction members (6;   carry cones directed against complementary inner cones in piston scraper segments (10,11) axially movable.   Gear pump according to Claim 1, characterized in that the axially movable piston scraper rings (10, 11) are radially sealed in a chamber (15) of the casing (1) to form a pressure cylinder. being capable of being engaged by a frictional connection or by means of counter-clockwise action on the integral friction surfaces housing rotation (1).   6) Gear pump according to claim 1, characterized in that the integral friction surfaces in rotation of the housing (1) are formed by a friction ring (13) integral with the housing (1), provided between the axial surfaces directed to one another segments piston scrapers (l10; 1).   7) Gear pump according to claim 1,   characterized in that the solidly   rotation in the housing (1) are formed by   gripping arms (14) distributed in the form of a tablecloth   and which can be engaged with the interlocking teeth   quetting against the axial surfaces of the scraper segments piston (10; 11).   8) Gear pump according to claim 1, characterized in that between the pairs of gear wheels (3; 3A; 4; 4A) there is in each case a sealing partition (16). 9) Gear pump according to claim 1, characterized in that the chamber halves (15A;   are solicited by a valve (21) which is   nominal pressure, when the nominal pressure is exceeded or can be discharged when this pressure is released.   10) Gear pump according to claims 1   and 8, characterized in that the pressure channel (19A) of the pair of gears (4; 4A) which attaches to the housing (1) is connected or can be discharged directly with the interposition of a shut-off valve. (17) working at rated pressure or a 2/3 way distributor connected to the common pressure channel (19) of the wheel pair toothed (3; 3A; 4,4A).   11) Gear pump according to claims 9   and 10, characterized in that the valve (21) controlled by the nominal pressure forms an assembly mechanically coupled with the shut-off valve (17)   or the 2/3 way distributor (18).   12) Adjustable gear pump having at   at least two pairs of toothed wheels juxtaposed in a box   tier and having the following structure:   - pairs of gear wheels mounted with parallel axes   in separate chambers with a common suction channel and a pressure channel   - one of the pairs of toothed wheels comprises a wheel den-   driving shaft coupled integrally in rotation to a drive shaft while the one or more pairs of gear wheels comprise a gear which can be alternately driven by or disengaged from the drive shaft, characterized in that   - the toothed wheel (4) which can alternatively be   born or uncoupled from the drive shaft (2) is connected to   motor (2) by a friction connection, - between pairs of toothed wheels (3; 3A; 4; 4A) there is   each time a partition (16) sealing that can cou-   axially smoothing, - the pressure channel (19A) of the detachable pair of gears (4; 4A) can be connected or discharged through a pressure channel common to the pair of gears (3; 3A; 4 4A) by interposition of a distributor to 2/3, channels (18). 13) Gear pump, adjustable having a pair of gear wheels characterized in that it comprises a gear which can be alternately driven or decoupled from the motor shaft can be coupled on   the motor shaft by a coupling device via a link   pressure-controlled friction on the propeller shaft   tor, and the pressure channel of the gear pair   can be directly connected with the interposition of a   stopper working at nominal pressure or   2/3 way tribulator to the pressure accumulator and   outlet pressure channel or be discharged in the ple.