US3644072A - Hydraulic gear pumps and motors - Google Patents

Hydraulic gear pumps and motors Download PDF

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Publication number
US3644072A
US3644072A US856108A US3644072DA US3644072A US 3644072 A US3644072 A US 3644072A US 856108 A US856108 A US 856108A US 3644072D A US3644072D A US 3644072DA US 3644072 A US3644072 A US 3644072A
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United States
Prior art keywords
gears
bearings
ducts
casing
duct
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Expired - Lifetime
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US856108A
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English (en)
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Robert Gelin
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Sigma
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Sigma
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C14/00—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations
    • F04C14/24—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valves
    • F04C14/26—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valves using bypass channels
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C2/00—Rotary-piston machines or pumps
    • F04C2/08—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
    • F04C2/12—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type
    • F04C2/14—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons

Definitions

  • This invention relates to improvements in hydraulic gear pumps and motors having component parts in common and being capable of different displacements or deliveries per revolution, particularly though not exclusively those disclosed in the aforementioned patents, as representative of a class of hydraulic volumetric machinery having a generally analogous concept.
  • Such machinery comprises essentially a casing, two intermeshing gears inside the casing and mounted, respectively, on a driving shaft protruding through one side of the casing and on a driven shaft entirely within the casing.
  • the shafts whose axes are spaced apart an interaxial distance E, are carried on each side thereof by a common bearing, which is rigid and movable in the axial direction toward the casing interior.
  • Other parts including bearings, gaskets, and side plates (front and rear), complete such machinery, whose displacement depends essentially upon the gears, characterized by a modulus or diametral pitch m, number of teeth N, tooth width 1 and finally a tooth correction having to do with the geometric profile of the teeth.
  • a primary object of the present invention is provision of families of volumetric machinery of this kind such that the number of parts common to machinery in the same family is increased and that consequently such machinery can be constructed beginning with a more limited stock of parts.
  • the invention consists principally, in a family of machinery of this kind, in obtaining differences in displacement among different members of the family, by effecting variation in at least one of the following parameters: the modulus m, the number of teeth N, and the tooth width 1; while maintaining constant the interaxial distance E (between the axes of the driving and driven shafts), and minimizing variations in external diameter of the gears, in such a way that the driving and driven shafts in the same family have the same dimensions independent of the displacement and that preferably the overall dimensions of the casings of the members of the same family are identical.
  • the invention consists in certain arrangements used preferably together but also capable of being used separately when the occasion arises and as will be specified hereinafter, especially in an arrangement relating more particularly to a return pathway for the internal leakages of each member of the family of the kind in question, which consists in providing for this pathway a direct line. It comprises, on the one hand, two ducts bored respectively in each of the bearings in the vicinity of the driving shaft and the gear carried thereby and extending substantially perpendicular to the axial direction and, on the other hand, drains bored in the casing enabling the ducts to be connected to the zone of low pressure.
  • FIG. 1 is an axial sectional elevation, taken along 1-1 on FIG. 2, of a gear pump according to this invention
  • FIG. 2 is a transverse sectional elevation thereof taken along IIII on FIG. 1;
  • FIG. 3 is a sectional plan, taken along III-III on FIG. 1, with the gears removed;
  • FIG. 4 is a fragmentary sectional plan taken along IV-IV on FIG. 2.
  • the pump comprises, according to the arrangements disclosed in the aforementioned patent documents, a casing 1 and two sideplates (front and rear) 2 and 2a, held together by screws 3, and comprises also two intenneshing gears 4 and 5 disposed in two blind bores 6 and 7.
  • Gear 4 is affixed by means of key 50 to driving shaft 8, which protrudes through sideplate 2a only.
  • Shaft 8 turns in the direction indicated by arrow F (FIG. 2).
  • An intake opening 9 and a discharge opening 10 communicate with the region of overlapping of bores 6 and 7.
  • Gear 5 is itself affixed by means of another key (not shown) to driven shaft 11, which does not protrude through either of sideplates 2 and 2a.
  • a packing gland 21 is provided where shaft 8 passes through sideplate 2a.
  • Shafts 8 and 11 are arranged parallel to one another in bearings 12 and 12a, located on opposite sides of the gears, each being a rigid one-piece bearing having approximately a figure-eight configuration.
  • Interaxial distance E between the axes of the driving and driven shafts is indicated in FIGS. 1 and 2.
  • Bearings 12 and 12a are housed, respectively, in blind bores 13, 14 and 13a, 14a coaxial with bores 6 and 7 in the casing.
  • Roller bearings 15, 16 and 15a, 16a are advantageously placed between bearings 12 and 12a and respective shafts 8 and 1 1.
  • each bearing 12, 12a furtherrnost from the side of the corresponding gear forms one of the inside walls of a chamber 24 or 240 which receives liquid under pressure tending to displace the bearing concerned toward the side of the gear.
  • the liquid is conducted away from the discharge of the pump by channels (not visible) traversing the bearings.
  • Stop means are provided limiting, at a value slightly greater than tooth width l (FIG. 1), minimum distance d (also FIG. 1) between the opposing faces of bearings 12 and 12a.
  • the stop means advantageously are made up of shoulders 17, 17a and 18, provided in pump casing 1 between central bore 6 or 7 and side bores 13, 13a or 14, 14a. Shoulders 17, 17a and 18, 18a are thus separated by distance 11'.
  • the shoulders in question are made up of the edges of an extra thickness of the body of easing 1, with bores 6 and 7 each having diameter 2 (FIG. 2) slightly less than those of side bores 13, 13a and 14, 14a.
  • Rabbets 19, 19a and 20, 20a cut into the side bores of the casing permit a reduction in the guideways of bearings 12 and 12a.
  • Gears 4 and 5 are shown with enough axial clearance that they can be centered automatically by abutment of bearings 12 and 12a against shoulders 17, 17a and 18, 18a.
  • Annular gaskets 26, 26a and 27, 27a isolate the liquid under pressure in chambers 24, 24a from the outside or zones 28, 280 under low or intake pressure by a leakage pathway, as will be seen hereinafter.
  • Spacer rings 29, 29a and 30, 30a function as axial thrust bearings.
  • Spacer rings 30, 30a are designed so as to enable liquid under pressure in chambers 24, 24a to fill freely zones 32, 32a located adjacent the ends of shaft 11. To do so these rings have, on their faces bearing against sideplates 2 and 2a, radial grooves 51, 51a intercommunicating between zones 32, 32a and all of respective chambers 24, 24a.
  • gears 4 and 5 When gears 4 and 5 are set into rotation in the direction of arrows F, and F respectively, they drive liquid from intake opening 9 toward discharge opening 10 (FIG. 2) confining it in cells 52 having cross section 8 (also FIG. 2) bounded by the hollows between the gear teeth, the adjacent inside walls of bearings 12 and 12a, and bores 6 and 7. The liquid is displaced in the direction of arrows F
  • the discharge pressure which is built up in chambers 24 and 24a forces the bearings against their stops, centering the gears without hindering their rotation.
  • the compressive forces acting upon the opposite ends of shaft 11 balance it.
  • tooth width 1 An important disadvantage of such variation in tooth width 1 is a resulting variation in the length of driving shaft 8 and driven shaft 11 within the same family. Accordingly, casing 1 for the same family retained a constant height L (FIG. 2) but had a variable length L (FIGS. 1 and 3) so that a single model of bearings 12, 12a would fit only one such length.
  • the interaxial distance E (FIGS. 1 and 2) is kept constant, with the aid of tooth corrections, i.e., by slightly altering the profile of teeth 53.
  • the tooth correction affects chiefly the tooth height h (FIG. 2) and, therefore, the
  • tooth corrections can be accomplished alone, independently of variations in modulus or in number of teeth, so as to produce changes in displacement. For example, for the same modulus, a reduction in tooth height reduces cross section S and hence the displacement.
  • casing 1 can be obtained starting with identical rough outlines having an extra thickness provided in the region of bores 6 and 7.
  • Final diameter 2 is obtained during the fine machining of bore 6.
  • Displacement variations as a function of tooth height are rather great and can be continuous between an upper limit and a lower limit.
  • cross section S (FIG. 2) has substantially the shape of an isosceles trapezoid and that a variation in tooth height amounts to displacing parallel thereto the long side of the trapezoid, which produces a rapid variation in area.
  • dimension 1 (the tooth width) remains constant for the same family, and only one model of driving shaft and one model of driven shaft will be enough for all the pumps in the family. The same is true for the affixing keys 50.
  • interaxial distance E is kept constant and the parts that were common to pumps in the same family, in the case where displacement variations were obtained by variations in I alone, remain so.
  • bearings 12 and 12a and sideplates 2 and 2a are common to all the pumps.
  • a direct line (FIG. 4) is provided for such return pathway, comprising: on the one hand, two ducts 54 and 54a bored, respectively, in bearings 12 and 12a in the vicinity of driving shaft 8 and gear 4 carried thereby and which extend substantially perpendicular to the direction of the driving and driven shafts; on the other hand, drain channels 55, 56, and 57 bored through casing l, enabling aforementioned ducts 54 and 54a to be connected to the zone of low pressure, i.e., the intake zone for a pump.
  • Channel 57 is coaxial with duct 54a and opens to the outside so as to be connected to the intake zone. Draining of the leakages by duct 54a is accomplished then in a straight line, as directly as possible.
  • Channel 55 is coaxial with and of the same diameter as duct 54, which it continues in casing 1.
  • Plug 58 stops the outlet of channel 55 at the outer wall of the casing.
  • Channel 56 connects channels 55 and 57. Its end that opens against sideplate 2a is stopped by plug 59.
  • channel 57 is greater than that of ducts 54 and 54a because channel 57 receives the leakages flowing out from the two ducts toward the intake.
  • the cross section of channel 57 is substantially equal to the sum of the cross sections of ducts 54 and 54a.
  • Such a pathway can be especially beneficial when it is applied to an hydraulic motor.
  • the internal leakages increase considerably and must be drained rapidly; otherwise the pressure can increase drastically in zones 28 and 28a and deteriorate the packing gland.
  • the leakage pathway permits these increases or instantaneous peaks of pressure to be reduced.
  • a hydraulic gear pump or motor having a casing with an intake and an outlet forming respectively a highor lowpressure zone, two intermeshing gears therein, a driving shaft with one of the gears affixed thereon, a driven shaft with the other of the gears affixed thereon, rigid bearings flanking the gears and supporting the shafts for rotation on rotary bearings.
  • the improvement comprising at least one interior leakage passageway opening at the side of said rotary bearings nearest the gears including a duct through the rigid bearings between an interior location adjacent the outlet and an interior location adjacent the intake and thereby communicating with said low-pressure zone, each such duct extending substantially perpendicular to the plane passing through the axes of said shafts.
  • Hydraulic volumetric apparatus constituting a gear motor with rapid reversal of its direction of rotation.
  • each such duct is located adjacent the driving shaft.
  • each such duct is also located adjacent one side of the gear affixed on the driving shaft.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Rotary Pumps (AREA)
  • Hydraulic Motors (AREA)
US856108A 1968-09-09 1969-09-08 Hydraulic gear pumps and motors Expired - Lifetime US3644072A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR165536 1968-09-09

Publications (1)

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US3644072A true US3644072A (en) 1972-02-22

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US856108A Expired - Lifetime US3644072A (en) 1968-09-09 1969-09-08 Hydraulic gear pumps and motors

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US (1) US3644072A (enrdf_load_stackoverflow)
JP (1) JPS4924482B1 (enrdf_load_stackoverflow)
FR (1) FR1584193A (enrdf_load_stackoverflow)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4840965A (en) * 1987-07-07 1989-06-20 Syntex (U.S.A.) Inc. Naphthalene anti-psoriatic agents

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5754308U (enrdf_load_stackoverflow) * 1980-09-13 1982-03-30

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1940410A (en) * 1930-10-02 1933-12-19 Auburn Foundry Pumping apparatus
US2627232A (en) * 1948-09-07 1953-02-03 Borg Warner Hydraulic power unit
US2672100A (en) * 1949-07-01 1954-03-16 United States Steel Corp Construction for rotary pumps
US2769396A (en) * 1953-09-28 1956-11-06 Borg Warner Pressure loaded gear pump
US3043230A (en) * 1956-06-30 1962-07-10 Eckerle Otto High pressure gear pump
US3173374A (en) * 1962-12-31 1965-03-16 Clark Equipment Co Bearing for pumps and motors
US3395646A (en) * 1965-02-16 1968-08-06 Mecanique Appliquee S I G M A Hydraulic gear pumps and motors

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1940410A (en) * 1930-10-02 1933-12-19 Auburn Foundry Pumping apparatus
US2627232A (en) * 1948-09-07 1953-02-03 Borg Warner Hydraulic power unit
US2672100A (en) * 1949-07-01 1954-03-16 United States Steel Corp Construction for rotary pumps
US2769396A (en) * 1953-09-28 1956-11-06 Borg Warner Pressure loaded gear pump
US3043230A (en) * 1956-06-30 1962-07-10 Eckerle Otto High pressure gear pump
US3173374A (en) * 1962-12-31 1965-03-16 Clark Equipment Co Bearing for pumps and motors
US3395646A (en) * 1965-02-16 1968-08-06 Mecanique Appliquee S I G M A Hydraulic gear pumps and motors

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4840965A (en) * 1987-07-07 1989-06-20 Syntex (U.S.A.) Inc. Naphthalene anti-psoriatic agents

Also Published As

Publication number Publication date
JPS4924482B1 (enrdf_load_stackoverflow) 1974-06-24
FR1584193A (enrdf_load_stackoverflow) 1969-12-12

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