EP0667453A1 - Gear for gear pumps - Google Patents

Gear for gear pumps Download PDF

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Publication number
EP0667453A1
EP0667453A1 EP95420030A EP95420030A EP0667453A1 EP 0667453 A1 EP0667453 A1 EP 0667453A1 EP 95420030 A EP95420030 A EP 95420030A EP 95420030 A EP95420030 A EP 95420030A EP 0667453 A1 EP0667453 A1 EP 0667453A1
Authority
EP
European Patent Office
Prior art keywords
gear
flat
matrix
distance
toothing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP95420030A
Other languages
German (de)
French (fr)
Other versions
EP0667453B1 (en
Inventor
Henri Gueydan
Gérard Puente
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sintertech SAS
Original Assignee
Sintertech SAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sintertech SAS filed Critical Sintertech SAS
Publication of EP0667453A1 publication Critical patent/EP0667453A1/en
Application granted granted Critical
Publication of EP0667453B1 publication Critical patent/EP0667453B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • 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
    • F04C2/082—Details specially related to intermeshing engagement type machines or pumps
    • F04C2/084—Toothed wheels
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
    • B22F5/08—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product of toothed articles, e.g. gear wheels; of cam discs
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/12—Both compacting and sintering
    • B22F3/16—Both compacting and sintering in successive or repeated steps
    • B22F3/164—Partial deformation or calibration
    • B22F2003/166—Surface calibration, blasting, burnishing, sizing, coining
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
    • B22F2998/10—Processes characterised by the sequence of their steps
    • 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
    • F04C2230/00—Manufacture
    • F04C2230/20—Manufacture essentially without removing material
    • F04C2230/22—Manufacture essentially without removing material by sintering

Definitions

  • the invention relates to a gear for a gear pump and a manufacturing method.
  • the gears of gear pumps are generally obtained by powder metallurgy.
  • the gears according to the invention therefore comprise an external surface forming the toothing and 2 parallel lateral faces, on which there is in relief a continuous and closed rib, located in the vicinity of the toothing, of any section, and carrying at its top a flat width 1 between 0.5 and 2 mm.
  • This flat is located at a distance d from the outer edge of the gear, generally between 0 and 5 mm, preferably between 0 and 2.5 mm, and more particularly at 0.5 mm ⁇ 0.1 mm.
  • the powder is compressed in a tool comprising an annular matrix with the design of the teeth and 2 punches carrying in hollow, on each of their active surfaces, a concave groove, continuous and closed on itself, located in line with the final ribs.
  • These ribs preferably have a convex shape in cross section, with positive undercuts, such as triangle, trapezoid, 1 ⁇ 2 hexagon, 1 ⁇ 2 circle, 1 ⁇ 2 ellipse, allowing its easy extraction of tools.
  • positive undercuts such as triangle, trapezoid, 1 ⁇ 2 hexagon, 1 ⁇ 2 circle, 1 ⁇ 2 ellipse, allowing its easy extraction of tools.
  • the distance between the lateral faces is such that, given the sintering shrinkage, it is slightly less than that of the gear housing in the pump, the distance between the tops of the ribs being slightly greater than that -this.
  • the sintered gear is then cold calibrated in an annular matrix using 2 lower and upper punches to ensure the final geometry of the teeth. These punches do not occupy the entire lateral surface of the gear and leave free an outer ring sparing the ribs.
  • the calibrated sintered part undergoes a slight plastic deformation of the top of the ribs between 2 punches with parallel faces, perpendicular to the axis, to bring the dimension between the flats of the ribs to the desired value.
  • This dimension is determined using a mechanical stop, on a hydraulic press or a mechanical press with hydraulic adapter.
  • FIG. 1 represents a gear 1 according to the invention comprising an external toothing 2 of a primitive circle 7 and two lateral faces 3 and 4 (fig. 2).
  • a rib 5 On each of the lateral faces is a rib 5, the profile of which is shown in 6, about 1mm in width, 0.3mm in height and situated approximately 0.5mm from the edge of the toothing 2.
  • FIG. 3 represents the device for compressing the powder in which an annular matrix 10, of axis 11, a lower punch 15, of the same axis 11, is recognized, comprising a circular groove 12i in the form of a half-torus whose dimensions are reported in fig.4 and an upper punch 13, of the same axis 11, also provided with an identical circular groove 12s.
  • the compressed part is shown at 14.
  • the part 14 is calibrated in an annular die 20 (fig. 5), between two lower 21 and upper 22 punches, having at their flat ends an annular recess 23 (fig. 6).
  • annular die 20 fig. 5
  • lower 21 and upper 22 punches having at their flat ends an annular recess 23
  • FIG. 6 there is shown at 24 in dotted lines, the profile of the part 14, before calibration.
  • the toothing (2) has its final geometry and surface condition.
  • the calibrated part is then placed in a flat bottom finishing matrix 17 (fig. 7) where it is crushed by a flat punch 18, the stroke of the latter being limited by the matrix itself forming a stop, which prints on the ribs 5 the flats 6, at a very precise distance h from each other.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Powder Metallurgy (AREA)

Abstract

Toothed gear is claimed for a geared pump incorporating a set of teeth (2) and two parallel lateral faces (3,4). Each lateral face carries a raised continuous and closed rib (5), which presents a ledge (6) at its top with a width of between 0.5 and 2 mm. This ledge is between 0 and 5 mm, and preferably between 0 and 2.5 mm, from the edge of the teeth. The method used to fabricate this gear is also claimed.

Description

L'invention a pour objet un engrenage pour pompe à engrenages et un procédé de fabrication.The invention relates to a gear for a gear pump and a manufacturing method.

Les engrenages de pompes à engrenages, en particulier celles utilisées dans l'industrie automobile, sont généralement obtenus par métallurgie des poudres.The gears of gear pumps, in particular those used in the automotive industry, are generally obtained by powder metallurgy.

Cependant, dans le procédé classique de fabrication, les tolérances dimensionnelles entre les faces latérales des pignons, nécessaires à l'obtention d'une bonne étanchéité et en conséquence d'une pression suffisante, surtout aux faibles régimes du moteur, exigent un usinage mécanique précis (+0/-0,02 mm) des faces latérales. Cette opération est coûteuse et prend beaucoup de temps.However, in the conventional manufacturing process, the dimensional tolerances between the lateral faces of the pinions, necessary for obtaining a good seal and consequently sufficient pressure, especially at low engine speeds, require precise mechanical machining. (+ 0 / -0.02 mm) of the side faces. This operation is expensive and takes a long time.

La demanderesse a donc cherché à supprimer cette opération.The plaintiff therefore sought to suppress this operation.

Les engrenages selon l'invention comportent donc une surface externe formant la denture et 2 faces latérales parallèles, sur lesquelles se trouve en relief une nervure continue et fermée, située au voisinage de la denture, de section quelconque, et portant à son sommet un méplat de largeur 1 comprise entre 0,5 et 2 mm.
Ce méplat est situé à une distance d du bord externe de l'engrenage, généralement comprise entre 0 et 5 mm, de préférence entre 0 et 2,5 mm, et plus particulièrement à 0,5 mm ± 0,1 mm.The gears according to the invention therefore comprise an external surface forming the toothing and 2 parallel lateral faces, on which there is in relief a continuous and closed rib, located in the vicinity of the toothing, of any section, and carrying at its top a flat width 1 between 0.5 and 2 mm.
This flat is located at a distance d from the outer edge of the gear, generally between 0 and 5 mm, preferably between 0 and 2.5 mm, and more particularly at 0.5 mm ± 0.1 mm.

Le procédé de fabrication comporte les opérations suivantes :

  • compression de la poudre
  • frittage de l'ébauche comprimée
  • et calibrage de la pièce frittée.
The manufacturing process includes the following operations:
  • powder compression
  • sintering of the compressed blank
  • and calibration of the sintered part.

La poudre est comprimée dans un outillage comprenant une matrice annulaire au dessin de la denture et de 2 poinçons portant en creux, sur chacune de leurs surfaces actives, une rainure concave, continue et fermée sur elle-même, située au droit des nervures finales.The powder is compressed in a tool comprising an annular matrix with the design of the teeth and 2 punches carrying in hollow, on each of their active surfaces, a concave groove, continuous and closed on itself, located in line with the final ribs.

Ces nervures ont de préférence en section droite une forme convexe, avec dépouilles positives, tel que triangle, trapèze, ½ hexagone, ½ cercle, ½ ellipse, permettant son extraction aisée des outillages.
Lors de cette compression, la distance entre les faces latérales est telle que, compte tenu du retrait au frittage, elle est légèrement inférieure à celle du logement de l'engrenage dans la pompe, la distance entre les sommets des nervures étant légèrement supérieure à celle-ci.These ribs preferably have a convex shape in cross section, with positive undercuts, such as triangle, trapezoid, ½ hexagon, ½ circle, ½ ellipse, allowing its easy extraction of tools.
During this compression, the distance between the lateral faces is such that, given the sintering shrinkage, it is slightly less than that of the gear housing in the pump, the distance between the tops of the ribs being slightly greater than that -this.

L'engrenage fritté est ensuite calibré à froid dans une matrice annulaire à l'aide de 2 poinçons inférieur et supérieur pour assurer la géométrie finale de la denture. Ces poinçons n'occupent pas toute la surface latérale de l'engrenage et laissent libre une couronne extérieure épargnant les nervures.The sintered gear is then cold calibrated in an annular matrix using 2 lower and upper punches to ensure the final geometry of the teeth. These punches do not occupy the entire lateral surface of the gear and leave free an outer ring sparing the ribs.

Enfin dans une dernière matrice, fermée, la pièce frittée calibrée subit une légère déformation plastique du sommet des nervures entre 2 poinçons à faces parallèles, perpendiculaires à l'axe, pour amener la cote entre les méplats des nervures à la valeur recherchée. Cette cote est déterminée à l'aide d'une butée mécanique, sur une presse hydraulique ou une presse mécanique avec adaptateur hydraulique.Finally in a final, closed die, the calibrated sintered part undergoes a slight plastic deformation of the top of the ribs between 2 punches with parallel faces, perpendicular to the axis, to bring the dimension between the flats of the ribs to the desired value. This dimension is determined using a mechanical stop, on a hydraulic press or a mechanical press with hydraulic adapter.

L'invention sera mieux comprise à l'aide de l'exemple de réalisation suivant, illustré par les fig. 1 à 6. Bien que cet exemple soit relatif à un engrenage à denture extérieure, l'invention s'applique également aux engrenages à denture intérieure.

  • La fig. 1 représente, en plan, une vue partielle de l'engrenage suivant l'invention.
  • La fig. 2 représente une coupe détaillée selon la section I.I de la fig.l.
  • Les fig. 3 à 6 représentent différentes phases de la fabrication de l'engrenage suivant l'invention en coupe suivant la ligne II-II de la fig. 1
    • . la fig. 3 montre une vue en coupe de la disposition générale des outillages de compression
    • . la fig. 4 donne le détail de la rainure de la fig.3
    • . la fig. 5 représente une vue en coupe de la phase de calibrage
    • . la fig. 6 montre une vue en coupe du détail A de la fig. 5.
    • . la fig. 7 représente une vue en coupe des outillages de finition.
The invention will be better understood with the aid of the following exemplary embodiment, illustrated by FIGS. 1 to 6. Although this example relates to a gear with external teeth, the invention also applies to gears with internal teeth.
  • Fig. 1 shows, in plan, a partial view of the gear according to the invention.
  • Fig. 2 shows a detailed section according to section II of fig.l.
  • Figs. 3 to 6 represent different phases of the manufacture of the gear according to the invention in section along the line II-II of FIG. 1
    • . fig. 3 shows a sectional view of the general arrangement of the compression tools
    • . fig. 4 gives the detail of the groove in fig. 3
    • . fig. 5 shows a sectional view of the calibration phase
    • . fig. 6 shows a sectional view of detail A of FIG. 5.
    • . fig. 7 shows a sectional view of the finishing tools.

Exemple 1Example 1

La figure 1 représente un engrenage 1 selon l'invention comportant une denture externe 2 de cercle primitif 7 et deux faces latérales 3 et 4 (fig. 2). Sur chacune des faces latérales se trouve une nervure 5 dont le profil est représenté en 6, de 1mm de largeur env., de 0,3mm de hauteur et situé sensiblement à 0,5mm du bord de la denture 2.FIG. 1 represents a gear 1 according to the invention comprising an external toothing 2 of a primitive circle 7 and two lateral faces 3 and 4 (fig. 2). On each of the lateral faces is a rib 5, the profile of which is shown in 6, about 1mm in width, 0.3mm in height and situated approximately 0.5mm from the edge of the toothing 2.

La figure 3 représente le dispositif de compression de la poudre dans lequel on reconnait une matrice annulaire 10, d'axe 11, un poinçon inférieur 15, de même axe 11, comportant une rainure circulaire 12i en forme de demi-tore dont les dimensions sont reportées à la fig.4 et un poinçon supérieur 13, de même axe 11, muni également d'une rainure circulaire 12s identique. La pièce comprimée est représentée en 14.FIG. 3 represents the device for compressing the powder in which an annular matrix 10, of axis 11, a lower punch 15, of the same axis 11, is recognized, comprising a circular groove 12i in the form of a half-torus whose dimensions are reported in fig.4 and an upper punch 13, of the same axis 11, also provided with an identical circular groove 12s. The compressed part is shown at 14.

Après frittage, la pièce 14 est calibrée dans une matrice annulaire 20 (fig. 5), entre deux poinçons inférieur 21 et supérieur 22, comportant à leurs extrémités planes un évidement annulaire 23(fig.6). Sur la fig.6, on a représenté en 24 en pointillés, le profil de la pièce 14, avant calibrage.
Après calibrage, la denture (2) possède sa géométrie et son état de surface définitifs.After sintering, the part 14 is calibrated in an annular die 20 (fig. 5), between two lower 21 and upper 22 punches, having at their flat ends an annular recess 23 (fig. 6). In fig.6, there is shown at 24 in dotted lines, the profile of the part 14, before calibration.
After calibration, the toothing (2) has its final geometry and surface condition.

La pièce calibrée est ensuite disposée dans une matrice de finition à fond plat 17 (fig. 7) où elle est écrasée par un poinçon plan 18, la course de celui-ci étant limitée par la matrice elle-même formant butée, ce qui imprime sur les nervures 5 les méplats 6, à une distance h très précise l'un de l'autre.The calibrated part is then placed in a flat bottom finishing matrix 17 (fig. 7) where it is crushed by a flat punch 18, the stroke of the latter being limited by the matrix itself forming a stop, which prints on the ribs 5 the flats 6, at a very precise distance h from each other.

Claims (6)

Engrenage de pompe à engrenages comportant une denture (2) et deux faces latérales (3,4) caractérisé en ce que chaque surface latérale porte une nervure en relief (5) continue et fermée sur elle-même, située au voisinage de la denture et présentant à son sommet un méplat (6).Gear pump gear comprising a toothing (2) and two lateral faces (3,4) characterized in that each lateral surface carries a raised rib (5) continuous and closed on itself, located in the vicinity of the toothing and having at its top a flat (6). Engrenage selon la revendication 1 caractérisé en ce que le méplat a une largeur 1 comprise entre 0,5 et 2 mm.Gear according to claim 1 characterized in that the flat has a width 1 between 0.5 and 2 mm. Engrenage selon l'une des revendications 1 ou 2, caractérisé en ce que le méplat est à une distance d du bord de la denture comprise entre 0 et 5 mm.Gear according to one of claims 1 or 2, characterized in that the flat is at a distance d from the edge of the teeth between 0 and 5 mm. Engrenage selon la revendication 3 caractérisé en ce que la distance d est comprise entre 0 et 2,5mm.Gear according to claim 3 characterized in that the distance d is between 0 and 2.5mm. Engrenage selon la revendication 4 caractérisé en ce que la distance d est de 0,5 mm ± 0,1 mm.Gear according to claim 4 characterized in that the distance d is 0.5 mm ± 0.1 mm. Procédé de fabrication d'un engrenage, selon l'une des revendications 1 à 5, comportant les opérations de compression, de frittage et de calibrage à froid, caractérisé en ce que la poudre est comprimée dans un outillage comprenant une matrice (10) et des poinçons (13,15) portant sur leur face active une rainure (12i-12s) concave, continue et fermée sur elle-même, et en ce qu'après frittage, l'ébauche est calibrée à froid dans une première matrice (20), puis mise à la cote finale dans une deuxième matrice de finition (17), par déformation plastique à froid, du sommet des nervures (5).Method of manufacturing a gear, according to one of claims 1 to 5, comprising the operations of compression, sintering and cold calibration, characterized in that the powder is compressed in a tool comprising a matrix (10) and punches (13,15) carrying on their active face a groove (12i-12s) concave, continuous and closed on itself, and in that after sintering, the blank is cold calibrated in a first matrix (20 ), then put to the final dimension in a second finishing matrix (17), by cold plastic deformation, of the top of the ribs (5).
EP95420030A 1994-02-15 1995-02-13 Gear for gear pumps and obtaining process Expired - Lifetime EP0667453B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9401948 1994-02-15
FR9401948A FR2716240B1 (en) 1994-02-15 1994-02-15 Gear pump gear and process for obtaining it.

Publications (2)

Publication Number Publication Date
EP0667453A1 true EP0667453A1 (en) 1995-08-16
EP0667453B1 EP0667453B1 (en) 1998-07-01

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EP95420030A Expired - Lifetime EP0667453B1 (en) 1994-02-15 1995-02-13 Gear for gear pumps and obtaining process

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EP (1) EP0667453B1 (en)
DE (1) DE69503158T2 (en)
FR (1) FR2716240B1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BRPI0816446A2 (en) * 2007-09-07 2015-03-03 Gkn Sinter Metals Llc SYNTERIZED POWDER METAL COMPONENT, GENERATOR PUMP, ASSEMBLY AND METHOD OF PRODUCING A SPRAY METAL COMPONENT

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2403796A (en) * 1943-05-15 1946-07-09 Hanna Engineering Works Gear pump
FR1241456A (en) * 1958-11-24 1960-09-16 Bayer Ag Synthetic gears
DE2847710A1 (en) * 1978-11-03 1980-05-14 Bosch Gmbh Robert Gear type hydraulic pump or motor - has axial ends of gears slanted to produce hydrodynamic lubrication of end face
JPS58217788A (en) * 1982-06-10 1983-12-17 Taiho Kogyo Co Ltd Rotary oil pump
EP0549057A1 (en) * 1991-12-23 1993-06-30 VOLVO CAR SINT-TRUIDEN, naamloze vennootschap Method for the manufacturing of gear-wheels, gear-wheels thus obtained and gear-wheel pump equipped therewith

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2403796A (en) * 1943-05-15 1946-07-09 Hanna Engineering Works Gear pump
FR1241456A (en) * 1958-11-24 1960-09-16 Bayer Ag Synthetic gears
DE2847710A1 (en) * 1978-11-03 1980-05-14 Bosch Gmbh Robert Gear type hydraulic pump or motor - has axial ends of gears slanted to produce hydrodynamic lubrication of end face
JPS58217788A (en) * 1982-06-10 1983-12-17 Taiho Kogyo Co Ltd Rotary oil pump
EP0549057A1 (en) * 1991-12-23 1993-06-30 VOLVO CAR SINT-TRUIDEN, naamloze vennootschap Method for the manufacturing of gear-wheels, gear-wheels thus obtained and gear-wheel pump equipped therewith

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 8, no. 69 (M - 286)<1506> 31 March 1984 (1984-03-31) *

Also Published As

Publication number Publication date
DE69503158T2 (en) 1999-04-01
FR2716240A1 (en) 1995-08-18
EP0667453B1 (en) 1998-07-01
FR2716240B1 (en) 1996-04-12
DE69503158D1 (en) 1998-08-06

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