WO2023243665A1 - Internal gear pump - Google Patents

Internal gear pump Download PDF

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Publication number
WO2023243665A1
WO2023243665A1 PCT/JP2023/022105 JP2023022105W WO2023243665A1 WO 2023243665 A1 WO2023243665 A1 WO 2023243665A1 JP 2023022105 W JP2023022105 W JP 2023022105W WO 2023243665 A1 WO2023243665 A1 WO 2023243665A1
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WO
WIPO (PCT)
Prior art keywords
ring gear
oil passage
transmission oil
pressure
teeth
Prior art date
Application number
PCT/JP2023/022105
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French (fr)
Japanese (ja)
Inventor
夏氷 石
孝明 大西
博昭 竹田
Original Assignee
住友精密工業株式会社
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.)
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Publication date
Application filed by 住友精密工業株式会社 filed Critical 住友精密工業株式会社
Priority to CN202380011294.5A priority Critical patent/CN117597515A/en
Publication of WO2023243665A1 publication Critical patent/WO2023243665A1/en

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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
    • F04C2/10—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member

Definitions

  • Patent Document 1 describes an internal gear pump (1).
  • This internal gear pump (1) has a separating element (7) (a so-called crescent).
  • the tooth tips of the internal gear (2) and the pinion (3) each abut against the separation member (7).
  • the separating member (7) also has an intermediate space (17) between the inner part (13) and the outer part (14).
  • the intermediate space (17) communicates with the pressurized region (9) of the internal gear pump (1).
  • the inner part (13) and the outer part (14) have a penetration (19).
  • the penetration part (19) radially penetrates each of the inner part (13) and the outer part (14), and extends the intermediate part (17) into the space between the teeth of the pinion (3) and the internal gear (2). communicate with.
  • the intermediate space (17) is at the same pressure as the pressurized area (9), so that through the penetration (19), between the teeth of the pinion (3) and the internal gear (2)
  • the pressure in the space increases.
  • the high pressure in the space between the teeth suppresses sudden pressure changes at the pump discharge and suppresses the noise of the internal gear pump (1).
  • the technology disclosed herein achieves both noise suppression of an internal gear pump and suppression of a decrease in pump efficiency.
  • the internal gear pump (1) described in Patent Document 1 has a structure in which a crescent moves.
  • internal gear pumps are known which have a non-movable crescent.
  • the space between the teeth of the ring gear is a space sandwiched between adjacent teeth of the ring gear.
  • the pressure in the space between the pinion gear teeth is high even without a pressure transmission oil path. Also on the pinion gear side, rapid pressure changes at the discharge port are suppressed.
  • the pressure transmission oil passage promotes leakage flow of the internal gear pump, but the pressure transmission oil passage is formed only in the area on the ring gear side and not in the area on the pinion gear side. Increase in leakage flow from the internal gear pump is suppressed. Therefore, a decrease in pump efficiency is suppressed.
  • the internal gear pump described above achieves both noise suppression and reduction in pump efficiency.
  • the housing has a sliding surface on which the outer peripheral surface of the ring gear slides
  • the internal gear pump includes a high-pressure oil supply section that supplies high-pressure hydraulic oil between the outer peripheral surface and the sliding surface through an inlet opening to the sliding surface,
  • the introduction port may be located on the opposite side of the crescent across the ring gear.
  • the high-pressure oil supply section supplies high-pressure hydraulic oil between the outer peripheral surface of the ring gear and the sliding surface of the housing.
  • the supplied high-pressure hydraulic oil pushes the ring gear toward the ring gear rotation axis. Since the introduction port is located on the opposite side of the crescent across the ring gear, the internal teeth of the ring gear are pressed against the second arcuate wall of the crescent. Leakage of hydraulic oil from between the internal teeth and the second arcuate wall is suppressed.
  • the high pressure oil supply increases the pumping efficiency of the internal gear pump.
  • the internal teeth of the ring gear are pressed against the second circular arc wall of the crescent, which increases pump efficiency while suppressing the pressure increase in the space between the teeth of the ring gear due to leakage flow from the discharge port.
  • the low pressure in the space between the ring gear teeth increases the noise of the internal gear pump.
  • the internal gear pump described above has a pressure transmission oil passage formed in the housing in the region on the ring gear side.
  • the pressure transmission oil passage increases the pressure in the space between the teeth of the ring gear.
  • the combination of the high-pressure oil supply section and the pressure transmission oil passage on the ring gear side achieves both a high level of noise suppression of the internal gear pump and suppression of reduction in pump efficiency.
  • the housing has a first support surface and a second support surface that respectively support two side surfaces of the ring gear that are orthogonal to the rotation axis,
  • the discharge port is formed on each of the first support surface and the second support surface,
  • the pressure transmission oil passage is formed to be recessed from the first support surface, the second support surface, or the first support surface and the second support surface, The pressure transmission oil passage may overlap a space between teeth of the ring gear when viewed in the direction of the rotation axis.
  • the pressure transmission oil passage formed in the first support surface and/or the second support surface overlaps with the space between the teeth of the ring gear when viewed in the direction of the rotation axis, so Hydraulic oil can be supplied to the space.
  • Hydraulic oil can be supplied to the space.
  • the pressure in the space between the teeth of the ring gear increases.
  • the cross section of the pressure transmission oil passage formed on the first support surface and/or the second support surface may be triangular.
  • the cross section of the pressure transmission oil passage formed on the first support surface and/or the second support surface may be quadrangular.
  • the pressure transmission oil passage may be a groove formed in the first support surface and/or the second support surface.
  • the pressure transmission oil passage may be linear.
  • the pressure transmission oil passage may be curved.
  • the pressure transmission oil passage may be formed so as to be recessed from the second arcuate wall of the crescent.
  • the pressure transmission oil passage may be formed by cutting out the surface of the crescent.
  • the pressure transmission oil passage formed in the second arcuate wall of the crescent communicates with the space between the teeth of the ring gear.
  • the pressure transmission oil passage can supply hydraulic oil from the discharge port to the space between the teeth of the ring gear. The pressure in the space between the teeth of the ring gear increases.
  • the depth of the pressure transmission oil passage may become gradually shallower as it moves away from the discharge port.
  • the depth of the pressure transmission oil passage may be a constant depth.
  • the width of the pressure transmission oil passage may be gradually narrowed away from the discharge port.
  • the width of the pressure transmission oil passage may be a constant width.
  • the tip of the pressure transmission oil passage is formed at the crescent, which extends from the edge of the discharge port at an angle ⁇ 1 or more corresponding to the tooth width of the ring gear, with the rotation axis of the ring gear as the center, and extends from the discharge port to the suction port. It may be located within a range of angle ⁇ 2 or less to an intermediate position.
  • a pressure transmission oil path with an appropriate length can suppress both the noise of the internal gear pump and the reduction in pump efficiency.
  • the pressure transmission oil passage is too short. That is, a pressure transmission oil passage that is too short cannot increase the pressure in the space between the teeth of the ring gear before the space is opened to the discharge port.
  • the internal gear pump described above can both suppress noise and suppress a decrease in pump efficiency.
  • FIG. 1 is an exploded view of an internal gear pump.
  • FIG. 2 is a cross-sectional view of the internal gear pump.
  • FIG. 3 illustrates a pressure transmission oil passage.
  • FIG. 4 shows a modification of the pressure transmission oil passage.
  • FIG. 5 shows a modification of the pressure transmission oil passage.
  • FIG. 1 and 2 illustrate an internal gear pump 1.
  • the internal gear pump 1 includes a shaft 2, a pinion gear 3, a ring gear 4, a gear housing 5, and a front cover 6.
  • the gear housing 5 and the front cover 6 constitute a housing 10 of the internal gear pump 1.
  • FIG. 1 is an exploded view in which the front cover 6 is removed from the gear housing 5.
  • the pinion gear 3 is integrally formed at an intermediate position of the first shaft 21.
  • the pinion gear 3 and the shaft 2 are coaxial.
  • the pinion gear 3 rotates together with the shaft 2.
  • the pinion gear 3 has external teeth 31.
  • the ring gear 4 meshes with the pinion gear 3.
  • the ring gear 4 is arranged eccentrically with respect to the shaft 2.
  • C1 in FIG. 1 is the rotation axis of the pinion gear 3
  • C2 is the rotation axis of the ring gear 4.
  • Internal teeth 41 are formed on the inner peripheral surface of the ring gear 4.
  • a portion of the external teeth 31 of the pinion gear 3 meshes with a portion of the internal teeth 41 of the ring gear 4 in the region on the right side of the paper.
  • the gear housing 5 accommodates the pinion gear 3 and ring gear 4.
  • the gear housing 5 has an inner hole 53 formed therein. The end of the first shaft 21 is located within the inner bore 53.
  • a support hole 62 through which the shaft 2 passes is formed through the front cover 6.
  • the shaft 2 is rotatably supported by the front cover 6 and the gear housing 5 via a bearing 63 and a bearing member 64.
  • the opening of the support hole 62 is closed by a sealing member 621.
  • a discharge port 12 is also formed in the front cover 6 and the gear housing 5.
  • the discharge port 12 is a port that discharges hydraulic oil from the space 50 inside the housing 10.
  • the outlet of the discharge port 12 is open to the outer peripheral surface of the gear housing 5, as shown in FIG. Note that the direction of the inlet of the suction port 11 and the direction of the outlet of the discharge port 12 may be different directions as illustrated in FIG. 2, or may be the same direction although not shown. .
  • the inlet of the discharge port 12 opens on the second support surface 61 of the front cover 6 and the first support surface 52 of the gear housing 5, respectively. As shown in FIG. 1, the inlet of the discharge port 12 also extends in the circumferential direction along the rotational direction of the shaft 2 on the opposite side of the shaft 2 from the suction port 11.
  • the crescent 54 extends in the circumferential direction over a predetermined angular range along the rotational direction of the shaft 2. As shown in FIG. 1, the crescent 54 has a crescent shape when viewed in the axial direction of the shaft 2.
  • the crescent 54 has two arc walls, a first arc wall 541 and a second arc wall 542, and the first arc wall 541 and the second arc wall 542 are respectively attached to the first support surface 52 of the gear housing 5. It is erected.
  • the internal gear pump 1 includes a high-pressure oil supply section 8.
  • the high-pressure oil supply section 8 supplies high-pressure hydraulic oil between the outer peripheral surface 42 of the ring gear 4 and the sliding surface 51 of the gear housing 5. Note that the high-pressure oil supply section 8 is illustrated only in FIG. 1.
  • the high-pressure oil supply unit 8 uses high-pressure hydraulic oil to push and move the ring gear 4 from the outer periphery of the third region toward the rotation axis C2. Since the tooth tips of the ring gear 4 are pressed against the second arcuate wall 542 of the crescent 54, leakage of hydraulic oil from the high pressure side to the low pressure side within the housing 10 is suppressed.
  • the high-pressure oil supply section 8 has an inlet 81 that opens to the sliding surface 51 and a supply path 82 that connects the discharge port 12 and the inlet 81.
  • the introduction port 81 is located in the third region, as shown in FIG. More specifically, the introduction port 81 faces the crescent 54 in the radial direction with the ring gear 4 interposed therebetween.
  • the inlet 81 introduces a portion of the high-pressure hydraulic oil discharged from the discharge port 12 into the housing 10 .
  • the introduction port 81 is preferably located at a position facing the crescent 54.
  • the inlet 81 has a third region that is divided into a low-pressure side region and a high-pressure side region. In the region, it is preferably located in a region on the high pressure side.
  • the pressure transmission oil passage 91 is a groove formed in the second support surface 61. As shown in FIG. 3, the cross-sectional shape of the pressure transmission oil passage 91 is triangular. Note that the cross-sectional shape of the pressure transmission oil passage 91 is not limited to a triangle. The shape of the cross section may be, for example, a quadrangle.
  • the pressure transmission oil passage 91 is formed in the housing only in the area on the ring gear 4 side, and no pressure transmission oil passage is formed in the area on the pinion gear 3 side. Both noise suppression of the internal gear pump 1 and improvement of pump efficiency are achieved.
  • the pressure transmission oil passage 91 has the function of increasing the pressure in the space between the teeth of the ring gear 4 before the space communicates with the discharge port 12. If the pressure transmission oil passage 91 is too short, it is difficult to increase the pressure in the space between the teeth of the ring gear 4 before the space communicates with the discharge port 12. There is a minimum length of the pressure transmission oil passage 91 for the pressure transmission oil passage 91 to perform its function.
  • the intermediate position of the crescent 54 is the intermediate position in the circumferential direction of the crescent 54 that extends in the circumferential direction from the discharge port 12 to the suction port 11. Since the pressure transmission oil passage 91 is not too long, the pressure in the space between the teeth of the ring gear 4 can be sufficiently increased, and an increase in leakage flow can be suppressed.
  • the pressure transmission oil passage 91 is formed on the second support surface 61 of the front cover 6.
  • the pressure transmission oil passage 91 may be formed to be recessed from the first support surface 52 of the gear housing 5.
  • the pressure transmission oil passage 91 may be formed on each of the second support surface 61 of the front cover 6 and the first support surface 52 of the gear housing 5.
  • the pressure transmission oil passage 92 extends in an arc shape along the curve of the second arc wall 542 of the crescent 54. When viewed in the direction of the rotation axis C2 of the ring gear 4, the pressure transmission oil passage 92 overlaps the space between the teeth of the ring gear 4. The pressure transmission oil passage 92 communicates with the space between the teeth of the ring gear 4. Since the pressure in the space between the teeth of the ring gear 4 increases in the third region, when the space is opened to the discharge port 12, the pressure difference between the pressure in the discharge port 12 and the pressure in the space between the teeth is small. . The noise of the internal gear pump 1 is suppressed.
  • FIG. 5 is a perspective view of the internal gear pump 1 with the front cover 6 removed. This internal gear pump 1 has a pressure transmission oil passage 93 formed in the crescent 54.
  • the pressure transmission oil passage 93 is formed at the upper end of the second arcuate wall 542 of the crescent 54.
  • the pressure transmission oil passage 93 is formed by cutting out the surface of the crescent 54. Note that the upper end here is the end of the crescent 54 that stands up from the first support surface 52 of the gear housing 5 on the opposite side to the first support surface 52 .
  • the upper end of the second arcuate wall 542 is the end that comes into contact with the second support surface 61 of the front cover 6 .
  • the pressure transmission oil passage 93 extends from the high-pressure side end of the crescent 54 (that is, the left end in FIG. 5) to an intermediate position of the crescent 54.
  • the pressure transmission oil passage 93 communicates with the discharge port 12 that opens into the second support surface 61 of the front cover 6 .
  • the length of the pressure transmission oil passage 93 can be set arbitrarily within the above-mentioned range of ⁇ 1 or more and ⁇ 2 or less.
  • the pressure transmission oil passage 93 has a width/depth that gradually becomes narrower/shallower as it moves away from the discharge port 12.
  • the width/depth of the pressure transmission oil passage 93 may be constant.
  • the pressure transmission oil passage 93 formed in the crescent 54 also communicates the space between the teeth of the ring gear 4 and the discharge port 12. Since the pressure in the space between the teeth of the ring gear 4 increases in the third region, when the space is opened to the discharge port 12, the pressure difference between the pressure in the discharge port 12 and the pressure in the space between the teeth is small. . Since pressure fluctuations are suppressed, the noise of the internal gear pump 1 is suppressed.
  • pressure transmission oil passage formed in the crescent 54 is not limited to being formed at the upper end of the crescent 54.
  • the pressure transmission oil passage may be formed at an intermediate position in the vertical direction on the second arcuate wall 542 of the crescent 54.
  • a pressure transmission oil passage may be formed at the lower end of the crescent 54.

Abstract

An internal gear pump (1) comprises a pinion gear (3), a ring gear (4), a housing (10), and a crescent (54) having a first arcuate wall (541) with which external teeth (31) come into contact, and a second arcuate wall (542) with which internal teeth (41) come into contact, wherein: the first arcuate wall and the second arcuate wall are both fixed walls that do not move toward the external teeth or the internal teeth; a pressure transmission oil passage (91) extending from a discharge port is formed inside the housing, in only a ring gear side region among a pinion gear side region and the ring gear side region, which sandwich the crescent; and the pressure transmission oil passage provides communication between the discharge port and a space between teeth of the ring gear.

Description

内接ギヤポンプinternal gear pump
　ここに開示する技術は、内接ギヤポンプに関する。 The technology disclosed herein relates to an internal gear pump.
　特許文献１には、内接歯車ポンプ（１）が記載されている。この内接歯車ポンプ（１）は、分離部材（７）（いわゆるクレセント）を有している。内歯車（２）の歯先とピニオン（３）の歯先とはそれぞれ、分離部材（７）に当接する。 Patent Document 1 describes an internal gear pump (1). This internal gear pump (1) has a separating element (7) (a so-called crescent). The tooth tips of the internal gear (2) and the pinion (3) each abut against the separation member (7).
　分離部材（７）は、内側部分（１３）と外側部分（１４）とばね（１６）とを有している。ばね（１６）は、内側部分（１３）をピニオン（３）の歯先に押し当て、外側部分（１４）を内歯車（２）の歯先に押し当てる。分離部材（７）は、可動する構造を有している。可動する分離部材（７）は、内接歯車ポンプ（１）内の漏れ流れを抑制して、ポンプ効率を向上させる。 The separating member (7) has an inner part (13), an outer part (14) and a spring (16). The spring (16) presses the inner part (13) against the tooth tips of the pinion (3) and the outer part (14) against the tooth tips of the internal gear (2). The separation member (7) has a movable structure. The movable separation member (7) suppresses leakage flow within the internal gear pump (1) and improves pump efficiency.
　分離部材（７）はまた、内側部分（１３）と外側部分（１４）との間に中間空間（１７）を有している。中間空間（１７）は、内接歯車ポンプ（１）の加圧領域（９）と連通している。内側部分（１３）及び外側部分（１４）は、貫通部（１９）を有している。貫通部（１９）は、内側部分（１３）及び外側部分（１４）のそれぞれを径方向に貫通し、中間部分（１７）を、ピニオン（３）及び内歯車（２）の歯の間の空間と連通させる。内接歯車ポンプ（１）の作動時に中間空間（１７）は加圧領域（９）と同じ圧力であるため、貫通部（１９）を通じて、ピニオン（３）及び内歯車（２）の歯の間の空間の圧力が上昇する。歯の間の空間の高い圧力は、ポンプ吐出部での急激な圧力変化を抑制し、内接歯車ポンプ（１）の騒音を抑制する。 The separating member (7) also has an intermediate space (17) between the inner part (13) and the outer part (14). The intermediate space (17) communicates with the pressurized region (9) of the internal gear pump (1). The inner part (13) and the outer part (14) have a penetration (19). The penetration part (19) radially penetrates each of the inner part (13) and the outer part (14), and extends the intermediate part (17) into the space between the teeth of the pinion (3) and the internal gear (2). communicate with. During operation of the internal gear pump (1), the intermediate space (17) is at the same pressure as the pressurized area (9), so that through the penetration (19), between the teeth of the pinion (3) and the internal gear (2) The pressure in the space increases. The high pressure in the space between the teeth suppresses sudden pressure changes at the pump discharge and suppresses the noise of the internal gear pump (1).
特許第６２９７２７７号公報Patent No. 6297277
　特許文献１の内接歯車ポンプ（１）の貫通部（１９）は、騒音の抑制のために、分離部材（７）とピニオン（３）との間、及び、分離部材（７）と内歯車（２）との間の両方へ、ポンプ吐出部から液体を供給する。しかしながら、こうした液体の供給は、内接歯車ポンプ（１）内の漏れ流れを増やすことになる。従来の内接ギヤポンプは、騒音が抑制される一方で、ポンプ効率の低下を招く。 The penetration part (19) of the internal gear pump (1) of Patent Document 1 is provided between the separation member (7) and the pinion (3) and between the separation member (7) and the internal gear in order to suppress noise. (2) Supply liquid from the pump discharge part to both. However, such a liquid supply will increase the leakage flow within the internal gear pump (1). While conventional internal gear pumps reduce noise, they suffer from reduced pump efficiency.
　ここに開示する技術は、内接ギヤポンプの騒音抑制と、ポンプ効率の低下抑制とを両立させる。 The technology disclosed herein achieves both noise suppression of an internal gear pump and suppression of a decrease in pump efficiency.
　特許文献１に記載された内接歯車ポンプ（１）は、クレセントが可動する構造を有している。これとは異なり、可動しない構造のクレセントを有する内接ギヤポンプが知られている。 The internal gear pump (1) described in Patent Document 1 has a structure in which a crescent moves. In contrast to this, internal gear pumps are known which have a non-movable crescent.
　本願発明者らが検討をしたところ、クレセントが可動しない構造の場合、ピニオンギヤの歯の間の空間の圧力は比較的高いことが、新たにわかった。これは、クレセントの壁がピニオンギヤの外歯に押し付けられないため、ピニオンギヤの歯とクレセントの壁との間に微少な隙間が存在しているためと考えられる。微少な隙間は、吐出ポートからの漏れ流れを許容し、その漏れ流れが、ピニオンギヤの歯の間の空間の圧力を高める。 Upon investigation, the inventors of this application newly discovered that in the case of a structure in which the crescent does not move, the pressure in the space between the teeth of the pinion gear is relatively high. This is thought to be because the wall of the crescent is not pressed against the external teeth of the pinion gear, so a small gap exists between the teeth of the pinion gear and the wall of the crescent. The small gap allows leakage flow from the discharge port, which increases the pressure in the space between the teeth of the pinion gear.
　騒音抑制を目的として、吐出ポートからピニオンギヤの歯の間の空間へ作動油が供給される構造を内接ギヤポンプに追加しても、漏れ流れが増えてポンプ効率が低下するだけで、内接ギヤポンプの騒音抑制効果は、実質的に向上しない。 Even if a structure is added to an internal gear pump in which hydraulic oil is supplied from the discharge port to the space between the teeth of the pinion gear for the purpose of noise suppression, this will only increase leakage flow and reduce pump efficiency. The noise suppression effect is not substantially improved.
　そこで、本願発明者らは、可動しない構造のクレセントを有する内接ギヤポンプにおいて、吐出ポートからリングギヤの歯の間の空間へ延びる圧力伝達油路のみを、ハウジング内に形成することにした。 Therefore, the inventors of the present application decided to form only the pressure transmission oil passage extending from the discharge port to the space between the teeth of the ring gear in the housing in an internal gear pump having a crescent with an immovable structure.
　具体的に、ここに開示する技術は、内接ギヤポンプに係る。この内接ギヤポンプは、
　外歯を有するピニオンギヤと、
　前記外歯に噛み合う内歯を有するリングギヤと、
　吸込ポート及び吐出ポートを有すると共に、前記ピニオンギヤ及び前記リングギヤを回転可能に収容するハウジングと、
　前記ピニオンギヤと前記リングギヤとの噛み合いが離れる箇所に位置しかつ、前記外歯が当接する第１円弧壁、及び、前記内歯が当接する第２円弧壁を有するクレセントと、を備え、
　前記第１円弧壁及び前記第２円弧壁は共に、前記外歯及び前記内歯の方へ移動しない固定壁であり、
　前記クレセントを挟んだ前記ピニオンギヤ側の領域と前記リングギヤ側の領域とのうち、前記リングギヤ側の領域にのみ、前記吐出ポートから延びる圧力伝達油路が、前記ハウジング内に形成され、
　前記圧力伝達油路は、前記吐出ポートと前記リングギヤの歯の間の空間とを連通させる。 Specifically, the technology disclosed herein relates to an internal gear pump. This internal gear pump is
a pinion gear having external teeth;
a ring gear having internal teeth that mesh with the external teeth;
a housing having a suction port and a discharge port and rotatably housing the pinion gear and the ring gear;
a crescent that is located at a location where the pinion gear and the ring gear are separated from each other and has a first arcuate wall that the external teeth abut, and a second arcuate wall that the internal teeth abut,
Both the first circular arc wall and the second circular arc wall are fixed walls that do not move toward the external teeth and the internal teeth,
A pressure transmission oil passage extending from the discharge port is formed in the housing only in the region on the ring gear side of the region on the pinion gear side and the region on the ring gear side that sandwich the crescent,
The pressure transmission oil passage communicates the discharge port with a space between the teeth of the ring gear.
　尚、リングギヤの歯の間の空間は、リングギヤにおいて隣合う歯と歯に挟まれた空間である。 Note that the space between the teeth of the ring gear is a space sandwiched between adjacent teeth of the ring gear.
　この内接ギヤポンプは、クレセントが可動しない構造を有している。前述したように、ピニオンギヤの歯の間の空間の圧力は比較的高い。 This internal gear pump has a structure in which the crescent does not move. As mentioned above, the pressure in the space between the teeth of the pinion gear is relatively high.
　圧力伝達油路は、クレセントを挟んだピニオンギヤ側の領域とリングギヤ側の領域とのうち、リングギヤ側の領域にのみ、ハウジング内に形成されている。吐出ポートから延びる圧力伝達油路は、吐出ポートから低圧側へ作動油の一部を流す。圧力伝達油路は、吐出ポートとリングギヤの歯の間の空間とを連通させるため、吐出ポートの高圧の作動油の一部がリングギヤの歯の間の空間へ流れる。リングギヤの歯の間の空間の圧力が高まる。歯の間の空間の高い圧力は、吐出ポートでの急激な圧力変化を抑制する。 The pressure transmission oil passage is formed in the housing only in the area on the ring gear side between the area on the pinion gear side and the area on the ring gear side across the crescent. The pressure transmission oil passage extending from the discharge port allows a portion of the hydraulic oil to flow from the discharge port to the low pressure side. Since the pressure transmission oil passage communicates the discharge port with the space between the teeth of the ring gear, a portion of the high-pressure hydraulic oil in the discharge port flows into the space between the teeth of the ring gear. The pressure in the space between the teeth of the ring gear increases. The high pressure in the space between the teeth suppresses sudden pressure changes at the discharge port.
　ピニオンギヤの歯の間の空間の圧力は、圧力伝達油路が無くても高い。ピニオンギヤ側においても、吐出ポートでの急激な圧力変化が抑制される。 The pressure in the space between the pinion gear teeth is high even without a pressure transmission oil path. Also on the pinion gear side, rapid pressure changes at the discharge port are suppressed.
　可動しない構造のクレセントを挟んだリングギヤ側の領域にのみ圧力伝達油路を形成することは、リングギヤ側及びピニオンギヤ側のそれぞれにおいて、吐出ポートでの急激な圧力変化を抑制するから、内接ギヤポンプの騒音が抑制される。 Forming the pressure transmission oil passage only in the area on the ring gear side across the crescent, which has an immovable structure, suppresses sudden pressure changes at the discharge port on both the ring gear side and the pinion gear side, so it is effective for internal gear pumps. Noise is suppressed.
　また、圧力伝達油路は、内接ギヤポンプの漏れ流れを助長するが、圧力伝達油路は、リングギヤ側の領域にのみ形成され、ピニオンギヤ側の領域には形成されていない。内接ギヤポンプの漏れ流れの増大が抑制される。よって、ポンプ効率の低下が抑制される。 Further, the pressure transmission oil passage promotes leakage flow of the internal gear pump, but the pressure transmission oil passage is formed only in the area on the ring gear side and not in the area on the pinion gear side. Increase in leakage flow from the internal gear pump is suppressed. Therefore, a decrease in pump efficiency is suppressed.
　従って、前記の内接ギヤポンプは、騒音抑制と、ポンプ効率の低下抑制とが両立する。 Therefore, the internal gear pump described above achieves both noise suppression and reduction in pump efficiency.
　前記ハウジングは、前記リングギヤの外周面が摺動する摺動面を有し、
　前記内接ギヤポンプは、前記摺動面に開口する導入口を通じて、前記外周面と前記摺動面との間に高圧の作動油を供給する高圧油供給部を備え、
　前記導入口は、前記リングギヤを挟んだ前記クレセントとは反対側に位置している、としてもよい。 The housing has a sliding surface on which the outer peripheral surface of the ring gear slides,
The internal gear pump includes a high-pressure oil supply section that supplies high-pressure hydraulic oil between the outer peripheral surface and the sliding surface through an inlet opening to the sliding surface,
The introduction port may be located on the opposite side of the crescent across the ring gear.
　高圧油供給部は、リングギヤの外周面と、ハウジングの摺動面との間に高圧の作動油を供給する。供給された高圧の作動油は、リングギヤを、リングギヤの回転軸の方へ押す。導入口は、リングギヤを挟んだクレセントとは反対側に位置しているため、リングギヤの内歯はクレセントの第２円弧壁に押し付けられる。内歯と第２円弧壁との間から作動油が漏れることが抑制される。高圧油供給部は、内接ギヤポンプのポンプ効率を高める。 The high-pressure oil supply section supplies high-pressure hydraulic oil between the outer peripheral surface of the ring gear and the sliding surface of the housing. The supplied high-pressure hydraulic oil pushes the ring gear toward the ring gear rotation axis. Since the introduction port is located on the opposite side of the crescent across the ring gear, the internal teeth of the ring gear are pressed against the second arcuate wall of the crescent. Leakage of hydraulic oil from between the internal teeth and the second arcuate wall is suppressed. The high pressure oil supply increases the pumping efficiency of the internal gear pump.
　リングギヤの内歯がクレセントの第２円弧壁に押し付けられることは、ポンプ効率を高める一方で、吐出ポートからの漏れ流れによるリングギヤの歯の間の空間の圧力上昇を抑制する。リングギヤの歯の間の空間の圧力が低いことは、内接ギヤポンプの騒音を増大させる。 The internal teeth of the ring gear are pressed against the second circular arc wall of the crescent, which increases pump efficiency while suppressing the pressure increase in the space between the teeth of the ring gear due to leakage flow from the discharge port. The low pressure in the space between the ring gear teeth increases the noise of the internal gear pump.
　前記の内接ギヤポンプは、リングギヤ側の領域においてハウジングに形成された圧力伝達油路を有している。前述したように、圧力伝達油路は、リングギヤの歯の間の空間の圧力を高める。高圧油供給部と、リングギヤ側の圧力伝達油路との組み合わせは、内接ギヤポンプの騒音抑制と、ポンプ効率の低下抑制とを、高いレベルで両立させる。 The internal gear pump described above has a pressure transmission oil passage formed in the housing in the region on the ring gear side. As mentioned above, the pressure transmission oil passage increases the pressure in the space between the teeth of the ring gear. The combination of the high-pressure oil supply section and the pressure transmission oil passage on the ring gear side achieves both a high level of noise suppression of the internal gear pump and suppression of reduction in pump efficiency.
　前記ハウジングは、前記リングギヤの側面であって、回転軸に直交する二つの側面をそれぞれ支持する第１支持面及び第２支持面を有し、
　前記吐出ポートは、前記第１支持面及び前記第２支持面のそれぞれに形成され、
　前記圧力伝達油路は、前記第１支持面、前記第２支持面、又は、前記第１支持面及び前記第２支持面から凹陥するように、形成され、
　前記圧力伝達油路は、前記回転軸の方向に見た場合に、前記リングギヤの歯の間の空間と重なっている、としてもよい。 The housing has a first support surface and a second support surface that respectively support two side surfaces of the ring gear that are orthogonal to the rotation axis,
The discharge port is formed on each of the first support surface and the second support surface,
The pressure transmission oil passage is formed to be recessed from the first support surface, the second support surface, or the first support surface and the second support surface,
The pressure transmission oil passage may overlap a space between teeth of the ring gear when viewed in the direction of the rotation axis.
　第１支持面及び／又は第２支持面に形成された圧力伝達油路は、回転軸の方向に見た場合にリングギヤの歯の間の空間と重なるため、吐出ポートからリングギヤの歯の間の空間へ作動油を供給できる。リングギヤの歯の間の空間の圧力が高まる。 The pressure transmission oil passage formed in the first support surface and/or the second support surface overlaps with the space between the teeth of the ring gear when viewed in the direction of the rotation axis, so Hydraulic oil can be supplied to the space. The pressure in the space between the teeth of the ring gear increases.
　第１支持面及び／又は第２支持面に形成された前記圧力伝達油路の横断面は、三角形である、としてもよい。第１支持面及び／又は第２支持面に形成された前記圧力伝達油路の横断面は、四角形である、としてもよい。 The cross section of the pressure transmission oil passage formed on the first support surface and/or the second support surface may be triangular. The cross section of the pressure transmission oil passage formed on the first support surface and/or the second support surface may be quadrangular.
　前記圧力伝達油路は、第１支持面及び／又は第２支持面に形成された溝である、としてもよい。 The pressure transmission oil passage may be a groove formed in the first support surface and/or the second support surface.
　前記圧力伝達油路は、直線状である、としてもよい。前記圧力伝達油路は、曲線状である、としてもよい。 The pressure transmission oil passage may be linear. The pressure transmission oil passage may be curved.
　前記圧力伝達油路は、前記クレセントの前記第２円弧壁から凹陥するように、形成されている、としてもよい。 The pressure transmission oil passage may be formed so as to be recessed from the second arcuate wall of the crescent.
　前記圧力伝達油路は、前記クレセントの表面が切り欠かれて形成されている、としてもよい。 The pressure transmission oil passage may be formed by cutting out the surface of the crescent.
　クレセントの第２円弧壁に形成された圧力伝達油路は、リングギヤの歯の間の空間と連通する。圧力伝達油路は、吐出ポートからリングギヤの歯の間の空間へ作動油を供給できる。リングギヤの歯の間の空間の圧力が高まる。 The pressure transmission oil passage formed in the second arcuate wall of the crescent communicates with the space between the teeth of the ring gear. The pressure transmission oil passage can supply hydraulic oil from the discharge port to the space between the teeth of the ring gear. The pressure in the space between the teeth of the ring gear increases.
　前記圧力伝達油路の深さは、前記吐出ポートから離れるに従い、次第に浅くなっている、としてもよい。前記圧力伝達油路の深さは、一定深さである、としてもよい。前記圧力伝達油路の幅は、前記吐出ポートから離れるに従い、次第に狭くなっている、としてもよい。前記圧力伝達油路の幅は、一定幅である、としてもよい。 The depth of the pressure transmission oil passage may become gradually shallower as it moves away from the discharge port. The depth of the pressure transmission oil passage may be a constant depth. The width of the pressure transmission oil passage may be gradually narrowed away from the discharge port. The width of the pressure transmission oil passage may be a constant width.
　前記圧力伝達油路の先端は、前記リングギヤの回転軸を中心として、前記吐出ポートの縁から、前記リングギヤの歯幅に相当する角度θ１以上でかつ、前記吐出ポートから前記吸込ポートまで延びる前記クレセントの中間位置までの角度θ２以下の範囲に位置している、としてもよい。 The tip of the pressure transmission oil passage is formed at the crescent, which extends from the edge of the discharge port at an angle θ1 or more corresponding to the tooth width of the ring gear, with the rotation axis of the ring gear as the center, and extends from the discharge port to the suction port. It may be located within a range of angle θ2 or less to an intermediate position.
　適切な長さの圧力伝達油路は、内接ギヤポンプの騒音抑制と、ポンプ効率の低下抑制とを両立させる。 A pressure transmission oil path with an appropriate length can suppress both the noise of the internal gear pump and the reduction in pump efficiency.
　圧力伝達油路の先端がθ１未満の位置に位置している場合、圧力伝達油路が短すぎる。つまり、短すぎる圧力伝達油路は、リングギヤの歯の間の空間の圧力を、当該空間が吐出ポートに開放される前に上昇させることができない。 If the tip of the pressure transmission oil passage is located at a position less than θ1, the pressure transmission oil passage is too short. That is, a pressure transmission oil passage that is too short cannot increase the pressure in the space between the teeth of the ring gear before the space is opened to the discharge port.
　圧力伝達油路の先端がθ２を超える位置に位置しても、騒音抑制効果がθ２以下の場合と実質的に同じである。一方で、長すぎる圧力伝達油路は、作動油の漏れ流れを増やしてポンプ効率の低下を招く。 Even if the tip of the pressure transmission oil path is located at a position exceeding θ2, the noise suppression effect is substantially the same as when it is below θ2. On the other hand, a pressure transmission oil passage that is too long increases the leakage flow of hydraulic oil, leading to a decrease in pump efficiency.
　圧力伝達油路の先端が、角度θ１以上でかつ、角度θ２以下の範囲に位置している場合、騒音抑制と、ポンプ効率の低下抑制とが両立する。 When the tip of the pressure transmission oil path is located within the range of angle θ1 or more and angle θ2 or less, both noise suppression and reduction in pump efficiency are achieved.
　前記の内接ギヤポンプは、騒音抑制とポンプ効率の低下抑制とを両立できる。 The internal gear pump described above can both suppress noise and suppress a decrease in pump efficiency.
図１は、内接ギヤポンプの分解図である。FIG. 1 is an exploded view of an internal gear pump. 図２は、内接ギヤポンプの断面図である。FIG. 2 is a cross-sectional view of the internal gear pump. 図３は、圧力伝達油路を例示している。FIG. 3 illustrates a pressure transmission oil passage. 図４は、圧力伝達油路の変形例である。FIG. 4 shows a modification of the pressure transmission oil passage. 図５は、圧力伝達油路の変形例である。FIG. 5 shows a modification of the pressure transmission oil passage.
　以下、内接ギヤポンプの実施形態について、図面を参照しながら説明する。ここで説明する内接ギヤポンプは例示である。 Hereinafter, embodiments of the internal gear pump will be described with reference to the drawings. The internal gear pump described here is an example.
　（内接ギヤポンプの全体構造）
　図１及び２は、内接ギヤポンプ１を例示している。内接ギヤポンプ１は、シャフト２と、ピニオンギヤ３と、リングギヤ４と、ギヤハウジング５と、フロントカバー６と、を備えている。ギヤハウジング５、及び、フロントカバー６は、内接ギヤポンプ１のハウジング１０である。尚、図１は、フロントカバー６がギヤハウジング５から取り外された分解図である。 (Overall structure of internal gear pump)
1 and 2 illustrate an internal gear pump 1. FIG. The internal gear pump 1 includes a shaft 2, a pinion gear 3, a ring gear 4, a gear housing 5, and a front cover 6. The gear housing 5 and the front cover 6 constitute a housing 10 of the internal gear pump 1. Note that FIG. 1 is an exploded view in which the front cover 6 is removed from the gear housing 5.
　シャフト２は、図２における紙面左右方向に伸びている。シャフト２は、第１シャフト２１と第２シャフト２２とからなる。第１シャフト２１と第２シャフト２２とは、同軸となるように結合され、一体に回転する。第２シャフト２２は、ハウジング１０から突出していて、図示を省略する原動機に接続される。原動機は、例えば電気モータである。 The shaft 2 extends in the left-right direction on the paper in FIG. The shaft 2 includes a first shaft 21 and a second shaft 22. The first shaft 21 and the second shaft 22 are coupled coaxially and rotate together. The second shaft 22 protrudes from the housing 10 and is connected to a prime mover (not shown). The prime mover is, for example, an electric motor.
　ピニオンギヤ３は、第１シャフト２１の中間位置に一体に形成されている。ピニオンギヤ３とシャフト２とは同軸である。ピニオンギヤ３は、シャフト２と共に回転する。ピニオンギヤ３は、外歯３１を有している。 The pinion gear 3 is integrally formed at an intermediate position of the first shaft 21. The pinion gear 3 and the shaft 2 are coaxial. The pinion gear 3 rotates together with the shaft 2. The pinion gear 3 has external teeth 31.
　リングギヤ４は、ピニオンギヤ３に噛み合う。リングギヤ４は、シャフト２に対して偏心して配置されている。図１のＣ１は、ピニオンギヤ３の回転軸であり、Ｃ２は、リングギヤ４の回転軸である。リングギヤ４の内周面には、内歯４１が形成されている。図１の右図において、紙面右側の領域にて、ピニオンギヤ３の外歯３１の一部がリングギヤ４の内歯４１の一部に噛み合う。 The ring gear 4 meshes with the pinion gear 3. The ring gear 4 is arranged eccentrically with respect to the shaft 2. C1 in FIG. 1 is the rotation axis of the pinion gear 3, and C2 is the rotation axis of the ring gear 4. Internal teeth 41 are formed on the inner peripheral surface of the ring gear 4. In the right diagram of FIG. 1, a portion of the external teeth 31 of the pinion gear 3 meshes with a portion of the internal teeth 41 of the ring gear 4 in the region on the right side of the paper.
　ギヤハウジング５は、ピニオンギヤ３及びリングギヤ４を収容する。ギヤハウジング５には、内孔５３が形成されている。第１シャフト２１の端部は、内孔５３内に位置する。 The gear housing 5 accommodates the pinion gear 3 and ring gear 4. The gear housing 5 has an inner hole 53 formed therein. The end of the first shaft 21 is located within the inner bore 53.
　ピニオンギヤ３及びリングギヤ４は、回転可能に、ギヤハウジング５に収容される。ギヤハウジング５は、リングギヤ４の外周面４２が摺動する摺動面５１を有している。リングギヤ４の外周面４２は、横断面円形状を有している。ギヤハウジング５の摺動面５１も、横断面円形状を有している。摺動面５１は、シャフト２に対して偏心している。 The pinion gear 3 and ring gear 4 are rotatably housed in the gear housing 5. The gear housing 5 has a sliding surface 51 on which the outer peripheral surface 42 of the ring gear 4 slides. The outer peripheral surface 42 of the ring gear 4 has a circular cross section. The sliding surface 51 of the gear housing 5 also has a circular cross section. The sliding surface 51 is eccentric with respect to the shaft 2.
　ギヤハウジング５は、摺動面５１に直交する第１支持面５２を有している。摺動面５１及び第１支持面５２は、ピニオンギヤ３及びリングギヤ４を収容する空間５０を形成する。当該空間５０は、図２における紙面左側に開放されている。ピニオンギヤ３の第１側面３２、及び、リングギヤ４の第１側面４３はそれぞれ、ギヤハウジング５の第１支持面５２に支持されると共に、第１支持面５２を摺動する。尚、ピニオンギヤ３の第１側面３２は、ピニオンギヤ３の回転軸Ｃ１に直交する面であって、図２の右の側面である。リングギヤ４の第１側面４３は、リングギヤ４の回転軸Ｃ２に直交する面であって、図２の右の側面である。 The gear housing 5 has a first support surface 52 that is perpendicular to the sliding surface 51. The sliding surface 51 and the first support surface 52 form a space 50 that accommodates the pinion gear 3 and the ring gear 4. The space 50 is open on the left side of the paper in FIG. The first side surface 32 of the pinion gear 3 and the first side surface 43 of the ring gear 4 are each supported by the first support surface 52 of the gear housing 5 and slide on the first support surface 52. Note that the first side surface 32 of the pinion gear 3 is a surface perpendicular to the rotation axis C1 of the pinion gear 3, and is the right side surface in FIG. The first side surface 43 of the ring gear 4 is a surface perpendicular to the rotation axis C2 of the ring gear 4, and is the right side surface in FIG.
　フロントカバー６は、ギヤハウジング５に隣接して配設されている。フロントカバー６、及び、ギヤハウジング５は、互いに固定されることによって一体化されている。フロントカバー６は、ギヤハウジング５に接すると共に、空間５０を閉じる第２支持面６１を有している。ピニオンギヤ３の第２側面３３、及び、リングギヤ４の第２側面４４はそれぞれ、フロントカバー６の第２支持面６１に支持されると共に、第２支持面６１を摺動する。尚、ピニオンギヤ３の第２側面３３は、ピニオンギヤ３の回転軸Ｃ１に直交する面であって、図２の左の側面である。リングギヤ４の第２側面４４は、リングギヤ４の回転軸Ｃ２に直交する面であって、図２の左の側面である。 The front cover 6 is arranged adjacent to the gear housing 5. The front cover 6 and the gear housing 5 are integrated by being fixed to each other. The front cover 6 has a second support surface 61 that contacts the gear housing 5 and closes the space 50 . The second side surface 33 of the pinion gear 3 and the second side surface 44 of the ring gear 4 are each supported by the second support surface 61 of the front cover 6 and slide on the second support surface 61. The second side surface 33 of the pinion gear 3 is a surface perpendicular to the rotation axis C1 of the pinion gear 3, and is the left side surface in FIG. The second side surface 44 of the ring gear 4 is a surface perpendicular to the rotation axis C2 of the ring gear 4, and is the left side surface in FIG.
　フロントカバー６には、シャフト２が通る支持孔６２が貫通して形成されている。シャフト２は、ベアリング６３と軸受部材６４とを介して、フロントカバー６及びギヤハウジング５に、回転可能に支持されている。支持孔６２の開口は、封止部材６２１によって塞がれている。 A support hole 62 through which the shaft 2 passes is formed through the front cover 6. The shaft 2 is rotatably supported by the front cover 6 and the gear housing 5 via a bearing 63 and a bearing member 64. The opening of the support hole 62 is closed by a sealing member 621.
　フロントカバー６及びギヤハウジング５には、吸込ポート１１が形成されている。吸込ポート１１は、ハウジング１０の内部の空間５０へ作動油を吸い込むポートである。吸込ポート１１の入口は、図２に示すように、フロントカバー６の外周面に開口している。吸込ポート１１の出口は、図１及び２に示すように、フロントカバー６の第２支持面６１及びギヤハウジング５の第１支持面５２のそれぞれに開口している。吸込ポート１１の出口はまた、シャフト２の回転方向に沿うように、周方向に延びている。 A suction port 11 is formed in the front cover 6 and the gear housing 5. The suction port 11 is a port that sucks hydraulic oil into the space 50 inside the housing 10 . The inlet of the suction port 11 opens on the outer peripheral surface of the front cover 6, as shown in FIG. As shown in FIGS. 1 and 2, the outlet of the suction port 11 opens on the second support surface 61 of the front cover 6 and the first support surface 52 of the gear housing 5, respectively. The outlet of the suction port 11 also extends in the circumferential direction along the rotational direction of the shaft 2.
　フロントカバー６、及び、ギヤハウジング５にはまた、吐出ポート１２が形成されている。吐出ポート１２は、ハウジング１０の内部の空間５０から作動油を吐き出すポートである。吐出ポート１２の出口は、図２に示すように、ギヤハウジング５の外周面に開口している。尚、吸込ポート１１の入口の向きと、吐出ポート１２の出口の向きとは、図２に例示するように異なる方向であってもよいし、図示は省略するが、同じ方向であってもよい。 A discharge port 12 is also formed in the front cover 6 and the gear housing 5. The discharge port 12 is a port that discharges hydraulic oil from the space 50 inside the housing 10. The outlet of the discharge port 12 is open to the outer peripheral surface of the gear housing 5, as shown in FIG. Note that the direction of the inlet of the suction port 11 and the direction of the outlet of the discharge port 12 may be different directions as illustrated in FIG. 2, or may be the same direction although not shown. .
　吐出ポート１２の入口は、フロントカバー６の第２支持面６１及びギヤハウジング５の第１支持面５２のそれぞれに開口している。吐出ポート１２の入口はまた、図１に示すように、吸込ポート１１に対して、シャフト２を挟んだ反対側において、シャフト２の回転方向に沿うように、周方向に延びている。 The inlet of the discharge port 12 opens on the second support surface 61 of the front cover 6 and the first support surface 52 of the gear housing 5, respectively. As shown in FIG. 1, the inlet of the discharge port 12 also extends in the circumferential direction along the rotational direction of the shaft 2 on the opposite side of the shaft 2 from the suction port 11.
　ギヤハウジング５には、クレセント５４が設けられている。クレセント５４は、ピニオンギヤ３とリングギヤ４との噛み合いが離れる箇所に配設されている。クレセント５４は、後述する第２領域と第１領域とを分離する。 A crescent 54 is provided in the gear housing 5. The crescent 54 is disposed at a location where the pinion gear 3 and ring gear 4 are separated from each other. The crescent 54 separates a second region and a first region, which will be described later.
　クレセント５４は、シャフト２の回転方向に沿うように、所定の角度範囲に亘って周方向に伸びている。図１に示すように、クレセント５４は、シャフト２の軸方向に見たときに、三日月形状を有している。クレセント５４は、第１円弧壁５４１と、第２円弧壁５４２との二つの円弧壁を有し、第１円弧壁５４１及び第２円弧壁５４２はそれぞれ、ギヤハウジング５の第１支持面５２に立設している。 The crescent 54 extends in the circumferential direction over a predetermined angular range along the rotational direction of the shaft 2. As shown in FIG. 1, the crescent 54 has a crescent shape when viewed in the axial direction of the shaft 2. The crescent 54 has two arc walls, a first arc wall 541 and a second arc wall 542, and the first arc wall 541 and the second arc wall 542 are respectively attached to the first support surface 52 of the gear housing 5. It is erected.
　ピニオンギヤ３の外歯３１の歯先は、クレセント５４の第１円弧壁５４１に、実質的に当接する。リングギヤ４の内歯４１の歯先は、クレセント５４の第２円弧壁５４２に、実質的に当接する。第１円弧壁５４１及び第２円弧壁５４２は共に、外歯３１及び内歯４１の方へ移動しない固定壁である。 The tips of the external teeth 31 of the pinion gear 3 substantially abut against the first arcuate wall 541 of the crescent 54. The tips of the internal teeth 41 of the ring gear 4 substantially abut against the second arcuate wall 542 of the crescent 54 . Both the first circular arc wall 541 and the second circular arc wall 542 are fixed walls that do not move toward the external teeth 31 and internal teeth 41.
　ハウジング１０内は、リングギヤ４の回転軸Ｃ２を中心として周方向に、吸込ポート１１が開口する第１領域と、吐出ポート１２が開口する第２領域と、第１領域及び第２領域の間であってクレセント５４が配設されている第３領域と、の三領域に分けることができる。第１領域は低圧領域であり、第２領域は高圧領域である。 Inside the housing 10, in the circumferential direction around the rotation axis C2 of the ring gear 4, there is a first region where the suction port 11 opens, a second region where the discharge port 12 opens, and a region between the first region and the second region. It can be divided into three regions: a third region where the crescent 54 is disposed; and a third region where the crescent 54 is provided. The first region is a low pressure region and the second region is a high pressure region.
　次に、内接ギヤポンプ１の運転を簡単に説明する。原動機によってシャフト２が、図１の右図における時計回りの方向に回転すると、ピニオンギヤ３及びリングギヤ４がそれぞれ、第１領域から、第３領域を経て、第２領域に至る方向に回転する。 Next, the operation of the internal gear pump 1 will be briefly explained. When the shaft 2 is rotated by the prime mover in the clockwise direction in the right diagram of FIG. 1, the pinion gear 3 and ring gear 4 are rotated in a direction from the first region, through the third region, and then to the second region.
　ハウジング１０内の第１領域において、噛み合っていたピニオンギヤ３の外歯３１とリングギヤ４の内歯４１とが離れるに伴って、吸込ポート１１から外歯３１と内歯４１との間に作動油が吸い込まれる。吸い込まれた作動油は、ピニオンギヤ３及びリングギヤ４の回転に伴い、第１領域から、第３領域を経て第２領域へ運ばれる。 In the first region inside the housing 10, as the external teeth 31 of the pinion gear 3 and the internal teeth 41 of the ring gear 4, which were in mesh with each other, separate, hydraulic oil flows from the suction port 11 between the external teeth 31 and the internal teeth 41. It gets sucked in. As the pinion gear 3 and ring gear 4 rotate, the sucked hydraulic oil is transported from the first area to the second area via the third area.
　ハウジング１０内の第２領域においては、離れていたピニオンギヤ３の外歯３１とリングギヤ４の内歯４１とが次第に近づいて噛み合う。このことにより、作動油が、外歯３１と内歯４１との間から吐出ポート１２を通じて吐き出される。 In the second region inside the housing 10, the external teeth 31 of the pinion gear 3 and the internal teeth 41 of the ring gear 4, which were separated, gradually approach and mesh with each other. As a result, the hydraulic oil is discharged from between the outer teeth 31 and the inner teeth 41 through the discharge port 12.
　（ポンプ効率を高める構造）
　内接ギヤポンプ１は、高圧油供給部８を備えている。高圧油供給部８は、リングギヤ４の外周面４２とギヤハウジング５の摺動面５１との間に高圧の作動油を供給する。尚、高圧油供給部８は、図１にのみ図示される。 (Structure that increases pump efficiency)
The internal gear pump 1 includes a high-pressure oil supply section 8. The high-pressure oil supply section 8 supplies high-pressure hydraulic oil between the outer peripheral surface 42 of the ring gear 4 and the sliding surface 51 of the gear housing 5. Note that the high-pressure oil supply section 8 is illustrated only in FIG. 1.
　高圧油供給部８は、高圧の作動油によって、リングギヤ４を、第３領域の外周囲から回転軸Ｃ２の方へ押して移動させる。リングギヤ４の歯先がクレセント５４の第２円弧壁５４２に押し当てられるから、ハウジング１０内で、高圧側から低圧側へ作動油が漏れることが抑制される。 The high-pressure oil supply unit 8 uses high-pressure hydraulic oil to push and move the ring gear 4 from the outer periphery of the third region toward the rotation axis C2. Since the tooth tips of the ring gear 4 are pressed against the second arcuate wall 542 of the crescent 54, leakage of hydraulic oil from the high pressure side to the low pressure side within the housing 10 is suppressed.
　高圧油供給部８は、摺動面５１に開口する導入口８１と、吐出ポート１２と導入口８１とをつなぐ供給路８２とを有している。 The high-pressure oil supply section 8 has an inlet 81 that opens to the sliding surface 51 and a supply path 82 that connects the discharge port 12 and the inlet 81.
　導入口８１は、図１に示すように、第３領域に位置している。より詳細に、導入口８１は、クレセント５４に対し、リングギヤ４を挟んで径方向に向かい合っている。導入口８１は、吐出ポート１２から吐出される高圧の作動油の一部を、ハウジング１０内へ導入する。リングギヤ４の歯先をクレセント５４に効率的に押し付けるために、導入口８１は、クレセント５４に向かい合う位置であることが好ましい。また、ハウジング１０内に導入した高圧の作動油が低圧の第１領域へ流れることを抑制するために、導入口８１は、低圧側の領域と高圧側の領域とに二等分される第３領域において、高圧側の領域に位置することが好ましい。 The introduction port 81 is located in the third region, as shown in FIG. More specifically, the introduction port 81 faces the crescent 54 in the radial direction with the ring gear 4 interposed therebetween. The inlet 81 introduces a portion of the high-pressure hydraulic oil discharged from the discharge port 12 into the housing 10 . In order to efficiently press the tips of the ring gear 4 against the crescent 54, the introduction port 81 is preferably located at a position facing the crescent 54. In addition, in order to suppress the high-pressure hydraulic oil introduced into the housing 10 from flowing into the low-pressure first region, the inlet 81 has a third region that is divided into a low-pressure side region and a high-pressure side region. In the region, it is preferably located in a region on the high pressure side.
　供給路８２は、ギヤハウジング５内に形成されている。供給路８２は、ギヤハウジング５の第１支持面５２に開口する吐出ポート１２と、導入口８１とをつないでいる。尚、供給路は、フロントカバー６の第２支持面６１に開口する吐出ポート１２と、導入口８１とをつなぐように、フロントカバー６及びギヤハウジング５に形成されてもよい。また、供給路は、第１支持面５２に開口する吐出ポート１２と導入口８１とをつなぐと共に、第２支持面６１に開口する吐出ポート１２と導入口８１とをつないでもよい。 The supply path 82 is formed within the gear housing 5. The supply path 82 connects the discharge port 12 that opens to the first support surface 52 of the gear housing 5 and the introduction port 81 . Incidentally, the supply path may be formed in the front cover 6 and the gear housing 5 so as to connect the discharge port 12 opened to the second support surface 61 of the front cover 6 and the introduction port 81. Further, the supply path may connect the discharge port 12 that opens on the first support surface 52 and the introduction port 81, and may also connect the discharge port 12 that opens on the second support surface 61 and the introduction port 81.
　前述したように、内接ギヤポンプ１の運転中に、吐出ポート１２の高圧の作動油の一部は、供給路８２及び導入口８１を通じて、リングギヤ４の外周面とギヤハウジング５の摺動面５１との間に導入される。高圧の作動油は、リングギヤ４を、第３領域の外周囲から回転軸Ｃ２の方へ押す。リングギヤ４の歯先はクレセント５４の第２円弧壁５４２に押し付けられる。第３領域において、リングギヤ４の歯先とクレセント５４の第２円弧壁５４２との間を通って、作動油が高圧側から低圧側へ漏れることが抑制される。ハウジング１０内の漏れ流れが抑制されることによって、内接ギヤポンプ１のポンプ効率が向上する。 As described above, during operation of the internal gear pump 1, a portion of the high-pressure hydraulic oil in the discharge port 12 passes through the supply path 82 and the inlet 81 to the outer circumferential surface of the ring gear 4 and the sliding surface 51 of the gear housing 5. will be introduced between. The high-pressure hydraulic oil pushes the ring gear 4 from the outer periphery of the third area toward the rotation axis C2. The tooth tips of the ring gear 4 are pressed against the second arcuate wall 542 of the crescent 54. In the third region, hydraulic oil is prevented from leaking from the high pressure side to the low pressure side through between the tooth tips of the ring gear 4 and the second circular arc wall 542 of the crescent 54. By suppressing leakage flow within the housing 10, the pumping efficiency of the internal gear pump 1 is improved.
　尚、高圧油供給部８は、供給路８２の途中に絞りを有していてもよい。絞りは、リングギヤ４の外周面とギヤハウジング５の摺動面５１との間に導入される作動油の圧力を調整する。 Note that the high-pressure oil supply section 8 may have a restriction in the middle of the supply path 82. The throttle adjusts the pressure of the hydraulic oil introduced between the outer peripheral surface of the ring gear 4 and the sliding surface 51 of the gear housing 5.
　内接ギヤポンプ１において、高圧油供給部８は省略されてもよい。高圧油供給部８は、内接ギヤポンプ１において必須の要素ではない。 In the internal gear pump 1, the high pressure oil supply section 8 may be omitted. The high-pressure oil supply section 8 is not an essential element in the internal gear pump 1.
　（騒音を抑制する構造）
　内接ギヤポンプ１では、ピニオンギヤ３の歯の間の空間及びリングギヤ４の歯の間の空間が、第３領域を通過して、吐出ポート１２に開放される際に、吐出ポート１２の圧力と歯の間の空間の圧力との圧力差に起因して騒音が生じる。吐出ポート１２の圧力と歯の間の空間の圧力との圧力差が大きいほど歯の間の空間が吐出ポート１２に開放される際の圧力変動が大きいから、内接ギヤポンプの騒音は大きくなる。内接ギヤポンプ１は、騒音を抑制させる圧力伝達油路９１を有している。 (Structure that suppresses noise)
In the internal gear pump 1, when the space between the teeth of the pinion gear 3 and the space between the teeth of the ring gear 4 pass through the third region and are opened to the discharge port 12, the pressure of the discharge port 12 and the tooth Noise is generated due to the pressure difference with the pressure in the space between the two. The larger the pressure difference between the pressure of the discharge port 12 and the pressure of the space between the teeth, the greater the pressure fluctuation when the space between the teeth is opened to the discharge port 12, and therefore the noise of the internal gear pump becomes louder. The internal gear pump 1 has a pressure transmission oil passage 91 that suppresses noise.
　圧力伝達油路９１は、吐出ポート１２の高い圧力を利用して、歯の間の空間に閉じ込められている作動油の圧力を第３領域において予め高め、それによって、吐出ポート１２の圧力と歯の間の空間の圧力との圧力差を小さくする。圧力差が小さいと、歯の間の空間が吐出ポート１２に開放される際の圧力変動が小さくなるから、内接ギヤポンプの騒音は抑制される。 The pressure transmission oil passage 91 utilizes the high pressure of the discharge port 12 to increase the pressure of the hydraulic oil confined in the space between the teeth in advance in the third region, thereby increasing the pressure of the discharge port 12 and the tooth. Reduce the pressure difference between the pressure in the space between the If the pressure difference is small, the pressure fluctuation when the space between the teeth is opened to the discharge port 12 will be small, so the noise of the internal gear pump will be suppressed.
　図１及び３に例示する内接ギヤポンプ１において、圧力伝達油路９１は、フロントカバー６の第２支持面６１から凹陥するように形成されている。尚、図１の右図及び図３において二点鎖線で示す圧力伝達油路９１は、圧力伝達油路９１、リングギヤ４、及び、クレセント５４の位置関係を明確にするために、フロントカバー６に形成された圧力伝達油路９１を、ギヤハウジング５に投影して示している。 In the internal gear pump 1 illustrated in FIGS. 1 and 3, the pressure transmission oil passage 91 is formed to be recessed from the second support surface 61 of the front cover 6. Note that the pressure transmission oil passage 91 shown by the two-dot chain line in the right diagram of FIG. 1 and FIG. The formed pressure transmission oil passage 91 is shown projected onto the gear housing 5.
　圧力伝達油路９１は、第２支持面６１に形成された溝である。図３に示すように、圧力伝達油路９１の横断面の形状は、三角形である。尚、圧力伝達油路９１の横断面の形状は、三角形に限らない。横断面の形状は、例えば四角形であってもよい。 The pressure transmission oil passage 91 is a groove formed in the second support surface 61. As shown in FIG. 3, the cross-sectional shape of the pressure transmission oil passage 91 is triangular. Note that the cross-sectional shape of the pressure transmission oil passage 91 is not limited to a triangle. The shape of the cross section may be, for example, a quadrangle.
　圧力伝達油路９１は、吐出ポート１２の縁から、第３領域における低圧側の方へ、真っ直ぐに延びている。図３に示すように、圧力伝達油路９１の深さは、吐出ポート１２から離れるに従い、次第に浅くなりかつ、圧力伝達油路９１の幅は、吐出ポート１２から離れるに従い、次第に狭くなる。尚、圧力伝達油路の深さは一定深さであってもよいし、圧力伝達油路の幅は一定幅であってもよい。 The pressure transmission oil passage 91 extends straight from the edge of the discharge port 12 toward the low pressure side in the third region. As shown in FIG. 3, the depth of the pressure transmission oil passage 91 becomes gradually shallower as the distance from the discharge port 12 increases, and the width of the pressure transmission oil passage 91 gradually becomes narrower as the distance from the discharge port 12 increases. Note that the depth of the pressure transmission oil passage may be a constant depth, and the width of the pressure transmission oil passage may be a constant width.
　圧力伝達油路９１は、リングギヤ４の回転軸Ｃ２の方向に見た場合に、換言すると図１の右図又は図３において、リングギヤ４の歯の間の空間と重なっている。圧力伝達油路９１は直線状である一方、クレセント５４は三日月形状であるため、圧力伝達油路９１の基端（つまり、圧力伝達油路９１と吐出ポート１２との接続端）は、吐出ポート１２における径方向の最も外側の縁の近くに位置し、圧力伝達油路９１の中間部は、クレセント５４の第２円弧壁５４２の近くに位置し、圧力伝達油路９１の先端は、クレセント５４の第２円弧壁５４２から離れて位置する。圧力伝達油路９１は、クレセント５４との干渉を避けて延びることができる。 The pressure transmission oil passage 91 overlaps with the space between the teeth of the ring gear 4 when viewed in the direction of the rotation axis C2 of the ring gear 4, in other words, in the right view of FIG. 1 or in FIG. 3. Since the pressure transmission oil passage 91 is linear, and the crescent 54 is crescent shaped, the base end of the pressure transmission oil passage 91 (that is, the connection end between the pressure transmission oil passage 91 and the discharge port 12) is connected to the discharge port. The middle part of the pressure transmission oil passage 91 is located near the second circular arc wall 542 of the crescent 54, and the tip of the pressure transmission oil passage 91 is located near the radially outermost edge of the crescent 54. The second arcuate wall 542 is located away from the second arcuate wall 542 . The pressure transmission oil passage 91 can extend while avoiding interference with the crescent 54.
　第３領域において、リングギヤ４の歯の間の空間は、リングギヤ４の歯先がクレセント５４の第２円弧壁５４２に押し付けられているため閉じている。圧力伝達油路９１は、リングギヤ４の歯の間の空間に対して、図１又は３の紙面に直交する方向に連通する。吐出ポート１２の高圧の作動油の一部は、圧力伝達油路９１を通じて、リングギヤ４の歯の間の空間に流入し、当該空間の圧力を高める。本願発明者らが、ハウジング１０内の圧力を実際に計測した結果によれば、圧力伝達油路９１が形成されていない場合、第３領域のクレセント５４を挟んだリングギヤ４側において、リングギヤ４の歯の間の空間の圧力は、吐出圧力に対して低下する一方、圧力伝達油路９１が形成されることにより、当該空間の圧力が高まることが確認できた。リングギヤ４の歯の間の空間の圧力が第３領域において予め高まるから、吐出ポート１２の圧力と歯の間の空間の圧力との圧力差が小さくなる。当該空間が吐出ポート１２に開放される際の圧力変動が抑制されるから、内接ギヤポンプ１の騒音が抑制される。本願発明者らの検討によれば、圧力伝達油路９１が形成されることによる騒音レベルの低減が確認でき、騒音レベルの改善効果は、内接ギヤポンプ１の吐出圧力が高いほど高いことがわかった。 In the third region, the space between the teeth of the ring gear 4 is closed because the tips of the teeth of the ring gear 4 are pressed against the second arcuate wall 542 of the crescent 54. The pressure transmission oil passage 91 communicates with the space between the teeth of the ring gear 4 in a direction perpendicular to the paper plane of FIG. 1 or 3. A portion of the high-pressure hydraulic oil in the discharge port 12 flows into the space between the teeth of the ring gear 4 through the pressure transmission oil path 91, increasing the pressure in the space. According to the results of actual measurement of the pressure inside the housing 10 by the inventors of the present application, when the pressure transmission oil passage 91 is not formed, on the ring gear 4 side across the crescent 54 in the third region, the ring gear 4 It was confirmed that while the pressure in the space between the teeth decreased relative to the discharge pressure, the pressure in the space increased due to the formation of the pressure transmission oil passage 91. Since the pressure in the space between the teeth of the ring gear 4 increases in advance in the third region, the pressure difference between the pressure in the discharge port 12 and the pressure in the space between the teeth becomes small. Since pressure fluctuations when the space is opened to the discharge port 12 are suppressed, the noise of the internal gear pump 1 is suppressed. According to the studies conducted by the inventors of the present application, it was confirmed that the noise level was reduced by forming the pressure transmission oil passage 91, and it was found that the effect of improving the noise level was higher as the discharge pressure of the internal gear pump 1 was higher. Ta.
　内接ギヤポンプ１は、第３領域におけるクレセント５４を挟んだピニオンギヤ３側の領域とリングギヤ４側の領域とのうち、リングギヤ４側の領域にのみ、ハウジング１０内に形成されている。ピニオンギヤ３側の領域に、圧力伝達油路は形成されていない。 The internal gear pump 1 is formed in the housing 10 only in the region on the ring gear 4 side of the region on the pinion gear 3 side and the region on the ring gear 4 side with the crescent 54 in the third region. No pressure transmission oil passage is formed in the region on the pinion gear 3 side.
　本願発明者らの検討によると、ピニオンギヤ３の歯の間の空間の圧力は、圧力伝達油路が無くても比較的高くて、圧力伝達油路９１が形成されている場合のリングギヤ４側の圧力と同等かそれよりも高いことが分かった。ピニオンギヤ３の歯の間の空間が吐出ポート１２に開放された際の圧力変動は、比較的小さい。これは、クレセント５４が、第１円弧壁５４１及び第２円弧壁５４２が可動しない構造を有し、ピニオンギヤ３の歯先と第１円弧壁５４１との間に、微少の隙間が存在しているためである。ピニオンギヤ３側においては、当該隙間を通じた、吐出ポート１２からピニオンギヤ３の歯の間の空間へ漏れ流れが発生する。その結果、第３領域において、ピニオンギヤ３の歯の間の空間の圧力は比較的高い。 According to studies by the inventors of the present application, the pressure in the space between the teeth of the pinion gear 3 is relatively high even without a pressure transmission oil passage, and that the pressure in the space between the teeth of the pinion gear 3 is relatively high when the pressure transmission oil passage 91 is formed. It was found that the pressure was equal to or higher than that. The pressure fluctuation when the space between the teeth of the pinion gear 3 is opened to the discharge port 12 is relatively small. This is because the crescent 54 has a structure in which the first arcuate wall 541 and the second arcuate wall 542 do not move, and a small gap exists between the tooth tip of the pinion gear 3 and the first arcuate wall 541. It's for a reason. On the pinion gear 3 side, leakage flow occurs from the discharge port 12 to the space between the teeth of the pinion gear 3 through the gap. As a result, in the third region, the pressure in the space between the teeth of the pinion gear 3 is relatively high.
　ピニオンギヤ３の歯の間の空間の圧力が比較的高いため、ピニオンギヤ３側の領域に圧力伝達油路が形成されても当該空間の圧力はそれ以上に高まらない。内接ギヤポンプ１の騒音抑制効果は向上しにくい。その一方で、圧力伝達油路が形成されると、その分、漏れ流れが増えてしまう。内接ギヤポンプ１のポンプ効率が低下する恐れがある。 Since the pressure in the space between the teeth of the pinion gear 3 is relatively high, even if a pressure transmission oil passage is formed in the area on the pinion gear 3 side, the pressure in the space does not increase any further. The noise suppression effect of the internal gear pump 1 is difficult to improve. On the other hand, when a pressure transmission oil passage is formed, leakage flow increases accordingly. There is a possibility that the pump efficiency of the internal gear pump 1 will decrease.
　そこで、内接ギヤポンプ１では、リングギヤ４側の領域にのみ、圧力伝達油路９１がハウジング内に形成され、ピニオンギヤ３側の領域に、圧力伝達油路は形成されていない。内接ギヤポンプ１の騒音抑制と、ポンプ効率の向上とが両立する。 Therefore, in the internal gear pump 1, the pressure transmission oil passage 91 is formed in the housing only in the area on the ring gear 4 side, and no pressure transmission oil passage is formed in the area on the pinion gear 3 side. Both noise suppression of the internal gear pump 1 and improvement of pump efficiency are achieved.
　次に、圧力伝達油路９１の好ましい長さについて検討する。ここでは、圧力伝達油路９１の先端がハウジング１０内の第３領域におけるどの位置に位置しているか、によって、圧力伝達油路９１の長さを特定する。ここで言う圧力伝達油路９１の長さは、直線状の圧力伝達油路９１に沿った長さではない。 Next, a preferable length of the pressure transmission oil passage 91 will be discussed. Here, the length of the pressure transmission oil passage 91 is specified depending on where the tip of the pressure transmission oil passage 91 is located in the third region within the housing 10. The length of the pressure transmission oil passage 91 referred to here is not the length along the linear pressure transmission oil passage 91.
　前述したように、圧力伝達油路９１は、リングギヤ４の歯の間の空間が吐出ポート１２に連通する前に、当該空間の圧力を高める機能を有している。圧力伝達油路９１が短すぎると、リングギヤ４の歯の間の空間が吐出ポート１２に連通する前に、当該空間の圧力を予め高めることが難しい。圧力伝達油路９１が機能を発揮できるための、圧力伝達油路９１の最低長さが存在する。 As described above, the pressure transmission oil passage 91 has the function of increasing the pressure in the space between the teeth of the ring gear 4 before the space communicates with the discharge port 12. If the pressure transmission oil passage 91 is too short, it is difficult to increase the pressure in the space between the teeth of the ring gear 4 before the space communicates with the discharge port 12. There is a minimum length of the pressure transmission oil passage 91 for the pressure transmission oil passage 91 to perform its function.
　具体的に、図３に示すように、圧力伝達油路９１の先端は、リングギヤ４の回転軸Ｃ２を中心として、吐出ポート１２の縁から、リングギヤ４の歯幅ＴＷに相当する角度θ１以上となる位置に位置している。角度θ１以上の位置まで圧力伝達油路９１が延びていると、圧力伝達油路９１は、リングギヤ４の少なくとも一つの歯を超えて、吐出ポート１２と、歯の間の空間とを互いに連通させることができる。圧力伝達油路９１は、歯の間の空間が吐出ポート１２に到達する前に、当該空間内へ高圧の作動油を供給できる。つまり、圧力伝達油路９１は、リングギヤ４の歯の間の空間が吐出ポート１２に連通する前に、当該空間の圧力を予め高めることができる。 Specifically, as shown in FIG. 3, the tip of the pressure transmission oil passage 91 is formed at an angle θ1 or more corresponding to the tooth width TW of the ring gear 4 from the edge of the discharge port 12 with the rotation axis C2 of the ring gear 4 as the center. It is located in a position where When the pressure transmission oil passage 91 extends to a position equal to or greater than the angle θ1, the pressure transmission oil passage 91 passes over at least one tooth of the ring gear 4 and allows the discharge port 12 and the space between the teeth to communicate with each other. be able to. The pressure transmission oil passage 91 can supply high-pressure hydraulic oil into the space between the teeth before the space reaches the discharge port 12 . In other words, the pressure transmission oil passage 91 can increase the pressure in the space between the teeth of the ring gear 4 before the space communicates with the discharge port 12 .
　圧力伝達油路９１を長くすることは、リングギヤ４の歯の間の空間の圧力を高める上で有利である。しかし、圧力伝達油路９１がある程度長くなれば、圧力伝達油路９１をそれ以上に長くしても歯の間の空間の圧力は高まらない。一方、圧力伝達油路９１が長くなればなるほど、ハウジング１０内の漏れ流れが増える。そこで、圧力伝達油路９１の先端は、吐出ポート１２の縁から、クレセント５４の中間位置までの角度θ２以下の範囲に位置している。図例の圧力伝達油路９１は、その先端がクレセント５４の中間位置に位置している。クレセント５４の中間位置は、吐出ポート１２から吸込ポート１１まで周方向に延びるクレセント５４の、周方向についての中間位置である。圧力伝達油路９１が長すぎないことによって、リングギヤ４の歯の間の空間の圧力が十分に高まると共に、漏れ流れの増加が抑制できる。 Increasing the length of the pressure transmission oil passage 91 is advantageous in increasing the pressure in the space between the teeth of the ring gear 4. However, if the pressure transmission oil passage 91 becomes long to a certain extent, the pressure in the space between the teeth will not increase even if the pressure transmission oil passage 91 is made longer than that. On the other hand, as the pressure transmission oil passage 91 becomes longer, leakage flow within the housing 10 increases. Therefore, the tip of the pressure transmission oil passage 91 is located within a range of angle θ2 or less from the edge of the discharge port 12 to the intermediate position of the crescent 54. The illustrated pressure transmission oil passage 91 has its tip located at an intermediate position of the crescent 54 . The intermediate position of the crescent 54 is the intermediate position in the circumferential direction of the crescent 54 that extends in the circumferential direction from the discharge port 12 to the suction port 11. Since the pressure transmission oil passage 91 is not too long, the pressure in the space between the teeth of the ring gear 4 can be sufficiently increased, and an increase in leakage flow can be suppressed.
　（圧力伝達油路の変形例）
　図１に示す内接ギヤポンプ１において、圧力伝達油路９１は、フロントカバー６の第２支持面６１に形成されている。圧力伝達油路９１は、ギヤハウジング５の第１支持面５２から凹陥するように形成されてもよい。圧力伝達油路９１は、フロントカバー６の第２支持面６１と、ギヤハウジング５の第１支持面５２とのそれぞれに形成されてもよい。 (Modified example of pressure transmission oil path)
In the internal gear pump 1 shown in FIG. 1, the pressure transmission oil passage 91 is formed on the second support surface 61 of the front cover 6. The pressure transmission oil passage 91 may be formed to be recessed from the first support surface 52 of the gear housing 5. The pressure transmission oil passage 91 may be formed on each of the second support surface 61 of the front cover 6 and the first support surface 52 of the gear housing 5.
　圧力伝達油路は直線状に限定されない。図４は、曲線状の圧力伝達油路９２を示している。圧力伝達油路９２は、圧力伝達油路９１と同様に、フロントカバー６の第２支持面６１に形成されている。尚、図４の圧力伝達油路９２も、図３と同様に、フロントカバー６に形成された圧力伝達油路９２を、ギヤハウジング５に投影して示している。 The pressure transmission oil path is not limited to a straight line. FIG. 4 shows a curved pressure transmission oil passage 92. Like the pressure transmission oil passage 91, the pressure transmission oil passage 92 is formed on the second support surface 61 of the front cover 6. Note that the pressure transmission oil passage 92 in FIG. 4 is also shown by projecting the pressure transmission oil passage 92 formed in the front cover 6 onto the gear housing 5, similarly to FIG.
　圧力伝達油路９２は、クレセント５４の第２円弧壁５４２の曲線に沿うように、円弧状に延びている。リングギヤ４の回転軸Ｃ２の方向に見た場合に、圧力伝達油路９２は、リングギヤ４の歯の間の空間と重なる。圧力伝達油路９２は、リングギヤ４の歯の間の空間に連通する。リングギヤ４の歯の間の空間の圧力が第３領域において高まるから、当該空間が吐出ポート１２に開放される際の、吐出ポート１２の圧力と歯の間の空間の圧力との圧力差は小さい。内接ギヤポンプ１の騒音が抑制される。 The pressure transmission oil passage 92 extends in an arc shape along the curve of the second arc wall 542 of the crescent 54. When viewed in the direction of the rotation axis C2 of the ring gear 4, the pressure transmission oil passage 92 overlaps the space between the teeth of the ring gear 4. The pressure transmission oil passage 92 communicates with the space between the teeth of the ring gear 4. Since the pressure in the space between the teeth of the ring gear 4 increases in the third region, when the space is opened to the discharge port 12, the pressure difference between the pressure in the discharge port 12 and the pressure in the space between the teeth is small. . The noise of the internal gear pump 1 is suppressed.
　尚、図４に示す圧力伝達油路９２の円弧形状は例示である。曲線状の圧力伝達油路９２は、円弧状に限定されない。圧力伝達油路９２の深さは、吐出ポート１２から離れるに従い、次第に浅くなってもよいし、一定深さであってもよい。圧力伝達油路９２の幅は、吐出ポート１２から離れるに従い、次第に狭くなってもよいし、一定幅であってもよい。また、圧力伝達油路９２の先端の位置は、前述したθ１以上θ２以下の範囲で、任意に設定できる。圧力伝達油路９２は、フロントカバー６の第２支持面６１に形成される代わりに、又は、第２支持面６１に形成されることに加えて、ギヤハウジング５の第１支持面５２に形成されてもよい。 Note that the arcuate shape of the pressure transmission oil passage 92 shown in FIG. 4 is an example. The curved pressure transmission oil passage 92 is not limited to an arc shape. The depth of the pressure transmission oil passage 92 may become gradually shallower as it moves away from the discharge port 12, or may be a constant depth. The width of the pressure transmission oil passage 92 may become gradually narrower as it moves away from the discharge port 12, or may have a constant width. Further, the position of the tip of the pressure transmission oil passage 92 can be set arbitrarily within the above-mentioned range of θ1 or more and θ2 or less. The pressure transmission oil passage 92 may be formed on the first support surface 52 of the gear housing 5 instead of being formed on the second support surface 61 of the front cover 6 or in addition to being formed on the second support surface 61. may be done.
　また、第１支持面５２及び／又は第２支持面６１に形成される圧力伝達油路は、その途中で折れ曲がっていてもよい。 Further, the pressure transmission oil passage formed on the first support surface 52 and/or the second support surface 61 may be bent in the middle.
　圧力伝達油路は、第１支持面５２及び／又は第２支持面６１に形成されることに限定されない。図５は、フロントカバー６を取り外した状態における内接ギヤポンプ１の斜視図である。この内接ギヤポンプ１は、クレセント５４に形成された圧力伝達油路９３を有している。 The pressure transmission oil passage is not limited to being formed on the first support surface 52 and/or the second support surface 61. FIG. 5 is a perspective view of the internal gear pump 1 with the front cover 6 removed. This internal gear pump 1 has a pressure transmission oil passage 93 formed in the crescent 54.
　圧力伝達油路９３は、クレセント５４の第２円弧壁５４２の上端に形成されている。圧力伝達油路９３は、クレセント５４の表面が切り欠かれて形成されている。尚、ここでいう上端は、ギヤハウジング５の第１支持面５２から立設したクレセント５４における、第１支持面５２とは逆側の端である。第２円弧壁５４２の上端は、フロントカバー６の第２支持面６１に当接する端である。 The pressure transmission oil passage 93 is formed at the upper end of the second arcuate wall 542 of the crescent 54. The pressure transmission oil passage 93 is formed by cutting out the surface of the crescent 54. Note that the upper end here is the end of the crescent 54 that stands up from the first support surface 52 of the gear housing 5 on the opposite side to the first support surface 52 . The upper end of the second arcuate wall 542 is the end that comes into contact with the second support surface 61 of the front cover 6 .
　圧力伝達油路９３は、クレセント５４における高圧側の端（つまり、図５における左端）から、クレセント５４の中間位置まで延びている。圧力伝達油路９３は、フロントカバー６の第２支持面６１に開口する吐出ポート１２に連通する。圧力伝達油路９３の長さは、前述したθ１以上θ２以下の範囲で、任意に設定できる。圧力伝達油路９３は、図５の構成例では、その幅／深さが、吐出ポート１２から離れるに従い、次第に狭く／浅くなっている。圧力伝達油路９３の幅／深さは、一定であってもよい。 The pressure transmission oil passage 93 extends from the high-pressure side end of the crescent 54 (that is, the left end in FIG. 5) to an intermediate position of the crescent 54. The pressure transmission oil passage 93 communicates with the discharge port 12 that opens into the second support surface 61 of the front cover 6 . The length of the pressure transmission oil passage 93 can be set arbitrarily within the above-mentioned range of θ1 or more and θ2 or less. In the configuration example shown in FIG. 5, the pressure transmission oil passage 93 has a width/depth that gradually becomes narrower/shallower as it moves away from the discharge port 12. The width/depth of the pressure transmission oil passage 93 may be constant.
　クレセント５４に形成された圧力伝達油路９３も、前述した圧力伝達油路９１、９２と同様に、リングギヤ４の歯の間の空間と吐出ポート１２とを連通させる。リングギヤ４の歯の間の空間の圧力が第３領域において高まるから、当該空間が吐出ポート１２に開放される際の、吐出ポート１２の圧力と歯の間の空間の圧力との圧力差は小さい。圧力変動が抑制されるから、内接ギヤポンプ１の騒音が抑制される。 Similarly to the pressure transmission oil passages 91 and 92 described above, the pressure transmission oil passage 93 formed in the crescent 54 also communicates the space between the teeth of the ring gear 4 and the discharge port 12. Since the pressure in the space between the teeth of the ring gear 4 increases in the third region, when the space is opened to the discharge port 12, the pressure difference between the pressure in the discharge port 12 and the pressure in the space between the teeth is small. . Since pressure fluctuations are suppressed, the noise of the internal gear pump 1 is suppressed.
　尚、クレセント５４に形成される圧力伝達油路は、クレセント５４の上端に形成されることに限定されない。圧力伝達油路は、クレセント５４の第２円弧壁５４２における上下方向の中間位置に形成されてもよい。圧力伝達油路は、クレセント５４の下端に形成されてもよい。 Note that the pressure transmission oil passage formed in the crescent 54 is not limited to being formed at the upper end of the crescent 54. The pressure transmission oil passage may be formed at an intermediate position in the vertical direction on the second arcuate wall 542 of the crescent 54. A pressure transmission oil passage may be formed at the lower end of the crescent 54.
１　内接ギヤポンプ
１０　ハウジング
１１　吸込ポート
１２　吐出ポート
３　ピニオンギヤ
３１　外歯
４　リングギヤ
４１　内歯
４２　外周面
４３　第１側面
４４　第２側面
５　ギヤハウジング（ハウジング）
５１　摺動面
５２　第１支持面
５４　クレセント
５４１　第１円弧壁
５４２　第２円弧壁
６　フロントカバー（ハウジング）
６１　第２支持面
８　高圧油供給部
８１　導入口
９１　圧力伝達油路
９２　圧力伝達油路
９３　圧力伝達油路
Ｃ２　回転軸 1 Internal gear pump 10 Housing 11 Suction port 12 Discharge port 3 Pinion gear 31 External teeth 4 Ring gear 41 Internal teeth 42 Outer surface 43 First side surface 44 Second side surface 5 Gear housing (housing)
51 Sliding surface 52 First support surface 54 Crescent 541 First arc wall 542 Second arc wall 6 Front cover (housing)
61 Second support surface 8 High pressure oil supply section 81 Inlet 91 Pressure transmission oil passage 92 Pressure transmission oil passage 93 Pressure transmission oil passage C2 Rotating shaft

Claims (5)

  1. 　外歯を有するピニオンギヤと、
    　前記外歯に噛み合う内歯を有するリングギヤと、
    　吸込ポート及び吐出ポートを有すると共に、前記ピニオンギヤ及び前記リングギヤを回転可能に収容するハウジングと、
    　前記ピニオンギヤと前記リングギヤとの噛み合いが離れる箇所に位置しかつ、前記外歯が当接する第１円弧壁、及び、前記内歯が当接する第２円弧壁を有するクレセントと、を備え、
    　前記第１円弧壁及び前記第２円弧壁は共に、前記外歯及び前記内歯の方へ移動しない固定壁であり、
    　前記クレセントを挟んだ前記ピニオンギヤ側の領域と前記リングギヤ側の領域とのうち、前記リングギヤ側の領域にのみ、前記吐出ポートから延びる圧力伝達油路が、前記ハウジング内に形成され、
    　前記圧力伝達油路は、前記吐出ポートと前記リングギヤの歯の間の空間とを連通させる、内接ギヤポンプ。     a pinion gear having external teeth;
    a ring gear having internal teeth that mesh with the external teeth;
    a housing having a suction port and a discharge port and rotatably housing the pinion gear and the ring gear;
    a crescent that is located at a location where the pinion gear and the ring gear are separated from each other and has a first arcuate wall that the external teeth abut, and a second arcuate wall that the internal teeth abut,
    Both the first circular arc wall and the second circular arc wall are fixed walls that do not move toward the external teeth and the internal teeth,
    A pressure transmission oil passage extending from the discharge port is formed in the housing only in the region on the ring gear side of the region on the pinion gear side and the region on the ring gear side that sandwich the crescent,
    In an internal gear pump, the pressure transmission oil passage communicates the discharge port with a space between the teeth of the ring gear.
  2. 　請求項１に記載の内接ギヤポンプにおいて、
    　前記ハウジングは、前記リングギヤの外周面が摺動する摺動面を有し、
    　前記摺動面に開口する導入口を通じて、前記外周面と前記摺動面との間に高圧の作動油を供給する高圧油供給部を備え、
    　前記導入口は、前記リングギヤを挟んだ前記クレセントとは反対側に位置している、内接ギヤポンプ。     The internal gear pump according to claim 1,
    The housing has a sliding surface on which the outer peripheral surface of the ring gear slides,
    a high-pressure oil supply section that supplies high-pressure hydraulic oil between the outer circumferential surface and the sliding surface through an inlet opening to the sliding surface;
    The inlet port is an internal gear pump located on the opposite side of the crescent across the ring gear.
  3. 　請求項１又は２に記載の内接ギヤポンプにおいて、
    　前記ハウジングは、前記リングギヤの側面であって、前記リングギヤの回転軸に直交する二つの側面をそれぞれ支持する第１支持面及び第２支持面を有し、
    　前記吐出ポートは、前記第１支持面及び前記第２支持面のそれぞれに形成され、
    　前記圧力伝達油路は、前記第１支持面、前記第２支持面、又は、前記第１支持面及び前記第２支持面から凹陥するように、形成され、
    　前記圧力伝達油路は、前記回転軸の方向に見た場合に、前記リングギヤの歯の間の空間と重なっている、内接ギヤポンプ。     The internal gear pump according to claim 1 or 2,
    The housing has a first support surface and a second support surface that respectively support two side surfaces of the ring gear that are orthogonal to the rotation axis of the ring gear,
    The discharge port is formed on each of the first support surface and the second support surface,
    The pressure transmission oil passage is formed to be recessed from the first support surface, the second support surface, or the first support surface and the second support surface,
    An internal gear pump, wherein the pressure transmission oil passage overlaps a space between the teeth of the ring gear when viewed in the direction of the rotation axis.
  4. 　請求項１又は２に記載の内接ギヤポンプにおいて、
    　前記圧力伝達油路は、前記クレセントの前記第２円弧壁から凹陥するように、形成されている、内接ギヤポンプ。     The internal gear pump according to claim 1 or 2,
    In the internal gear pump, the pressure transmission oil passage is formed to be recessed from the second arcuate wall of the crescent.
  5. 　請求項１又は２に記載の内接ギヤポンプにおいて、
    　前記圧力伝達油路の先端は、前記リングギヤの回転軸を中心として、前記吐出ポートの縁から、前記リングギヤの歯幅に相当する角度θ１以上でかつ、前記吐出ポートから前記吸込ポートまで延びる前記クレセントの中間位置までの角度θ２以下の範囲に位置している、内接ギヤポンプ。     The internal gear pump according to claim 1 or 2,
    The tip of the pressure transmission oil passage is formed at the crescent, which extends from the edge of the discharge port at an angle θ1 or more corresponding to the tooth width of the ring gear, with the rotation axis of the ring gear as the center, and extends from the discharge port to the suction port. An internal gear pump located within the range of angle θ2 or less to the intermediate position.
PCT/JP2023/022105 2022-06-16 2023-06-14 Internal gear pump WO2023243665A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1553014A1 (en) * 1963-03-04 1969-08-21 Otto Eckerle Equipment on pumps to reduce the development of noise
JPH04203373A (en) * 1990-11-29 1992-07-23 Shimadzu Corp Inscribed gear pump or motor
JPH11229802A (en) * 1997-12-03 1999-08-24 Luk Getriebe Syst Gmbh Hydraulic gear machine

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1553014A1 (en) * 1963-03-04 1969-08-21 Otto Eckerle Equipment on pumps to reduce the development of noise
JPH04203373A (en) * 1990-11-29 1992-07-23 Shimadzu Corp Inscribed gear pump or motor
JPH11229802A (en) * 1997-12-03 1999-08-24 Luk Getriebe Syst Gmbh Hydraulic gear machine

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