US3817117A - Gear pump or motor - Google Patents

Gear pump or motor Download PDF

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Publication number
US3817117A
US3817117A US00283823A US28382372A US3817117A US 3817117 A US3817117 A US 3817117A US 00283823 A US00283823 A US 00283823A US 28382372 A US28382372 A US 28382372A US 3817117 A US3817117 A US 3817117A
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US
United States
Prior art keywords
torque transmitting
transmitting side
gear
tooth
tooth profile
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.)
Expired - Lifetime
Application number
US00283823A
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English (en)
Inventor
Y Kita
J Hida
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.)
Shimadzu Corp
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Shimadzu Corp
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Filing date
Publication date
Application filed by Shimadzu Corp filed Critical Shimadzu Corp
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Publication of US3817117A publication Critical patent/US3817117A/en
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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H55/00—Elements with teeth or friction surfaces for conveying motion; Worms, pulleys or sheaves for gearing mechanisms
    • F16H55/02—Toothed members; Worms
    • F16H55/08—Profiling
    • F16H55/0806—Involute profile
    • 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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T74/00—Machine element or mechanism
    • Y10T74/19—Gearing
    • Y10T74/19949—Teeth
    • Y10T74/19963—Spur
    • Y10T74/19972—Spur form

Definitions

  • This invention generally relates to gear pumps or motors. In particular this invention relates to an improvement of the intermeshing gears of the gear pump or motor.
  • involute teeth for the intermeshing gears of the gear pump or motor for such reasons as easy workability, higher finishing accuracy, etc.
  • a conventional gear pump or motor having involute tooth gears incorporated therein cannot escape a fluctuation in the fluid discharge which in turn leads to undesired as well as uncomfortable noise production during operation.
  • the amount of fluid discharged from the gear pump or motor changes from moment to moment and it reaches a maximum level at the instant when the gears intermesh with each other at the pitch point. While on the other hand, the amount of the discharged fluid at the instant when the gears intermesh with each other at points other than the pitch point is smaller than the maximum level.
  • the fluid discharge of the gear pump or motor fluctuates from moment to moment and this fluctuation of the fluid discharge is a major, though not a sole, cause for the undesired noise production in the gear pump or motor during operation. This is particularly true when the gear pump or motor is operated at higher pressures.
  • displacement volume the amount of fluid discharged from the gear pump during one rotation of the gear.
  • the result is that the displacement volume of the gear pump is substantially reduced if the number of the gear teeth of the intermeshing gears is increased with the pitch circles of the gears being the same.
  • it is undesirably necessary to have a large-sized gear pump to obtain a particular displacement volume.
  • a gear pump or motor includes a casing and at least one pair of intermeshing gears located within the casing as in any conventional gear pumps or motors.
  • the tooth profile of the intermeshing gears according to this invention is involutely formed at least on the torque transmitting side, while on the opposite side, namely, the non-torque transmitting side it is not necessarily formed involutely.
  • the tooth profile on the non-torque transmitting side is made at least steeper than an imaginary profile which is symmetrical with the profile on the torque transmitting side.
  • the tooth profile on the non-torque transmitting side may also be formed involutely.
  • the pressure angle on the torque transmitting side is selected at a greater value than the pressure angle on the non-torque transmitting side, thus resulting in a non-symmetrical tooth form.
  • intermeshing gears of a non-symmetrical tooth profile having a pressure angle of 23 on the torque transmitting tooth surface and a pressure angle of on the non-torque transmitting tooth surface may be suitably used in accordance with this invention.
  • FIG. 1 is a cross-sectional view of a gear pump having incorporated therein intermeshing gears embodying this invention
  • FIG. 2 is a schematic illustration of a prior-art standard basic rack
  • FIG. 3 is a schematic illustration similar to FIG. 2 of another basic rack having an increased number of the gear teeth with the same pitch diameter and tooth height as in the basic rack of FIG. 2 and with a reduced circular pitch;
  • FIG. 4 is a schematic illustration similar to FIG. 2 of still another basic rack with a pressure angle on the torque transmitting side being made greater than a pressure angle on the non-torque transmitting side in accordance with this invention
  • FIG. 5 is an elevational view of a pair of gears according to this invention arranged in a meshed relationship with each other to form a gear pump or motor;
  • FIG. 6 is a fragmental view showing on an enlarged scale only one gear tooth profile of one of the intermeshing gears illustrated in FIG. 5.
  • the pump includes a pair of intermeshing gears 11 and 12 mounted within a cylindrical casing 13.
  • the casing 13 comprises a cylindrical side wall body 14 and end closures 15, 16 at opposite ends of the body 14.
  • One end closure 15 is hereinafter referred to as the front head while the other end closure 16 is referred as the end cover plate.
  • the cylindrical body 14 is clamped between the front head 15 and the end cover plate 16 by four bolts (only one of which is shown as 17) which extend through the cylindrical body 14 from the cover plate 16 to the front head 15.
  • the end of the bolt 17 may terminate at the front head 15 and be screwthreaded thereinto.
  • the front head 15 is recessed to contain a roller bearing (not shown) and a suitable oil-seal assembly 18.
  • a drive shaft 21 extends through the oil-seal assembly 18 and into the inside chamber of the casing 13 to engage and drive the drive gear 11.
  • the gear 11 is keyed in a conventional manner to the shaft 21.
  • the drive shaft 21 is supported on the opposite sides of the gear 11 by a pair of bearing means 26 and 27 which are in turn received within the inside of the side wall body 14.
  • a driven shaft is supported on the opposite sides of the driven gear 12 by a pair of bearing means 31) and 31 which are in turn received within the inside of side wall body 14.
  • the intermeshed gears 11 and 12 are also supported between said pairs of bearing means 26 and 27, and between and 31, respectively.
  • the bearing means 26 and 30 are at their inner ends in sliding contact and in sealing relationship with the left end face of the intermeshing gears 11 and 12 and abut at their outer ends the end wall 36 of the front head 15.
  • the bearing means 27 and 31 are at their inner ends in sliding contact and in sealing relationship with the right end face of the gears 11 and 12 and abut at their outer ends.
  • the reference numerals 40 and 41 indicates sealing means which are inserted between the end wall 36 of the front head 11 and bearing means 26, 30 and between the end wall of the cover plate 16 and bearing means 27, 31, 38, respectively.
  • Inlet and outlet ports for the fluid under pressure are provided in the casing 13, preferably in the front head 15 and they are communicated with a suction side and a discharge side of the meshed gears, respectively, via fluid passageways in a conventional manner.
  • the fluid passageways may be arranged in any suitable manner. However, it is preferable to arrange those passageways such that the fluid under pressure may be introduced into the suction side of the meshed gears 11, 12 and released from the discharge side thereof in an axial direction of the gears. Also, in order to avoid fluid entrapping when the two gears engage with each other at two points simultaneously, escape channels for the entrapped fluid may be suitably formed in bearing means 26, 27, 30 and 31.
  • the tooth profile at least on the torque transmitting side is involutely formed.
  • the tooth profile is formed involutely on both the torque transmitting and non-torque transmitting sides.
  • the involute tooth profile is designed such that the pressure angle on the torque transmitting side is greater than the pressure angle on the non-torque transmitting side.
  • the tall involute tooth gear of this invention When employed in a gear pump or motor, the tall involute tooth gear of this invention is effective to substantially reduce the fluctuation of the fluid discharge from the gear pump thereby attenuating the operating noise of the gear pump to a minimum level.
  • the unique tall involute gear of this invention together with its noise reducing effect will be explained in more detail having reference to the basic racks which are schematically illustrated in FIGS. 2 to 4.
  • FIG. 2 shows such a conventional standard basic rack.
  • the circular pitch thereof is decreased to UK.
  • This basic rack is schematically illustrated in FIG. 3.
  • the present invention has devised a unique tooth profile as shown in FIG. 4 on the basis of the fact that the higher pressure side in gear pumps is invariably predetermined in almost all applications and hence the tooth surface of the gear for transmitting driving force by meshing engagement with other mating gear is also predetermined (the tooth surface on the opposite side is just spaced away from the corresponding tooth surface of the mating gear by an amount equal to a backlash) and that the fluid discharge from a gear pump (including the instantaneous fluid discharge thereof) depends substantially on the profile of the tooth surface which transmits force by the meshing engagement.
  • the pressure angle 011 on the torque transmitting side of the gear tooth is maintained large enough to have a contact interval of not less than unity, while the pressure angle (12 on the non-torque transmitting side is made relatively smaller than the pressure angle al but large enough to secure a proper tooth top land for avoiding an excessive sharp tooth top which is harmful to satisfactory intermeshing operation of the gears. It should be noted at this point that even if the contact interval on the non torque transmitting side of the gear tooth is reduced to less than unity due to the presence of the larger undercut, it causes no harmful effect on the desired intermeshing operation of the gears.
  • Tooth height module/pitch module z This means that the displacement volume is increased by 30 percent. If it is attempted to obtain the same tooth height as in the gear of the present invention using the conventional standard tooth profile with the same pitch diameter, the number of the gear teeth is as follows;
  • the percentage fluctuation or pulsation of the instantaneous fluid discharge of the gear pump using a pair of intermeshing gears having nine teeth, respectively is approximately 24 percent, whereas it is approximately 18 percent when intermeshing gears each having twelve teeth is employed.
  • the fluctuation of the fluid discharge is effectively reduced to three-fourths of that when the conventional tooth profile is used. This results in a substantial reduction of noise which is produced during operation of the gear pump or motor.
  • FIG. 6 shows in an enlarged scale the profile of only one gear tooth in one of the meshed gears of FIG. 5.
  • a drive gear 11 is arranged in an intermeshing relationship with a driven gear 12 and is adapted to rotate in clockwise direction thereby to drive the driven gear in counter-clockwise direction.
  • the left hand tooth surface of each of the gear teeth in the drive gear 11 as seen in FIG.
  • the torque transmitting tooth surface 41 is involutely formed at the pressure angle of 23.
  • the tooth surface 42 is involutely formed at the pressure angle of l4.5 along the addendum portion 42a.
  • the dedendum portion 42b of the non-torque transmitting surface 42 is cut away to avoid undercutting interference with the gear teeth of the mating gear.
  • the greater pressure angle on the torque transmitting side is selected at 23
  • the pressure angle on the torque transmitting side may be within the range of 14 to 30.
  • Concerning the pressure angle on the non-torque transmitting side there is no significance to define the pressure angle on this side since the non-torque transmitting tooth surface does not participate in the intermeshing engagement. However, it may be suitably determined depending on such factors, for example, as an amount of undercut, a minimum allowable tooth top land and tooth thickness necessary to maintain the desired tooth strength. In actual practice, it is preferred to select the pressure angle on the non-torque transmitting side within the range of 0 and 20.
  • the tooth profile on the torque transmitting side has been formed involutely at least along its addendum.
  • the tooth profile on the torque transmitting side is not necessarily be limited to the involute tooth profile and any other suitable tooth profile may be employed.
  • the tooth profile on the non-torque transmitting side is formed steeper than the imaginary tooth profile which is symmetrical with the tooth profile on the torque transmitting side in order to reduce the tooth thickness to a possible minimum thereby to provide a tall tooth type intermeshing gear with a greatest possible number of gear teeth.
  • any suitable form may be chosen as the tooth profile on the non-torque transmitting side including straight-line and cliff-like profiles.
  • the pressure angle on the torque transmitting side is made relatively greater than the pressure angle on the non-torque transmitting side.
  • a gear pump which incorporates intermeshing gears of this invention proloses only a substantially reduced noise while displacing an increased amount of fluid as compared to a gear pump having intermeshing gears of the conventional standard tooth profile with the same pitch diameter, tooth thickness and tooth height.
  • a gear pump or motor including a casing and at least one pair of intermeshing gears arranged within said casing, an improvement in which the tooth profile of said intermeshing gears is formed involutely at least on the torque transmitting side and the tooth profile on the non-torque transmitting side is made steeper than an imaginary tooth profile which is symmetrical with that on the torque transmitting side.
  • a gear pump or motor including a casing and at least one pair of intermeshing gears arranged within said casing, and wherein said intermeshing gears each include a plurality of teeth each having a top land surface portion of a non-symmetrical profile
  • the improvement therein which comprises: the non-torque transmitting side of each gear tooth profile has a steeper angle of inclination with respect to said top land than the angle of inclination of the torque transmitting side 8 of each gear tooth profile with respect to said top land.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Rotary Pumps (AREA)
  • Hydraulic Motors (AREA)
  • Gears, Cams (AREA)
US00283823A 1971-08-28 1972-08-25 Gear pump or motor Expired - Lifetime US3817117A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP46066123A JPS50702B2 (enrdf_load_stackoverflow) 1971-08-28 1971-08-28

Publications (1)

Publication Number Publication Date
US3817117A true US3817117A (en) 1974-06-18

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Application Number Title Priority Date Filing Date
US00283823A Expired - Lifetime US3817117A (en) 1971-08-28 1972-08-25 Gear pump or motor

Country Status (5)

Country Link
US (1) US3817117A (enrdf_load_stackoverflow)
JP (1) JPS50702B2 (enrdf_load_stackoverflow)
DE (1) DE2242269C3 (enrdf_load_stackoverflow)
FR (1) FR2151943A5 (enrdf_load_stackoverflow)
GB (1) GB1400577A (enrdf_load_stackoverflow)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4041794A (en) * 1975-10-28 1977-08-16 Ebauches S.A. Mechanism of transmission
US4653340A (en) * 1986-03-03 1987-03-31 Pitney Bowes Inc. Beveled spur gear
US4939953A (en) * 1987-12-08 1990-07-10 Toyota Jidosha Kabushiki Kaisha Limited slip differential
US6729855B2 (en) * 2002-02-01 2004-05-04 S & S Cycle, Inc. Oil pump and gears
US20090251080A1 (en) * 2008-04-03 2009-10-08 Honda Giken Kogyo Kabushiki Kaisha Dc motor with directionally determined torque
US20120141316A1 (en) * 2010-12-06 2012-06-07 Wakefield David L Gear root geometry for increased carryover volume
US9038988B1 (en) * 2010-11-01 2015-05-26 Akron Brass Company Valve having reduced operating force and enhanced throttling capability
KR20150094652A (ko) * 2012-12-18 2015-08-19 덴포스 파워 솔루션즈 에스.알.엘. 기어형 유압 머신 및 상대 기어 휠
CN106461056A (zh) * 2014-06-17 2017-02-22 马里奥·安东尼奥·莫尔塞利 单向传递扭矩的齿轮传动装置
US20170183061A1 (en) * 2015-12-28 2017-06-29 Shimano Inc. Gear and bicycle gear change mechanism including gear
US20170299039A1 (en) * 2016-04-19 2017-10-19 Ford Global Technologies, Llc Gears With Varying Pressure Angle
US10989190B2 (en) 2015-12-04 2021-04-27 Audi Ag External gear pump
US20220097159A1 (en) * 2020-09-28 2022-03-31 GM Global Technology Operations LLC Scattered topography rolling of powered metal gears
US11383025B2 (en) * 2008-07-18 2022-07-12 Becton, Dickinson And Company Dual chamber and gear pump assembly for a high pressure delivery system

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1467441A (en) * 1973-03-15 1977-03-16 Lucas Industries Ltd Hydraulic gear pumps and motors
DE3141193A1 (de) * 1980-10-17 1982-05-19 Hobourn-Eaton Ltd., Strood, Rochester, Kent Pumpe
DE3809721C1 (enrdf_load_stackoverflow) * 1988-03-23 1989-06-01 Robert Bosch Gmbh, 7000 Stuttgart, De
DE4138913C1 (enrdf_load_stackoverflow) * 1991-11-27 1993-06-09 John S. Barnes Gmbh, 8670 Hof, De
JP3559061B2 (ja) * 1994-03-15 2004-08-25 栃木富士産業株式会社 デファレンシャル装置
US6123533A (en) * 1997-04-22 2000-09-26 Dana Corporation Cavitation-free gear pump
DE10003735A1 (de) * 2000-01-28 2000-11-16 Bosch Gmbh Robert Hydraulische Zahnradmaschine
EP1635063A1 (de) * 2004-09-08 2006-03-15 Johann Sagawe Hydraulischer Zahnradmotor mit reduziertem Schluckvolumen
DE102017108484A1 (de) 2017-04-21 2018-10-25 Eberhard Kist Umlaufverdrängermaschine

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US462073A (en) * 1891-10-27 Sawing-machine
GB190722001A (en) * 1907-10-05 1908-06-11 Stuart William Buchan Mcgregor Improvements in Toothed Gearing
US2752751A (en) * 1952-07-12 1956-07-03 Vaucher Eric Automatic winding gear for watches

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US462073A (en) * 1891-10-27 Sawing-machine
GB190722001A (en) * 1907-10-05 1908-06-11 Stuart William Buchan Mcgregor Improvements in Toothed Gearing
US2752751A (en) * 1952-07-12 1956-07-03 Vaucher Eric Automatic winding gear for watches

Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4041794A (en) * 1975-10-28 1977-08-16 Ebauches S.A. Mechanism of transmission
US4653340A (en) * 1986-03-03 1987-03-31 Pitney Bowes Inc. Beveled spur gear
US4939953A (en) * 1987-12-08 1990-07-10 Toyota Jidosha Kabushiki Kaisha Limited slip differential
US6729855B2 (en) * 2002-02-01 2004-05-04 S & S Cycle, Inc. Oil pump and gears
USRE42408E1 (en) * 2002-02-01 2011-05-31 S & S Cycle, Inc. Oil pump and gears
US8242736B2 (en) * 2008-04-03 2012-08-14 Honda Motor Co., Ltd. DC motor with directionally determined torque
US20090251080A1 (en) * 2008-04-03 2009-10-08 Honda Giken Kogyo Kabushiki Kaisha Dc motor with directionally determined torque
US11383025B2 (en) * 2008-07-18 2022-07-12 Becton, Dickinson And Company Dual chamber and gear pump assembly for a high pressure delivery system
US9038988B1 (en) * 2010-11-01 2015-05-26 Akron Brass Company Valve having reduced operating force and enhanced throttling capability
US9709175B2 (en) 2010-11-01 2017-07-18 Akron Brass Company Valve having reduced operating force and enhanced throttling capability
US9057372B2 (en) * 2010-12-06 2015-06-16 Hamilton Sundstrand Corporation Gear root geometry for increased carryover volume
CN102536810A (zh) * 2010-12-06 2012-07-04 哈米尔顿森德斯特兰德公司 用于增加的遗留容积的齿轮根部几何形状
US20120141316A1 (en) * 2010-12-06 2012-06-07 Wakefield David L Gear root geometry for increased carryover volume
CN102536810B (zh) * 2010-12-06 2016-04-06 哈米尔顿森德斯特兰德公司 用于增加的遗留容积的齿轮根部几何形状
JP2016502049A (ja) * 2012-12-18 2016-01-21 ダンフォス パワー ソリューションズ ソシエタ ア レスポンサビリタ リミタータ 歯車式油圧機械及び関連する歯車
RU2646274C2 (ru) * 2012-12-18 2018-03-02 Данфосс Пауэр Солюшнс С.Р.Л. Шестеренчатая гидромашина и соответствующее зубчатое колесо
US10024317B2 (en) * 2012-12-18 2018-07-17 Danfoss Power Solutions S.R.L. Geared hydraulic machine and relative gear wheel
KR20150094652A (ko) * 2012-12-18 2015-08-19 덴포스 파워 솔루션즈 에스.알.엘. 기어형 유압 머신 및 상대 기어 휠
CN106461056A (zh) * 2014-06-17 2017-02-22 马里奥·安东尼奥·莫尔塞利 单向传递扭矩的齿轮传动装置
US10989190B2 (en) 2015-12-04 2021-04-27 Audi Ag External gear pump
US20170183061A1 (en) * 2015-12-28 2017-06-29 Shimano Inc. Gear and bicycle gear change mechanism including gear
CN106985961A (zh) * 2015-12-28 2017-07-28 株式会社岛野 齿轮和具备该齿轮的自行车用变速机构
US10407129B2 (en) * 2015-12-28 2019-09-10 Shimano Inc. Gear and bicycle gear change mechanism including gear
US20170299039A1 (en) * 2016-04-19 2017-10-19 Ford Global Technologies, Llc Gears With Varying Pressure Angle
US10634231B2 (en) * 2016-04-19 2020-04-28 Ford Global Technologies, Llc Gears with varying pressure angle
US20220097159A1 (en) * 2020-09-28 2022-03-31 GM Global Technology Operations LLC Scattered topography rolling of powered metal gears
US11707792B2 (en) * 2020-09-28 2023-07-25 GM Global Technology Operations LLC Scattered topography rolling of powered metal gears

Also Published As

Publication number Publication date
JPS4832201A (enrdf_load_stackoverflow) 1973-04-27
DE2242269A1 (de) 1973-03-08
GB1400577A (en) 1975-07-16
JPS50702B2 (enrdf_load_stackoverflow) 1975-01-10
DE2242269C3 (de) 1981-02-19
FR2151943A5 (enrdf_load_stackoverflow) 1973-04-20
DE2242269B2 (de) 1980-06-12

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