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
  • F04C2/102—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 the two members rotating simultaneously around their respective axes
• • 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
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C2230/00—Manufacture
  • F04C2230/60—Assembly methods
  • F04C2230/602—Gap; Clearance

Definitions

• the present invention relates to an internal gear pump that sucks and discharges a fluid by a change in the volume of a cell formed between the tooth surfaces of both rotors when the inner rotor and the outer rotor rotate in mesh with each other.
• an internal gear pump has an inner rotor having n external teeth, an outer rotor having n + 1 internal teeth formed so as to mesh with the external teeth, and a suction port through which fluid is sucked. And a casing having a discharge port through which fluid is discharged.
• the outer teeth are formed by rotating an inner rotor connected to a drive shaft in a state in which both rotors are housed in holes formed in the casing. Meshes with the internal teeth to rotate the outer rotor, so that the fluid is suctioned and discharged by a change in the volume of a plurality of cells formed between the two rotors.
• the cells are individually partitioned by contact between the outer teeth of the inner rotor and the inner teeth of the outer rotor on the front side and the rear side in the rotation direction, respectively. Configure an independent fluid transfer chamber! During the process of engagement between the external teeth and the internal teeth, each cell has a minimum volume, and then does not move along the suction port to increase the force volume, thereby allowing fluid to flow from the suction port. Inhale. Then, the cell having the maximum volume reduces the volume while moving along the discharge port, and discharges the fluid from the discharge port (for example, see Patent Document 1).
• the inner rotor and the outer rotor are arranged eccentrically by a predetermined amount, and the outer rotor and the hole of the casing are arranged coaxially.
• the internal gear pump having such a configuration is widely used as a lubricant pump for an automobile, an oil pump for an automatic transmission, and the like because of its small size and simple structure.
• As means for driving the pump when mounted on an automobile there is a crankshaft direct drive in which an inner rotor is directly connected to a crankshaft of the engine and driven by rotation of the engine.
• Such an inscribed gear pump is generally set to have dimensions such that each member has a predetermined play when the gear pump is formed, for convenience in assembling and the like. It is a target.
• the inner diameter of the through-hole formed in the center of the inner rotor is larger than the outer diameter of the drive shaft inserted into the through-hole by about 0.1 mm to 0.6 mm, and is formed in a casing.
• the inner diameter of the hole is larger than the outer diameter of the outer rotor by about 0.1 mm to 0.6 mm, and the outer rotor and the hole of the casing are coaxially arranged as described above. Accordingly, a clearance of about 0.05 mm to 0.3 mm is provided between the outer circumferential surface of the outer rotor and the inner circumferential surface of the hole formed in the casing over the entire circumference.
• the clearance between the inner rotor and the drive shaft causes the inner rotor to move radially with respect to the center axis of the drive shaft.
• the outer rotor is rotated about 0.35mm-0.3mm while rotating, and due to the clearance between the outer rotor and the hole formed in the casing, the outer rotor moves radially with respect to the center axis of the casing hole.
• the outer teeth of the inner rotor collide with the inner teeth of the outer rotor, and the driving force received by the outer rotor at this time further causes the outer peripheral surface of the outer rotor to form an inner peripheral surface of a hole formed in the casing. May collide with Therefore, when the internal gear pump is driven, noise may be generated and the pump efficiency may decrease.
• an inner port is conventionally provided at the radial center of the inner rotor. This spigot is inserted into a groove formed in the bottom surface of the hole of the casing to suppress the whirling of the inner rotor, and to prevent collision between the outer peripheral surface of the outer rotor and the inner peripheral surface of the hole of the casing. Is adopted.
• Patent Document 1 Japanese Patent No. 3293507
• the inner rotor formed on the inner rotor and the casing formed on the inner rotor have a different shape.
• a sliding resistance is generated between the groove and the formed groove, and the energy loss due to the sliding resistance accounts for about 25% of the total energy loss generated when the internal gear pump is driven. There has been a limit in achieving higher efficiency.
• the present invention has been made in view of such circumstances, and it is possible to reduce the sliding resistance of an internal gear pump.
• An object of the present invention is to provide an internal gear pump capable of minimizing a reduction in pump efficiency.
• the present invention proposes the following means.
• An internal gear pump that conveys a fluid by sucking and discharging a fluid according to a change, wherein an inner diameter of a hole formed in the casing and accommodating the two rotors is smaller than an outer diameter of the outer rotor.
• the outer teeth of the inner rotor and the inner teeth of the outer rotor mesh with each other to minimize the cell volume.
• the distance between the peripheral surface and the outer peripheral surface of the outer rotor is minimized.
• the driving force is transmitted to the external teeth force of the inner rotor and the internal teeth of the outer rotor, and the outer rotor force moves forward in the rotation direction in the tangential direction of the meshing position of the rotor, and the hole in the casing.
• the forward movement in the rotational direction is restricted by the inner peripheral surface of the hole formed in the casing.
• the outer rotor force is restricted from moving forward in the rotation direction, and moves along the inner peripheral surface of the hole of the casing, thereby moving toward the position facing the engagement position with the rotation center interposed therebetween.
• the outer rotor is biased toward the opposed position. Thereby, the occurrence of collision between the outer teeth of the inner rotor and the inner teeth of the outer rotor at the opposed position is suppressed.
• the inner rotor is formed at the center in the radial direction, and the inner rotor is inserted into the groove formed on the bottom surface of the hole of the casing. And the occurrence of collision between the outer teeth of the inner rotor and the inner teeth of the outer rotor can be suppressed. Therefore, it is possible to reduce the sliding resistance of the internal gear pump, and even with such a configuration, it is possible to minimize the reduction in noise generating pump efficiency.
• the sliding resistance of the internal gear pump can be reduced, and even with such a configuration, noise generation and pump efficiency are reduced. Can be minimized.
• FIG. 1 is a plan view showing an internal gear pump according to an embodiment of the present invention.
• FIG. 2 shows specifications shown as the first embodiment of the internal gear pump shown in FIG.
• FIG. 3 shows specifications of an internal gear pump according to a second embodiment of the present invention.
• the internal gear pump shown in FIG. 1 includes an inner rotor 10 having eight external teeth 11 formed thereon, and an outer rotor 20 having nine internal teeth 21 meshed with the external teeth 11.
• the casing 30 has a suction port through which a fluid is sucked and a casing 30 having a discharge port through which the fluid is discharged.
• a hole 31 is formed in the casing 30, and the rotor 31 and the rotor 20 are accommodated in the hole 31.
• the suction port and the discharge port are not shown in FIG.
• the inner rotor 10 is provided with a through hole 12 at the center in the radial direction.
• the inner diameter of the inner rotor 10 is about 0.1 mm to 0.6 mm from the outer diameter of the drive shaft inserted into the through hole 12.
• This drive shaft is directly connected to the crankshaft of the engine (not shown), so that the inner rotor 10 can rotate in the circumferential direction inside the casing 30 around the axis Ol by the rotation of the engine. It is a structure supported by. Accordingly, this axis Ol is not only the center of rotation of the inner rotor 10 and the drive shaft, but also the center of the through hole 12.
• the outer rotor 20 is arranged such that the shaft center 02 is eccentric (the amount of eccentricity: er) with respect to the shaft center Ol of the inner rotor 10, and the inner teeth 21 are aligned with the outer teeth 11. It is supported rotatably in the circumferential direction inside the casing 30 around the center.
• the external teeth 11 of the inner rotor 10 are formed by an abduction cycloid created by a first abduction circle Ai in which the tooth profile of the tip 11a circumscribes the first base circle Di and rolls without slipping.
• the shape is based on the curve, and the tooth profile of the tooth space l ib is inscribed in the first base circle Di without slippage.
• the shape is based on the adduction cycloid curve created by the first adduction circle Bi that rolls.
• the internal teeth 21 of the outer rotor 20 have an adduction cycloid curve created by a second adduction circle Bo that is inscribed in the second base circle Do and rolls without slippage at the tooth form force of the tip 21a. And a shape based on the abduction cycloid curve created by the second abduction circle Ao, in which the tooth shape of the tooth space 21b circumscribes the second base circle Do and rolls without slipping. It is said that.
• the eccentricity er between the axis Ol of the inner rotor 10 and the axis 02 of the outer rotor 20 described above is determined in such a manner that the top of the tooth tip 1 la of each external tooth 11 of the inner rotor 10 extends in the circumferential direction.
• the circular diameter obtained by sequentially tying i.e., the large diameter of the inner rotor is d
• the circular diameter obtained by sequentially tying the bottom of 1 lb of the tooth groove portion of each outer tooth 11 of the rotor 10 in the circumferential direction is d. That is, when the small diameter of the inner rotor 10 is D, it is obtained by the following equation.
• Both rotors 10, 20 are rotated by the rotation of the drive shaft while meshing with each other due to their respective tooth flank shapes.
• a cell S which is a fluid transfer chamber, is formed between the meshing points of the two rotors 10 and 20 that mesh with each other.
• a suction port and a discharge port that open to the cell S are formed in the casing 30, and fluid exchange with each cell S is performed from the suction port and the discharge port.
• the volume of the cell S changes while rotating with the rotation of the rotors 10, 20. Fluid is sucked from the suction port during the expansion of the volume of the cell S, and the volume of the cell S is increased. During the reduction process, the fluid is discharged from the discharge port!
• the casing 30 is formed with the hole 31 for accommodating the two rotors 10 and 20, and the inner diameter of the hole 31 is about 0.1 mm or more and 0.6 mm or more than the outer diameter of the outer rotor 20. Below it is getting bigger. Then, as shown in FIG. 1, the center 03 of the hole 31 is separated from the axis 02 of the outer rotor 20 to the axis Ol of the inner rotor 10 and the engagement position A with the axis 02 interposed therebetween. In the direction, it is positioned eccentrically by 0.005 mm or more and 0.030 mm or less, more preferably 0.010 mm or more and 0.002 mm or less. That is, the amount of eccentricity between the inner rotor 10 and the outer rotor 20 is er, and the distance between the inner rotor 10 and the hole 31 of the casing 30 is er. When the amount of eccentricity is eh,
• the engagement position A is a position at which the rotational driving force of the inner rotor 10 is transmitted to the outer rotor 20, as shown in FIG.
• the clearance t between the inner peripheral surface of the hole 31 of the casing 30 and the outer peripheral surface of the outer rotor 20 is such that the clearance tA at the engagement position A is minimized.
• the clearance tA at the engagement position A is not less than 0.020 mm and not more than 0.295 mm
• the clearance tB at the position B is not less than 0.055 mm and not more than 0.330 mm.
• Example 1 specification values of the inner rotor 10, the outer rotor 20, and the casing 30 shown in FIG. 1 are referred to as Example 1, and FIGS. 2 (a) and 2 (b) are shown together with Comparative Example 1 as the prior art. Show.
• the large diameter of the outer rotor indicates a circular diameter obtained by sequentially connecting the bottoms of the tooth grooves 21b of the respective internal teeth 21 in the circumferential direction. Indicates a circular diameter obtained by sequentially connecting the tops of the tips 21a of the internal teeth 21 in the circumferential direction.
• the inner diameter of the hole formed in the casing and accommodating both rotors is 79.99 mm or more and 80. Olmm or less.
• the outer diameter of the outer peripheral surface of the outer rotor facing the inner peripheral surface is 79.75 mm or more and 79.80 mm or less.
• Example 1 is different from Comparative Example 1 as a conventional technique in that the inner mouth 10 (axial center Ol) and the hole 31 (center 03) of the casing 30 are different from each other. Without changing the position, only the rotor 20 (axis 02) is engaged, the position is shifted by 0.015 mm toward the position A side, that is, the lower side of the paper in FIG. 1, and the eccentricity er is compared. 0.015mm from Example 1 I'm making it smaller.
• Example 1 is realized by reducing the size by 0.015 mm as compared with Example 1.
• the external teeth 11 of the inner rotor 10 and the internal teeth 21 of the outer rotor 20 mesh with each other to minimize the volume of the cell S.
• the clearance tA between the inner peripheral surface of the hole 31 formed in the casing 30 and the outer peripheral surface of the outer rotor 20 can be minimized.
• the driving force is transmitted from the outer teeth 11 of the inner rotor 10 to the inner teeth 21 of the outer rotor 20, and the outer rotor 20 is rotated forward in the tangential direction of the engagement position A of the rotor 20.
• this forward movement in the rotational direction is restricted by the inner peripheral surface of the hole 31 of the casing 30. become.
• the arrangement position of the outer rotor 20 in the hole 31 of the casing 30 is stabilized, so that the outer teeth 11 of the inner rotor 10 collide with the inner teeth 21 of the outer rotor 20, and the outer rotor 20 Collision between the outer peripheral surface of the housing and the inner peripheral surface of the hole 31 of the casing 30 can be suppressed to a minimum. Even if these collisions occur, the amount of collision energy at this time can be minimized. Further, the outer rotor 20 is restricted from moving forward in the rotation direction, and follows the inner peripheral surface of the hole 31 of the casing 30.
• the amount of movement toward the circumferential position B shifted 180 ° to the front side or the rear side increases by the amount of the restraint, that is, the outer rotor 20 is biased to the position B. Thereby, the occurrence of collision between the outer teeth 11 of the inner rotor 10 and the inner teeth 21 of the outer rotor 20 at the position B can be suppressed.
• the inner rotor 20 is formed with a spigot at the center in the radial direction, and the spigot is inserted into the groove formed in the bottom surface of the hole 31 of the casing 30 without having to adopt a configuration. It is possible to suppress the collision between the one rotor 20 and the casing 30 and the collision between the outer teeth 11 of the inner rotor 10 and the inner teeth 21 of the outer rotor 20. Therefore, it is possible to greatly reduce the sliding resistance of the internal gear pump, and even in such a configuration, it is possible to minimize noise generation and reduction in pump efficiency.
• a force indicating a tooth profile formed based on a cycloid curve is not limited thereto.
• the present invention can be applied even to a tooth profile formed by forming.
• the specification values according to the present invention are shown in FIG. 3 together with Comparative Example 2 as the prior art as Example 2.
• Comparative Example 2 As both Example 2 and Comparative Example 2 shown in this figure, the inside diameter of the hole formed in the casing and accommodating the two rotors is 59.99 mm or more and 60.Olmm or less.
• the outer diameter of the outer peripheral surface of the facing outer rotor is 59.80mm or more and 59.85mm or less, the number of external teeth of the inner rotor is 9, and the number of internal teeth of the outer rotor is 10. Also in this case, the same operation and effect as the above embodiment can be obtained.
• the inner rotor 10-force is directly connected to the crankshaft of the engine.
• the configuration of the crankshaft direct drive which is connected to the drive shaft and driven by the rotation of the engine, has been described.
• the present invention is not limited to this configuration. It is also applicable to internal gear pumps that transport fuel such as light oil of viscosity. That is, as described above, according to the present invention, it is possible to realize a so-called inlawless configuration without causing a problem such as occurrence of a collision or the like, and therefore, it is a force capable of realizing a great reduction in sliding resistance.
• an extension line obtained by connecting the center 03 of the hole 31 of the casing 30 to the axis Ol of the inner rotor 10 and the axis 02 of the outer rotor 20 shows a configuration in which the shaft center Ol and the engagement with the shaft center 02 are interposed, and are disposed in a portion located on the opposite side to the position A.
• the angle between the straight line obtained by connecting the axis Ol and the center 03 and the extension line on the circumference of the radius eh centered on the axis Ol should be 0 ° or more and 30 ° or less.
• the shaft center Ol and the engagement with the shaft center 02 interposed therebetween may be arranged at a portion opposite to the position A.
• an internal gear pump that can reduce the sliding resistance of the internal gear pump and can minimize noise generation and reduction in pump efficiency even with such a configuration. it can.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Rotary Pumps (AREA)

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ID=34736633

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• 2003
  • 2003-12-26 JP JP2003435370A patent/JP2005194890A/ja active Pending
• 2004
  • 2004-12-22 KR KR1020067014980A patent/KR20060129309A/ko not_active Application Discontinuation
  • 2004-12-22 CN CNA2004800390204A patent/CN1902401A/zh active Pending
  • 2004-12-22 EP EP04807610A patent/EP1710436A1/en not_active Withdrawn
  • 2004-12-22 WO PCT/JP2004/019253 patent/WO2005064163A1/ja not_active Application Discontinuation

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