Yamada Manufacturing Co., Ltd.

Keihin Corporation

Kenichi Fujiki

Masato Izutsu

Takatoshi Watanabe

Yasunori Ono

Keiichi Kai

Masaru Amano

Naoki Oikawa

Hiroyuki Taguchi

Toru Kobayashi

Atsushi Kaneko

Masahiro Kasahara

Kosuke Yamane

Yoshiaki Senga

Kazuo Enzaka

Yoshiro Umezawa

Yasuhiko Kan

Shimpei Iizuka

Syu Murayama

Takahiro Satou

Ken Kaneko

Yuji Senbongi

Yoshiaki Kawaura

Yuhki Jyo

Kentaro Yamanaka

Yoshiharu Segawa

Haruyo Kobayashi

A hydraulic control apparatus is provided including: an electromagnetic valve that has an input port communicating with a supply destination unit of oil and a control port that is switched between communication and disconnection by resultant force of a hydraulic pressure of the supply destination unit and electromagnetic force; a variable displacement pump which has a suction port communicating with a supply source of the oil, an ejection port communicating with the supply destination unit, and a control chamber communicating with the control port and rotates in accordance with drive of the supply destination unit, in which an amount of the oil ejected to the supply destination unit through the ejection port changes in accordance with a pressure in the control chamber; and a control unit that controls a value of a necessary current that is caused to flow through the electromagnetic valve.

Hydraulic control apparatus and hydraulic control method

A hydraulic control apparatus includes: a branch path that branches from a passage connected to an oil pump and equipment to which oil is supplied by the oil pump; an accumulator connected to the branch path to accumulate and discharge high-pressure oil supplied from the branch path; a check valve provided in an oil inlet path through which oil flows into the accumulator; a balance valve unit including a reference pressure chamber, a balance valve body that is biased toward an opening side by an opening compression spring, and a control pressure chamber; and a control solenoid that introduces or discharges the high-pressure oil into or from the control pressure chamber.

An internal gear pump in which an inner rotor and an outer rotor are arranged in a rotor housing chamber. A deepest meshing section is located in the vicinity on a line connecting a center of the inner rotor and a center of the outer rotor. A center of the rotor housing chamber is offset, from a position in which the center and the center of the outer rotor coincide with each other, to the deepest meshing section side by an amount smaller than a tip clearance, which is a gap between the tooth tip of the inner rotor and the tooth tip of the outer rotor in the vicinity of a seal land between a terminal end side of an intake port and a start end side of a discharge port.

Internal gear pump having an eccentric inner rotor and outer rotor having teeth non-trochoid tooth profiles and a moving center of the outer rotor

An oil pump includes: a rotor chamber; an outer rotor; and an inner rotor. A partition surface between a starting end side of the intake port and a terminal end side of the discharge port is set as a first seal land. An intake groove portion that projects from the starting end side of the intake port toward the terminal end side of the discharge port and a discharge groove portion that projects from the terminal end side of the discharge port toward the starting end side of the intake port are formed in positions which are located on the first seal land. The intake groove portion and the discharge groove portion are provided in intermediate tooth height direction positions of a meshing location between the inner rotor and the outer rotor.

Oil pump

A pump rotor is an inner rotor of an internal gear pump, the inner rotor having a tooth profile, wherein a half-tooth portion of the tooth profile is formed of three tooth-profile formation circles that are elliptical or true-circular. Two of the tooth-profile formation circles are a combination of a small tooth-profile formation circle and a large tooth-profile formation circle in which the small tooth-profile formation circle is inscribed and is entirely included. A portion of the small tooth-profile formation circle forms an addendum portion of the half-tooth portion. A portion of the large tooth-profile formation circle in which the small tooth-profile formation circle is inscribed and is entirely included forms an engagement portion of the half-tooth portion. A portion of another tooth-profile formation circle that circumscribes the large tooth-profile formation circle forms a dedendum portion of the half-tooth portion.

Pump rotor

A rotor for an oil pump according to the present invention is a rotor that includes an inner rotor configured by teeth, each of which has a plurality of ellipses or circles, and an outer rotor that is disposed on the outside of the inner rotor and has one tooth more than the inner rotor, wherein, in a tooth of the inner rotor, a tooth top and a tooth root of a drive-side half-tooth region extending from the tooth top to the tooth root and a tooth top and a tooth root of a non-drive-side half-tooth region extending from the tooth top to the tooth root are each configured by a different ellipse or a circle. A circumferential axis along a circumferential direction of the ellipse or circle configuring the tooth top is longer in the non-drive-side half-tooth region than in the drive-side half-tooth region.

Rotor for oil pump with different contours for the drive-side versus non-drive side of the teeth

An oil pump is increased to inhibit noise generation and durability is also improved. The oil pump includes a pump body, an inner rotor having outer teeth, and an outer rotor having inner teeth. A maximum partition portion is formed between a trailing end side of an intake port and a leading end side of a discharge port in a rotor chamber of the pump body. Among cells constituted by the outer teeth of the inner rotor and the inner teeth of the outer rotor, a central cell positioned in the location of the maximum partition portion and adjacent cells positioned before and after the central cell in the direction of rotation are sealed by mutual contact of the outer teeth and the inner teeth. The outer teeth and the inner teeth constituting cells other than the central cell and adjacent cells are not in contact with each other.

A device including a first discharge passage from a first rotor assembly to an engine, a first return passage that returns to an intake side of the first rotor assembly, a second discharge passage from a second rotor assembly to the engine, a second return passage that returns to an intake side of the second rotor assembly, and a pressure control valve whose valve main body is provided between a discharge port from the second rotor assembly and the first discharge passage. The first discharge passage and the second discharge passage are coupled, and a flow passage control is executed in each of: a low revolution range; an intermediate revolution range; and a high revolution range.

Oil pump pressure control device

The present invention enables the manufacture of a trochoid pump having a crescent which has been considered theoretically impossible by employing an inner rotor of a trochoid pump. An inner rotor having a predetermined number N of teeth that is equal to or larger than 4 is formed in advance. In order to manufacture an outer rotor with a predetermined number (N plus a natural number equal to or larger than 2) of teeth, row circles that are identical to a drawn circle are disposed so as to bring the row circles into contact with the tooth bottomland of the inner rotor tooth profile, the inner rotor tooth profile is rotated by half a tooth about the center of the inner rotor and the outer rotor tooth profile is also rotated by half a tooth of the predetermined number (N plus a natural number equal to or larger than 2) of teeth about a virtual center of the outer rotor including the row circles, an established center is determined from the virtual center or the like at the time at which the contact state is assumed, a reference circle is drawn that has a radius from the established center to the row circles and that has the total predetermined number (N plus a natural number equal to or larger than 2) of the equidistantly spaced row circles to form the row circles as outer rotor tooth tips, thereby manufacturing the outer rotor tooth profile.

Method for manufacturing trochoid pump and trochoid pump obtained

The present invention enables the manufacture of a trochoid pump having a crescent which has been considered theoretically impossible, by employing an inner rotor of a trochoid pump. An inner rotor having a predetermined number N of teeth that is equal to or larger than 4 is formed in advance. In order to manufacture an outer rotor with a predetermined number (N plus a natural number equal to or larger than 2) of teeth, row circles of a diameter slightly smaller than that of a drawn circle are disposed so as to bring the row circles into contact with the tooth bottomland of the inner rotor tooth profile, the inner rotor tooth profile is rotated by half a tooth about the center of the inner rotor and the outer rotor tooth profile is also rotated by half a tooth of the predetermined number (N plus a natural number equal to or larger than 2) of teeth about a virtual center of the outer rotor including the row circles, an established center is determined from the virtual center or the like at the time at which the contact state is assumed, a reference circle is drawn that has a radius from the established center to the row circles and that has the total predetermined number (N plus a natural number equal to or larger than 2) of the equidistantly spaced row circles to form the row circles as outer rotor tooth tips, thereby manufacturing the outer rotor tooth profile.

A trochoid oil pump, which enables the endurance to be increased and the reduction of discharge pulsations and noise to be achieved, and in which those results can be realized with a very simple structure. An interdental space constituted by an inner rotor and an outer rotor having trochoid tooth profile or substantially trochoid tooth profile starts a compression stroke in the location of a partition section between an intake port and a discharge portion, and a linking gap L is composed by the interdental space and a preceding adjacent interdental space realized in a discharge stroke. The linking gap expands gradually from the start of compression stroke to the discharge stroke.

Trochoid oil pump

A trochoidal oil pump which makes it possible to achieve an improved reduction in discharge pulsation and noise, and which makes it possible to realize such a reduction using an extremely simple structure. The trochoidal oil pump of the present invention comprises a rotor chamberwhich has an intake portand discharge port, an outer rotorand an inner rotor. A plurality of inter-tooth spaces S, S, . . . that are formed by the tooth shapesandof the inner rotorand outer rotorcomprise a maximum sealed space Sthat is positioned in the region of the partition partbetween the intake portand discharge port, a plurality of inter-tooth spaces S, S, . . . within the region of the intake port, and a plurality of inter-tooth spaces S, S, . . . within the region of the discharge port. The plurality of inter-tooth spaces S, S, . . . in the intake portand discharge portrespectively communicate with each other

Trochoidal oil pump

To reduce noise caused by pulsation generated when fluid is expelled, in a trochoidal pump comprising an inner rotor and outer rotor having trochoidal toothed shapes. [Means of Solution] The inner rotorand outer rotorhaving trochoidal toothed shapes are set in such a manner that when they are in a mutually intermeshing state, a tip clearance dis created between the respective tooth crestsof the inner rotorand the outer rotor. In at least one position of this group of tip clearances d, a large clearance dforming a large interval is provided.

Growing community of inventors

Gunma-ken, Japan

Kenichi Fujiki