Yamada Manufacturing Co., Ltd.

Masato Izutsu

Takatoshi Watanabe

Kenichi Fujiki

Junichi Miyajima

Hiroyuki Taguchi

Manabu Watanabe

Kosuke Yamane

Yoshiro Umezawa

Yasuhiro Kosugi

Yasuhiko Kan

Shimpei Iizuka

Yoshiaki Kawaura

Masaki Ogawara

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.

Hydraulic control apparatus and hydraulic control method

The internal gear pump according to the present invention includes: an inner rotor; an outer rotor that rotates with predetermined eccentricity to a rotation center of the inner rotor; an outer ring that rotatably holds the outer rotor, and has at least three cam protruded parts formed; a pump housing that has a rotor chamber; pins in the same number as that of the cam protruded parts; and operation means for oscillating the outer ring. Positions of the pins are set so that a diameter center of the holding-inner peripheral part of the outer ring is moved by the operation means along a locus of a circle, the radius of which is the eccentricity to the rotation center of the inner rotor.

Internal gear pump including an outer ring having cam protruded parts

An oil pump structure including: an oil pump having a first hydraulic control chamber and a second hydraulic control chamber; a hydraulic control valve having a valve operating oil passage, a first inflow passage, a second inflow passage, a first outflow passage, a second outflow passage and a drain flow passage; and an oil circuit, wherein the hydraulic control valve is connected to a branching flow passage of the oil circuit; a spool valve body of the hydraulic control valve has a front valve section, a rear valve section and an intermediate valve section, which are formed perpendicularly to the axial direction of a connecting shaft; an axial-direction dimension of the intermediate valve section is larger than an axial-direction dimension of the second outflow passage; the second outflow passage and the drain flow passage are both accommodated temporarily between the intermediate valve section and the front valve section due to movement of the spool valve body; and in the hydraulic control valve, a control hydraulic pressure is applied at all times to the first hydraulic control chamber, and the control hydraulic pressure is increased and decreased in the second hydraulic control chamber.

Oil pump structure

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

The internal gear pump includes: an inner rotor; an outer rotor that rotates by having predetermined eccentricity to a rotation center of the inner rotor; an outer ring that holds the outer rotor in a freely rotatable state, and is also formed with at least three cam protruded parts; a pump housing having a rotor chamber; protruded-wall surface parts that are formed on an inner periphery side surface of the rotor chamber and are also formed in the same number as that of the cam protruded parts; and operation means for oscillating the outer ring. A diameter center of the holding-inner peripheral part of the outer ring is moved by the operation means along a locus of a circle of which a radius is the eccentricity to the rotation center of the inner rotor.

Internal gear pump

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 oil pump includes a pump housing in which a first partitioning section is formed between a trailing end section of the intake port and a leading end section of the discharge port, and a second partitioning section is formed between a trailing end section of a discharge port and a leading end section of an intake port. A width dimension of the second partitioning section is the same as or larger than the formation range of a space between teeth which is constituted by an inner rotor and an outer rotor passing the second partitioning section during low-speed rotation. A protruding surface section is formed in the same plane as and continuously with the second partitioning section from the vicinity of an inner diameter side of the trailing end section of the discharge port.

Variable oil pump with improved partitioning section

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

The invention has: a housing; a pump section formed of a drive gear unit and a driven gear unit; a main flow channel through which oil pressure is applied to the driven gear unit in a discharge volume reduction direction; a first branching flow channel through which oil pressure that assists oil pressure from the main flow channel is applied; a second branching flow channel through which oil pressure is applied to the driven gear unit in a discharge increase direction; a first flow channel control section; a second flow channel control section; and a spring that elastically urges the driven gear unit in a discharge increase direction. The first flow channel control section and the second flow channel control section can perform switching control in accordance with each increase or decrease of engine revolutions and in pressure.

Pump device

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.

Growing community of inventors

Isesaki, Japan

Masato Izutsu