Hitachi, Ltd.

Hitachi Appliances, Inc

Hitachi Home and Life Solutions, Inc.

Hitachi, Ltd., Trustee for Benefit of Air Conditiong Systems Co., Ltd.

Isamu Tsubono

Isao Hayase

Masahiro Takebayashi

Koichi Sekiguchi

Kenichi Oshima

Atsushi Shimada

Koichi Inaba

Takehiro Akizawa

Kenji Hiraku

Mutsunori Matsunaga

Toshiyuki Terai

Toru Takahashi

Mitsuo Sasaki

Shinji Seto

Takeshi Tsuchiya

Hirokatsu Kohsokabe

Masaki Koyama

Kazuo Sekigami

Kazuya Matsuo

Yuugo Mukai

Makoto Yamakado

Yoshio Okamoto

Nobuyuki Kaku

Kenji Tojo

Kazutaka Suefuji

Shigeru Machida

Ayumu Miyajima

Takao Mizuno

Junichi Tamamoto

Kenmei Masuda

Yukio Sudo

Yasuhito Nakakuki

Masakazu Kurata

Takaomi Nishigaito

Hiroshi Iwata

Tooru Takahashi

Eiji Sato

Masatsugu Chikano

Satoshi Nakamura

Masaru Ohtahara

Toshimitsu Sakaki

Kazuyuki Fujimura

Yuichi Yanagase

Tatsuo Matsumura

Syunsuke Yasunori

Kazuyuki Matsunaga

Kazumi Tamura

Atsushi Onuma

Seiji Ohtake

Masaaki Busujima

A scroll compressor is provided in which the amount of lubricant oil supply is appropriately controlled over a low to high rotational frequency range of the scroll compressor. The scroll compressor has an oil supply unit and an oil supply passage. The oil supply unit includes a small hole with a diameter not exceeding a seal ring width of the sealing part and a groove which are formed on the end plate of the boss portion on the back side of the orbiting scroll. As the orbiting scroll orbitally moves, oil in the high pressure hydraulic chamber pools in the small hole to be discharged, across the seal ring, into the back pressure chamber. The oil supply passage communicates between the high pressure hydraulic chamber and the back pressure chamber.

Scroll compressor with oil supply across a sealing part

There is provided a mechanism for converting rotary motion into linear motion in which high positioning accuracy can be obtained in mutual conversion between rotary motion and linear motion. The mechanism includes a plurality of rollers having a roller annular groove member and a pair of thrust bearings, a thrust bearing portion that is convex shaped and is held between the pair of thrust bearings on an outer surface of an end of the roller shaft, a step surface that is disposed on an inner surface of the roller annular groove member and facing to the thrust bearing portion putting one of the pair of thrust bearing in between, a thrust facing member that is in mesh with an inner surface of the roller annular groove member and is facing to the thrust bearing portion putting the other one of the pair of thrust bearing in between.

Mechanism for converting rotary motion into linear motion and lifting device

A rotational-to-linear conversion mechanism inhibits interference from occurring in places except for an engagement site to increase the efficiency of conversion mechanism and reliability, which has: a rack rodincluding thread on its outer peripheral face; a holder memberprovided on the outer periphery of the rack rod, rotating about the rack rod and moving in the axis direction; and revolving rollersrotatably supported in the holder member, each having ring-shaped grooves formed in its outer peripheral face to be engaged with the thread, and placed at an axis angle with respect to a center axis of the rack rod to allow the ring-shaped grooves to be engaged with the thread on the rack rod. A contact face of the thread with each ring-shaped groove in an engagement site of the thread and the ring-shaped groove is formed as a convex face having different curvatures in a radial direction.

Mechanism for converting rotational motion to linear motion

A mechanism for converting rotary motion into linear motion includes a rod having a thread or threaded part at its outer peripheral surface, and a holder member on the outer peripheral surface of the rod, rotatable relative to the rod, and axially movable relative to the rod. Rollers are supported rotatably by the holder member and have annular grooves at their outer peripheral surfaces. Each roller is torsionally disposed at an axial angle greater than or equal to a lead angle of the thread with respect to a central axis of the rod. Both ends of the roller shaft are secured to the holder member, and the mechanism has a structure in which a hole having a diameter greater than that of the roller shaft is provided at one end of the holder member and the roller shaft is secured by a roller mounting member.

Mechanism for converting rotary motion into linear motion

Revolving rollers, each provided on an outer peripheral surface thereof with revolving roller grooves extending therearound, are caused to mesh with a rack rod thread of a central rack rod with an axial angle over a lead angle of the rack rod thread and arranged for rotation on a holder member to be twisted. The holder member is rotated round the rack rod by a motor to translate the rack rod. A large thrust can be generated while ensuring a high reliability since a high efficiency is achieved by realizing rolling contact in set points of mesh of the rack rod thread and the revolving roller grooves, points of mesh are made planar, and interference in other points than the points of mesh can be suppressed. Also, play can be restricted by assembling the revolving rollers to the rack rod thread while applying torque in a direction, in which the axial angle is increased.

In order to realize cost reduction in a gear pump apparatus by reducing form accuracy of a gear while securing pump performance, a running-in coating is provided on a tooth sliding contact portion when forming a confinement area in at least one of gears of the gear pump apparatus. By this feature, the running-in coating is gradually worn away and deformed according to rotary drive of the pump, and thus it is possible to obtain an optimal gear form in meshing combinations of the gears. Further, it is possible to reduce leakage inside the pump to secure the pump performance even if the form accuracy of the gear is reduced for the sake of the cost reduction.

Pump apparatus and power steering

In a power steering system comprising a power cylinder for assisting a steering power of a steering mechanism, a hydraulic pump for supplying a hydraulic pressure to the power cylinder, a first oil passage and a second oil passage connecting the power cylinder and the hydraulic pump respectively, a motor for driving the hydraulic pump, and power steering control means for calculating a command value to the motor based on the steering torque, a flow rate of the working oil supplied from a high-pressure side oil passage to a low-pressure side oil passage is restrained at the transition from the end of the steering state (lock end) of the steering mechanism to the returning. The flow-rate restraint increasingly corrects a driving current of the motor in the steering direction or limits the flow rate of the working oil.

Power steering system

There is provided a scroll compressor having high overall adiabatic efficiency and reliability in a wide pressure operating range. A backside excess-suction-pressure region is provided such that pressure higher than suction pressure by a constant value is applied to a backside of scroll members to produce an attractive force to attract both scroll members. A control bypass is also provided for communicating compression chambers with a discharge system only when pressure in the compression chambers is high.

Scroll compressor having a valved back pressure chamber and a bypass for overcompression

Scroll compressor

Scroll compressor having a back-pressure chamber control valve

A scroll compressor enabling decrease of a flow path loss in a communication groove extending from a suction port toward a suction chamber to decrease a loss of suction power is disclosed. In the scroll compressor, a movable scroll is provided so as to perform a swivel motion relative to a fixed scroll, a fixed scroll lap and a movable scroll lap are engaged with each other to form a suction chamber and compression chambers, a suction port communicating with the suction chamber is formed in the fixed scroll, and a communication groove extending from the suction port toward the suction chamber is formed in the fixed scroll. The communication groove has a shape such that the bottom thereof is inclined so as to become shallower from the suction port side to the suction chamber side.

A second frame is arranged between a first frame and an orbiting scroll, and a central space and an outer peripheral space are sealed off by a seal portion, which is formed between an end surface of a shaft support of the orbiting scroll and the second frame. Also, a balance weight is arranged in a space between an underside of the second frame and the first frame. Thereby, most of an oil having lubricated respective shaft supports flows into the space below the second frame, and the oil accumulated in the space is discharged through an oil scavenge pipe into an oil reservoir in a lower portion of a closed vessel. Also, since the balance weight can be assembled from a side of the orbiting scroll in a state, in which the second frame is removed, it is possible to mount the balance weight close to the orbiting scroll.

Scroll fluid machine

A displacement type fluid machine has a first lubricating fluid pump, provided at the rotating shaft and immersed in the lubricating fluid stored in the lubricating fluid-storing chamber, for feeding lubricating fluid to a first one of the two sliding portions via a lubricating fluid-guiding path formed at the rotating shaft; a second lubricating fluid pump, provided at the rotating shaft, for raising the pressure of lubricating fluid which has been fed via the lubricating fluid-guiding path by a predetermined pump head, and for feeding that lubricating fluid to a second one of the two sliding portions; and a third lubricating fluid pump, which is provided at or near the rotating shaft, for raising the pressure of lubricating fluid which has been fed via the lubricating fluid-guiding path by a predetermined pump head, and for feeding that lubricating fluid to a third one of the two sliding portions.

Displacement type fluid machine

There is provided a scroll compressor having high overall efficiency and reliability in a wide pressure operating range. A backside excess-suction-pressure region is provided such that pressure higher than suction pressure by a constant value is applied to a backside of scroll members to produce an attractive force to attract both scroll members. A control bypass is also provided for communicating compression chambers with a discharge system only when pressure in the compression chambers is high.

Scroll compressor having a valved back-pressure chamber and a bypass for over-compression

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Ushiku, Japan

Isamu Tsubono