Tochigi, Japan
Tochigi, Japan

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Patent
Hitachi Appliances Inc. | Date: 2016-02-25

A DC power supply unit is provided that allows for improving efficiency and reducing harmonic currents. A DC power supply unit includes: a bridge rectification circuit having diodes and MOSFETs; a reactor that is arranged between the AC power supply and the bridge rectifier circuit; a smoothing capacitor that is connected to an output side of the bridge rectifier circuit and smoothes a voltage; and a converter control unit that executes, based on predetermined threshold values, a diode rectification control that uses diodes and parasitic diodes of the MOSFETs, a synchronous rectification control that switches the MOSFETs in synchronization with a polarity of the voltage of the AC power supply, a partial switching control that repeats partially short-circuiting the reactor multiple times in a half cycle of the AC power supply, or a fast switching control that short-circuits the reactor at a predetermined frequency over a full AC cycle.


Patent
Hitachi Appliances Inc. | Date: 2015-03-24

A rotor is formed such that a concave section is formed on the q axis and a gap between the concave section and a tooth of a stator is larger than a gap between an outer circumferential section and the tooth on the d axis. The concave section is formed in a substantially trapezoidal shape and formed such that an opening degree p2 on an outer circumference side is large with respect to an opening degree p1 on an inner circumference side. The opening degree p2 is set within a range of approximately 60 degrees in the electrical angle. A slit is not formed near the d axis on the outer circumference side of the permanent magnet insertion hole and a plurality of slits are formed on left and right both sides a predetermined distance or more apart from the d axis.


Patent
Hitachi Appliances Inc. | Date: 2016-02-03

The purpose of the present invention is to suppress the contact between the wrap tooth tip and the tooth bottom by enlarging the tooth bottom step, and to reduce the loss owing to the gap as a result of enlarging the tooth bottom step. The fixed scroll includes a fixed scroll-side flat plate and a fixed-side wrap standing on one surface of the fixed-side plate while retaining the spiral shape. The orbiting scroll includes an orbiting-side plate and an orbiting-side wrap standing on one surface of the orbiting-side plate while retaining the spiral shape. The orbiting-side wrap orbits with respect to the fixed scroll while being in mesh with the fixed-side wrap to form a compression chamber. Each of the fixed-side plate and the orbiting-side plate has the step on the tooth bottom at the inner periphery deeper than the step on the tooth bottom at the outer periphery. The step at the outer or the inner periphery, which is formed on the tooth bottom of the orbiting-side plate, has the depth smaller than the one on the tooth bottom of the fixed-side plate.


Patent
Hitachi Appliances Inc. | Date: 2015-12-17

An indoor unit of an air conditioner of the present invention includes a cabinet; an air inlet through which air is sucked into the cabinet; a centrifugal fan which blows the air sucked in to the surrounding portions; and an a heat exchanger which is provided in the direction of air supply of the centrifugal fan and allows heat exchange between the air and a refrigerant flowing thereinside, in which the following equation is satisfied: 0.16L/D0.19, where D is an outer diameter of the centrifugal fan and L is a distance between the centrifugal fan and the heat exchanger in their closest positions. Thus, a variation in a velocity distribution created in the heat exchanger can be suppressed, and the indoor unit of the air conditioner which achieves an improved energy saving property due to a reduced pressure loss and an improved heat exchange efficiency of the heat exchanger can be provided.


Patent
Hitachi Appliances Inc. | Date: 2015-12-30

In order to suppress that a velocity in the vicinity of a bell mouth is lowered to induce non-uniformity in velocity at an outlet of a blade and an outlet of the bell mouth caused by adoption of a forward-swept blade which makes a tip vortex small as means for noise reduction, in a blade of a propeller fan, a trailing edge portion which has been rotationally projected on a plane passing through a rotational axis is formed from the rotational axis toward a blade tip portion so as to bend from the suction side to the discharge side with a first curvature, and is further formed so as to bend with a second curvature which is smaller than the aforementioned first curvature with an inflection point interposed.


Patent
Hitachi Appliances Inc. | Date: 2015-12-17

The present invention provides an air conditioning unit having an indoor unit, the indoor unit including: a casing; a centrifugal fan having a hub, a shroud, and blades disposed therebetween; and an indoor heat exchanger which surrounds the centrifugal fan, the casing containing the centrifugal fan and the indoor heat exchanger. In the indoor unit, the indoor heat exchanger has a planar air inflow surface allowing an inflow of air discharged from an air outlet of the centrifugal fan, the air inflow surface is provided with a rectifying member, the rectifying member includes a support having an insertion portion fixed between fins on the air inflow surface, and a vane having a shape extending from the support toward a direction opposite a rotating direction of the centrifugal fan, the rectifying member configured to block some of the air flowing between the centrifugal fan and the air inflow surface, and an angle formed by the insertion portion and the vane in the plane orthogonal to a rotation axis of the centrifugal fan is set to become parallel to the air inflow from the air outlet to the air inflow surface at least at the hub side to increase a static pressure of the air at upstream and downstream sides of the vane.


Patent
Hitachi Appliances Inc. | Date: 2015-12-17

An air-conditioning remote controller allowing a user to intuitively grasp a setting status of an air-conditioner and to use the controller commonly between a plurality of models of the main body of the air-conditioners, the air-conditioning remote controller including an input unit to input setting values for setting items relating to air-conditioning control, and a display unit having a predetermined area to display a plurality of icons thereon and displaying setting values and icons depending on the number of taps, wherein the display unit changes the number of displayable icons depending on the number of taps for the main body of the air-conditioner controlled using the setting values, and also displays the icons with the larger size per tap as the number of the icons in the air-conditioner is getting smaller.


Patent
Hitachi Appliances Inc. | Date: 2015-08-05

Heat transfer pipes 26b1 and 26b2 extend from the other end section 21B to one end section 21A in an intermediate row L2 and combine in the one end section 21A to be heat transfer pipes 26c1 and 26c2. The heat transfer pipes 26c1 and 26c2 are configured to extend back and forth once between the one end section 21A and the other end section 21B in a upstream row L1. Heat transfer pipes 26b3 and 26b4 extend from the other end section 21B to the one end section 21A in the intermediate row L2 and combine in the one end section 21A to be heat transfer pipes 26c3 and 26c4. The heat transfer pipes 26c3 and 26c4 are configured to extend back and forth once between the one end section 21A and the other end section 21B in the upstream row L1. The heat transfer pipe 26c2 extending from the other end section 21B to the one end section 21A and the heat transfer pipe 26c4 from the other end section 21B to the one end section 21A are arranged to be adjacent to each other.


Patent
Hitachi Appliances Inc. | Date: 2016-02-03

An object is to enable suppression of degradation of reliability by supporting a flange portion of a crankshaft with a bearing while downsizing a scroll compressor by reducing the size of the flange portion of the crankshaft. A scroll compressor includes: a fixed scroll fixed to a frame; an orbiting scroll forming a compression chamber by performing an orbital motion with respect to the fixed scroll; an electric motor that drives the orbiting scroll via the crankshaft; and a bearing part provided on the lower side from the flange portion of the crankshaft that rotatably supports a main shaft part of the crankshaft. The scroll compressor furthers has a thrust stopper, provided between the flange portion and the bearing part, in contact with the flange portion on the upper side and in contact with the bearing part on the lower side. Assuming that the outer diameter of the flange portion 12d is Dt and the outer diameter of the thrust stopper is Ds, Dt


Patent
Hitachi Appliances Inc. | Date: 2015-05-20

A machine management device for providing a management screen by which multiple machines are classified into groups and are managed is configured to be able to, when the machine has entered a specific state, make it easy for the user to see where the machine is in a group entirety and thereby to attain improvement in convenience. Therefore, the machine management device for providing a management screen by which multiple machines are classified into groups and are managed has: a group display part for displaying as many groups as can be settled in a prescribed display area of the management screen among the groups; and a group entirety display part for displaying information of all groups in an order in which the groups are displayed in the group display part and so that the information may be settled in the prescribed display area of the management screen, and is characterized in that when the machine has entered a predetermined state, a form of positions of the group entirety display part corresponding to the group to which the machine belongs changes correspondingly to the predetermined state.

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