Abstract: A drainage water pumping system. A number of drainage pumps are positioned at two different levels. Drainage water flowing into a drainage water pumping system from an underground inflow main pipeline is pumped to a discharge destination. Preferably the drainage pumps installed at the lower installation level have a high pump head and a small capacity, while the drainage pumps installed at the higher installation level have a low pump head and a large capacity. The drainage pumps can be in a circular arrangement with a congregated delivery pipeline installed lengthwise at the center of the circular arrangement and having each of the drainage pumps connected to it.

Abstract: An underground water channel is provided in an underground of a large depth, and rain water and the like flow into this underground channel from flood control channels, conduits and rivers through vertical shafts. A pump well of a pump station is connected to a downstream end of the underground channel, and water flowing into the pump well is discharged by a pump to a discharge tank. The pump is disposed generally at a medium water level of the underground channel, and a lowest water level L.W.L enabling draining is the medium water level of the underground channel. In an open channel flow operation of an open channel-closed channel mixed flow operation, water level of the underground channel is maintained at the lowest water level L.W.L, so that the underground channel is in an open channel condition.

Abstract: A single semiconductor chip containing a control portion and a power portion including a power element associated with the control portion and a concave portion formed between the control portion and the power portion is mounted on a die pad so as to separate the control portion and the power portion. The die pad has a convex portion which is received in the concave portion and the semiconductor chip is divided to separate the control portion and the power portion by applying pressure to the chip or by applying laser beams, and the separated semiconductor chip portions are simultaneously bonded to the die pad.

Abstract: An underground water channel is provided in an underground of a large depth, and rain water and the like flow into this underground channel from flood control channels, conduits and rivers through vertical shafts. A pump well of a pump station is connected to a downstream end of the underground channel, and water flowing into the pump well is discharged by a pump to a discharge tank. The pump is disposed generally at a medium water level of the underground channel, and a lowest water level L.W.L enabling draining is the medium water level of the underground channel. In an open channel flow operation of an open channel-closed channel mixed flow operation, water level of the underground channel is maintained at the lowest water level L.W.L, so that the underground channel is in an open channel condition.

Abstract: Disclosed is a bearing unit which can be used in a drainage pump operated without supply of clean water or a hydraulic pump, which exhibits excellent wear resistance against water containing earth and sand and satisfactory assembling facility, and a method of manufacturing the bearing unit.The contact surface of a bearing made of stainless steel and/or that of a sleeve is applied with a sprayed coating, the main component of which is WC, and which contains one or more elements selected from a group consisting of nickel, chromium and cobalt as a binder material thereof, or a sprayed coating, the main component of which is Cr.sub.3 C.sub.2, and which contains NiCr as a binder material, after the sprayed coating has been formed, heating at from 300.degree. C. to 550.degree. C. is performed for one hour or longer so that hardness and wear resistance equivalent to those of a WC-12% sintered article is attained.

Abstract: A plural drainage pumps PH are disposed on the high floor gradation state at the circular shape. A plural drainage pumps PL are disposed on the low floor gradation state at the circular shape. The drainage pump PH disposed on the high floor gradation is installed at the high level. The drainage pump PH is set one having the low pump head and the large capacity in comparison with those of the drainage pump PL disposed on the low floor gradation. An outer shape of an underground pump construction building is formed a circular cone shape spreading toward an upper portion. The discharge water power can be reduced and the construction area for the underground pump construction building can be reduced and further the engineering working amount such as a digging working at the underground can be lessen.

Abstract: An underground water channel is provided in an underground of a large depth, and rain water and the like flow into this underground channel from flood control channels, conduits and rivers through vertical shafts. A pump well of a pump station is connected to a downstream end of the underground channel, and water flowing into the pump well is discharged by a pump to a discharge tank. The pump is disposed generally at a medium water level of the underground channel, and a lowest water level L.W.L enabling draining is the medium water level of the underground channel. In an open channel flow operation of an open channel-closed channel mixed flow operation, water level of the underground channel is maintained at the lowest water level L.W.L, so that the underground channel is in an open channel condition.

Abstract: A plurality of drainage pumps are disposed on a high floor gradation state in a circular arrangement. A plurality of drainage pumps are disposed on a low floor gradation state in a circular arrangement. The drainage pumps disposed on the high floor gradation are installed at a high level, with the drainage pumps having a low pump head and a large capacity in comparison with the drainage pumps disposed at the low floor gradation. An outer shape of an underground pump construction building is in the form of a circular cone shape spreading toward an upper portion of the underground pump construction building. The amount of power for discharging the drainage can be reduced and the construction area for the underground pump construction building can be reduced thereby minimizing the necessary requirement for installation of the underground pump construction.

Abstract: A plural drainage pumps PH are disposed on the high floor gradation state at the circular shape. A plural drainage pumps PL are disposed on the low floor gradation state at the circular shape. The drainage pump PH disposed on the high floor gradation is installed at the high level. The drainage pump PH is set one having the low pump head and the large capacity in comparison with those of the drainage pump PL disposed on the low floor gradation. An outer shape of an underground pump construction building is formed a circular cone shape spreading toward an upper portion. The discharge water power can be reduced and the construction area for the underground pump construction building can be reduced and further the engineering working amount such as a digging working at the underground can be lessen.

Abstract: An underground water channel is provided in an underground of a large depth, and rain water and the like flow into this underground channel from flood control channels, conduits and rivers through vertical shafts. A pump well of a pump station is connected to a downstream end of the underground channel, and water flowing into the pump well is discharged by a pump to a discharge tank. The pump is disposed generally at a medium water level of the underground channel, and a lowest water level L.W.L enabling draining is the medium water level of the underground channel. In an open channel flow operation of an open channel-closed channel mixed flow operation, water level of the underground channel is maintained at the lowest water level L.W.L, so that the underground channel is in an open channel condition.

Abstract: Disclosed is a bearing unit which can be used in a drainage pump operated without supply of clean water or a hydraulic pump, which exhibits excellent wear resistance against water containing earth and sand and satisfactory assembling facility, and a method of manufacturing the bearing unit.The contact surface of a bearing made of stainless steel and/or that of a sleeve is applied with a sprayed coating, the main component of which is WC, and which contains one or more elements selected from a group consisting of nickel, chromium and cobalt as a binder material thereof, or a sprayed coating, the main component of which is Cr.sub.3 C.sub.2, and which contains NiCr as a binder material, after the sprayed coating has been formed, heating at from 300.degree. C. to 550.degree. C. is performed for one hour or longer so that hardness and wear resistance equivalent to those of a WC-12% sintered article is attained.

Abstract: A plurality of drainage pumps are disposed on a high floor gradation state in a circular arrangement. A plurality of drainage pumps are disposed on a low floor gradation state in a circular arrangement. The drainage pumps disposed on the high floor gradation are installed at a high level, with the drainage pumps having a low pump head and a large capacity in comparison with the drainage pumps disposed at the low floor gradation. An outer shape of an underground pump construction building is in the form of a circular cone shape spreading toward an upper portion of the underground pump construction building. The amount of power for discharging the drainage can be reduced and the construction area for the underground pump construction building can be reduced thereby minimizing the necessary requirement for installation of the underground pump construction.

Abstract: Disclosed is a bearing unit which can be used in a drainage pump operated without supply of clean water or a hydraulic pump, which exhibits excellent wear resistance against water containing earth and sand and satisfactory assembling facility, and a method of manufacturing the bearing unit.The contact surface of a bearing made of stainless steel and/or that of a sleeve is applied with a sprayed coating, the main component of which is WC, and which contains one or more elements selected from a group consisting of nickel, chromium and cobalt as a binder material thereof, or a sprayed coating, the main component of which is Cr.sub.3 C.sub.2, and which contains NiCr as a binder material, after the sprayed coating has been formed, heating at from 300.degree. C. to 550.degree. C. is performed for one hour or longer so that hardness and wear resistance equivalent to those of a WC - 12% sintered article is attained.

Abstract: A motor control apparatus for rotating a motor smoothly. A sine wave form which is an ideal wave form of a signal is stored, and the motor is driven by a signal having the ideal wave form obtained by correcting the period and the phase of the stored sine wave form. A comparator receives a detection signal which indicates the rotating state of the motor through an A/D converter, and obtains the correction values of the current period and phase. A wave form setting means corrects the set period and phase, generates a sine wave having the corrected period and phase on the basis of the sine wave data stored in a sine wave data region, and outputs a driving signal having the sine wave form through a D/A converter.

Abstract: When any component equipment of a draining pump plant is failed, the present necessity of drainage and a failure level of a drain pump involved with the failure are evaluated to determine conditions of continuing or stopping operation of the drain pump involved with the failure on the basis of the evaluated values. When the necessity of continuing the drainage operation is high, the operation is continued as far as possible, taking into account the pump failure level. The possibility of the drainage preference operation is thus maximized in the case of not only a minor failure but also a major failure of the pump, for preventing damage from a flood.

Abstract: A motor drive circuit, in which a first transistor at a drive stage, a second transistor at an output stage to be driven by the first transistor and a third transistor downstream the output stage for a short braking operation are formed in a common substrate or a common well of the substrate, a region of either a P type or an N type in either the substrate or the well is connected with the first transistor via a conductor so that a parasitic transistor is formed in which the substrate or the well serves as its base, whereby a current flowing from the first transistor to the second transistor during the short braking operation is sinked by turning on the parasitic transistor.

Abstract: A drainage system comprises a drainage passage for a drain water, a pump for pumping up the drain water from the drainage passage to a drain portion which is arranged above the drainage passage, and a storage tank which has an inlet connected to the drainage passage to receive the drain water therethough from the drainage passage into the storage tank, and a height of the inlet is higher than that of the drainage passage and lower than that of the drain portion so that an ascent of upper surface of the drain water from the drainage passage is restrained after the drain water ascends to the inlet from the drainage passage.

Abstract: In a drainage system wherein drain water is collected from a drainage path including a small river, guided to a plurality of drainage pump facilities, and drained into a destination river, a drainage distribution amount is determined for each of the plurality of drainage pump facilities in accordance with an actual precipitation or estimated precipitation, a river water level at a drainage point of each of the plurality of drainage pump facilities is estimated in accordance with the drainage distribution amount and a change in a detected water level at an upstream of the destination river, and the drainage distribution amount for each of the plurality of drainage pump facilities is corrected so as to make the estimated river water level have a value equal to or smaller than an upper limit of the river water level at the drainage point.