Abstract: The invention relates to a rotor for an electric machine, particularly to a rotor for a hermetic refrigerating compressor. The rotor core contains a number of axial slots, containing the electric conductors of the rotor, which are short-circuited by short-circuiting rings. The rotor has a spindle hole with at least one increased internal diameter for accommodating the bearing neck of the motor. The increased internal diameter of the core results in increased magnetic field strength in the area with increased internal diameter. The invention reduces the magnetic field strength in the area with increased internal diameter by the axial slots having varying profiles in their longitudinal direction.
Abstract: In a hydraulic system with a pump (1) and a load (4, 104), a pressure relief valve (16) is connected to the pump pressure side (3) and open when a difference between pump pressure and maximum load pressure exceeds a predetermined pressure. Pump pressure is controlled by a pump controller (22), such that the pressure difference set by the pressure relief valve is greater than a pressure difference set by the pump controller. A controller (20) presets the pump delivery rate, depending on changes in input signals (s1, s2) and regulates the pump delivery rate in dependence on a pressure difference signal (U). The pressure relief valve includes a position sensor, which generates the pressure difference signal.
Abstract: A hydraulic pumping device for use in a hydraulic machine having a piston and slider shoe unit made of a combination of plastic and metal material to operate with virtually lubricant free fluid.
Type:
Grant
Filed:
July 13, 1994
Date of Patent:
November 28, 1995
Assignee:
Danfoss A/S
Inventors:
Lars Martensen, Ove T. Hansen, Henry M. Moeller, Hardy Jepsen
Abstract: A unity power factor power supply for an electric motor. A switch-mode circuit is employed which, in a first mode, transfers power from AC main to a constant voltage DC bus. In a second mode, power generated on the DC bus is fed back to the main power supply. The circuit of the invention automatically maintains the DC bus voltage constant and sets an adequate operation mode by processing the DC bus voltage signal. In both operation modes, the unity power factor and sinusoidal waveform of the AC main side are maintained.
Abstract: A miniature actuating device with a carrier, a diaphragm, a hollow space formed between the carrier and the diaphragm and an insulating layer arranged between them and with two electrode terminals for producing an electrostatic field between the diaphragm and the carrier for an activated state. With an actuating device of this kind, it is desired that the throw can be achieved under the influence of the electrostatic field be rendered as large as possible. To that end, the hollow space is present only in the state of rest and in the activated state virtually disappears maintaining the diaphragm buckle free.
Abstract: A hydraulic system has a pump (1) with at least one load (4, 5) and accompanying bi-directional valves (8, 8a). A first comparator (A) establishes which motor line (6, 7) is carrying the higher load pressure. A second comparator (B) establishes whether the input-side motor line (6, 7) allocated a directional signal identifying the direction of the valve displacement is carrying the higher pressure or whether a load (4, 5) is being operated with negative loading. Depending on the result of the comparison, the load pressure signal (y1, y2) can be processed differently.
Abstract: The invention relates to a shower control valve assembly which includes a casing mountable in a wall with inlets for hot and cold water. A cartridge is insertable into the casing in one of two orientations so that the hot water inlet of the cartridge can be aligned with either one of the casing inlets, depending on which one is the hot water inlet. The casing has two outlets, one for the shower and the other for the tub. There is an integral bypass which takes water from the tub outlet to the shower outlet upon activation of a diverter valve. The cartridge is of the pressure and temperature balancing type, with water of the desired temperature flowing to the tub outlet and then to the tub or shower as desired. Each water inlet in the cartridge includes a check valve which, in one position allows water to enter the cartridge, and in the other position prevents water from leaving the cartridge through the inlet.
Abstract: A refrigeration system having a compressor, a condenser and an evaporator between the condenser and the compressor. A controllable valve unit at the input side of the evaporator has degrees of opening for controlling fluid flow through said evaporator. A control unit controls the degrees of opening of the valve unit. Sensors connected to the control unit and opposite ends of the evaporator detect superheat temperatures between the input and output sides of the evaporator. The control unit is operable to control the degrees of valve opening in accordance with the superheat temperatures (1) at a first greater desired opening and closing displacement rate between desired predetermined minimum and maximum values of a first range of superheat temperature values and (2) at a second opening and closing rate lesser than the first displacement rate for a second range of superheat temperature values lower than the first range of values.
Abstract: A flow amplifier (1) with an inlet (4) and an outlet (5) is provided, between which a first branch (6), through which a flow of a fluid to be amplified is flowing, with a first throttling device (8), the throttle resistance of which is adjusted in dependence on the pressure across and by the flow rate through the first throttling device, and a second branch (7) with a second throttling device (11), the throttle resistance of which is adjusted in dependence on the throttle resistance of the first throttling device. In a flow amplifier of that kind, the amplification factor is intended to be made independently of pressure losses in the generation of the flow to be amplified. For that purpose, at least one pressure-divider (14, 15; 17, 18) with a central take-off point (16; 19) is provided, which is supplied by a pressure difference between inlet (4) and outlet (5), the pressure at the central take-off point (15, 19) controlling the flow rate through the second throttling device (11).
Abstract: A pressure control valve of the type having pump, tank and load-sensing connections used in conjunction with one or more proportional type valves. In this type of system a load-sensing signal is tapped off from the output side of the proportional valves and conveyed to the load-sensing connection of the pressure control valve. A pressure control valve of the type herein has load-sensing and pressure chambers at opposite ends thereof with a slide valve therebetween which is spring biased towards the pressure chamber and controls the internal flow from the pump connection to the tank connection. The slide valve has an auxiliary change-over type valve which selectively connects the pressure chamber to the pump and load-sensing connections in response to a pressure differential between the pump and load-sensing connections to achieve a pressure balance between the load-sensing chamber and the pressure chamber.
Type:
Grant
Filed:
March 30, 1993
Date of Patent:
August 16, 1994
Assignee:
Danfoss A/S
Inventors:
Svend E. Thomsen, Thorkild Christensen, Siegfried Zenker