# US 10,767,890 B2 · Load operation control system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,767,890 B2 - Document ID: US10767890B2 - Status: Granted - Kind: B2 - Application number: 16/609,085 - Filed: 2018-05-08 - Published: 2020-03-26 - Granted: 2020-09-08 - Earliest claimed: 2017-05-09 - Assignees: Daikin Industries, Ltd. - Applicants: Daikin Industries, LTD. - Inventors: Yuji Nakazawa; Atsushi Sakawaki - Web page: https://patentgrep.com/patent/US10767890B2 ## CPC - F24F 11/86: by controlling compressors within refrigeration or heat pump circuits - H02P 25/024: controlled by supply frequency - F04D 25/0606: {the electric motor being specially adapted for integration in the pump} - F04D 27/02: Surge control {(surge detection F04D27/001)} - F04D 29/058: magnetic; electromagnetic - F24F 11/62: characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values - F25B 1/053: of turbine type - F25B 49/025: {Motor control arrangements} - H02K 7/003: {Couplings; Details of shafts (means for mounting rotors on shafts H02K1/28)} - H02K 7/09: with magnetic bearings - H02K 7/14: Structural association with mechanical loads, e.g. with hand-held machine tools or fans (with fan or impeller for cooling the machine H02K9/06) - H02K 9/10: by gaseous cooling medium flowing in closed circuit, a part of which is external to the machine casing - H02P 5/747: mechanically coupled by gearing - H02P 23/14: Estimation or adaptation of motor parameters, e.g. rotor time constant, flux, speed, current or voltage - F25B 2400/07: Details of compressors or related parts - F24F: AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING (removing dirt or fumes from areas where they are produced B08B15/00; vertical ducts for carrying away waste gases from buildings E04F17/02; tops for chimneys or ventilating shafts, terminals for flues F23L17/02) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) ## Abstract A drive shaft rotates a load. A drive support rotates the drive shaft and supports a radial load of the drive shaft in a non-contact manner, by an electromagnetic force generated by the flow of a current within a predetermined current range through the drive support. A control section controls an operation of the load based on a magnetic flux margin degree expressed by the difference between a total magnetic flux amount generated at the drive support and a predetermined limit of the total magnetic flux amount for the drive support. The total magnetic flux amount includes driving magnetic flux and the supporting magnetic flux in a predetermined operation region of the load. The driving magnetic flux is generated at the drive support for rotating the drive shaft. The supporting magnetic flux is generated at the drive support for supporting a radial load of the drive shaft. ## Claims ### Claim 1 A load operation control system, comprising: a drive shaft which rotates a load; a drive support which rotates the drive shaft and supports a radial load of the drive shaft in a non-contact manner, by an electromagnetic force generated by flow of a current within a predetermined current range through the drive support; and a control section which controls an operating condition of the load based on a magnetic flux margin degree expressed by a difference between: a total magnetic flux amount including driving magnetic flux and supporting magnetic flux; and a predetermined limit of the total magnetic flux amount for the drive support, the driving magnetic flux being generated at the drive support for rotating the drive shaft and the supporting magnetic flux being generated at the drive support for supporting the radial load of the drive shaft in a predetermined operation region of the load. ### Claim 2 (depends on 1) The system of claim 1, wherein the drive support has at least one bearingless motor having a set of a rotor and a stator to rotate the drive shaft and supporting the radial load of the drive shaft in a non-contact manner. ### Claim 3 (depends on 2) The system of claim 2, wherein the control section calculates, as the total magnetic flux amount, an amount of magnetic flux at a slot where a total value of the driving magnetic flux and the supporting magnetic flux is the largest among a plurality of slots formed in the stator. ### Claim 4 (depends on 3) The system of claim 3, wherein the control section calculates the total magnetic flux amount, using a sum of the driving magnetic flux, the supporting magnetic flux, and further magnetic flux of a permanent magnet included in the rotor as the total value. ### Claim 5 (depends on 1) The system of claim 1, wherein the load is a turbo compressor which compresses a refrigerant in a refrigerant circuit configured to perform a refrigeration cycle, and the control section if the magnetic flux margin degree exceeds a predetermined value, adjusts at least one of a rotational speed of the turbo compressor and a flow rate of the refrigerant such that a temperature of the refrigerant discharged from the turbo compressor increases, and if the magnetic flux margin degree is below the predetermined value, adjusts at least one of the rotational speed of the turbo compressor and the flow rate of the refrigerant such that the temperature of the refrigerant discharged from the turbo compressor decreases. ### Claim 6 (depends on 5) The system of claim 5, further comprising: an update section which updates the predetermined operation region, based on an operating state of the turbo compressor at a time when the control section increases the temperature of the refrigerant discharged from the turbo compressor. ### Claim 7 (depends on 1) The system of claim 1, wherein the load is a turbo compressor which compresses a refrigerant in a refrigerant circuit configured to perform a refrigeration cycle, and the control section if the magnetic flux margin degree exceeds a predetermined value, adjusts at least one of a rotational speed of the turbo compressor and a flow rate of the refrigerant such that an output of an air conditioner having the refrigerant circuit decreases, and if the magnetic flux margin degree is below the predetermined value, adjusts at least one of the rotational speed of the turbo compressor and the flow rate of the refrigerant such that the output of the air conditioner increases. ### Claim 8 (depends on 7) The system of claim 7, further comprising: an update section which updates the predetermined operation region, based on an operating state of the turbo compressor at a time when the control section decreases the output of the air conditioner.