US3877837A - Compressor control with thermal density sensor - Google Patents

Compressor control with thermal density sensor Download PDF

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Publication number
US3877837A
US3877837A US428831A US42883173A US3877837A US 3877837 A US3877837 A US 3877837A US 428831 A US428831 A US 428831A US 42883173 A US42883173 A US 42883173A US 3877837 A US3877837 A US 3877837A
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US
United States
Prior art keywords
compression mechanism
motor
circuit state
temperature
predetermined value
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US428831A
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English (en)
Inventor
Sidney A Parker
Richard E Cawley
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Lennox Industries Inc
Original Assignee
Lennox Industries Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Lennox Industries Inc filed Critical Lennox Industries Inc
Priority to US428831A priority Critical patent/US3877837A/en
Priority to NL7416308A priority patent/NL7416308A/xx
Priority to SE7415685A priority patent/SE7415685L/xx
Priority to DK652774A priority patent/DK652774A/da
Priority to AU76510/74A priority patent/AU7651074A/en
Priority to IT54662/74A priority patent/IT1026089B/it
Priority to GB5493174A priority patent/GB1442557A/en
Priority to CA216,539A priority patent/CA1029117A/fr
Priority to JP50003003A priority patent/JPS5097916A/ja
Priority to FR7442909A priority patent/FR2256382B3/fr
Application granted granted Critical
Publication of US3877837A publication Critical patent/US3877837A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B49/00—Arrangement or mounting of control or safety devices
    • F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
    • F25B49/022—Compressor control arrangements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
    • F04B49/02—Stopping, starting, unloading or idling control
    • F04B49/022—Stopping, starting, unloading or idling control by means of pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
    • F04B49/10—Other safety measures
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B31/00—Compressor arrangements
    • F25B31/02—Compressor arrangements of motor-compressor units
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
    • H02K11/20—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection for measuring, monitoring, testing, protecting or switching
    • H02K11/25—Devices for sensing temperature, or actuated thereby

Definitions

  • ABSTRACT Freeh Attorney, Agent, or Firm-Molinare, Allegretti, Newitt & Witcoff
  • the disclosure describes a thermal density sensor for preventing the start-up of a compressor motor operatively connected to the piston and cylinder means of a compression mechanism when the temperature of the compression mechanism is below a predetermined value to prevent damage to the running parts of the compression mechanism due to inadequate lubrication.
  • Control circuitry for operating the compressor motor is contained in a single control box on the compressor so that the wiring of the circuitry is simplified. The control circuitry is entirely factory wired and the circuitry is maintained in a tamper-proof environment.
  • FIGJ 82 38 us I2 48 on.
  • This invention relates to an improved refrigerant compressor of the type housed in an outer casing and more particularly relates to improved apparatus for preventing the start up ofthe compressor if the temperature of the running parts within the outer casing is below a predetermined value.
  • Modern compressors also utilize metals having different coefficients of expansion. For example, it is not uncommon for a compressor to utilize an aluminum piston rod that is fitted with a steel wrist pin. If the temperature of these components is too low, the diverse coefficients of expansion of the metals may reduce bearing clearances below acceptable tolerances. This condition, coupled with inadequate lubrication, can cause excessive wear or damage to the components.
  • a compressor which is started-up in a cold condition may experience valve flutter.
  • the resonant condition set up by the valve flutter can cause annoying noise and also can reduce the operating efficiency of the compressor.
  • thermal density sensor which is responsive to the temperature within an outer casing that surrounds the compression mechanism of a refrigerant compressors.
  • the thermal density sensor is arranged to prevent the start-up of a motor which drives the compression mechanism when the temperature of the running parts in the compression mechanism is below a predetermined value.
  • control circuitry required to protect and operate the compressor motor is contained within a single control box mounted on the outer casing or within the outer casing itself.
  • This arrangement facilitates the wiring of the circuitry during manufacture and thereby reduces the cost of the compressor.
  • the control box package is factory wired and tested, thus reducing chance of field problems due to the faulty hook-up of the separate elements of the control circuit in the field.
  • the control box prevents theft of and tampering with the sensitive control circuitry.
  • Still another object of the invention is to provide a thermal density sensor in physical contact with the block of a compression mechanism which prevents an electrical motor from driving the running parts of the compression mechanism if the temperature sensed by the thermal density sensor is too low.
  • Yet another object of the present invention is to enclose all electrical control circuitry needed to operate and protect the motor of a compressor within a single control box or an outer casing surrounding the compressor.
  • FIG. 1 is an isometric, fragmentary, partially crosssectional view of a refrigerant compressor embodying control apparatus made in accordance with the present invention.
  • FIG. 2 is a top plan view of the control box shown in FIG. 1 with the top cover removed;
  • FIG. 3 is a top plan view of a control box showing an alternative arrangement of the components illustrated in FIG. 2;
  • FIG. 4 is an electrical schematic diagram of the motor control circuitry contained within the control box illustrated in FIGS. 1 and 2.
  • Compressor 10 comprises a sealed outer casing 11 which comprises an upper shell 12 (having a top surface 13) that is welded to a lower shell 14.
  • a plurality of legs 16 are suitably secured to compressor 10 to support it in an upright position.
  • the compression mechanism comprises a compressor block 24 which defines a cylinder 26, together with additional cylinders (not shown).
  • a movable piston 28 reciprocates within cylinder 26 in order to compress a refrigerant vapor.
  • Additional pistons like piston 28, reciprocate in the additional cylinders, not shown.
  • Each of the pistons is driven from a vertical disposed drive shaft 30.
  • the lower portion of the outer casing froms an oil sump in which the oil level is visible through an oil sight glass 31.
  • An electric motor 32 is used to drive compression mechanism 22.
  • the motor comprises a stator 34 which includes windings 36.
  • a rotatable rotor 38 is inductively coupled to stator 34 and is mechanically coupled to drive shaft 30.
  • valve assembly 40 Provided at the end of each cylinder, including cylinder 26, and closing the end of each cylinder cavity, is a valve assembly, such as a valve assembly 40.
  • the valve assembly includes a discharge valve and a suction valve.
  • the suction valve opens on the suction stroke of piston 28 to permit refrigerant gas (suction gas) to enter cylinder 26 through a suction line 46.
  • the suction valve closes and the discharge valve opens to permit the flow of compressed refrigerant gas to a discharge muffler in the compression mechanism and then to discharge lines 48.
  • the compressed gas is transmitted through the discharge lines to a conventional condensor (not shown).
  • the sensor preferably comprises a thermostat which is screwed into compressor block 24 in the position shown in FIG. 1.
  • the thermostat is preferably the same type of temperature limiting device shown in US. Pat. No. 3,278,l ll (Parker Oct. ll, I966) in which switch contacts 58 (FIG. 4) and a temperature responsive element are contained within a single housing.
  • Sensor 50 is set to open electrical contacts 58 at about 22F, plus or minus 3F. and to close contacts 58 at about 32F, plus or minus 3F.
  • Contacts 58 are electrically connected to other components of the compressor by conductors 54 and 55 that are attached to terminals 54T and 55T (FIG. 2).
  • sensor 50 is an important feature because it prevents the start-up of motor 32 when the temperature of the running parts of the compression mechanism is below a predetermined value which inhibits adequate lubrication.
  • control box assembly 62 incorporating all of the electrical control circuitry for the compressor therein.
  • the control box assembly 62 which comprises a top 64 and sidewalls 66-69, is physically coupled to top surface 13 of outer casing 11.
  • FIG. 2 illustrates the layout of an electrical control assembly 72 contained within control box 62. Most of the wiring is not illustrated so that the layout of the components can be made easily seen.
  • the control assembly includes a contactor 74, as well as compressor terminals T1-T6.
  • a motor protection module 76 opens switch contacts 77 (FIG. 4) if detector 78 (shown schematically in the motor windings) senses a temperature higher than a desired value. Detector 78 is electrically connected to protection terminal block through conductors 79 and 80. The operation of switch contacts 77 is such that terminals 79T and 80T are closed if the motor temperature is sufficiently low and are opened if the temperature exceeds a preset value.
  • Control assembly 72 also comprises a high pressure switch assembly 82 located in the discharge gas spud 99 on the exterior of the outer casing.
  • Switch contacts 84 (FIG. 4) are connected across terminals 86T and 87T (FIG. 2).
  • the control assembly also includes a low pressure switch assembly 90 that incorporates switch contacts 92.
  • the switch contacts are connected across terminals MT and 95T (FIG. 2).
  • Control assembly 72 further comprises a discharge gas temperature sensor 100 which is the same type of device as sensor 50 described above.
  • Sensor 100 includes a set of switch contacts 102 which are connected by conductors 104 and 105 to terminals 104T and 105T located in control box 62.
  • the discharge gas temperature sensor senses discharge gas temperature at its source so as to terminate compressor motor operation if the discharge gas temperature exceeds a predetermined high value (on the order of 300F) to prevent breakdown of the compressor oil and damage to the running parts of the compression mechanism.
  • the various control terminals are interconnected by conductors 108 to form the series pilot circuit schematically illustrated in FIG. 4.
  • the pilot circuit also includes a 2 ampere fuse 110 which is held by a fuse holder 112.
  • a conductor 114 is connected to a source of AC voltage, such as a low voltage transformer. AC power is supplied to the control box through a shielded cable 116.
  • thermal density sensor 50 opens switch contacts 58, thereby preventing motor 32 from starting up and damaging the compression mechanism. If highpressure switch assembly 82 detects pressure aboveapproximately 410 P816 in discharge lines 48, switch contacts 84 are open circuited or opened to stop motor 32. Likewise, if a temperature above approximately 300F. in the discharge manifold is detected by discharge gas temperature sensor 100, switch contacts 102 are opened to stop motor 32.
  • control motor 32 the electrical terminals necessary to control motor 32 are all contained within control box 62,.thereby facilitating the wiring of the controls.
  • Contactor 74 is advantageously placed on top of module 76, thereby conserving space inside the control box.
  • FIG. 3 illustrates an alternative embodiment in which contactor 74 is placed along side module 76. Otherwise, as indicated by the like-numbered elements, the
  • FIGS. 2 and 3 are identical.
  • the thermal density sensor will prevent operation of the compressor motor until the ambient heats up.
  • the compressor will remain inoperative until the sun heats the ambient and by heat transfer heats the running parts and lubricant within the outer casing.
  • a control for external heat may be included in the control circuitry. Should there be a demand for compressor operation negated only by the thermal density sensor sensing too low a temperature, then an external heat source or additional crankcase heat will be actuated to elevate the temperature within the outer casing.
  • accompa compression mechanism comprising a block for defining a cylinder, a movable member inside the cylinder receiving refrigerant gas and discharging the compressed refrigerant gas through a discharge line, shaft means for moving the movable member, a motor for rotating the shaft means and control means for controlling the operation of the motor, the improvement comprising thermal densiy sensor means including a thermostat mounted on the compression mechanism responsive to the temperature of the compression mechanism for preventingthe start-up of the motor when the temperature of the compression mechanism is below a predetermined value to prevent damage to the compression mechanism.
  • control means comprises:
  • high pressure switch means for switching between a closed circuit state and an open circuit state when the pressure in the discharge line rises above a predetermined value
  • low pressure switch means for switching between a closed circuit state and an open circuit state when the pressure in the outer casing falls below a predetermined value
  • motor protection switch means for switching between a closed circuit state and an open circuit state in response to a predetermined condition of the motor
  • discharge gas switch means for operating between a closed circuit state and an open circuit state when the temperature of the discharge gas rises above a predetermined value.
  • control means further comprises:
  • terminal means located inside the control box
  • first conductor means for connecting the terminal means to the high and low pressure switch means, motor protection switch means, and discharge gas switch means;
  • second conductor means located inside the control box for interconnecting the terminal means
  • a method of operating a refrigerant compressor of the type having a compression mechanism with an outer casing and motor means for actuating the running parts in the compression mechanism comprising the steps of preventing start-up of the motor means when the temperature of the running parts in the compression mechanism is below a predetermined value so as to prevent damage to the running parts due to inadequate lubrication or inadequate clearance.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Control Of Positive-Displacement Pumps (AREA)
  • Compressor (AREA)
US428831A 1973-12-27 1973-12-27 Compressor control with thermal density sensor Expired - Lifetime US3877837A (en)

Priority Applications (10)

Application Number Priority Date Filing Date Title
US428831A US3877837A (en) 1973-12-27 1973-12-27 Compressor control with thermal density sensor
SE7415685A SE7415685L (fr) 1973-12-27 1974-12-13
DK652774A DK652774A (fr) 1973-12-27 1974-12-13
NL7416308A NL7416308A (nl) 1973-12-27 1974-12-13 Koelcompressor en beveiligingsschakeling oor.
AU76510/74A AU7651074A (en) 1973-12-27 1974-12-17 Compressor control with thermal density sensor
IT54662/74A IT1026089B (it) 1973-12-27 1974-12-19 Perfezionamento nei compressori per frigoriferi
GB5493174A GB1442557A (en) 1973-12-27 1974-12-19 Refrigerant compressor
CA216,539A CA1029117A (fr) 1973-12-27 1974-12-20 Regulateur de compresseur a capteur thermostatique
JP50003003A JPS5097916A (fr) 1973-12-27 1974-12-24
FR7442909A FR2256382B3 (fr) 1973-12-27 1974-12-26

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US428831A US3877837A (en) 1973-12-27 1973-12-27 Compressor control with thermal density sensor

Publications (1)

Publication Number Publication Date
US3877837A true US3877837A (en) 1975-04-15

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Application Number Title Priority Date Filing Date
US428831A Expired - Lifetime US3877837A (en) 1973-12-27 1973-12-27 Compressor control with thermal density sensor

Country Status (10)

Country Link
US (1) US3877837A (fr)
JP (1) JPS5097916A (fr)
AU (1) AU7651074A (fr)
CA (1) CA1029117A (fr)
DK (1) DK652774A (fr)
FR (1) FR2256382B3 (fr)
GB (1) GB1442557A (fr)
IT (1) IT1026089B (fr)
NL (1) NL7416308A (fr)
SE (1) SE7415685L (fr)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4059366A (en) * 1976-03-26 1977-11-22 Tecumseh Products Company Thermal overload protective system
US4621438A (en) * 1980-12-04 1986-11-11 Donald M. Thompson Energy efficient clothes dryer
US4936747A (en) * 1987-05-19 1990-06-26 Tokico Ltd. Compressor with condition responsive cut-off means
US6142741A (en) * 1995-02-09 2000-11-07 Matsushita Electric Industrial Co., Ltd. Hermetic electric compressor with improved temperature responsive motor control
US20090185921A1 (en) * 2008-01-17 2009-07-23 Bitzer Scroll Inc. Scroll Compressor Having Standardized Power Strip
US20100028184A1 (en) * 2008-07-31 2010-02-04 Hahn Gregory W Temperature protection switch biased against scroll compressor shell
WO2011117341A1 (fr) * 2010-03-25 2011-09-29 Continental Teves Ag & Co. Ohg Procédé de régulation d'un compresseur
US20120294733A1 (en) * 2010-01-20 2012-11-22 Daikin Industries, Ltd. Compressor
US20160061505A1 (en) * 2012-11-16 2016-03-03 Emerson Climate Technologies, Inc. Compressor crankcase heating control systems and methods
US9879894B2 (en) 2013-09-19 2018-01-30 Emerson Climate Technologies, Inc. Compressor crankcase heating control systems and methods
US10161400B2 (en) 2014-07-21 2018-12-25 Danfoss Scroll Technologies, Llc Snap-in temperature sensor for scroll compressor
CZ307581B6 (cs) * 2007-12-10 2018-12-27 Mitsubishi Electric Corporation Způsob provozování hermetického kompresoru

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62153583A (ja) * 1985-12-27 1987-07-08 Kyodo Gijutsu Center:Kk レシプロ形コンプレツサの異常検出方法及び装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1838409A (en) * 1928-06-05 1931-12-29 Pratt & Whitney Aircraft Compa Internal combustion engine
US2125066A (en) * 1937-04-01 1938-07-26 Fed Aircraft Corp Internal combustion engine control
US3250461A (en) * 1964-09-08 1966-05-10 Lennox Ind Inc Hermetic compressor assembly
US3278111A (en) * 1964-07-27 1966-10-11 Lennox Ind Inc Device for detecting compressor discharge gas temperature
US3383031A (en) * 1965-10-24 1968-05-14 Lennox Ind Inc Hermetic compressor pressure switch
US3673811A (en) * 1970-09-15 1972-07-04 Ranco Inc Control device for pressure lubricated compressors

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1838409A (en) * 1928-06-05 1931-12-29 Pratt & Whitney Aircraft Compa Internal combustion engine
US2125066A (en) * 1937-04-01 1938-07-26 Fed Aircraft Corp Internal combustion engine control
US3278111A (en) * 1964-07-27 1966-10-11 Lennox Ind Inc Device for detecting compressor discharge gas temperature
US3250461A (en) * 1964-09-08 1966-05-10 Lennox Ind Inc Hermetic compressor assembly
US3383031A (en) * 1965-10-24 1968-05-14 Lennox Ind Inc Hermetic compressor pressure switch
US3673811A (en) * 1970-09-15 1972-07-04 Ranco Inc Control device for pressure lubricated compressors

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4059366A (en) * 1976-03-26 1977-11-22 Tecumseh Products Company Thermal overload protective system
US4621438A (en) * 1980-12-04 1986-11-11 Donald M. Thompson Energy efficient clothes dryer
US4936747A (en) * 1987-05-19 1990-06-26 Tokico Ltd. Compressor with condition responsive cut-off means
US6142741A (en) * 1995-02-09 2000-11-07 Matsushita Electric Industrial Co., Ltd. Hermetic electric compressor with improved temperature responsive motor control
CZ307581B6 (cs) * 2007-12-10 2018-12-27 Mitsubishi Electric Corporation Způsob provozování hermetického kompresoru
US20090185921A1 (en) * 2008-01-17 2009-07-23 Bitzer Scroll Inc. Scroll Compressor Having Standardized Power Strip
US7997877B2 (en) * 2008-01-17 2011-08-16 Bitzer Kuhlmaschinenbau Gmbh Scroll compressor having standardized power strip
US20100028184A1 (en) * 2008-07-31 2010-02-04 Hahn Gregory W Temperature protection switch biased against scroll compressor shell
US20120294733A1 (en) * 2010-01-20 2012-11-22 Daikin Industries, Ltd. Compressor
US9568000B2 (en) * 2010-01-20 2017-02-14 Daikin Industries, Ltd. Compressor
CN102822526A (zh) * 2010-03-25 2012-12-12 大陆-特韦斯贸易合伙股份公司及两合公司 用于调节压缩机的方法
CN102822526B (zh) * 2010-03-25 2014-12-24 大陆-特韦斯贸易合伙股份公司及两合公司 用于调节压缩机的方法
US9243627B2 (en) 2010-03-25 2016-01-26 Continetal Teves Ag & Co. Ohg Compressor temperature control by indirect temperature measurement
WO2011117341A1 (fr) * 2010-03-25 2011-09-29 Continental Teves Ag & Co. Ohg Procédé de régulation d'un compresseur
US20160061505A1 (en) * 2012-11-16 2016-03-03 Emerson Climate Technologies, Inc. Compressor crankcase heating control systems and methods
US9851135B2 (en) * 2012-11-16 2017-12-26 Emerson Climate Technologies, Inc. Compressor crankcase heating control systems and methods
US10801764B2 (en) 2012-11-16 2020-10-13 Emerson Climate Technologies, Inc. Compressor crankcase heating control systems and methods
US9879894B2 (en) 2013-09-19 2018-01-30 Emerson Climate Technologies, Inc. Compressor crankcase heating control systems and methods
US10161400B2 (en) 2014-07-21 2018-12-25 Danfoss Scroll Technologies, Llc Snap-in temperature sensor for scroll compressor

Also Published As

Publication number Publication date
DK652774A (fr) 1975-08-18
JPS5097916A (fr) 1975-08-04
FR2256382B3 (fr) 1977-09-23
CA1029117A (fr) 1978-04-04
SE7415685L (fr) 1975-06-30
IT1026089B (it) 1978-09-20
GB1442557A (en) 1976-07-14
FR2256382A1 (fr) 1975-07-25
NL7416308A (nl) 1975-07-01
AU7651074A (en) 1976-06-17

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