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US4912937A Expired / Lapsed US ⏱️ 0.0 years remaining

Air conditioning apparatus

Assignee: Mitsubishi Electric Corp
•
Filing: 1989-03-17
•
Granted: 1990-04-03
•
Expires: 2009-03-17
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Abstract

Abstract An air conditioning apparatus comprises a switching valve for switching the flowing direction of a refrigerant discharged from a compressor to carry out either cooling operation, heating operation or defrosting operation; an outdoor heat exchanger for receiving the refrigerant supplied by the compressor through the switching valve to make the refrigerant heat exchange with air to be heat exchanged; an indoor heat exchanger for making the refrigerant heat exchange with a fluid to be heat exchanged; an oil separator which is arranged in a discharging side refrigerant pipe connecting the switching valve and the discharge port of the compressor to separate the refrigerant and a refrigerating machine oil which are discharged from the compressor; a first and second accumulators which are connected in series in an intake side refrigerant pipe connecting the switching valve and the intake port of the compressor; a first bypass passage for connecting the oil separator and the second accumulator through a solenoid valve; and a second bypass passage for connecting the oil separator and the intake port of the compressor through a metering device. As a result, the refrigeranting machine oil is returned to the compressor through the first bypass passage or the first and second bypass passages to prevent the compressor from failing due to shortage of the refrigeranting machine oil.

Inventors

  • 👤 Takashi Nakamura
  • 👤 Kouji Ishikawa
  • 👤 Yoshinobu Igarashi
  • 👤 Hidekazu Tani

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 23:27
CPC Classifications
F; F25; F25B; F25B13/00; F24; F24F; F24F1/00; F24F1/02; F24F1/022; F24F13/00; F25B31/00; F25B31/002; F25B31/004; F25B43/00; F25B43/02; F25B2313/00; F25B2313/001; F25B2313/025; F25B2313/0253; F25B2313/02531; F25B2313/02532; F25B2313/02533; F25B2600/00; F25B2600/25; F25B2600/2501

Claims Analysis

Total Claims: 19
Claim 1
Independent Claim 179 words
An air conditioning apparatus comprising: a switching valve for switching the flowing direction of a refrigerant discharged from a compressor to carry out either cooling operation, heating operation or defrosting operation; an outdoor heat exchanger for receiving the refrigerant supplied by the compressor through the switching valve to make the refrigerant heat exchange with air to be heat exchanged; an indoor heat exchanger for making the refrigerant heat exchange with a fluid to be heat exchanged; an oil separator which is arranged in a discharging side refrigerant pipe connecting the switching valve and the discharge port of the compressor to separate the refrigerant and a refrigerating machine oil which are discharged from the compressor; a first and second accumulators which are connected in series in an intake side refrigerant pipe connecting the switching valve and the intake port of the compressor; a first bypass passage for connecting the oil separator and the second accumulator through a solenoid valve; and a second bypass passage for connecting the oil separator and the intake port of the compressor through a metering device.
Claim 2
Dependent Claim 179 words
An air conditioning apparatus comprising: a switching valve for switching the flowing direction of a refrigerant discharged from a compressor to carry out either cooling operation, heating operation or defrosting operation; an outdoor heat exchanger for receiving the refrigerant supplied by the compressor through the switching valve to make the refrigerant heat exchange with air to be heat exchanged; an indoor heat exchanger for making the refrigerant heat exchange with a fluid to be heat exchanged; an oil separator which is arranged in a discharging side refrigerant pipe connecting the switching valve and the discharge port of the compressor to separate the refrigerant and a refrigerating machine oil which are discharged from the compressor; a first and second accumulators which are connected in series in an intake side refrigerant pipe connecting the switching valve and the intake port of the compressor; a first bypass passage for connecting the oil separator and the second accumulator through a solenoid valve; and a second bypass passage for connecting the oil separator and the intake port of the compressor through a metering device.
Claim 3
Dependent Claim 29 words
An air conditioning apparatus according to claim 1, wherein the first bypass passage is connected to the second accumulator through a connecting pipe connecting the first and second accumulators.
Claim 4
Dependent Claim 39 words
An air conditioning apparatus according to claim 1, wherein the second bypass passage is connected to the intake port of the compressor through the intake side refrigerant pipe connecting the second accumulator and the intake port of the compressor.
Claim 5
Dependent Claim 39 words
An air conditioning apparatus according to claim 2, wherein the second bypass passage is connected to the intake port of the compressor through the intake side refrigerant pipe connecting the second accumulator and the intake port of the compressor.
Claim 6
Dependent Claim 43 words
An air conditioning apparatus according to claim 1, wherein the second bypass passage is connected to the intake port of the compressor through the second accumulator, and the intake side refrigerant pipe connecting the second accumulator and the intake port of the compressor.
Claim 7
Dependent Claim 43 words
An air conditioning apparatus according to claim 2, wherein the second bypass passage is connected to the intake port of the compressor through the second accumulator, and the intake side refrigerant pipe connecting the second accumulator and the intake port of the compressor.
Claim 8
Dependent Claim 52 words
An air conditioning apparatus according to claim 1, wherein the second bypass passage is connected to the intake port of the compressor through the connecting pipe connecting the first and second accumulators, the second accumulator, and the intake side refrigerant pipe connecting the second accumulator and the intake port of the compressor.
Claim 9
Dependent Claim 52 words
An air conditioning apparatus according to claim 2, wherein the second bypass passage is connected to the intake port of the compressor through the connecting pipe connecting the first and second accumulators, the second accumulator, and the intake side refrigerant pipe connecting the second accumulator and the intake port of the compressor.
Claim 10
Dependent Claim 29 words
An air conditioning appararus according to claim 1, wherein the flow rate in the first bypass passage is set to be greater than that in the second bypass passage.
Claim 11
Dependent Claim 29 words
An air conditioning appararus according to claim 2, wherein the flow rate in the first bypass passage is set to be greater than that in the second bypass passage.
Claim 12
Dependent Claim 29 words
An air conditioning appararus according to claim 3, wherein the flow rate in the first bypass passage is set to be greater than that in the second bypass passage.
Claim 13
Dependent Claim 29 words
An air conditioning appararus according to claim 4, wherein the flow rate in the first bypass passage is set to be greater than that in the second bypass passage.
Claim 14
Dependent Claim 29 words
An air conditioning appararus according to claim 5, wherein the flow rate in the first bypass passage is set to be greater than that in the second bypass passage.
Claim 15
Dependent Claim 29 words
An air conditioning appararus according to claim 6, wherein the flow rate in the first bypass passage is set to be greater than that in the second bypass passage.
Claim 16
Dependent Claim 29 words
An air conditioning appararus according to claim 7, wherein the flow rate in the first bypass passage is set to be greater than that in the second bypass passage.
Claim 17
Dependent Claim 29 words
An air conditioning appararus according to claim 8, wherein the flow rate in the first bypass passage is set to be greater than that in the second bypass passage.
Claim 18
Dependent Claim 28 words
An air conditioning apparatus according to claim 1, wherein there is provided control means for opening the solenoid valve during a predetermined time after the compressor has started.
Claim 19
Dependent Claim 29 words
An air conditioning apparatus according to claim 17, wherein the control means is constructed to continuously open the solenoid valve in the first bypass passage during the defrosting operation.

References Cited (Backward Citations)

US2590741A Cited
US2966043A Cited
US3315484A Cited
US3919859A Cited
US4199960A Cited
US4266405A Cited
US4557115A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-04-02 1993-10-02 1994-04-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-04-02 1997-10-02 1998-04-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-04-02 2001-10-02 2002-04-03 $7700.00 Window Closed / Lapsed

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