초록 ▼

A heat source unit and refrigerant used in an existing refrigeration system are replaced with new refrigerant and a new heat source unit which employs the new refrigerant and is equipped with an oil separator and extraneous-matter trapping device. An indoor unit of the existing refrigeration system

A heat source unit and refrigerant used in an existing refrigeration system are replaced with new refrigerant and a new heat source unit which employs the new refrigerant and is equipped with an oil separator and extraneous-matter trapping device. An indoor unit of the existing refrigeration system may be used, in its present form, or replaced with a new indoor unit. Further, connecting pipes used for the existing refrigeration are reused. After replacement of refrigerant, the refrigeration system performs an ordinary operation after having performed a cleaning operation. The extraneous-matter trapping device is provided in a refrigerant pipe close to the heat source unit or in a bypass channel connected to the refrigerant pipe close to the heat source unit. Alternatively, only the heat source unit of the existing refrigeration system is replaced with a new one, and there is employed refrigeration oil which has no mutual solubility with respect to HFC or has very low mutual solubility.

대표청구항 ▼

A heat source unit and refrigerant used in an existing refrigeration system are replaced with new refrigerant and a new heat source unit which employs the new refrigerant and is equipped with an oil separator and extraneous-matter trapping device. An indoor unit of the existing refrigeration system

A heat source unit and refrigerant used in an existing refrigeration system are replaced with new refrigerant and a new heat source unit which employs the new refrigerant and is equipped with an oil separator and extraneous-matter trapping device. An indoor unit of the existing refrigeration system may be used, in its present form, or replaced with a new indoor unit. Further, connecting pipes used for the existing refrigeration are reused. After replacement of refrigerant, the refrigeration system performs an ordinary operation after having performed a cleaning operation. The extraneous-matter trapping device is provided in a refrigerant pipe close to the heat source unit or in a bypass channel connected to the refrigerant pipe close to the heat source unit. Alternatively, only the heat source unit of the existing refrigeration system is replaced with a new one, and there is employed refrigeration oil which has no mutual solubility with respect to HFC or has very low mutual solubility. limiting compression of the spring to less than full compression by exerting the second force from the load compensation adjuster to the main frame. 2. The method of claim 1, wherein the load compensation adjuster is a coil spring. 3. The method of claim 1, wherein the load compensation adjuster is a shock absorber. 4. The method of claim 1, wherein the load compensation adjuster is an air shock. 5. The method of claim 1, wherein the load compensation adjuster is an airbag. 6. The method of claim 1, wherein compressing the load compensation adjuster includes exerting an increasing reactive force against compression responsive to increasing compression of the spring. 7. The method of claim 1 wherein: the spring has a range of compression; and the load compensation adjuster exerts a reactive force to compression of the spring only in a portion of the range of compression of the spring. 8. The method of claim 1, further comprising limiting compression of the spring from a bottomed out condition via the load compensation adjuster. 9. A method of compensating for load change in a lawnmower having independent suspension, the method comprising: providing a main frame having first and second wheels coupled to the main frame and to respective independent suspensions, each independent suspension having a first spring and a second spring, the first spring having a range of compression between uncompressed and fully compressed; moving the main frame downward with respect to the first wheel independently of movement of the second wheel; compressing the first spring to a position within the uncompressed and fully compressed range in response to movement of the main frame; exerting a first force from the first spring to the main frame in response to compressing the first spring; compressing the second spring in response to movement of the main frame; exerting a second force from the second spring to the main frame in response to compressing the second spring; and preventing the first spring from being fully compressed by the main frame as a result of the second force from the second spring to the main frame. 10. The method of claim 9, wherein the second spring is compressed after partial compression of the first spring. 11. The method of claim 9, wherein the second spring is a shock absorber. 12. The method of claim 9, wherein the second spring is an air shock. 13. The method of claim 9, wherein the second spring is an airbag. 14. The method of claim 9, wherein compressing the second spring includes exerting an increasing reactive force against compression responsive to increasing compression of the first spring. 15. The method of claim 9, further comprising limiting compression of the first spring from a bottomed out condition via the second spring. 16. A method of compensating for load change in a lawnmower having independent suspension, the method comprising: providing a main frame having first and second wheels coupled to the main frame by respective independent suspensions, each independent suspension having a spring and a load compensation adjuster; moving the mower across a surface; moving the first wheel upward and downward relative to the main frame; moving the second wheel upward and downward relative to the main frame independently of movement of the first wheel; changing compression of the springs of the independent suspensions in response to movement of the first and second wheels; compressing the load compensation adjuster of each independent suspension in response to upward movement of the first and second wheels with respect to the main frame; and generating forces from the load compensation adjusters to prevent the springs from fully compressing and binding upon movement of the first and second wheels. 17. The method of claim 16, wherein the load compensation adjuster is a coil spring. 18. The method of claim 16, wherein the load compensation adjuster is a shock absorber. 19. The method of clai m 16, wherein the load compensation adjuster is an air shock. 20. The method of claim 16, wherein the load compensation adjuster is an airbag. 21. The method of claim 16, further comprising exerting an increasing reactive force against compression of the load compensation adjusters responsive to increasing compression of the springs. 22. The method of claim 16, wherein the springs have respective ranges of compression, the method further comprising exerting reactive forces by the load compensation adjusters responsive to compression of the springs only in a portion of the ranges of compression of the springs. 23. The method of claim 16, further comprising preventing the springs from bottoming out. 24. The method of claim 16, further comprising a cutter deck positioned below the main frame, wherein the cutter deck moves independently of the main frame. 25. A method of compensating for load change in a lawnmower having independent suspension, the method comprising: providing a main frame having first and second wheels coupled to the main frame by respective independent suspensions, each independent suspension having a first spring and a second spring; moving the mower across a surface; moving the first wheel upward and downward relative to the main frame; moving the second wheel upward and downward relative to the main frame independently of movement of the first wheel; changing compression of the first spring of the first independent suspension in response to movement of the first wheel; compressing the second spring of the first independent suspension in response to movement of the first wheel in an upward direction with respect to the main frame; and limiting compression of the first spring with the second spring to less than full compression upon movement of the first and second wheels in order to prevent binding of the first spring. 26. The method of claim 25, wherein the first and second springs are coil springs. 27. The method of claim 25, wherein the second spring is a shock absorber. 28. The method of claim 25, wherein the second spring is an air shock. 29. The method of claim 25, wherein the second spring is an airbag. 30. The method of claim 25, wherein compressing the second spring includes exerting an increasing reactive force against compression responsive to increasing compression of the first spring of the first independent suspension. 31. The method of claim 25, wherein the first spring has a range of compression, the method further comprising exerting a reactive force to compression of the second spring only in a portion of the range of compression of the first spring. 32. The method of claim 25, further comprising exerting a force from the second spring to prevent the first spring from bottoming out. 33. The method of claim 25, further comprising a cutter deck positioned below the main frame, wherein the cutter deck moves independently of the main frame. 34. A method for assembling a mower, the method comprising: providing a main frame with a cutter deck and at least one rotatable cutter in the cutter deck; placing two wheels on opposite sides of the main frame; coupling each wheel to the main frame with a respective independent suspension, each independent suspension having a spring and a load compensation adjuster, wherein each independent suspension and wheel is movable vertically up and down relative to the main frame, respectively against and with force exerted by the spring and by the load compensation adjuster when compressed, independently of movement of the other wheel; positioning the spring of each independent suspension to bias a respective wheel of the two wheels in a downward direction, the spring having a range of compression between uncompressed and fully compressed states; positioning the load compensation adjuster of each independent suspension in a location inside a respective spring of the independent suspension, the load compensation adjuster having a range of compression ; preventing full compression of the spring with the load compensation adjuster; placing two additional wheels on opposite sides of the main frame; coupling each additional wheel to the main frame; and coupling the cutter deck to the main frame. 35. The method of claim 34, wherein positioning the spring includes pre-compressing the spring. 36. The method of claim 35, wherein pre-compressing the spring includes tightening a threaded fastener passed through the spring. 37. The method of claim 36, wherein attaching the threaded fastner includes threading a nut on the fastner to attain a desired spring pre-compression. 38. The method of claim 34, wherein the load compensation adjuster is a coil spring. 39. The method of claim 34, wherein the load compensation adjuster is a shock absorber. 40. The method of claim 34, wherein the load compensation adjuster is an air shock. 41. The method of claim 40, further comprising changing air pressure in the air shock to change a spring rate of the air shock. 42. The method of claim 34, wherein the load compensation adjuster is an airbag. 43. The method of claim 42, further comprising changing an inflation level of the airbag to change a spring rate of the airbag. 44. The method of claim 34, wherein the load compensation adjuster is positioned to prevent the spring from bottoming out. 45. The method of claim 34, wherein the load compensation adjuster is positioned to exert reactive force to compression only in a portion of the range of compression of the spring. 46. The method of claim 34, wherein the load compensation adjuster is positioned to exert reactive force to compression in the range of compression of the spring. 47. The method of claim 34, wherein coupling each additional wheel to the main frame includes coupling each additional wheel to the main frame by a respective independent suspension. 48. The method of claim 34, wherein the cutter deck is coupled to the main frame by the independent suspensions.