Rotary expansible chamber devices – Working member has planetary or planetating movement – Helical working member – e.g. – scroll
Reexamination Certificate
1999-12-28
2001-04-03
Denion, Thomas (Department: 3748)
Rotary expansible chamber devices
Working member has planetary or planetating movement
Helical working member, e.g., scroll
C418S063000, C418S088000, C418S091000, C418S094000
Reexamination Certificate
active
06210137
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a scroll fluid machine suitable for use in an air compressor, a vacuum pump, etc.
A generally known scroll fluid machine has a casing and a fixed scroll member provided in the casing. The fixed scroll member has a spiral wrap portion standing on an end plate. A driving shaft is rotatably provided in the casing. An orbiting scroll member is orbitably provided on the distal end of the driving shaft in the casing. The orbiting scroll member has a spiral wrap portion standing on an end plate so as to overlap the wrap portion of the fixed scroll member to define a plurality of compression chambers.
In this type of known scroll fluid machine, the driving shaft is externally driven to rotate, causing the orbiting scroll member to perform an orbiting motion with a predetermined eccentricity with respect to the fixed scroll member, thereby sucking a fluid, e.g. air, from a suction opening provided at the outer periphery of the fixed scroll member, and successively compressing the fluid in the compression chambers formed between the wrap portions of the fixed and orbiting scroll members. Finally, the compressed fluid is discharged to the outside from a discharge opening provided in the center of the fixed scroll member.
In another known scroll fluid machine, a lubrication pump is provided between the casing and the outer periphery of the end plate of the orbiting scroll member. The lubrication pump operates in response to the orbiting motion of the orbiting scroll member to lubricate the driving shaft, the orbiting scroll member, etc. That is, a lubricant contained in the casing is led to the area between the casing and the outer periphery of the end plate of the orbiting scroll member by the lubrication pump and thus supplied to the driving shaft, the orbiting scroll member, etc.
Incidentally, in the above-described known scroll fluid machine, the lubrication pump is provided between the inner periphery of the casing and the outer periphery of the end plate of the orbiting scroll member. Consequently, the lubrication pump is placed near the sliding contact surfaces of the orbiting and fixed scroll members, and it is likely that the lubricant pressurized by the lubrication pump will enter the area between the sliding contact surfaces of the orbiting and fixed scroll members.
Therefore, the prior art involves the danger that the high-pressure lubricant, which has been pressurized in the pump chamber of the lubrication pump, may enter the area between the sliding contact surfaces of the fixed and orbiting scroll members and leak into the compression chambers. If the lubricant leaks into the compression chambers, it is difficult to discharge a clean compressed fluid to the outside. Thus, if there is likelihood that the lubricant may leak, the apparatus cannot be improved in performance and reliability.
In view of the above-described problems with the prior art, an object of the present invention is to provide a scroll fluid machine designed to be capable of preventing the entry of the lubricant from the lubrication pump into the compression chambers and of discharging a clean compressed fluid at all times and also capable of efficiently lubricating the driving shaft, etc. and hence improving the apparatus in performance, reliability and so forth.
SUMMARY OF THE INVENTION
The present invention is applicable to a scroll fluid machine including a casing and a fixed scroll member provided in the casing. The fixed scroll member has a spiral wrap portion standing on an end plate. A driving shaft is rotatably provided in the casing. An orbiting scroll member is orbitably provided at the distal end of the driving shaft through an orbiting bearing in the casing. The orbiting scroll member has a spiral wrap portion standing on an end plate so as to overlap the wrap portion of the fixed scroll member to define a plurality of compression chambers. A thrust bearing is provided in the casing so as to come in sliding contact with the rear side of the orbiting scroll member to bear a thrust load acting on the orbiting scroll member.
An arrangement adopted by the present invention is characterized by a lubrication pump provided between the rear side of the orbiting scroll member and the thrust bearing. The lubrication pump has a pump chamber defined between a sliding contact surface on the rear side of the orbiting scroll member and a sliding contact surface of the thrust bearing. The lubrication pump operates in response to the motion of the orbiting scroll member. A lubricant suction passage is provided in the thrust bearing to lead a lubricant contained in the casing into the pump chamber of the lubrication pump. A discharge passage is provided in the orbiting scroll member to deliver the lubricant sucked into the pump chamber of the lubrication pump to lubricating points.
With the above-described arrangement, as the orbiting scroll member orbits, the lubrication pump operates in response to the motion of the orbiting scroll member, causing the lubricant contained in the casing to be led into the pump chamber through the suction passage provided in the thrust bearing. The lubricant led into the pump chamber is delivered to lubricating points, for example, the driving shaft and the orbiting bearing, by the lubrication pump through the discharge passage provided in the orbiting scroll member to cool and lubricate the driving shaft, the orbiting bearing, etc. While flowing through the discharge passage, the lubricant from the lubrication pump cools the whole orbiting scroll member.
The pump chamber of the lubrication pump is provided between the sliding contact surface on the rear side of the orbiting scroll member and the sliding contact surface of the thrust bearing. That is, the pump chamber is provided on the side of the end plate of the orbiting scroll member remote from the compression chambers. Therefore, the pump chamber can be isolated from the compression chambers. Thus, the lubricant pressurized in the pump chamber of the lubrication pump can be prevented from leaking to the compression chamber side.
In the present invention, the lubrication pump may be arranged as follows. An orbiting member accommodating recess is provided in either one of the sliding contact surface on the rear side of the orbiting scroll member and the sliding contact surface of the thrust bearing to define a pump chamber between the orbiting member accommodating recess and the other of the sliding contact surfaces. An orbiting member projects from the other of the sliding contact surfaces into the orbiting member accommodating recess. The orbiting member performs a relative orbiting motion along the peripheral wall surface of the orbiting member accommodating recess in response to the motion of the orbiting scroll member. A movable partition is provided in the orbiting member accommodating recess so as to be movable relative to the orbiting member accommodating recess. The movable partition cooperates with the orbiting member to divide the pump chamber into a suction chamber and a discharge chamber in the orbiting member accommodating recess. A partition driving mechanism drives the movable partition to perform relative movement in the orbiting member accommodating recess in response to the motion of the orbiting member.
In the above-described arrangement, as the orbiting scroll member orbits, the orbiting member, which projects from the other of the sliding contact surfaces, performs a relative orbiting motion in the orbiting member accommodating recess, which is provided in the one of the sliding contact surfaces, along the peripheral wall surface thereof. In addition, the movable partition is driven by the partition driving mechanism to perform relative movement in the orbiting member accommodating recess in response to the motion of the orbiting member. At this time, the pump chamber in the orbiting member accommodating recess is divided into the suction chamber and the discharge chamber by the orbiting member and the movable partition. Therefore, the lubrica
Hidano Katsushi
Iwano Kiminori
Kobayashi Yoshio
Nagasawa Jun'ichi
Sakamoto Susumu
Denion Thomas
Tokico Ltd.
Trien Theresa
Wenderoth , Lind & Ponack, L.L.P.
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