1. Field of the Invention
The present invention relates to a gas compressor for use in a vehicle air conditioning system or the like and, more particularly, aims to prevent fretting wear due to vibration of an oil separation filter contained in an apparatus to thereby achieve an improvement in durability.
2. Description of the Related Art
Conventionally, a gas compressor of this type has, as shown, for example, in FIG. 7, a compression mechanism C in a compressor case 1, and this compression mechanism C sucks in low pressure refrigerant gas in a suction chamber 6 and compresses it before discharging it into a discharge chamber 5 as high pressure refrigerant gas. At this time, the high pressure refrigerant immediately after being discharged from the compression mechanism C contains oil in the mist state filled for the purpose, for example, of lubricating the sliding portion of the compression mechanism portion C, and the oil ingredient in such high pressure refrigerant gas is separated by an oil separator 20 contained in the gas compressor.
The oil separator 20 has an oil separation filter 21 formed by rolling a wire net into a cylinder, and the oil ingredient in the high pressure refrigerant gas is separated when a high speed gas flow of high pressure refrigerant gas strikes upon the wire net constituting the oil separation filter 21 or by the centrifugal force generated when high pressure refrigerant gas whirls inside the oil separation filter 21.
However, in the oil separator 20 of the conventional construction described above, in which a pulsating high speed gas flow incessantly strikes upon the wire net constituting the oil separation filter 21, if the wire net is not supported and fixed in a satisfactory manner, a vibration such as twist is generated in the entire wire net, with the result that the constituent wire materials of the wire net (wires) rub each other, and the wire net and the support member in contact therewith rub each other, resulting in the generation of so-called fretting wear of the wire net to damage the wire net.
The present invention has been made in view of the above problem. It is an object of the present invention to provide a gas compressor in which fretting wear due to vibration of the oil separation filter is prevented to thereby achieve an improvement in durability.
To achieve the above object, there is provided, in accordance with the present invention, a gas compressor comprising a compression mechanism portion which sucks in, compresses, and discharges refrigerant gas, a discharge chamber for temporarily storing the refrigerant gas discharged from the compression mechanism portion, a discharge passage which communicates the compression mechanism portion with the discharge chamber and which guides the refrigerant gas discharged from the compression mechanism portion to the discharge chamber, an oil separation filter which is arranged in the discharge chamber at the downstream end of the discharge passage and which is formed by shaping a lattice-like member into a cylindrical configuration, pressing means for pressing the end portions of the oil separation filter to elastically deform the oil separation filter sufficiently to suppress vibration thereof during use of the gas compressor, and an oil sump formed at the bottom of the discharge chamber and adapted to store the oil separated by the oil separation filter.
In the present invention, the oil separation filter as a whole is firmly fixed in a pressed state by the pressing force when the pressing means presses the end portions of the oil separation filter.
Here, as the pressing means, it is possible to adopt a construction comprising an abutment block portion against which the bottom end portion of the oil separation filter abuts, an outer peripheral block portion having a filter accommodating hole into which the oil separation filter is inserted, and a pressurizing plate put over the forward end portion of the oil separation filter and mounted and fixed to the outer peripheral block portion, wherein the forward end portion of the oil separation filter is provided so as to protrude from the filter accommodating hole on the surface of the outer peripheral block portion, and wherein the protruding forward end portion of the oil separation filter is pressurized and bent by the pressurizing plate to undergo elastic deformation.
In this construction, the forward end portion of the oil separation filter is pressurized and bent toward the abutment block portion by the pressurizing plate to undergo elastic deformation, and due to this elastic deformation of the oil separation filter, the oil separation filter is strongly pressed against the pressurizing plate, the abutment block, and the outer peripheral block portion and fixed thereto.
It is possible to adopt a construction in which the forward end portion of the oil separation filter is previously bent in a fixed direction by a bending amount smaller than a press-bending amount before being press-bent by the pressurizing plate.
In this construction, the forward end portion of the oil separation filter is press-bent by the pressurizing plate such that all the portions thereof are directed in the same direction, so that the construction proves superior in operability in fixing the bending direction.
Further, it is desirable that the direction in which the forward end portion of the oil separation filter is previously bent be toward the inner side of the filter.
In this construction, the forward end portion of the oil separation filter is press-bent by the pressurizing plate such that it is always directed to the inner side of the filter, so that there is no danger of the bent forward end portion of the oil separation filter being caught between the pressurizing plate and the outer peripheral block, making it possible to correctly mount and fix the pressurizing plate to the outer peripheral block portion.
It is possible to provide in the inner surface of the filter accommodating hole a clearance groove which allows entrance of the forward end portion of the oil separation filter when it is press-bent to the filter outer side.
In this construction, for example, there is no directivity in the bending of the forward end portion of the oil separation filter press-bent by the pressurizing plate, and even when the forward end portion of the oil separation filter is bent so as to be directed to the filter outer side, this press-bent portion enters the clearance groove, so that there is no danger of the bent forward end portion of the oil separation filter being caught between the pressurizing plate and the outer peripheral block, making it possible to correctly mount and fix the pressurizing plate to the outer peripheral block portion.
The oil separation filter may, for example, be formed of a lattice-like member, such as wire net or expanded metal; in particular, in the case of a wire net type oil separation filter, it is desirable to fuse by spot welding the regions where the constituent wire materials of the wire net (wires) intersect each other in order to prevent fretting wear as a result of the constituent wires of the wire net being rubbed against each other.
Further, the spot welding is performed in order to prevent fretting wear mainly due to vibration between the constituent wire materials of the wire net, and, from the viewpoint of the object of this spot welding, it is desirable to increase the number of spot welding points for the region where, for example, the high speed gas flow of high pressure refrigerant gas first strikes directly.