Patent Application
20150023813
The present application is based on and claims priority from Japanese Patent Application No. 2013-151543, filed on Jul. 22, 2013, the disclosure of which is hereby incorporated by reference in its entirety.
1. Field of the Invention
The present invention relates to a gas compressor (compressor), and specifically relates to an improvement in a mounting structure for an electromagnetic clutch configured to transmit a power to a rotation shaft.
2. Description of the Related Art
Conventional air condition systems use a gas compressor having a compression chamber configured to compress a gas such as a refrigerant gas into a high-pressure compressed gas.
Such a gas compressor configured to operate upon reception of a power from the outside includes an electromagnetic clutch to switch between accepting the power input and stopping the input.
The electromagnetic clutch includes: a rotor configured to rotate together with a pulley; an annularly-formed electromagnetic coil; and an armature configured to come into contact with an outer surface of the rotor when a magnetic flux is generated by passing an electric current through the electromagnetic coil and to depart from the outer surface of the rotor when the magnetic flux disappears by stopping passing the electric current through the electromagnetic coil.
The electromagnetic coil includes a core constituted of a coil main body having a copper wire wound therearound, and a core case serving as a housing configured to house the core. A portion of the core case is fixed to a housing of the gas compressor by a retainer, while abutting against a seating surface formed at a nose portion of the housing (JP-A 2002-106603).
In the gas compressor disclosed in JP-A 2002-106603, the seating surface formed at the nose of the housing is located only in the inside, in a radial direction, of a center radius (half a diameter of an area drawn by approximately middle positions between an outer peripheral diameter and an inner peripheral diameter) of the annularly-formed electromagnetic coil. The middle positions are at the centers of gravity of electromagnetic coil sections.
Here, the electromagnetic coil attracts the armature by a magnetic flux generated by passing an electric current. Meanwhile, by a reaction force of the attraction, the electromagnetic coil receives such a load that the electromagnetic coil itself is attracted toward the armature.
On the other hand, once passing an electric current is stopped, the electromagnetic coil itself no longer receives the load, and returns to a state where the electromagnetic coil is pushed against the seating surface.
Nevertheless, since the seating surface, against which an end surface of the electromagnetic coil abuts, is formed only in the inside of the area of the centers of gravity of the electromagnetic coil sections, the seating surface cannot face the centers of gravity of the electromagnetic coil sections.
If such a situation lasts for a long period, a gap is formed between the electromagnetic coil and the seating surface, causing rattling between the electromagnetic coil and the housing. The rattling then causes abnormal sound or vibration.
The present invention has been made in consideration of the above-described circumstance. An object of the present invention is to provide a gas compressor capable of preventing or suppressing rattling between an electromagnetic coil and a housing.
In a gas compressor according to one embodiment of the present invention, at least a portion of a seating surface formed on a housing extends to the outside of a center radius of an electromagnetic coil in a radial direction, so that rattling between the electromagnetic coil and the housing is prevented or suppressed.
Specifically, the gas compressor according to one embodiment of the present invention includes a housing configured to house a compressor main body having a rotation shaft, and an electromagnetic clutch having an electromagnetic coil formed annularly around the rotation shaft. A seating surface is formed on the housing and abuts against one end surface of the electromagnetic coil. At least a portion of the seating surface is formed to extend to the outside of a center radius of the electromagnetic coil in a radial direction.
The accompanying drawings are included to provide further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate an embodiment of the invention and, together with the specification, serve to explain the principle of the invention.
Hereinafter, an embodiment of a gas compressor of the present invention will be described with reference to the drawings.
An embodiment of the gas compressor according to the present invention is a vane rotary-type compressor 100 (hereinafter simply referred to as compressor 100). As shown in
The compressor 100 is formed as a part of an air condition system for cooling utilizing the vaporization heat of a refrigerant medium, and is provided together with other components of the air condition system, such as a condenser, an expansion valve, and an evaporator, in a refrigerant-medium circulation path.
The compressor 100 is configured to compress the refrigerant gas G introduced as a gaseous refrigerant medium from the evaporator of the air condition system, and to supply the compressed refrigerant gas G to the condenser of the air condition system.
The condenser is configured to exchange the heat of the compressed refrigerant gas G with those of the surrounding air and the like to dissipate the heat of the refrigerant gas G, so that the refrigerant gas G is liquefied. The resultant is sent as a high-pressure liquid refrigerant medium to the expansion valve.
The expansion valve is configured to reduce the pressure of the high-pressure liquid refrigerant medium. The medium is sent to the evaporator. In the evaporator, this low-pressure liquid refrigerant medium vaporizes by absorbing a heat from the surrounding air. By the heat exchange accompanying the vaporization of the refrigerant medium, the air around the evaporator is cooled.
The vaporized low-pressure refrigerant gas G is returned to and compressed by the compressor 100. Then, the aforementioned steps are repeated.
The housing 10 includes: a case 11 having one end closed and the other end opened; and a front head 12 configured to cover the opened end of the case 11. The front head 12 is assembled to the case 11 with a fastening member such as bolt.
With the front head 12 assembled to the case 11, a space is formed inside the housing 10. The compressor main body 60 and an oil separator 70 are housed in the space.
The compressor main body 60 is a so-called vane rotary-type compressor configured to compress the refrigerant gas G in a compression chamber whose volume changes in accordance with a rotation of a rotation shaft 51.
As shown in
The electromagnetic clutch 90 includes a pulley 91, a rotor 92, an electromagnetic coil 93, and an armature 94.
A belt is wound around the pulley 91 so that the pulley 91 can receive a power input from a power source such as an engine.
The rotor 92 is formed integrally with the pulley 91. The rotor 92 is fixed to the nose portion 14 of the front head 12 via a radial bearing, and is rotatable around the axis C of the rotation shaft 51.
Thus, when the pulley 91 receives a power input, the pulley 91 and the rotor 92 rotate around the axis C together.
The electromagnetic coil 93 includes a core 93a constituted of a coil main body having a copper wire wound therearound, a core case 93b serving as a housing configured to house the core 93a, and an annular plate 93c bonded to an end surface of the core case 93b.
While housed in the core case 93b, the core 93a is housed in an annular space partitioned by the pulley 91 and the rotor 92, but is not in contact with the pulley 91 and the rotor 92.
The annular plate 93c has a central hole 93d through which the nose portion 14 of the front head 12 is inserted. The annular plate 93c is fixed to the nose portion 14 by a retainer 95.
The annular plate 93c is formed to have an outer radius S1 (a radius from the axis C) longer than a center radius S2 that is a distance from the axis C to a center 93g of the core 93a. The center 93g is indicated by the chain double-dashed line.
With the annular plate 93c fixed to the nose portion 14, one end surface 93e of the annular plate 93c (one end surface of the electromagnetic coil) abuts against and in contact with a flat seating surface 13 (portion illustrated by hatching in
As shown in
Specifically, in
The armature 94 includes an inner ring 94a, an outer ring 94b, and a leaf spring 94c.
The inner ring 94a is fastened to an end portion of the rotation shaft 51 protruding from the front head 12.
The outer ring 94b is formed outside the inner ring 94a and projects in the radial direction. The outer ring 94b is made of a material having a high friction coefficient.
The outer ring 94b is disposed to a side wall surface of the rotor 92 with a small gap therebetween, the side wall surface being perpendicular to the axis C. Nevertheless, an elastic deformation of the leaf spring 94c brings the outer ring 94b into contact with the side wall surface of the rotor 92.
The leaf spring 94c connects the inner ring 94a and the outer ring 94b to each other, and allows a displacement of the outer ring 94b relative to the inner ring 94a within a range of the elastic deformation of the leaf spring 94c along a direction in which the axis C extends.
With the above-described configuration, the armature 94 as a whole is rotatable around the axis C together with the rotation shaft 51.
When an electric current is passed through the electromagnetic coil 93, the outer ring 94b is attracted toward the rotor 92 by a generated magnetic flux, and brought into contact with the side wall surface of the rotor 92. Then, by a friction force due to the contact between the outer ring 94b and the side wall surface of the rotor 92, a rotation of the rotor 92 is transmitted to the armature 94, thereby rotating the rotation shaft 51.
On the other hand, when passing the electric current through the electromagnetic coil 93 is stopped, the magnetic flux attracting the armature 94 disappears. Then, the outer ring 94b departs from the side wall surface of the rotor 92 by an elastic restoring force of the leaf spring 94c. Hence, no rotation of the rotor 92 is transmitted to the armature 94, so that the rotation shaft 51 does not rotate.
In the compressor 100 of this embodiment configured as described above, the pulley 91 and the rotor 92 rotate at all times by a power inputted from the power source.
In this respect, when no electric current is passed through the electromagnetic coil 93 of the electromagnetic clutch 90, the armature 94 is not in contact with the rotor 92 so that the armature 94 does not rotate. Hence, the compressor 100 does not perform a compression operation on the refrigerant gas G.
On the other hand, when an electric current is passed through the electromagnetic coil 93 of the electromagnetic clutch 90, the outer ring 94b of the armature 94 is attracted to the electromagnetic coil 93 by a magnetic flux generated by the electromagnetic coil 93, and brought into contact with the side wall surface of the rotor 92. Then, a friction force generated between the outer ring 94b and the side wall surface of the rotor 92 rotates the outer ring 94b of the armature 94.
Accordingly, the inner ring 94a connected to the outer ring 94b via the leaf spring 94c is also rotated together with the outer ring 94b and the leaf spring 94c, thereby rotating the rotation shaft 51 connected to the inner ring 94a. Hence, the compressor 100 performs a compression operation on the refrigerant gas G.
Herein, the center of gravity of the entire electromagnetic coil 93 is the axis C, while the centers of gravity of fine portions along a circumferential direction thereof are located on the center 93g of the core 93a.
For this reason, in a state where the center 93g on which the centers of gravity of sections of the core 93a are located is not in contact with the seating surface 13, the seating surface 13 does not support the centers of gravity. Hence, the portions may not be stably supported, and this may cause rattling and the like with respect to the electromagnetic coil 93 as a whole.
Nevertheless, in the compressor 100 of this embodiment, the five portions 13a, 13b, 13c, 13d, 13e of the seating surface 13 are formed to extend to the outside of the center 93g of the core 93a in the radial direction.
These five portions 13a, 13b, 13c, 13d, 13e are capable of supporting the center 93g, that is, the centers of gravity of the sections of the core 93a, and hence capable of preventing or suppressing rattling between the electromagnetic coil 93 and the housing 10.
Moreover, in the compressor 100 of this embodiment, the number of the portions formed to extend to the outside of the center 93g of the core 93a in the radial direction is five in the seating surface 13. Accordingly, at least three portions among these five portions 13a, 13b, 13c, 13d, 13e can define one plane (the seating surface 13) supporting the end surface 93e of the annular plate 93c (the end surface of the electromagnetic coil 93).
Note that if the number of these portions formed to extend to the outside of the center 93g of the core 93a in the radial direction is at least three, this makes it possible that the portions of the seating surface 13 formed to extend to the outside of the center 93g of the core 93a in the radial direction define one plane supporting the end surface 93e of the annular plate 93c (the end surface of the electromagnetic coil 93).
Thus, although the seating surface 13 in the compressor 100 of this embodiment has the five portions formed to extend to the outside of the center 93g of the core 93a in the radial direction, it is only necessary that, in the gas compressor according to the present invention, the seating surface 13 should have at least three portions formed to extend to the outside of the center 93g of the core 93a in the radial direction.
Nonetheless, if each of such portions of the seating surface 13 has a sufficient width, one plane can be defined without providing such three portions to the seating surface 13. Accordingly, the number of the portions of the seating surface 13 formed to extend to the outside of the center 93g of the core 93a in the radial direction may be two or one.
Meanwhile, in the seating surface 13, three portions (for example, the portions 13a, 13c, 13e) among the five portions 13a, 13b, 13c, 13d, 13e formed to extend to the outside of the center 93g of the core 93a in the radial direction are formed at positions surrounding the axis C of the rotation shaft 51.
Since the axis C is the center of gravity of the entire electromagnetic coil 93, the three portions 13a, 13c, 13e surrounding the axis C are portions surrounding the center of gravity of the entire electromagnetic coil 93.
Thus, these three portions 13a, 13c, 13e are capable of supporting the electromagnetic coil 93, while the electromagnetic coil 93 is prevented from inclining to the plane (the seating surface 13) perpendicular to the axis C.
It should be noted that, in the seating surface 13, at least three portions among the five portions 13a, 13b, 13c, 13d, 13e formed to extend to the outside of the center 93g of the core 93a in the radial direction are preferably formed at positions at equal angular intervals around the axis C of the rotation shaft 51.
In the seating surface 13, if portions formed to extend to the outside of the center 93g of the core 93a in the radial direction are arranged at equal angular intervals as described above, this makes it possible to support the entire electromagnetic coil 93 in a well-balanced manner.
Further, in the seating surface 13, all of three or more portions formed to extend to the outside of the center 93g of the core 93a in the radial direction (for example, all the five portions 13a, 13b, 13c, 13d, 13e) may be'arranged at equal angular intervals. Alternatively, some of the three or more portions (for example, any three portions or any four portions among the five portions 13a, 13b, 13c, 13d, 13e) may be arranged at equal angular intervals.
In the compressor 100 of the above-described embodiment, the portions of the seating surface 13 formed to extend to the outside of the center 93g of the core 93a in the radial direction are formed as the five portions 13a, 13b, 13c, 13d, 13e, which are apart from each other around the axis C. However, the gas compressor according to the present invention is not limited to this embodiment.
Specifically, in the gas compressor according to the present invention, the portions of the seating surface 13, formed to extend to the outside of the center 93g of the core 93a in the radial direction may be connected to each other along the entire circumference around the axis C.
In the seating surface 13, if the portions formed to extend to the outside of the center 93g of the core 93a in the radial direction are connected along the entire circumference around the axis C, rattling between the electromagnetic coil 93 and the housing 10 can be prevented or suppressed as in the above-described embodiment, and the entire electromagnetic coil 93 can be supported in the best balanced manner.
The gas compressor according to the present invention is not limited to the vane rotary-type compressor of the above-described embodiment, and may be a compressor of other types such as diagonal-type or scroll-type. The type of the compressor is not limited.
The gas compressor according to the embodiment of the present invention makes it possible to prevent or suppress rattling between the electromagnetic coil and the housing.
Although the embodiment of the present invention has been described above, the present invention is not limited thereto. It should be appreciated that variations may be made in the embodiment described by persons skilled in the art without departing from the scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013-151543 | Jul 2013 | JP | national |
