The present invention relates to a wobble plate compressor having a two-way piston.
Traditional compressors include swash plate compressors. Usually, a swash plate type compressor includes a drive shaft, a swash plate connected together with the drive shaft, and several pistons operatively connected with the swash plate. When a drive unit drives the drive shaft to rotate in a well-known manner, the swash plate will bring each piston within cylinders into reciprocating motion.
For example, U.S. Pat. No. 5,009,574 discloses a traditional swash plate compressor, in the structure of which a swash plate is fixedly integrated on a drive shaft, such that the swash plate rotates together with the drive shaft. In other words, the swash plate does not rotate relative to the drive shaft. During the operation of a traditional swash plate compressor, the piston simply performs reciprocating motion. In such a structure, it further includes a sliding shoe, through which the swash plate drives the piston into reciprocating motion. Since the swash plate rotates together with the drive shaft, it causes high speed sliding motion between each sliding shoe and the swash plate.
The characteristic high speed sliding motion between the sliding shoe and the swash plate within the swash plate compressor may result in high friction loss and low loading capacity, and particularly, the circumstances become more serious in large volume compressors. Thus, as an improvement to swash plate compressors, wobble plate compressors in the prior art disengage the motion of the swash plate from the drive shaft, trying to reduce the above described friction loss.
For example, U.S. Pat. No. 2,335,415 discloses a wobble plate compressor structure, and in this structure, a wobble plate is connected to a hub of a drive shaft via an anti-friction bearing, such that the wobble plate performs wobbling motion without rotating together with the drive shaft; in other words, there is only slight sliding motion between the wobble plate and the sliding shoe, and sliding friction with high speed motion between the traditional swash plate and the sliding shoe has been replaced by rolling friction of the bearing. However, the structure reduces friction loss, but it is not compact enough, and lacks industrial applicability.
U.S. Pat. No. 5,239,913 discloses another typical wobble plate compressor structure. In this structure, a force from a top of the piston is directed to a bearing via a connecting rod and the wobble plate; for compressors using a single-way piston, such a wobble plate structure is conventionally usable, however, for larger volume compressors requiring a two-way piston, this structure is obviously not suitable, because there is totally no sufficient space for mounting the bearing and the connecting rod at a same position.
In addition, in this and similar structures, the wobble plate is connected with each piston via a piston rod. Thus, in this piece of prior art, it essentially requires a wobble plate stopper to stop the wobble plate from rotating, which makes the compressor structure complicated, resulting in a uneven or unbalanced, complicated manner of rotation, which in turn produces vibrations and noises.
Thus, a novel wobble plate compressor structure is needed, which may, at the same time of maintaining its applicable range, reduce friction loss, improve energy conversion efficiency, and meanwhile overcome the above described problems of existing wobble plate structures.
An object of the present invention is to overcome the above described disadvantages of the existing wobble plate compressor structures, thereby providing a novel wobble plate compressor structure with low friction loss, and improved energy conversion ratio.
In order to achieve the above described object, the present invention provides a two-way wobble plate compressor, comprising:
a cylinder block, the cylinder block having a cylinder bore;
a two-way piston capable of reciprocating within the cylinder bore of the cylinder block;
a drive assembly driving the two-way piston, the drive assembly including a drive shaft, a rotor fixedly connected with the drive shaft, and an annular wobble plate fitting with the rotor, the rotor having a central plane angled to a perpendicular plane of the drive shaft, the central plane of the wobble plate being coincident with the central plane of the rotor, when the drive shaft rotates, the rotor drives the two-way piston via the wobble plate to perform reciprocating motion; particularly,
the rotor has an inner surface for fitting with the annular wobble plate, the inner surface including a first inner surface and a second inner surface, which are oppositely arranged, and a rotor contact surface arranged between the first inner surface and the second inner surface;
the wobble plate is partially encircled within the inner surface of the rotor, and includes respectively a first peripheral portion adjacent to the first inner surface, a second peripheral portion adjacent to the second inner surface and opposite to the first peripheral portion, and a wobble plate contact surface adjacent to the rotor contact surface and arranged between the first peripheral portion and the second peripheral portion;
wherein a first bearing is provided between the first inner surface and the first peripheral portion, a second bearing is provided between the second inner surface and the second peripheral portion, and a third bearing is provided between the rotor contact surface and the wobble plate contact surface.
Alternatively, an inner ring contact surface and an outer ring contact surface of said first bearing are respectively in contact with the first inner surface and the first peripheral portion;
An inner ring contact surface and an outer ring contact surface of said second bearing are respectively in contact with the second inner surface and the second peripheral portion; and
An inner ring contact surface and an outer ring contact surface of said third bearing are respectively in contact with the rotor contact surface and the wobble plate contact surface.
Preferably, a thrust washer is provided between the inner ring contact surface of said first bearing and said first inner surface, and/or between the outer ring contact surface of said first bearing and said first peripheral portion; and
A thrust washer is provided between the inner ring contact surface of said second bearing and said second inner surface, and/or between the outer ring contact surface of said second bearing and said second peripheral portion.
Said first bearing and the second bearing each is one of a needle roller thrust bearing, a roller pin thrust bearing, alternatively a double row needle roller thrust bearing, a double row roller pin thrust bearing, and a conical roller thrust bearing.
Said third bearing is one of a radial needle roller bearing, alternatively a radial roller pin bearing, or a radial ball bearing.
Preferably, a thrust washer is provided between the inner ring contact surface of said second bearing and said second surface, and between the outer ring contact surface of said second bearing and said second peripheral portion, and said third bearing is a radial ball bearing.
Preferably, said two-way piston includes two socket portions, two hemispherical sliding shoes are provided within the two socket portions for interacting with the first peripheral portion and the second peripheral portion of said wobble plate, respectively.
Preferably, said rotor includes a first annular flange and a second annular flange, and the first annular flange and the second annular flange are fastened together via a nut and said drive shaft.
As compared with the prior art, the wobble plate compressor of the present invention is of a compact structure with low design complexity, which improves efficiency and output power, and at the same time, cost can be successfully controlled, so it is suitable for application in commercial compressors.
With reference to particular embodiments and corresponding drawings, the structure composition and the operating principles of a two-way wobble plate compressor of the present invention will be described in detail in the following.
Generally speaking, the two-way wobble plate compressor of the present invention adopts a two-way piston structure, which uses a wobble plate to drive a two-way piston to reciprocate, and motion of the wobble plate is driven by a rotor fixed on a drive shaft. The present invention is particularly characterized by the manner of fitting between the wobble plate and the rotor. Bearing(s) may be fit between the wobble plate and the rotor so as to form a combined bearing unit; in other words, in addition to operating to drive the two-way piston into motion, the wobble plate may also directly serve as the outer ring of the combined bearing unit; and in addition to operating to drive the wobble plate into wobbling motion, the rotor mounted on drive shaft may also directly serve as the inner ring of the combined bearing unit. As such, high speed sliding motion in traditional swash plate compressors is replaced by rolling motion of the combined bearing unit; and meanwhile, as compared with the prior art, the wobble plate compressor of the present invention is of a compact structure with low design complexity, which improves efficiency and output power, and at the same time, cost can be successfully controlled, so it is suitable for application in commercial compressors.
Specifically, in
With reference to the drawing, in this embodiment, the two-way wobble plate compressor includes a cylinder block 100, the cylinder block having several cylinder bores 110. Conventionally, the cylinder block 100 consists of a front cylinder block 120 and a rear cylinder block 130, and includes a pair of central holes 140 along a longitudinal axis O-O of the cylinder block; and the cylinder bores 110 are evenly arranged around the central hole 140.
The two-way wobble plate compressor further includes several two-way pistons 200 capable of reciprocating in the cylinder bores 110 of the cylinder block 100. The two-way pistons 200 perform reciprocating motion in relevant cylinder bores 110 of the front cylinder block 120 and the rear cylinder block 130.
The two-way wobble plate compressor further includes a drive assembly 300 driving the two-way pistons 200, the drive assembly 300 including a drive shaft 310, a rotor 320 fixedly connected with the drive shaft 310, and an annular wobble plate 330 fitting with the rotor 320; and further with reference to
Conventionally, the drive shaft 310 is rotatably arranged the central hole 140 of the front cylinder block 120 and the rear cylinder block 130, and may be driven into rotation by an external driving force. The rotor 320 is fixedly connected with and integrated on the drive shaft, so it may rotate along with the rotation of the drive shaft 310. Further, with reference to
As described above, the central plane P-P of the rotor 320 and the perpendicular plane I-I of the drive shaft 310 form an included angle α. The included angle determines a stroke length when the two-way piston 200 performs reciprocating motion.
Particularly, with reference to
The wobble plate 330 is partially encircled within the inner surface 323 of the rotor 320, and includes respectively a first peripheral portion 334 adjacent to the first inner surface 324, a second peripheral portion 335 adjacent to the second inner surface 325 and opposite to the first peripheral portion 334, and a wobble plate contact surface 336 adjacent to the rotor 320 contact surface and arranged between the first peripheral portion 334 and the second peripheral portion 335.
As a most prominent feature of the present invention, a first bearing 340 is provided between the first inner surface 324 and the first peripheral portion 334; a second bearing 350 is provided between the second inner surface 325 and the second peripheral portion 335; and a third bearing 360 is provided between the rotor contact surface 326 and the wobble plate contact surface 336.
More specifically, as shown in
As shown in
With reference to
Of course, it will be easily understood that, the wobble plate 330 may also drive the two-way piston 200 into reciprocating motion by other conventional fitting means, for example, using a pin structure to implement a fitting connection between the wobble plate 330 and the two-way piston 200.
As such, when the peripheral portion of the wobble plate 330 slidingly passes between two flat portions of a pair of sliding shoes 230, and the sliding shoe 230 is provided between the two-way piston 200 and the wobble plate 330, the two-way piston 200, the sliding shoe 230, and the peripheral portion wobble plate 330 collectively form a universal bearing structure, and in the present embodiment, the universal bearing structure is a sliding shoe universal joint structure.
In the embodiment, when the drive shaft 310 of the wobble plate compressor rotates, the rotor 320 will rotate with the rotation of the drive shaft 310; due to the actions of the first bearing 340, the second bearing 350, and the third bearing 360, the wobble plate 330 performs wobbling motion but does not rotate along with the rotation of the drive shaft; due to the actions of the sliding shoe universal joint, the flat portion of the sliding shoe 230 and the peripheral portion of the wobble plate 330 move up and down with respect to each other in a diameter direction relative to wobble plate 330; and the two-way piston 200 performs forward and rearward reciprocating motion under the constraints of the corresponding cylinder bore in the cylinder block 100. Since there is no constraint on the rotation of the wobble plate 330, when the drive shaft 310 rotates, the wobble plate 330 may also disproportionately and slowly rotate along with the rotation of the drive shaft 310 under the actions of friction forces of the first bearing 340, the second bearing 350, and the third bearing 360, and such rotation will greatly reduce wear between surfaces of the peripheral portion of the wobble plate 330 and the flat portion of the sliding shoe 230.
Further, with reference to
In the above described embodiments, the first bearing 340 and the second bearing 350 are needle roller thrust bearings; however, alternatively, the first bearing and the second bearing each may also be one of a roller pin thrust bearing, a double row needle roller thrust bearing, a double row roller pin thrust bearing, and a conical roller thrust bearing. Similarly, in the above described embodiments, the third bearing 360 is a radial needle roller bearing; however, alternatively, the third bearing 360 may also be a radial roller pin bearing or a radial ball bearing.
For example, in the embodiment as shown in
As shown in
As shown in
Preferably, in an alternative embodiment, a thrust washer is provided between the inner ring contact surface of the first bearing 340 and the first inner surface 324, and/or between the outer ring contact surface of the first bearing 340 and the first peripheral portion 334; and a thrust washer is provided between the inner ring contact surface of the second bearing 350 and the second inner surface 325, and/or between the outer ring contact surface of the second bearing 350 and the second peripheral portion 335. With reference to
In addition, with reference to
Various examples illustrated in the above may be arbitrarily and suitably combined, and it has been demonstrated in practice that, a most preferable form of combination is: a thrust washer is provided both between the inner ring contact surface of the second bearing and the second surface, and between the outer ring contact surface of the second bearing and the second peripheral portion, and the third bearing is a radial ball bearing.
It will be easily understood that, the present invention is not limited to specific examples given by the above described embodiments, and any combinations and readily conceivable variants of these particular embodiments shall fall into the scope of protection of the present invention.
Number | Date | Country | Kind |
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2014 1 02157835 | May 2014 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN2015/079444 | 5/21/2015 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2015/176666 | 11/26/2015 | WO | A |
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Number | Date | Country | |
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20170089329 A1 | Mar 2017 | US |