Automatic preloaded biasing eccentric roller joint with retainer

Abstract

We provide a scroll-type compression mechanism that is quiet, smooth, and friction-free, and in principle has a permanent lifespan even at ultra-high speeds. [Solution] Double-ended conical rollers are aligned in the direction of the guide discs on the rotating and stationary sides of the spiral blade, and then fixed in place with a retainer. After that, a built-in elastic body automatically applies pre-pressure.

Description

Detailed Description of the Invention

Technical Field

[0001] The present invention relates to improving the performance of scroll compressors.

Background Art

[0002] When a scroll compressor rotates the scroll by arranging a pair of spiral blades on the revolving side and the fixed side with a 180° offset and eccentrically facing each other to prevent self-rotation, the fluid is compressed based on the principle that the crescent-shaped space volume between the blades shrinks toward the center. To drive this, an isokinetic eccentric coupling that rotates without self-rotation is essential.

[0003] In the development process of scroll compressors, in 1983, an eccentric coupling for a suitable isokinetic double-headed conical roller was proposed in Japanese Utility Model Application No. 59-168229. At that time, only thrust was targeted for this coupling. However, after 33 years, it was discovered that the roller has a bearing function that can handle the loads in the X, Y, and Z directions of the scroll impeller with high precision and pure rolling contact, and Japanese Patent Application Laid-Open No. 2017-207050 was patented.

[0004] However, 41 years after the domestication of scrolls, for all scroll machines in the world, an Oldham-type reciprocating slide friction cross key invented 200 years ago (1823), or a pin & ring type coupling that rotates a ring with the tip of a 4-mm stick citing the plate spinning of ancient Greek circus acts, is used. These sliding friction methods require a large amount of lubrication due to the friction, and are non-isokinetic couplings with a fluctuating angular velocity every rotation, generating high-frequency vibrations. The friction inside the coupling shown in FIG. 9, and even up to the outer circumference and side surface of the scroll body in FIG. 10, causes friction at the locations indicated by black dots, resulting in a total of more than 36 friction and wear points. In addition, there are machining errors in each component, so the accumulation causes backlash noise. All contact points are metal contacts, and when the coefficient of friction is calculated as μ = 0.07 - 0.1, it results in huge frictional losses. This loss is approximately three hundred times the calculated loss compared to the pure rolling friction of the double-headed conical roller with μ = 0.0003.

[0005] When scroll motors were first developed, they were praised as groundbreaking due to their low pulsation, quiet operation, high speed, miniaturization, and simplification. However, they now suffer from friction loss and wear, a short lifespan, and noise, and their speed is far inferior to reciprocating motors. Their durability is also said to be less than 10 years, exceeding local government noise regulations.

[0006] In the double-ended tapered roller type joint described in Patent Document 6, which has existed since the beginning, the backlash of the scroll spiral can be completely suppressed to zero in all directions (X, Y, Z) by preloading. If the roundness of the roller is 1 micron, the rotational accuracy of the spiral is also reflected at 1 micron, so a non-contact sealing accuracy can be obtained with a spiral sealing gap of 1 micron. Furthermore, since it operates at a perfectly constant speed, there is no vibration. Incidentally, the average roundness of current JIS standard rolling bearing rollers is supplied at 0.001 mm (effectively 0.0008 mm or less). In addition, the friction coefficient of this double-ended tapered roller is such that, as it is a pivot-type bearing, it is pure rolling contact at a single point, and both theoretically and in actual measurements the friction coefficient is μ = 0.0003 or less, so lubrication is not required.

[0007] Furthermore, as demonstrated in Japanese Patent Publication No. 2017-207050, double-ended tapered rollers do not even experience the spin slip that occurs with steel balls, so they float on a complete elastic fluid lubrication film (EHL), resulting in no metal-to-metal contact and virtually no wear. In addition, recent papers from major manufacturers indicate that the fatigue peeling life of rolling bearings is virtually permanent when the surface pressure is 2 GPa or less, using high-purity steel and heat treatment technology. Further advantages include the fact that, compared to sliding friction contact in bearings, they are overwhelmingly resistant to foreign matter contamination, misalignment, thermal deformation, and stress strain, allowing for weight reduction of surrounding components.

[0008] Furthermore, in current sliding joints, the mounting location of the spiral body is at the tip of the main shaft, resulting in an overhang, which is extremely unfavorable for resonance. In contrast, with this double-ended tapered roller bearing, the inner diameter of the spiral becomes a high-rigidity radial roller bearing with zero clearance (preload), so there is no overhang. Moreover, since the entire surface of the spiral is non-contact, the wear resistance of the material becomes irrelevant.

[0009] Incidentally, in interviews with manufacturers about why double-ended tapered roller couplings have been avoided, it was stated that they have no precedent in the history of bearing technology, and that the rhomboid-shaped rollers are difficult to control the position of during processing, making inspection, assembly, and even pre-loading difficult. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Actual Plan Showa 59-168229 [Patent Document 2] (11) [Publication Number] JP-A-9-4639 Connecting pins 2 x 3 Figure 5 High cost, [Patent Document 3] [Publication Number] JP 2013-19532 The tip of the roller is fitted and fixed with the hole in the race, difficult to implement, [Patent Document 4] Japanese Patent Publication No. 2016-130578 (P2016-130578A) applies only to thrust loads. [Patent Document 5] Japanese Patent Publication No. 2017-207050, No retainer, assembly is not possible with pre-pressure biasing. [Patent Document 6] Japanese Patent Publication No. 2020-190244: No retainer is present, making assembly impossible under pre-pressure biasing. [Patent Document 7] Japanese Patent Publication No. 2022-171161, Figures 2 and 3, Eccentric coupling using a disc-rotating mechanism (uneven velocity, unavoidable play). [Overview of the Initiative] [Problems that the invention aims to solve]

[0011] This invention is a solution to the problems described in Patent Document 6, which solves all of the problems associated with the aforementioned scroll compressor. As shown in Figure 2, an elastic body 13 is interposed between the crankshaft 45 and the inner diameter of the spiral side vortex, and its elastic reaction force biases the double-ended tapered rollers with radial preload, and is a means to absorb machining errors of each component and cumulative errors in assembly. However, due to the structure of the compressor, the elastic body and the double-ended tapered rollers are located in the center, making it impossible to preload them after assembly. Furthermore, if the aforementioned elastic body 13 is installed in advance, the edges of the double-ended tapered rollers protrude beyond the guide hole, causing them to collide with the hole 3c and preventing assembly.

[0012] Furthermore, the assembly process involves sliding the fixed disc 3a and the rotating disc 3b in Figure 1 parallel to the axis to join them. Therefore, during assembly, it is essential that all the rollers in Figure 7 are aligned simultaneously with high precision, and that all the components shown in Figure 1, including the housing 54, the spiral 6, the crankshaft 45, and the bearings 43, are aligned simultaneously. If even one part interferes, assembly becomes impossible. For this reason, all the double-ended tapered rollers must be aligned and fixed with high precision, and a sufficient clearance for assembly is required between the pocket hole and the double-ended tapered roller, as shown by the symbol 21 in Figure 2.

[0013] The second challenge is a method for pre-applying force to both tapered rollers. Prior art patents 2, 3, and 4 exist, but for example, in document 2, the method of connecting the fixed and rotating discs with a connecting pin, sandwiching the rollers, requires more than six parts, resulting in high costs. Moreover, the connecting parts are unnecessary during operation, and it is impossible to pre-apply force to the rollers, which is the crucial aspect.

[0014] Reference 3 deals only with thrust loads, and when the radial load of this application is applied, the thickness of the guide member needs to be half the thickness of the diameter of the double-ended tapered roller. Reference 3 is not feasible because the holding member is bulky and preloading to the roller is not possible.

[0015] Reference 4 describes a method in which a double-ended tapered roller is sandwiched in an elliptical hole formed by the combination of guide holes on the rotating and fixed sides, and the guide disc is secured with an elastic clip. However, this method has the drawback of the roller falling out in the axial direction, and due to variations in the precision of the hole diameters in the guide holes, a uniform holding force cannot be obtained, nor can pre-pressure biasing be applied.

[0016] In the case of Patent Document 7, a chip seal is embedded in the groove of the guide member, which requires the cost of machining the seal groove and the assembly time of the seal material, and also increases sliding friction. [Means for solving the problem]

[0017] Claim 1 is described as follows: A retainer member made of a thin film-like plate, having pocket holes for accommodating rollers, is placed on the surface of either the rotating-side guide disc or the stationary-side guide disc, and the double-ended tapered rollers are pressed against the inner wall of the holes in the guide disc and fixed in place by the inner diameter of the pocket holes. When the guide disc comes into contact with the raceway, the pins that were fixing the retainer detach from the retainer, and the retainer separates from the double-ended tapered rollers. Claim 2 is described as follows: When the fixed-side and rotating-side raceways are joined together, the tip 22 of the preload operating switch, which protrudes from the outer diameter of the guide disc and stops the reaction force of the elastic member provided on the inner diameter of the guide disc, disengages from the projection stopper 20 provided on the raceway 2b, thereby biasing the roller with preload. As explained in claim 3, the retaining member that is separated from the double-ended conical roller of claim 1 will be in a floating state and will be scattered by centrifugal force, and at the same time the lubricating grease will also be scattered, so this can be prevented by the cover shown in Figure 4, reference numeral 25. [Effects of the Invention]

[0018] Thus, all the problems associated with scroll compressors are resolved, and the advantages expected of scroll-type compressors are fully realized. In typical rolling bearing life tests, the total wear is 2-3 microns or less. In contrast, these tapered roller bearings have absolutely no spin slip, ensuring EHL lubrication and theoretically preventing wear. Therefore, the sealing of the scroll spiral's sliding contact surface becomes virtually permanent. Even if wear occurs in the joint, it acts to reduce the sealing gap of the spiral's sliding contact surface, so the compressor's sealing performance does not deteriorate.

[0019] The problems of the scroll compressor described above are as follows: 8 items, (1) Friction and wear do not occur because the friction between the orbiting scroll and the fixed scroll can be made non-contact. (2) Unlimited high-speed operation and high-pressure operation become possible. (3) Eliminate the noise caused by the unequal speed of the joint and the backlash noise. (4) Eliminate the overhang arrangement where the position of the eccentrically rotating scroll body is disadvantageous for vibration. (5) Eliminate 80% of the total losses of the friction loss and the compression leakage loss in the current product. Moreover, (6) The material of the scroll does not require wear-resistant material and the cost is reduced. (7) In the application of air compressors, only the joint part is isolated, sealed with grease by a seal, and the other parts are completely lubrication-free, so the oil contamination of the compressed air can be eliminated. (8) The refrigerant oil that has been essential for compressors becomes unnecessary.

[0020] Also, for carbon neutrality, more than 30 million scroll-type air conditioner compressors are shipped annually worldwide, and the total number of operating units in the world exceeds 1 billion. By replacing all of these with the invention technology, Freon can be completely phased out and natural refrigerant (CO2) can be used, resulting in a huge contribution to a decarbonized society.

Brief Description of the Drawings

[0021] Figure 1 Cross-sectional schematic view showing an example before assembly of scroll compression Figure 2 Cross-sectional schematic view of an example after assembly of scroll compression. Figure 3 Enlarged view of an example before assembly of the bi-helical scroll of scroll compression. Figure 4 Enlarged cross-sectional view of an example immediately before completion of assembly of the bi-helical scroll of the scroll compressor. Figure 5 Operating explanatory diagram of an example of the radial preloading actuating switch of the bi-helical scroll Figure 6 External view of an example of the cage of the bi-helical scroll Figure 7 Setup diagram of an example of the cage of the bi-helical scroll Figure 8 Explanatory diagram of the slide mechanism of the cage that restrains the bi-helical scroll Figure 9 Patent diagram of the dish-type pin drive mechanism commonly used in current car air conditioners Figure 10 Explanatory diagram of the location where sliding friction occurs between the scroll bodies of scroll compression

Modes for Carrying Out the Invention

[0022] Between the rotating side 3a in Figure 1 and the fixed guide disc 3b, there is a retainer member (16) made of resin or the like, approximately 0.2 mm thick, which houses the double-ended tapered roller 1n. A pocket hole (27) for the roller is provided in Figure 6, and the roller is placed in this hole and pressed against the inner wall of the hole (27) in the guide disc 3b, with the roller's direction precisely aligned, to fix it as shown in Figure 7. The pin hole (26) in the thin plate (16) in Figures 4 and 6 fits with the outer diameter of the body of the cylindrical resin pin (23) with a cone-shaped tip that protrudes from the guide member, and the retainer member is locked in place. To illustrate this with Figure 8, when the guide discs 3a and 3b slide in the joining direction, the surface of the guide disc 3a collides with the apex of the pin (25) as shown in the center diagram of Figure 8, and the pin is pushed into the hole. Then, because the apex of the pin 25 on the thin plate 16 is sloped, it disengages from the check valve, and the retainer member moves outward due to centrifugal force and stops at the outer seal ring 25 in Figure 3.

[0023] Embodiment of claim 2. An elastic member 13 provided between the crank bearing 43 and the swivel-side disc 3b shown in Figure 1c is compressed and temporarily fixed with the stopper hook 20, and the gap 21 between the corner 3c of the pocket hole 31 of the fixed-side disc 3a and the outer diameter of the roller is made as large as possible, 0.5 mm or more. The elastic body 13 may also be provided on the swivel-side guide member 3a. In the final stage of joining, the protrusion 29 protruding from the outer circumference of the swivel-side guide disc 3b shown in Figure 1c comes out of the pocket 24 (depth 5 mm or more) of the stopper 20, and the roller is pre-pressed by the expansion reaction force of the elastic body 13. If there are mutual errors in the position and inner diameter of the guide holes, the pre-pressure on each roller will vary, so in order to eliminate errors, the holes of the swivel-side and fixed-side guide discs are machined simultaneously on top of each other. Claim 3: A cover is provided on the rotating outer side of the double-ended cone as shown by reference numeral 25 in Figure 3, the cover is curved so as to bulge outwards due to back pressure and the sides lightly slide against the raceway. [Industrial applicability]

[0024] The scroll-type compression mechanism is quiet and smooth with no frictional resistance, and in principle has a permanent lifespan even at ultra-high speeds, thus expanding its applications. (Explanation of symbols)

[0025] 1. Double-ended cone roller 2a Fixed side raceway ring 2b...Swivel side track wheel 3a. Fixed disk 3b...Swivel side disc 6. Fixed side spiral 7. Swirling side vortex 13. Preload spring 16...retainer 20. Preloaded switch 21...Assembly gap 22... Step for setting gap during assembly 23. Retainer fixing pin 25...Shatterproof cover 26...pin holes 27...Hole for housing rollers in the retainer 28... Roller retaining claws 29...Axial stroke dimension before preloading 43. Bearings

Claims

1. An eccentric joint using double-ended tapered rollers, characterized in that the double-ended tapered rollers are fixed in alignment with the inner wall of the hole in the guide disc by a film-like thin plate retainer member provided between the rotating-side guide disc and the stationary-side guide disc.

2. An eccentric joint using double-ended tapered rollers according to claim 1, wherein when the guide disc is brought into contact with the raceway rings with the fixed side and the swivel side raceway rings sandwiching the double-ended tapered rollers, the elastic reaction force of the preloading elastic member acts on the double-ended tapered rollers, thereby biasing them with a fixed amount of preload.

3. An eccentric joint using double-ended tapered rollers according to claim 1, wherein a cover for preventing the retainer member from flying out and preventing grease from scattering is positioned on the outside where the double-ended tapered rollers rotate.

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