JP2006105380A - Ring foil bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide construction which is low in cost and is capable of machining and is capable of miniaturizing by simplifying construction of a dynamic pressure type gas bearing without using a high-class processing machine. <P>SOLUTION: The dynamic pressure type gas bearing is characterized in that a ring foil is provided with a protuberance on sheet similar to ring-like foil (ring foil) formed of sheet by a press etc. and is inserted in a cartridge which forms a protuberance by inserting a column or a cylinder by performing circular boring on a thick walled cylinder as the dynamic pressure type gas bearing which is construction which combines the column and the cylinder capable of manufacturing by a machine generally employed, such as a lathe and the press. In addition, the dynamic pressure type gas bearing is configured so that dump foil including a plurality of pawls is wound on outer periphery of the ring foil. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  Technical field on bearings using gas and air to support the rotating shaft of turbomachine

    Bearings that support the rotating shafts of rotating machinery are generally lubricated and cooled by lubricants such as oil, but they require additional equipment such as lubricant supply pumps, pressure regulators, and coolers. The system is complicated and large. For this reason, a bearing using a fluid used in a system such as a turbomachine as a lubricant is desired, and a gas bearing using a gas as a lubricant has been developed and put into practical use.

  The dynamic pressure type gas bearing has been researched and developed for many years and operates without supplying a lubricant and without supplying a fluid. The dynamic pressure type gas bearing has been put to practical use as a bearing for space or aircraft air conditioning systems. Gas bearings mainly include herringbone type and foil type bearings having grooves on the rotating shaft and bearing surface, and foil type is used for high-speed rotating machines. The foil type is roughly classified into a leaf foil type and a bump foil type. FIG. 26 shows a leaf foil type and a bump foil type gas bearing. The leaf foil type is formed by forming a thin plate into an arc shape and coating the bearing surface in a movable state on the casing, and reduces the wear and vibration during contact by making use of the thin plate's elasticity and frictional damping due to movement. In the bump foil type, a thin plate that goes around the rotation axis is constrained to the casing by a bump foil that acts as a spring, which is also made of a thin plate, and acts like a leaf foil type. Yes.

  The leaf foil type dynamic pressure type gas bearing having the simplest structure is that of Capstone Corporation shown in FIG. 27, and has claws (28) and (30) provided with three leaf foils (16) in the cartridge (12). The arc-shaped leaf foil is bent at both ends in the opposite direction to widen the gap between the ends. A spring plate (18) is provided between the leaf foil (16) and the cartridge (12), and a gap between the leaf foil (16) and the rotating shaft (14) is adjusted. For example, as shown in FIG. 28, the spring plate (18) is formed of a frame (66), (68) and a spring portion (70) by punching a thin plate, and the spring plate (18) is formed on the inner surface of the cartridge (12). When inserted along, the frames (66) and (68) are bent in an arc shape, but the spring portion (70) maintains a flat shape. When a radial force acts on the leaf foil (16), the planar spring plate (70) is bent to generate a half force. A necessary reaction force can be applied to a necessary place by changing the shape and size of the spring plate (70).

  By combining the leaf foil disclosed in the Capstone patent (US Pat. No. 5,958,841) shown in FIG. 27 and the spring plate structure (US Pat. No. 5,427,455) having elasticity and damping effect provided on the back surface of the leaf foil. An ideal and simple structure is constructed.

  The problem to be solved by the present invention is to simplify the structure of a dynamic pressure type gas bearing, and to provide a structure that can be processed at low cost and a structure that can be reduced in size without using a high-grade processing machine.

  Conventional foil-type gas bearings have a complicated shape, and various advanced processes are performed on both the foil and the cartridge. As shown in US Pat. Nos. 5,958,841 and 5,427,455, the cartridge has a complicated curved surface. Such machining is performed with high accuracy such as wire cutting and electric discharge machining, which requires a large number of machining steps and requires a long time for machining, resulting in high costs.

  The minimum shaft diameter of the current foil-type bearing is about 30 mm, and if it is downsized to about 10 mm, it is necessary to increase the processing accuracy to about 1/3. To process a complicated shape with high accuracy More expensive machine tools are required, special technology is required, the cost is high, and it is difficult to employ expensive bearings in small machines that are less expensive than large machines.

  Provided is a foil-type gas bearing configured with a plane that can be machined with high precision by an existing machine tool, a plane that can be machined by cylindrical machining, and a cylindrical shape.

  The foil is a cylindrical thin plate ring (hereinafter referred to as a ring foil), and the cartridge is manufactured by a simple process in which a cylindrical circular hole is drilled in the cylinder, and the protrusion is inserted into the circular hole or a cylinder. Form. This ring foil, cartridge, column or cylinder constitutes a bearing.

  The structure of Example 1 is shown in FIGS. The gas bearing of Example 1 is a cylindrical ring foil (100) formed of a thin plate and held by three protrusions (221) in the cartridge (200), and is suitable for the inside of the ring foil (100). A rotating shaft is installed with a sufficient gap. In the bearing, a levitation force is created by a wedge formed by a fluid entering a wedge-shaped gap between the rotating shaft and the ring foil (100). The ring foil (100) is a perfect circle as shown in FIG. 2, but is pressed toward the inner periphery by the protrusions (221), (222), and (223), so that the protrusions (221), (222), ( 223) is distorted, and the middle part of the protrusions (221), (222), (223) is depressed, and the wedge part extends from the intermediate part to the protrusions (221), (222), (223). It works as a bearing. FIG. 3 is a drawing of the cartridge (200) alone, which has a thick cylindrical shape and has three protrusions (221), (222), (223) on the inner diameter (210). In this figure, an example of three protrusions is shown, but it is sufficient that the number of ring foils (100) is three or more held at the center.

  The configuration of the second embodiment is shown in FIGS. In the second embodiment, the cartridge (200) is composed of a plurality of disc-shaped cartridges (200) having protrusions (221), (222), and (223) on the inner diameter (220) side. 1 has projections (221), (222), (223) that are long in the axial direction, whereas a plurality of projections (221), (222), (223) are provided in the axial direction. Yes. The protrusions (221), (222), and (223) of the plurality of disk-shaped cartridges (200) have a structure in which the phase may be changed for each plate. FIG. 5 shows the ring foil (100), and FIG. 6 shows the shape of one cartridge (200). In the above description, the protrusion (220) has a circular shape as described in the first and second embodiments, but a polygon is not contrary to the spirit of the present invention.

  The configuration of Example 3 is shown in FIG. In Example 3, the cartridge (200) is formed of a cylindrical thin plate, and the protrusions (221), (222), and (223) are formed by pressing or the like.

  The structure of Example 4 is shown in FIGS. FIG. 8 shows a combination of the cartridge (200) and the ring foil (100) of Example 3, FIG. 9 shows the shape of the cartridge (200), and FIG. 10 shows the ring foil (100). As shown in FIG. 9, the cartridge (200) is pressed into a cylindrical thin plate by a press or the like (221), (222), (223), (224), (225), (226), (227), ( 228) and (229) are provided in plural in the circumferential direction and the axial direction. In the example of FIG. 8, three protrusions (221), (222), (223) and protrusions (224), (225), (226) are arranged in the middle portion in the vicinity of both ends of the cartridge (200). Protrusions (227), (228), and (229) are provided with the phase changed to 30 degrees.

  The configuration of the fifth embodiment is shown in FIGS. In the gas bearing of Example 5, a circular hole (310) in which a part on the inner diameter side is opened is formed in a thick cylindrical cartridge (200), and a projection (221), ( 222) and (223). FIGS. 12A and 12B show the cross-sectional shape of the inserted cylinder, where FIG. 12A is a circle, FIG. 12B is an excised part (341) at the top, and FIG. 12C is an excision of (b). The position is relatively changed. FIG. 13 shows an overall view of the cylinder of FIG. FIG. 14 (a) shows the projection portion of FIG. 12 (b) in the axial direction by cutting away the cut portion (342), and a plurality of projections are provided in the axial direction. A plurality of protrusions (343) are provided by cutting a plurality of cut portions (342) of the protrusion portion c) in the axial direction.

  The configuration of Example 6 is shown in FIG. In the sixth embodiment, the column of the fifth embodiment is formed by a cylinder formed of a thin plate. (A) is a cylinder (351), (352), (353), and a circular hole (310) can be drilled. The cartridge (300) is provided with a protrusion, and (b) shows the cross-sectional shape of the cylinder (350).

  The structure of Example 7 is shown in FIG. A cylinder (350) having an opening (354) in FIG. 16 (b) is inserted into a cartridge (300) having a hole (310) as shown in FIG. 16 (a) to form a protrusion.

  The configuration of Example 8 is shown in FIG. A cartridge (350) having an open part (354) in FIG. 17 (b) and having one end (355) pushed outward, and a hole (310) as shown in (a) ( 300), a projection is formed, and the ring foil (100) is supported by the end (355).

  The configuration of Example 9 is shown in FIG. In the ninth embodiment, a rotation stopper (356) is added to the cylinder (350) of the eighth embodiment.

  In Example 10, as shown in FIG. 19, the cylinder (350) is provided with one or more notches (357).

  The structure of Example 11 is shown in FIGS. The dump foil (400) is provided on the outer periphery of the ring foil (100), and the claw (410) is formed by cutting the dump foil (400). As shown in the enlarged view of FIG. 21, the claw (410) formed by cutting a part of the dump foil (400) provided on the outer periphery of the ring foil (100) is in contact with the cartridge (300). The interval between the dump foil (410) and the cartridge (300) is adjusted by the cylinder (350). FIG. 22 shows the shapes of the dump foil (400) and the ring foil (100). FIG. 23 shows a detailed view of the dump foil (400) and the claws (410). The dimensions of the claws (410) provided on the dump foil (400) are set such that the rigidity of the claws (410) is smaller than the rigidity of the base (420) of the dump foil (400). In FIG. 23, the width and length of the nail (410) are set to be equal to or smaller than the interval. Local deformation of the ring foil (100) is prevented, and a smooth shape change is given to the ring foil (100).

  The configuration of Example 12 is shown in FIG. Example 12 is a cylinder (351), (352), (353), (361), (362), (363) inserted into a plurality of circular holes (310) provided in the cartridge (300). A ring foil (100) is held. The cylinders (361), (362), and (363) are installed near the cylinders with the same number at the end of the cylinders (351), (352), and (353), and the ring foil (100) is pressed toward the inner diameter side. ing. The ring foil (100) between the cylinders (351) and (352) is pushed toward the inner diameter side due to the provision of the cylinder (361), and the ring foil (100) is close to the cylinder (352). It is spread to the outer side. When the rotation shaft rotates counterclockwise, the distance between the rotation shaft and the ring foil (100) becomes the largest at a position past the cylinder (352) and becomes narrower toward the cylinder (361). That is, a wedge-shaped gap is formed from a position closer to the cylinder (352) than an intermediate position between the cylinder (352) and the cylinder (361) toward (361) (351).

FIG. 25 shows the configuration of the thirteenth embodiment. In Example 13, a ring foil (100) is provided inside a cartridge (300) provided with claws (451), (452),... (459) formed by cutting and pressing a notched cylinder made of a thin plate. ) Is retained. FIG. 25A is a front view, FIG. 25B is a side view, and FIG. 25C is an AA cross-sectional view of the cartridge (300).
It is possible to employ a material in which at least one of the inner and outer surfaces of the ring foil (100) described above is coated with a material having appropriate strength and slipperiness such as Teflon. Moreover, although the number of protrusions has been described as three, if it is three or more, it is consistent with the gist of the present invention.

The invention's effect

  In the ring foil bearing of Example 1 shown in FIGS. 1 to 3, the cylindrical ring foil (100) is changed into a cartridge (200) having cylindrical protrusions (221), (222), (223). The ring foil (100) is pressed against the inner diameter side by the three protrusions (221), (222), and (223), and the ring foil (100) becomes a sinusoidal curved surface and functions as a bearing. When excessive torque is applied due to contact between the rotating shaft and the ring foil (100), the ring foil (100) and the protrusions (221), (222), (223) slip and the ring foil (100) due to contact, etc. It works to minimize damage to the surface.

  4 to 6, the second embodiment shown in FIGS. 4 to 6 includes a plurality of disk-shaped cartridges (200) having protrusions (221), (222), and (223) arranged in the axial direction so that the ring foil (100) has an inner diameter. It is pressed to the side to form sinusoidal irregularities in the circumferential direction and the axial direction to function as a bearing. By arranging the protrusions of the disk-shaped cartridge (200) in different phases, various patterns of mesh-like pressure distribution that support the rotating shaft (500) are exhibited, so that the stability of the bearing can be improved. Further, the disc-shaped cartridge (200) can be manufactured by punching with a press, and thus is excellent in mass productivity.

  In Example 3 shown in FIG. 7, the cartridge (200) is formed as a protrusion by forming a hollow continuously in the axial direction with a press or the like in a thin cylindrical plate, and is excellent in productivity. Further, since the cartridge (200) is made of a thin plate, the outer diameter of the bearing can be reduced. Furthermore, since the cartridge (200) is also deformed with the deformation of the ring foil (100), a large damping capability is obtained.

  In Example 4 shown in FIG. 8 to FIG. 10, the cartridge (200) is formed into a protrusion by forming a plurality of depressions in the axial direction by pressing a thin plate cylinder into the cylinder, and the productivity is excellent. Further, since the cartridge (200) is made of a thin plate, the outer diameter of the bearing can be reduced. Furthermore, since the cartridge (200) is also deformed with the deformation of the ring foil (100), a large damping capability is obtained.

  In Example 5 shown in FIGS. 11 to 14, a circular hole (310) of a cylindrical cartridge (300) is provided, and a projection is formed by inserting a column (340). It can be manufactured by drilling and can be processed with high accuracy at low cost. By cutting out a part of the cylinder (340), the circumferential and axial deformations of the ring foil (100) can be controlled.

  The sixth embodiment shown in FIG. 15 uses a cylinder (350) instead of the column (340) of the fifth embodiment, and has the same effect as that of the fifth embodiment. Due to the deformation, it has a damping effect.

  In the seventh embodiment shown in FIG. 16, a part of the cylinder (350) of the sixth embodiment is cut out to adjust the elasticity, and the deformation, elasticity control and damping effect can be increased.

  In the eighth embodiment shown in FIG. 17, one notched portion of the seventh embodiment is extended to the outer peripheral side to increase the contact surface with the ring foil (100), and the elasticity is adjusted, the deformation and elasticity control and the damping effect are performed. Can be increased.

  The ninth embodiment shown in FIG. 18 is provided with a rotation stop (356) that prevents the ring foil (100) of the eighth embodiment from rotating, and adjusts the elasticity, increases the deformation and elasticity control, and the damping effect. be able to. The same effect can be obtained by adding the rotation stopper (356) to the column (340) and the cylinder (350) of the fifth to seventh embodiments.

  In the tenth embodiment shown in FIG. 19, the cylinder (350) used in the sixth to ninth embodiments is provided with at least one cut portion (357), and the elasticity of the cylinder (350) can be adjusted. It has become.

  In Example 11 shown in FIGS. 20 to 23, the dump foil (400) is brought into close contact with the outer periphery of the ring foil (100) and cut into a part of the dump foil (400) to form the claws (410). The claw (410) contacts the cartridge (300), and the claw (410) spring force acts to push the ring foil (100) toward the inner diameter side. By the deformation of the ring foil (100), the dump foil (400) and the claw (410), it functions to attenuate the shaft vibration of the rotating shaft.

  In Example 12, as shown in FIG. 24, another set of cylinders (361), (362), (363) is inserted between three cylinders (351), (352), (353). The amount of deformation of the ring foil (100) is controlled, and it is effective for forming a wedge shape important for a bearing. In the example of FIG. 24, the clearance is set so that the clearance is the largest near the cylinder (352) and narrows toward (351) with respect to the counterclockwise rotation axis. About 2/3 of the inner surface can share the load. Since the cylinder is made of a thin plate and has elasticity, if the load becomes too large in the supply section, the ring foil (100) escapes and the pressure receiving area increases, and contact can be avoided. In addition, when a large torque is applied upon contact, slip occurs between the cylinder and the ring foil (100), and no serious trouble occurs.

  In Example 13, as shown in FIG. 25, the ring foil (100) is held by claws (451), (452), (453),... (459) formed by cutting and pressing an appropriate thin plate. Consists of a bearing, where the ring foil (100) is pushed by the claws (451), (452), (453), ... (459) and protrudes toward the inner diameter side to form sinusoidal irregularities in the circumferential and axial directions Occurs, and a levitation force is generated between the rotary shaft and the rotating shaft. Since the bearing of this proposal is formed of a thin plate, the inner and outer diameter differences are small, and the bearing space can be reduced. Moreover, it can be manufactured with a lathe for processing a thin plate and a simple press machine, so that the capital investment is small and the manufacturing cost can be reduced.

Front view and side view of bearing of Example 1 Front view and side view of ring foil of Example 1 Front view and side view of cartridge of embodiment 1 Front view and side view of bearing of Example 2 Front view and side view of ring foil of embodiment 2 Front view and side view of cartridge of embodiment 2 Front view and side view of cartridge of embodiment 3 Front view and side view of bearing of Example 4 Front view and side view of cartridge of embodiment 4 Front view and side view of ring foil of Example 4 Front view and side view of cartridge of embodiment 5 Cross-sectional shape of a cylinder forming the protrusion of Example 5 The front view and side view of a cylinder which have a notch in the side surface of Example 5 Front view and side view of a cylinder having a notch and a protrusion on the side surface of Example 5 Front view and side view of bearing using cylindrical column of Example 6 for projection formation The front view and side view of a bearing which used the cylindrical column which has an axial direction cutting part of Example 7 for protrusion formation A front view and a side view of a bearing using a cylindrical column having an axial cut portion of Example 8 and having an end expanded to the outer peripheral side for forming a protrusion. The front view and side view of the bearing of Example 9 which provided the rotation stop in the cylindrical pillar of Example 8. Cylindrical column of Example 10 Front view and side view of bearing having ring foil on inner side of double thin plate cylinder of embodiment 11 and dump foil on outer side Partial detail of Example 11 Example 11 dump foil and ring foil Detailed view of dump foil of Example 11 Side view of cylindrical column double array bearing of Example 12 Front view and side view of cylindrical press-type cartridge bearing of Example 13 and press-type cartridge Conventional foil bearing Capstone leaf foil bearings Spring structure used for gas bearings

Explanation of symbols

(12) Cartridge (14) Rotating shaft (16) Leaf foil (18) Spring plate (28), (30) Claw (66), (68) Frame (70) Spring part (100) Ring foil (200) Cartridge ( 210) Inner surface (220), (221), (222), (223), (224), (225), (226), (227), (228), (229) Protrusion (230) Outer surface (300) Cartridge (310) Circular hole (340) Column (341), (342) Cutout (343) Protrusion (350), (351), (352), (353) Cylindrical column (354) Cutting part (355) End Part (356) rotation stop (357) excision part (400) dump foil (410) nail (450), (451), (452), (453), (454), (455), (4 6), (457), (458), (459) pawl (500) rotational axis

Claims (15)

  A thin ring-shaped foil (hereinafter referred to as a ring foil) on the inner diameter side of a compression cylinder having a circular or polygonal cross-sectional shape on the inner diameter side and provided with three or more projections continuous in the direction of the rotation axis A dynamic pressure type gas bearing characterized by being inserted.   A dynamic pressure type gas bearing characterized in that a ring foil is inserted into the inner diameter side of a plurality of discs provided with three or more circular or polygonal protrusions on the inner diameter side.   A ring foil is inserted into the inner diameter side of a thin-walled cylinder having a circular or polygonal cross-sectional shape on the inner diameter side and three or more protrusions continuous in the rotation axis direction provided in the circumferential direction. A hydrodynamic gas bearing characterized by that.   It is characterized in that a ring foil is inserted into the inner diameter side of a thin-walled cylinder in which six or more circular or polygonal protrusions are distributed in the rotation axis direction and the circumferential direction on the inner diameter side. Hydrodynamic gas bearing.   A cylinder is inserted into the circular hole of a thick cylindrical cartridge provided with a circular hole opened on the inner diameter side to form a protrusion, and a ring foil is inserted on the inner diameter side of the cartridge. A hydrodynamic gas bearing.   A cylindrical part is inserted into the circular hole of a thick cylindrical cartridge provided with a circular hole opened on the inner diameter side to form a protrusion, and a ring foil is inserted on the inner diameter side of the cartridge. A hydrodynamic gas bearing.   A cylindrical part with a notch is inserted into the circular hole of a thick-walled cylindrical cartridge provided with a circular hole opened on the inner diameter side to form a protrusion, on the inner diameter side of the cartridge. A hydrodynamic gas bearing comprising a ring foil inserted therein.   A cylindrical notch end partly cut out in the circular hole of the thick cylindrical cartridge provided with a circular hole opened on the inner diameter side is pushed open to the outer peripheral side of the cylinder and inserted. The hydrodynamic gas bearing is characterized in that a protrusion is formed and a ring foil is inserted on the inner diameter side of the cartridge.   9. The dynamic pressure type gas bearing according to claim 5, wherein a column or cylinder in which a rotation stop is provided on a part of the column or cylinder is attached to the cartridge.   A cylindrical part is inserted into the circular hole of a thick cylindrical cartridge provided with a circular hole opened on the inner diameter side to form a protrusion, and a part is cut on the inner diameter side of the cartridge. A hydrodynamic gas bearing comprising: a ring foil inserted into an inner diameter side of a thin-walled ring (hereinafter referred to as a dump foil) having at least one claw formed therein.   A cylindrical part is inserted into the circular hole of the thick cylindrical cartridge provided with a circular hole opened on the inner diameter side to form a protrusion, on the inner diameter side of the cartridge, on the inner diameter side of the dump foil A hydrodynamic gas bearing characterized in that an inserted ring foil is inserted.   A ring foil inserted into the inner diameter side of the dump foil is inserted into the inner diameter side of a thin-walled cylinder provided with six or more circular or polygonal protrusions distributed in the rotational axis direction and circumferential direction on the inner diameter side. A hydrodynamic gas bearing characterized by being constructed.   A ring foil inserted on the inner diameter side of the dump foil is inserted on the inner diameter side of a thin-walled cylinder in which three or more protrusions continuous in the direction of the circular or polygonal rotation axis are provided on the inner diameter side in the circumferential direction. A hydrodynamic gas bearing characterized by being configured.   A ring foil inserted on the inner diameter side of the dump foil is inserted into the inner diameter side of a plurality of discs having three or more circular or polygonal protrusions on the inner diameter side. Pressure type gas bearing.   A ring foil inserted on the inner diameter side of the dump foil is inserted into the inner diameter side of a thin-walled cylinder in which six or more circular or polygonal protrusions are distributed in the rotation axis direction and the circumferential direction on the inner diameter side. A hydrodynamic gas bearing characterized by being configured.

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