JP2021080984A - Non-contact slide fluid bearing and its forming method - Google Patents

Abstract

To provide a non-contact slide fluid bearing which allows opposing faces to slide in a non-contact manner by making a slide body float up from a support body by forming a large pressure space for transmitting uniform pressure between the support body and the slide body, and holding a clearance in which the support body and the slide body do not mechanically contact with each other, and a forming method of the non-contact slide fluid bearing.SOLUTION: A non-contact slide fluid bearing comprises a support body 1, and a slide body 2 which slides with respect to the support body 1, and also has a structure in which a dimension error with respect to target shapes of slide faces of the support body 1 and the slide body 2 is 1 μm or smaller, micro temples are formed at the slide faces of the support body 1 and the slide body 2, a clearance between the slide face of the support body 1 and the slide face of the slide body 2 is 1 μm to 5 μm, a pressure space 5 to which a pressurized viscous fluid is supplied is formed between the support body 1 and the slide body 2, being a position adjoining the slide faces of the support body 1 and the slide body 2, and the viscous fluid is held between the slide face of the support body 1 and the slide face of the slide body 2.SELECTED DRAWING: Figure 1

Description

The present invention relates to a non-contact sliding fluid bearing and a method for forming the same. More specifically, a large pressure space for propagating a uniform pressure is provided between the support and the sliding body, and the sliding body is subjected to fluid pressure from the support. The present invention relates to a non-contact sliding fluid bearing and a method for forming the same, which enables the facing sliding surfaces to slide in a non-contact manner by holding a gap in which the support and the sliding body do not mechanically contact each other.

As a non-contact sliding structure, a hydrostatic bearing using air pressure has been proposed (see, for example, Patent Document 1). In such a static pressure bearing, the dynamic pressure of air is converted into static pressure by using a self-control drawing or porous drawing sintered body in the bearing portion that opposes the load, and the sliding body is floated to cause friction on the sliding surface. Can be reduced. However, when high-pressure air is supplied to the bearing portion, deformation or the like occurs, so that the action is limited, and there is a problem that a large load cannot be withstood due to dimensional reasons. In addition, the fluid that can be used is limited to air, and the amount of air consumed at that time is large, so exhaust measures are also required. Further, since the bearing structure becomes complicated, there is a problem that the manufacturing cost becomes high.

Japanese Unexamined Patent Publication No. 2004-60833

An object of the present invention is to provide a large pressure space between the support and the sliding body to propagate a uniform pressure so that the sliding body is floated by fluid pressure from the support, and the support and the sliding body do not come into mechanical contact with each other. It is an object of the present invention to provide a non-contact sliding fluid bearing in which opposing sliding surfaces can slide in a non-contact manner by holding a gap, and a method for forming the non-contact sliding fluid bearing.

The non-contact sliding fluid bearing of the present invention for achieving the above object includes a support and a sliding body that slides with respect to the support, and has a target shape of the support and the sliding surface of the sliding body. The dimensional error with respect to the above is 1 μm or less, microdimples are formed on the sliding surfaces of the support and the sliding body, respectively, and the gap between the sliding surface of the support and the sliding surface of the sliding body is 1 μm to 5 μm. A pressure space for supplying the pressurized viscous fluid is formed between the support and the sliding body at a position adjacent to the supporting body and the sliding surface of the sliding body. It is characterized by having a structure in which the viscous fluid is held between the sliding surface of the support and the sliding surface of the sliding body.

Further, the method for forming the non-contact sliding fluid bearing of the present invention is the above-mentioned method for forming the non-contact sliding fluid bearing, and the micro dimples are formed by subjecting the FSPP (Fine Particle Shot Peening) treatment. It is characterized by.

As a new non-contact sliding structure, the inventor of the present invention provides a pressure space between the support and the sliding body to which a pressurized viscous fluid is supplied, and the sliding body is provided with the fluid pressure of the viscous fluid. The present invention has been made by discovering a structure (fluid bearing) in which the pressure space functions as a bearing portion that opposes a load by holding a gap in which the support and the sliding body do not mechanically contact each other. It came.

In the present invention, a support and a sliding body that slides with respect to the support are provided, and the dimensional error of the support and the sliding surface of the sliding body with respect to the target shape is 1 μm or less, and the sliding of the support and the sliding body. Micro dimples are formed on each of the moving surfaces, and the gap between the sliding surface of the support and the sliding surface of the sliding body is 1 μm to 5 μm. A pressure space for supplying a pressurized viscous fluid is formed at a position adjacent to the sliding surface, and a structure in which the viscous fluid is held between the sliding surface of the support and the sliding surface of the sliding body is formed. Since it has, the pressure space functions as a bearing portion that opposes the load, and is automatically centered in the gap between the sliding surfaces of the support and the sliding body, so that the support and the sliding body are completely in non-contact state. The non-contact state can be maintained at all times. In particular, since the rigidity against a load can be increased, vibration can be reduced, and since the sliding surfaces of the support and the sliding body are non-contact, friction and heat generation do not occur, and the rotation speed and reciprocating motion are not generated. Exercise speed is also difficult to limit. Further, microdimples are formed on the sliding surfaces of the support and the sliding body, respectively, which contributes to the surface protection of the sliding surfaces. Further, since the non-contact sliding fluid bearing of the present invention can be configured with a small number of parts, manufacturing cost and maintenance cost can be suppressed.

In the non-contact sliding fluid bearing of the present invention, the viscous fluid is preferably air. Further, the support and the sliding body are preferably made of non-metal.

Further, in the method for forming a non-contact sliding fluid bearing of the present invention, FPSP treatment is performed to form micro dimples. As this FPSP treatment, fine particles of ceramic or metal having a particle size in the range of 30 μm to 80 μm are sprayed onto the sliding surfaces of the support and the sliding body at a spraying speed of 50 m / sec to 200 m / sec, respectively, and the support and the sliding body are slid. It is preferable to form micro dimples on the sliding surfaces of the moving body. As a result, it is possible to form a sliding surface having an appropriate surface roughness with respect to the support and the sliding body.

In the present invention, the "target shape" is the shape of the sliding surface set so that the gap between the sliding surface of the support and the sliding surface of the sliding body is 1 μm to 5 μm. "The dimensional error with respect to the target shape is 1 μm or less" means, for example, that when the target shape is a flat surface, the flatness is 1 μm or less, and when the target shape is a circumferential surface, the cylindricity is It means that it is 1 μm or less, and when the target shape is drawn by a geometric curve, it means that the error with respect to the geometric curve is 1 μm or less.

It is a side view which shows an example of the air slider which applied the non-contact sliding fluid bearing which concerns on embodiment of this invention. It is sectional drawing which shows the air slider of FIG. It is sectional drawing which shows the part A of FIG. It is a side view which shows the modification of the air slider which applied the non-contact sliding fluid bearing which concerns on embodiment of this invention. It is sectional drawing which shows the air slider of FIG. It is sectional drawing which shows the main part of the air slider of FIG. It is a side view which shows the other modification of the air slider which applied the non-contact sliding fluid bearing which concerns on embodiment of this invention. It is sectional drawing which shows the air slider of FIG. It is sectional drawing which shows the main part of the air slider of FIG. It is sectional drawing which shows the air cylinder to which the non-contact sliding fluid bearing which concerns on embodiment of this invention is applied. (A) and (b) are cross-sectional views showing a main part of the air cylinder of FIG. It is sectional drawing which shows the inside of the gear turbine to which the non-contact sliding fluid bearing which concerns on embodiment of this invention is applied. It is sectional drawing which shows the gear turbine of FIG. (A) and (b) are cross-sectional views showing a main part of the gear turbine of FIG.

Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings. 1 and 2 show an air slider to which a non-contact sliding fluid bearing according to an embodiment of the present invention is applied.

As shown in FIGS. 1 and 2, the air slider 10 of the present embodiment includes a guide rail 11 as a support 1 and a slider 12 as a sliding body 2 slidably configured with respect to the guide rail 11. have.

The guide rail 11 is composed of a flat plate-shaped base portion 13 and a pair of rail portions 14 fixed to both ends of the base portion 13. The guide rail 11 has an accommodating hole 15 for accommodating the slider 12. A slider 12 is arranged in the accommodating hole 15.

The slider 12 is formed as a recess on the outer surface and has a pressure space 5 to which a pressurized viscous fluid is supplied. The pressure space 5 is arranged between the guide rail 11 and the slider 12 so as to be adjacent to the sliding surfaces of the guide rail 11 and the slider 12. Further, the slider 12 is formed with an air supply hole 6 for supplying the pressurized viscous fluid to the pressure space 5. The air supply hole 6 is connected to an air compressor 4 as an external pressurizing means via a directional control valve 3. The pressure space 5 is connected to the air supply hole 6 via the connecting portion 7. The pressure of the viscous fluid supplied to the pressure space 5 is appropriately determined according to the load applied to the slider 12 (sliding body 2) and the area of the pressure space 5.

In the air slider 10, the sliding surfaces of the guide rail 11 and the slider 12 are the inner surface of the guide rail 11 and the outer surface of the slider 12. Specifically, the bottom surface 12a of the slider 12 and the top surface 13a of the base portion 13 are sliding surfaces facing each other. Further, the side surface 12b of the slider 12 and the side surface 14a of the rail portion 14 are sliding surfaces facing each other. These sliding surfaces are slidable in a non-contact state. Through these sliding surfaces, the slider 12 is slidable with respect to the extending direction of the guide rail 11. A relatively large distance is provided between the side surface 12c of the slider 12 and the inner surface 14c of the rail portion 14 facing the side surface 12c so as not to affect the sliding of the guide rail 11 and the slider 12.

As shown in FIG. 3, there is a minute gap Mg whose dimension t is set according to the type of viscous fluid between the sliding surfaces facing each other. The dimension t of the gap Mg is set in the range of, for example, 1 μm to 5 μm. In FIG. 3, the gap Mg exists between the bottom surface 12a of the slider 12 forming the opposing sliding surfaces and the upper surface 13a of the base portion 13, and between the side surface 12b of the slider 12 and the side surface 14a of the rail portion 14. To do. As described above, the air slider 10 has a gap Mg of 1 μm to 5 μm on each sliding surface of the guide rail 11 and the slider 12. The dimension t of the gap Mg is determined in the above range according to the dimensional difference between the guide rail 11 and the slider 12. For example, when the horizontal dimensional difference between the inner dimension of the guide rail 11 and the outer dimension of the slider 12 is 5 μm, the dimensional difference is equally divided by the number of gap Mgs (two locations on both sides of the slider 12 in the horizontal direction). The dimension t of the gap Mg is fixed to 2.5 μm, respectively.

The sliding surfaces of the guide rail 11 and the slider 12 are set so that the dimensional error with respect to the target shape (plane) is 1 μm or less. In the case of the air slider 10, the dimensional error with respect to the target shape means the flatness of the sliding surface. The flatness refers to the distance between two planes when the distance between the two parallel planes is minimized when the target plane (sliding plane) is sandwiched between two geometrically correct parallel planes. As described above, by making the dimensional error with respect to the target shape of the sliding surface extremely small, it contributes to confining the viscous fluid in the gap Mg by its viscosity. Since the viscous fluid is extremely unlikely to leak from the gap Mg, the seal packing required for conventional bearings becomes unnecessary. As a result, replacement of parts and maintenance are not required.

In the air slider 10, the pressure space 5 propagates a uniform pressure to the slider 12 (sliding body 2), floats the slider 12 from the guide rail 11 (support 1) by fluid pressure, and functions as a bearing portion that opposes the load. To do. In other words, the fluid pressure of the pressurized viscous fluid acts only on the pressure space 5, and the fluid pressure acts on the pressure space 5 enables non-contact sliding. The size of the pressure space 5 can be appropriately set according to the load, and by setting this appropriately, the rigidity and operating accuracy of the device can be improved. On the other hand, although a viscous fluid exists in the gap Mg, the pressure in the gap Mg is extremely close to zero, and it does not have a function as a bearing portion that opposes the load. Therefore, the gap Mg of the air slider 10 does not correspond to the bearing portion of the conventional bearing. As described above, the non-contact sliding fluid bearing according to the present invention has a structure different from that of the conventional bearing that enables non-contact sliding (for example, a hydrostatic bearing).

Innumerable micro dimples are formed on the sliding surface of the guide rail 11 and the sliding surface of the slider 12 by FSPP (Fine Particle Shot Peening) treatment, respectively. That is, although micro dimples are formed on the bottom surface 12a of the slider 12, the side surface 12b of the slider 12, the top surface 13a of the base portion 13 and the side surface 14a of the rail portion 14, all the inner surfaces including the inner surface 14c of the rail portion 14 and the slider 12 It may be formed on the entire outer surface including the pressure space 5 of the above. The micro dimples processed by FPSP are formed as recesses on each sliding surface, and each has a substantially hemispherical shape. Since the gap Mg is very small (1 μm to 5 μm) on the sliding surfaces facing each other in this way, the viscous fluid may adhere to the sliding surfaces. Therefore, micro dimples are formed on the sliding surfaces for the purpose of protecting the surface of the sliding surfaces. This prevents sticking due to viscous fluid.

When the air slider 10 is used, when the directional control valve 3 is operated or controlled to supply pressurized air from the air supply hole 6, the pressure space 5 is filled with air. Then, air is also filled between the sliding surface of the guide rail 11 and the sliding surface of the slider 12 (gap Mg) via the pressure space 5, and the viscous fluid (air) is held in the gap Mg by the viscosity. Ru. As a result, the slider 12 is in a floating state with respect to the guide rail 11. At that time, the gap Mg is automatically centered so as to have a predetermined dimension t by the balance of the air pressure of the air filled in the pressure space 5, and the guide rail 11 and the slider 12 are in a non-contact state. Further, even when the sliding surfaces are about to approach each other, a fluid pressure (countermeasure pressure) is generated to counteract the sliding surfaces, and automatic alignment can be performed. As a result, the slider 12 can be held in a non-contact and slidable state with respect to the guide rail 11.

4 and 5 show a modified example of the air slider to which the non-contact sliding fluid bearing according to the embodiment of the present invention is applied. The same objects as those in FIGS. 1 to 3 are designated by the same reference numerals, and detailed description of the parts thereof will be omitted. As shown in FIGS. 4 and 5, the air slider 20 of the present embodiment includes a guide rail 21 as a support 1 and a slider 22 as a sliding body 2 slidably configured with respect to the guide rail 21. have.

The guide rail 21 is composed of a columnar rail portion 23 and a pair of support portions 24 fixed to both ends of the rail portion 23. The slider 22 has a columnar accommodating hole 25. The rail portion 23 of the guide rail 21 is inserted through the accommodating hole 25.

The slider 22 is formed as a recess on the inner peripheral surface and has a pressure space 5 to which a pressurized viscous fluid is supplied. The pressure space 5 is arranged between the guide rail 21 and the slider 22 so as to be adjacent to the sliding surfaces of the guide rail 21 and the slider 22. Further, the slider 22 is formed with an air supply hole 6 for supplying a pressurized viscous fluid.

In the air slider 20, the sliding surfaces of the guide rail 21 and the slider 22 are the outer peripheral surface 23a of the rail portion 23 of the guide rail 21 and the inner peripheral surface 22a of the slider 22. These sliding surfaces are slidable in a non-contact state. Through these sliding surfaces, the slider 22 is slidable with respect to the extending direction of the guide rail 21.

As shown in FIG. 6, the air slider 20 has a minute gap Mg of 1 μm to 5 μm as a dimension t between the outer peripheral surface 23a of the rail portion 23 forming the opposite sliding surface and the inner peripheral surface 22a of the slider 22. have. The sliding surfaces of the guide rail 21 and the slider 22 are set so that the dimensional error with respect to the target shape (circumferential surface) is 1 μm or less. In the case of the air slider 20, the dimensional error with respect to the target shape means the cylindricity of the sliding surface. The cylindricity is the case where the distance between two concentric circles is the minimum when the target circumferential surface (sliding surface) is sandwiched between two concentric geometric circles (least squares average circle). The difference in radius of the circle. In addition, innumerable micro dimples are formed on the sliding surface of the guide rail 21 and the sliding surface of the slider 22 by FPSP processing, respectively.

When the air slider 20 is used, when the directional control valve 3 is operated or controlled to supply pressurized air from the air supply hole 6, the pressure space 5 is filled with air. Then, air is also filled between the sliding surface of the guide rail 21 and the sliding surface of the slider 22 (gap Mg) via the pressure space 5, and the viscous fluid (air) is held in the gap Mg by the viscosity. Ru. As a result, the slider 22 is in a floating state with respect to the guide rail 21. At that time, the gap Mg is automatically centered so as to have a predetermined dimension t by the balance of the air pressure of the air filled in the pressure space 5, and the guide rail 21 and the slider 22 are in a non-contact state. Further, even when the sliding surfaces are about to approach each other, a fluid pressure (countermeasure pressure) is generated to counteract the sliding surfaces, and automatic alignment can be performed. As a result, the slider 22 can be held in a non-contact and slidable state with respect to the guide rail 21.

7 and 8 show other modifications of the air slider to which the non-contact sliding fluid bearing according to the embodiment of the present invention is applied. The same objects as those in FIGS. 1 to 3 are designated by the same reference numerals, and detailed description of the parts thereof will be omitted. As shown in FIGS. 7 and 8, the air slider 30 of the present embodiment includes a guide rail 31 as a support 1 and a slider 32 as a sliding body 2 slidably configured with respect to the guide rail 31. have.

The guide rail 31 is composed of a square columnar rail portion 33 and a pair of support portions 34 fixed to both ends of the rail portion 33. The slider 32 has a square columnar accommodating hole 35. The rail portion 33 of the guide rail 31 is inserted through the accommodating hole 35.

The slider 32 is formed as a recess on the inner surface and has a pressure space 5 to which a pressurized viscous fluid is supplied. The pressure space 5 is arranged between the guide rail 31 and the slider 32 so as to be adjacent to the sliding surface of the guide rail 31 and the slider 32. The pressure spaces 5 arranged on all sides of the guide rail 31 have the same area. Further, the slider 32 is formed with an air supply hole 6 for supplying a pressurized viscous fluid.

In the air slider 30, the sliding surfaces of the guide rail 31 and the slider 32 are the outer surface 33a of the rail portion 33 of the guide rail 31 and the inner surface 32a of the slider 32. These sliding surfaces are slidable in a non-contact state. Through these sliding surfaces, the slider 32 is slidable with respect to the extending direction of the guide rail 31.

As shown in FIG. 9, the air slider 30 has a minute gap Mg having a dimension t of 1 μm to 5 μm between the outer surface 33a of the rail portion 33 forming the opposite sliding surface and the inner surface 32a of the slider 32. ing. The sliding surfaces of the guide rail 31 and the slider 32 are set so that the dimensional error with respect to the target shape (plane) is 1 μm or less. In the case of the air slider 30, the dimensional error with respect to the target shape means the flatness of the sliding surface. In addition, innumerable micro dimples are formed on the sliding surface of the guide rail 31 and the sliding surface of the slider 32 by FPSP processing, respectively.

When the air slider 30 is used, when the directional control valve 3 is operated or controlled to supply pressurized air from the air supply hole 6, the pressure space 5 is filled with air. Then, air is also filled between the sliding surface of the guide rail 31 and the sliding surface of the slider 32 (gap Mg) via the pressure space 5, and the viscous fluid (air) is held in the gap Mg by the viscosity. Ru. As a result, the slider 32 is in a floating state with respect to the guide rail 31. At that time, the gap Mg is automatically centered so as to have a predetermined dimension t by the balance of the air pressure of the air filled in the pressure space 5, and the guide rail 31 and the slider 32 are in a non-contact state. Further, even when the sliding surfaces are about to approach each other, a fluid pressure (countermeasure pressure) is generated to counteract the sliding surfaces, and automatic alignment can be performed. As a result, the slider 32 can be held in a non-contact and slidable state with respect to the guide rail 31.

FIG. 10 shows an air cylinder to which a non-contact sliding fluid bearing according to an embodiment of the present invention is applied. As shown in FIG. 10, the air cylinder 40 of the present embodiment has a cylinder tube 41 as a support 1 and a piston 42 as a sliding body 2 slidably configured with respect to the cylinder tube 41. ing.

The cylinder tube 41 has a cylindrical cylinder body 43, an air supply hole 6, a head cover 44 fixed to one end side (left side in the drawing) of the cylinder body 43, and an air supply hole 6. It is composed of a rod cover 45 fixed to the other end side (right side in the drawing) of the cylinder body 43. Further, the cylinder tube 41 has a columnar accommodating hole 46. A piston 42 is inserted through the accommodating hole 46.

The piston 42 is integrally formed with the piston body 47 and the piston body 47, and has a rod portion 48 having a diameter smaller than that of the piston body 47 and a rod tip fixed to the tip side (right side in the figure) of the rod portion 48. It is composed of a part 49. The air supply holes 6 formed in each of the head cover 44 and the rod cover 45 are connected to the air compressor 4 as an external pressurizing means via the directional control valve 3.

The air cylinder 40 has a pressure space 5 to which a pressurized viscous fluid is supplied. The pressure space 5 is arranged between the cylinder tube 41 and the piston 42 so as to be adjacent to the sliding surfaces of the cylinder tube 41 and the piston 42.

In the air cylinder 40, the sliding surfaces of the cylinder tube 41 and the piston 42 are the inner peripheral surface of the cylinder tube 41 and the outer peripheral surface of the piston 42. Specifically, the inner peripheral surface 43a of the cylinder body 43 and the outer peripheral surface 47a of the piston body 47 are sliding surfaces facing each other. Further, the inner peripheral surface 45a of the rod cover 45 and the outer peripheral surface 48a of the rod portion 48 are sliding surfaces facing each other. These sliding surfaces are slidable in a non-contact state. Through these sliding surfaces, the piston 42 is slidable with respect to the axial direction of the cylinder tube 41.

As shown in FIG. 11, the air cylinder 40 has a minute gap Mg having a dimension t of 1 μm to 5 μm between the cylinder tube 41 and the piston 42 forming opposite sliding surfaces. The sliding surfaces of the cylinder tube 41 and the piston 42 are set so that the dimensional error with respect to the target shape (circumferential surface) is 1 μm or less. In the case of an air cylinder 40, the dimensional error with respect to the target shape means the cylindricity of the sliding surface. In addition, innumerable micro dimples are formed on the sliding surface of the cylinder tube 41 and the sliding surface of the piston 42 by FPSP treatment, respectively.

When the air cylinder 40 is used, when the direction control valve 3 is operated or controlled to supply air from the air supply hole 6 formed in the head cover 44 and exhaust the air from the air supply hole 6 formed in the rod cover 45. , The piston body 47 is pushed by air pressure, and the rod 48 protrudes. On the contrary, when air is supplied from the air supply hole 6 formed in the rod cover 45 and exhausted from the air supply hole 6 formed in the head cover 44, the piston main body 47 is pushed by air pressure and pulled in. Further, when air is supplied from the air supply hole 6, the pressure space 5 is filled with air. Then, air is also filled between the cylinder body 43 and the piston body 47 and between the rod cover 45 and the rod 48 (gap Mg) via the pressure space 5, and the viscous fluid (air) is introduced. It is held in the gap Mg due to its viscosity. At that time, the gap Mg is automatically centered so as to have a predetermined dimension t by the balance of the air pressure of the air filled in the pressure space 5, and the cylinder tube 41 and the piston 42 are in a non-contact state. Further, even when the sliding surfaces are about to approach each other, a fluid pressure (countermeasure pressure) is generated to counteract the sliding surfaces, and automatic alignment can be performed. As a result, the piston 42 can be held in a non-contact and slidable state with respect to the cylinder tube 41.

12 and 13 show a gear turbine to which a non-contact sliding fluid bearing according to an embodiment of the present invention is applied. As shown in FIGS. 12 and 13, the gear turbine 50 of the present embodiment includes a casing 51 as a support 1 and gears 52 and 53 as a sliding body 2 slidably configured with respect to the casing 51. have.

The casing 51 has a gearbox 54 that houses the gears 52 and 53, and side covers 55 that are fixed to both ends of the gearbox 54. The air supply hole 6 formed on one side of the casing 51 (right side in FIG. 12) is connected to the air compressor 4 as an external pressurizing means via the directional control valve 3, and is connected to the other side of the casing 51 (left side in FIG. 12). ) Is connected to an air discharge pipe (not shown). The gearbox 54 has a substantially oval accommodating hole 60. Gears 52 and 53 are arranged in the accommodating holes 60.

The gears 52 and 53 have the same dimensions and the same shape. The gears 52 and 53 include a columnar central shafts 56 and 57 extending in the same direction and gear body portions 58 and 59 attached to the central shafts 56 and 57 and integrally formed with three arcuate teeth. have. In order to insert the central shafts 56 and 57 into the casing 51, the side cover 55 is provided with a hole 55x penetrating in the thickness direction thereof.

The gear turbine 50 has a pressure space 5 to which a pressurized viscous fluid is supplied. The pressure space 5 is arranged between the gearbox 54 of the casing 51 and the gears 52 and 53 so as to be adjacent to the sliding surfaces of the casing 51 and the gears 52 and 53.

In the gear turbine 50, the sliding surfaces of the casing 51 and the gears 52 and 53 are the inner surface of the casing 51 and the outer surface of the gears 52 and 53. Specifically, the inner wall 54a of the gearbox 54 and the outer walls 58a, 59a of the gear main bodies 58, 59 are sliding surfaces facing each other. Further, the side surface 55a of the side cover 55 on the gearbox 54 side and the side surfaces 58b and 59b of the gear body portions 58 and 59 are sliding surfaces facing each other. Further, the outer wall 58a of the gear body 58 of the gear 52 and the outer wall 59a of the gear body 59 of the gear 53 are sliding surfaces facing each other. The outer peripheral surfaces 56a and 57a of the central shafts 56 and 57 and the inner peripheral surface 55b of the holes 55x of the side cover 55 are sliding surfaces facing each other. These sliding surfaces are slidable in a non-contact state. Through these sliding surfaces, the gears 52 and 53 are slidable around the central shafts 56 and 57, respectively.

As shown in FIGS. 14A and 14B, the gear turbine 50 has dimensions t between the casing 51 and the gears 52 and 53 and between the gear 52 and the gear 53, which form opposite sliding surfaces. It has a minute gap Mg of 1 μm to 5 μm. Specifically, the gap Mg is provided between the inner wall 54a of the gearbox 54 and the outer walls 58a and 59a of the gear main bodies 58 and 59, and between the outer wall 58a of the gear main body 58 and the outer wall 59a of the gear main body 59 ( It exists in FIG. 14 (a)). Further, the gap Mg is provided between the side surface 55a of the side cover 55 and the side surfaces 58b and 59b of the gear main bodies 58 and 59, and inside the outer peripheral surfaces 56a and 57a of the central shafts 56 and 57 and the holes 55x of the side cover 55. It exists between the peripheral surface 55b (see FIG. 14B).

The sliding surfaces of the casing 51 and the gears 52 and 53 are set so that the dimensional error with respect to the target shape (plane or circumferential surface) is 1 μm or less. In the case of the gear turbine 50, the dimensional error with respect to the target shape means the flatness or cylindricity of the sliding surface. Specifically, the sliding surfaces on which the flatness is set are the side surfaces 55a of the side cover 55 and the side surfaces 58b and 59b of the gear main bodies 58 and 59, and the sliding surfaces on which the cylindricity is set are gears. The inner wall 54a of the box 54, the outer walls 58a and 59a of the gear main bodies 58 and 59, the outer peripheral surfaces 56a and 57a of the central shafts 56 and 57, and the inner peripheral surface 55b of the hole 55x of the side cover 55. In addition, innumerable micro dimples are formed on the sliding surface of the casing 51 and the sliding surfaces of the gears 52 and 53, respectively, by the FPSP treatment.

When the gear turbine 50 is used, when the directional control valve 3 is operated or controlled to supply air from the air supply hole 6 formed on one side of the casing 51 (right side in FIG. 12), the gear 52 rotates counterclockwise. In addition, the gears 53 rotate clockwise, respectively. At that time, the position of the pressure space 5 is displaced around the central axes 56 and 57 according to the rotation of the gears 52 and 53, and when the pressure space 5 reaches the air discharge hole 8, the air in the pressure space 5 is discharged. It is exhausted from the hole 8. Further, when air is supplied from the air supply hole 6, air is also filled between the sliding surface of the casing 51 and the sliding surface of the gears 52 and 53 (gap Mg), and the viscous fluid (air) becomes viscous. Is held in the gap Mg by. As a result, the gap Mg is automatically centered so as to have a predetermined dimension t by the balance of the air pressure of the air filled in the pressure space 5, and the gearbox 54 and the gears 52 and 53 and the gear 52 and the gear 53 are not. It will be in contact. Further, even when the sliding surfaces are about to approach each other, a fluid pressure (countermeasure pressure) is generated to counteract the sliding surfaces, and automatic alignment can be performed. As a result, the gears 52 and 53 can be kept in a non-contact and slidable state with respect to the casing 51.

In the embodiments of FIGS. 12 to 14, an example in which the non-contact sliding fluid bearing of the present invention is applied to a gear turbine is shown, but the present invention is not limited to this, and for other devices such as a gear pump, for example. Can also be applied.

The non-contact sliding fluid bearing described above includes a support 1 and a sliding body 2 that slides with respect to the support 1, and the dimensional error with respect to the target shape of the sliding surface of the support 1 and the sliding body 2 is 1 μm or less. Micro dimples are formed on the sliding surfaces of the support 1 and the sliding body 2, respectively, and the gap Mg between the sliding surface of the support 1 and the sliding surface of the sliding body 2 is 1 μm to 5 μm. A pressure space 5 to which a pressurized viscous fluid is supplied is formed between 1 and the sliding body 2 at a position adjacent to the sliding surface of the support 1 and the sliding body 2, and the sliding surface of the support 1 is slid. Since the viscous fluid is held between the moving surface and the sliding surface of the sliding body 2, the pressure space 5 functions as a bearing portion that opposes the load, and each sliding of the support 1 and the sliding body 2 The centering is automatically adjusted in the gap Mg of the moving surface, and the support 1 and the sliding body 2 are in a completely non-contact state, and the non-contact state can always be maintained. In particular, since the rigidity against a load can be increased, vibration can be reduced, and since the sliding surfaces of the support 1 and the sliding body 2 are not in contact with each other, friction and heat generation are not generated, and the number of rotations is increased. And the reciprocating speed is also difficult to limit. Further, microdimples are formed on the sliding surfaces of the support 1 and the sliding body 2, respectively, which contributes to the surface protection of the sliding surfaces. Further, since the non-contact sliding fluid bearing of the present invention can be configured with a small number of parts, manufacturing cost and maintenance cost can be suppressed.

In the non-contact sliding fluid bearing, the viscous fluid is preferably air. It is preferable because continuous maintenance is relatively simpler than when oil or water is used as the viscous fluid, and the maintenance cost can be reduced thereby.

Further, the support 1 and the sliding body 2 are preferably made of a non-metal. As the non-metal, for example, it is preferable to use a resin. Metal can be used as the material constituting the support 1 and the sliding body 2, but when both the support 1 and the sliding body 2 are made of resin, self-lubricating property, wear resistance and quietness are obtained. It is excellent, and is suitable because it can be made lighter and more accurate.

Next, a method for forming the non-contact sliding fluid bearing of the present invention will be described. In forming the non-contact sliding fluid bearing described above, the sliding surfaces of the support 1 and the sliding body 2 are processed so as to be smooth. That is, each sliding surface is subjected to ultra-precision machining so that the dimensional error with respect to the target shape is 1 μm or less. By making the dimensional error with respect to the target shape of the sliding surface extremely small in this way, it contributes to confining the viscous fluid in the gap Mg by its viscosity.

For example, in the air slider 10 shown in FIGS. 1 to 3, the bottom surface 12a of the slider 12, the top surface 13a of the base portion 13, the side surface 12b of the slider 12, and the side surface 14a of the rail portion 14 are each processed to have a predetermined flatness. Then, in the air slider 30 shown in FIGS. 7 to 9, the outer surface 33a of the rail portion 33 and the inner surface 32a of the slider 32 are processed so as to have a predetermined flatness. Further, in the air slider 20 shown in FIGS. 4 to 6, the outer peripheral surface 23a of the rail portion 23 and the inner peripheral surface 22a of the slider 22 are processed so as to have a predetermined cylindricity, and in the air cylinder 40 shown in FIGS. , The inner peripheral surface 43a of the cylinder body 43, the outer peripheral surface 47a of the piston body 47, the inner peripheral surface 45a of the rod cover 45, and the outer peripheral surface 48a of the rod 48 are each processed to have a predetermined cylindricity. Further, in the gear turbine 50 shown in FIGS. 12 to 14 (a) and 14 (b), the side surfaces 55a of the side cover 55 and the side surfaces 58b and 59b of the gear main bodies 58 and 59 are set to have predetermined flatness, respectively. Along with processing, the inner wall 54a of the gearbox 54, the outer walls 58a, 59a of the gear bodies 58, 59, the outer peripheral surfaces 56a, 57a of the central shafts 56, 57, and the inner peripheral surface 55b of the hole 55x of the side cover 55 are predetermined. Process to the cylindricity of.

After the above-mentioned ultra-precision machining, FPSP treatment is performed to form micro dimples on each sliding surface of the support 1 and the sliding body 2. As this FPSP treatment, ceramic or metal fine particles having a particle size in the range of 30 μm to 80 μm are sprayed onto the sliding surfaces of the support 1 and the sliding body 2 at a spraying speed of 50 m / sec to 200 m / sec to support the support. Micro dimples are formed on each sliding surface of the body 1 and the sliding body 2. By forming the micro dimples in this way, the sliding surfaces of the support 1 and the sliding body 2 are repeatedly rapidly heated or rapidly cooled, the crystal grain boundaries disappear, and the surface is modified.

In the method for forming a non-contact sliding fluid bearing described above, FPSP treatment is performed to form micro dimples on each sliding surface of the support 1 and the sliding body 2. As this FPSP treatment, ceramic or metal fine particles having a particle size in the range of 30 μm to 80 μm are sprayed onto the sliding surfaces of the support 1 and the sliding body 2 at a spraying speed of 50 m / sec to 200 m / sec, respectively, to support the support. Since microdimples are formed on the sliding surfaces of 1 and the sliding body 2, respectively, it is possible to form a sliding surface having an appropriate surface roughness with respect to the support 1 and the sliding body 2.

A prototype of a metal air cylinder (structure shown in FIG. 10) to which the present invention was applied was manufactured. Using this air cylinder, the rod portion protrudes slightly in each of the cases where the pressure space is not supplied with pressurized air and the pressure space is supplied with 2 kPa of pressurized air. (For example, in the state of FIG. 10), the piston was rotated in the circumferential direction, and the number of rotations until the rotation stopped was measured. As a result, in the former case, the load was biased due to the presence of a slight gap, metal contact occurred on the sliding surface, and although it rotated slightly, it stopped immediately without reaching the measurable rotation speed. .. On the other hand, in the latter case, it continued to rotate for several minutes without rubbing noise. That is, it was confirmed that by supplying pressurized air to the pressure space, self-alignment is performed and a non-contact slidable state can be realized.

In addition, a prototype of a metal gear turbine to which the present invention was applied was manufactured. A demonstration test was conducted in which a small air compressor that supplies air to the gear turbine was connected, a small generator was connected to the gear turbine, and an LED light bulb powered by the small generator was turned on. The air compressor has a rotation speed of 1000 rpm. As a result, three 4W LED bulbs could be turned on. The electric power that the small generator can generate under the conditions such as the number of revolutions was 12 W. The measured value of the rotation speed of the gear turbine was 910 rpm, which was a rotation ratio of 91% with respect to the predicted rotation speed (1000 rpm) obtained from the air compressor, and the electric power measured at that time was 11.7 W. Considering that pulsation was observed in the rotation speed of the gear turbine and that there was a loss in the piping, it is estimated that the actual rotation ratio of the gear turbine was close to 100%. That is, it was confirmed that the gear turbine to which the present invention is applied has a small gap between the support and the sliding body, has a small pressure loss, and has high energy efficiency.

In the above description, an example in which air is used as the viscous fluid has been shown, but in the non-contact sliding fluid bearing of the present invention, not only air but also oil or water can be used.

1 Support 2 Sliding body 5 Pressure space 10, 20, 30 Air slider 11,21,31 Guide rail 12,22,32 Slider 40 Air cylinder 41 Cylinder tube 42 Piston 50 Gear turbine 51 Casing 52, 53 Gear

Claims (5)

A support and a sliding body that slides on the support are provided.
The dimensional error with respect to the target shape of the sliding surface of the support and the sliding body is 1 μm or less.
Micro dimples are formed on the sliding surfaces of the support and the sliding body, respectively.
The gap between the sliding surface of the support and the sliding surface of the sliding body is 1 μm to 5 μm.
A pressure space to which the pressurized viscous fluid is supplied is formed between the support and the sliding body at a position adjacent to the supporting body and the sliding surface of the sliding body.
A non-contact sliding fluid bearing having a structure in which the viscous fluid is held between the sliding surface of the support and the sliding surface of the sliding body. The non-contact sliding fluid bearing according to claim 1, wherein the viscous fluid is air. The non-contact sliding fluid bearing according to claim 1 or 2, wherein the support and the sliding body are made of a non-metal. The method for forming a non-contact sliding fluid bearing according to any one of claims 1 to 3, wherein the micro dimples are formed by subjecting an FSP SP treatment. .. As the FPSP treatment, ceramic or metal fine particles having a particle size in the range of 30 μm to 80 μm are sprayed onto the support and the sliding surface of the sliding body at a spraying speed of 50 m / sec to 200 m / sec, respectively, to support the support. The method for forming a non-contact sliding fluid bearing according to claim 4, wherein the micro dimples are formed on the body and the sliding surface of the sliding body, respectively.

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