JP2001174369A - Centrifugal force test device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the loading capacity, to prevent the applying of the excessive load to an arm box for increasing the loading capacity, and to lower the bending moment applied to a bearing structure while preventing the local concentration of the stress to each part of arms and buckets for increasing the loading capacity. SOLUTION: Buckets 29, 31 are oscillatably supported at both ends of arm structures 15, 16 supported by a rotary shaft 7 and rotated with the rotary shaft 7. The arm structures 15, 16 are in the centrifugal force direction having no connection part in the centrifugal direction, therefor a trouble due to the welding is not generated. Small rotational displacement of the arm is allowed and a large displacement thereof is prevented. The arm structure is formed with plates 17, 18, 21, 22 extended in the centrifugal force direction CD. These plural plates are respectively extended from the center to both sides to offset the centrifugal force. The plates 17, 18, 21, 22 are desirably formed of a rolled steel plate. Since the centrifugal force applied to such arm structure is not applied to a central on-equipment structure 12, the on-equipment structure 12 can be simply formed, and a space therein can be used wide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal force experimental device, and more particularly to a centrifugal force test for performing a centrifugal force test or a centrifugal force equivalent gravity test of a test object loaded on a bucket swung up by centrifugal force. Related to experimental equipment.

[0002]

2. Description of the Related Art Events such as the behavior of the ground when huge gravity is applied to a tunnel and the behavior of a high-rise building during an earthquake,
Simulated apparent gravity is generated by using a large centrifugal shaking table, and a high-precision full-scale test can be substantially performed. Such tests can be complemented by simulating in a short period of time a small model that can perform a large number of experiments inexpensively. If the actual object of such an experiment is a very large super-heavy object such as a tunnel in a soft undersea stratum, a dam in the mountains, or a high-rise building built on a landfill, in order to pursue the accuracy of the experiment, Also, the reduced test model needs to be enlarged to some extent.

A device for such an experiment, that is, a pseudogravity generating device (hereinafter, referred to as a centrifugal force device) called a centrifugal force experimental device, a centrifugal loading device, a centrifugal loading vibration device, etc., has a larger capacity. Generally, a loading space in which a trial model can be mounted and a loading capacity in which heavier objects can be mounted are required. Buckets with such space and capacity are fraught with structural problems.

FIGS. 6 and 7 show a known general centrifugal force experiment apparatus. Rotary shaft 1 supported by bearing stand 101
02, an arm box 103 is fixed to the arm box 103, and four arms 104, 105, 106, 1
07 are fixed in mirror symmetry, and four arms 104 and 10
Two buckets 10 rotatable on 5, 106, 107
8, 109 are mirror-symmetrically coupled, and the centrifugal force generated in the buckets 108, 109 on both sides swung up acts on the arm box 103 via the arms 104, 105, 106, 107 during rotational driving.

The centrifugal force has a radial component directed radially from the axis of rotation and a circumferential component directed circumferentially on the rotation surface. The arms 104, 105, 106, 107 The outer ends receive a circumferential force that extends in a direction away from each other. Arm 10 due to such circumferential force
As shown in FIG. 7, the arms 104, 105, 1
Reinforcing ribs 110 are welded to outer ends of 06 and 107. The arm box 103 includes an outer plate 111.
And reinforcing ribs 112 and 11 extending in the vertical and horizontal directions shown in FIG.
3, 114 is a welded structure formed by welding and structured. The rotating shaft 102 is supported on the bearing base 101 in both the radial direction and the vertical direction via a thrust bearing 115 and radial bearings 116 and 117 disposed at upper and lower portions, and is rotationally driven by a motor 118 disposed at a lower position. Is done.

[0006] Such a general centrifugal force experiment apparatus includes:
The following problems are piled up. (1) Arm and arm box (1-1) Strength of arm The strength of the welded joint tends to be lower than the strength of the base material. Such a tendency is stronger as the strength of the high-strength material is higher, and particularly, the fatigue strength is significantly reduced. This tendency has basically made it difficult to use a high-strength material, such as high-strength steel, to increase the loading capacity of the arms of the welded structure. If many welds are congested, the stress will be further concentrated at the stress concentration points,
The strength is further reduced from the original base material strength.

(1-2) Strength and rigidity of the arm box Stress also flows from the arm into the arm box integrated with the arm by welding, and a high stress portion and a low stress portion are generated, and the load is uniform. It is not efficient because it does not disperse. It is difficult to manufacture a welded structure exactly and uniformly. Due to manufacturing errors and distortions, the positions of the left and right arm bucket pins 119 (pins that freely connect the arm and the bucket by drawing) are shifted vertically in the vertical plane as shown in FIG. When the centrifugal force applied to the bucket does not act in the same rotation plane, bending stress acts on the arm box and the rotation shaft. The generation of such bending stress lowers the loading capacity. Further, the bending stress changes the load applied to the bearing pedestal every rotation and acts to pry the bearing, shortening the life of the bearing portion, and greatly affecting the fatigue strength of the bearing pedestal.

(1-3) Space of arm box In order to increase the rigidity of the arm box, reinforcing ribs are provided inside the arm box.
Other various mounting devices (not shown) are restricted in terms of space. (1-4) Workability of Arm and Arm Box If the number of ribs is large, the interval between the ribs becomes narrow, and welding and inspection are difficult to perform. (1-5) Maintenance Remodeling Welding is likely to cause distortion, and it is difficult to remodel the installed device again in the future to enhance the loading capacity.

(2) Bucket (2-1) Stress at Joint Section As shown in FIG.
0 and the bucket base 121, and the joining portion A where they are joined is a portion where the cross-sectional area changes rapidly, and stress concentrates there. Such concentration,
Limit loading capacity. (2-2) Bending moment The central part of the bucket base on which a large load is applied is bent,
Since the integrated bucket support is deformed by itself and is fixed by the arm bucket pin,
A bending moment acts on the joint A, and it is difficult to avoid an increase in stress due to stress concentration. Thus, loading capacity is increasingly limited.

(2-3) Moment of Inertia As a countermeasure to avoid such a restriction due to the bending moment, the thickness of the bucket, the arm thickness near the bucket,
It is conceivable to take measures to greatly increase the dimensions.
Such measures require that the weight of the outer peripheral portion increases, the moment of inertia becomes extremely large, and the acceleration / deceleration of the rotational speed of the arm is allowed to slow down, or the driving power needs to be greatly increased. There is. An increase in drive power causes an increase in the cost of the device. (2-4) Fatigue Fracture Even if the FPC is used under a limited load, cracks may occur in the joint A and the risk of fatigue failure may remain, requiring an inspection. It is generally difficult to do. When the shaking table is mounted on the bucket, the possibility of crack propagation is high at various points of welding, and the risk of such fatigue fracture is further increased.

(3) Arrangement of bearings and drive units (3-1) Opening The weight of the rotating part directly acts on the upper part of the bearing base, and the bearing base has a centrifugal load due to the unbalance of the rotating part and the weight of the rotating part. However, in order to make the bearing stand having high rigidity, the weight becomes large, and it becomes difficult to open an opening for checking and maintenance of the bearing and the driving device. (3-2) Workability Since the drive device is located directly below the center of the bearing base, it is difficult to perform inspection and replacement work for removing the flange connection portion of the shaft. (3-3) Damage to the drive unit In order to impart bending rigidity to the rotating shaft, the shaft diameter is generally manufactured to be larger than the shaft diameter of the driving device. Equipment may be damaged. (3-4) Bearing Life There are three bearings, the centers of which need to be aligned. If the three bearings are respectively fixed to a bearing stand, it is difficult to exactly match the three centers, and twisting A load is applied to one of the bearings, shortening the bearing life.

(4) Lubrication of bearings and gears Since each bearing requires a high load and a long service life, it is preferable to forcibly supply lubricating oil. However, if excessive lubrication is performed, pressure is applied to the inside of the bearing. Oil leaks easily from the seal. Since it is difficult to secure a space for the oil tank near the bearing, a space for the lubricating oil supply device is separately required, and the surroundings need to be installed at a considerable distance because the bucket rotates. Grease lubrication has limitations on load and life.

(5) Thrust bearing lubrication It is preferable to lubricate the rolling elements of the thrust bearing from the inner diameter side to the outer circumference side, but it is necessary to lubricate from the rotating shaft side, and the structure becomes complicated. . Preferably, a slight space is provided in the radial direction so that it can be automatically adjusted on the center of rotation determined by the other two bearings.
If the weight of the rotating part is large, oil is not supplied, and it is difficult to always reduce the frictional force between the thrust bearing and the bearing base over a long period of time.

It is desired to increase the load capacity. In order to increase the loading capacity, it is necessary that an unreasonable load is not applied to the arm box, and further, it is desired that stress is not locally concentrated on each of the arm and the bucket. It is desirable to reduce the bending moment acting on the bearing structure to increase the capacity of the transmission power required for increasing the loading capacity.

[0015]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a centrifugal force experiment apparatus capable of increasing the loading capacity. Another object of the present invention is to provide a centrifugal force experiment apparatus in which an unreasonable load is not applied to the arm box to increase the loading capacity. Still another object of the present invention is to provide a centrifugal force experiment apparatus in which stress is not locally concentrated on each part of an arm and a bucket due to an increase in loading capacity, and a bending moment acting on a bearing structure is reduced. To provide.

[0016]

Means for solving the problem are described as follows. The technical items appearing in the expression are appended with numbers, symbols, and the like in parentheses (). The numbers, symbols, and the like are technical items that constitute at least one embodiment or a plurality of the embodiments of the present invention, in particular, the embodiments or the examples. Corresponds to the reference numerals, reference symbols, and the like assigned to the technical matters expressed in the drawings corresponding to the above. Such reference numbers and reference symbols clarify the correspondence and bridging between the technical matters described in the claims and the technical matters of the embodiments or examples. Such correspondence / bridge does not mean that the technical matters described in the claims are interpreted as being limited to the technical matters of the embodiments or the examples.

The centrifugal force experiment apparatus according to the present invention comprises a rotating shaft (7), arm structures (15, 16) supported by the rotating shaft (7) and rotating in the same manner as the rotating shaft (7), and an arm structure. A bucket (29) supported swingably at the end of the body (15, 16), the arm structure (15, 16) receiving centrifugal force is free to centrifuge with respect to the rotation axis (7). Can extend in the direction (CD). Arm structure (1
5, 16) can freely extend in the centrifugal direction (CD) with respect to the rotation axis (7), so that the centrifugal force does not reach the rotation axis (7) and is fixed with respect to the rotation axis and the rotation axis. Does not exert any stress on the components.

It is desirable that the arm structures (15, 16) have no connecting portion for connecting in the centrifugal direction (CD). Arm structure (15, 1) that can extend freely
6) does not hinder the flow of stress in itself because there is no connecting portion, so that the arm structure (15,
16) Excellent in strength of itself. Arm structure (15,
16) is formed of a plate extending in the centrifugal direction (CD). A continuous, seamless plate allows free flow of stress. The plate is preferably a rolled steel plate.

Further, an arm box (12) is included as a device mounting structure. With respect to the arm box (12), the forehead structures (15, 16) extend freely in the centrifugal direction (CD). The elongation (elongation) is sliding and the elongation transmits little stress to the arm box (12).

The arm structures (15, 16) are pinned in a direction perpendicular to the centrifugal centrifugal direction (CD) and the axis of rotation (L) of the axis of rotation (7) with respect to the arm box (12). It is particularly excellent that it is rotatably supported. The arm structure (15, 16) includes an arm box (12).
The rotation around the pin is restricted in a certain angle range. The rotational displacement of the arm structures (15, 16) is allowed within a certain range in the rotation direction, but the allowable range is an appropriate range as described later.

The bucket (29) is connected to the bucket base (3
2) a branch portion (33) branching from the bucket base portion (32), respectively, and a bucket base portion (34) integrally joined at an end of the branch portion (33), and one or two buckets are provided. The base (32) and the bucket base (34) have a four-node link structure. Due to the four-bar mechanism, no stress is generated in the bucket, and no unreasonable stress is generated in the arm structure. It is preferable that the four nodes of the four-node link structure are formed by spherical bearings, so that stress generation is avoided three-dimensionally.

The bearing structure (1) supporting the rotating shaft (7)
5, 16) and a lubricating oil circulating device, the lubricating oil circulating device having an oil sump (41) in its circulating oil passage, and a bearing structure having an upper side supporting a rotating shaft (7). A radial bearing (9), a lower radial bearing (11) supporting a rotating shaft (7), a thrust bearing (8) supporting a rotating shaft (7), and a bottom plate (2) supporting a thrust bearing (8); )
The space between the thrust bearing (8) and the bottom plate (2) is communicated with the oil reservoir (41), the thrust bearing (8) is floatable by the oil film, and the axial center adjustment is automatically performed.

The motor further includes a motor (3) and a gear interposed between the motor (3) and the rotating shaft (7), and the gear is disposed in the circulation oil passage. Further, the gear is a small gear (5) connected to the motor side, a large gear (7) connected to the rotating shaft side, and another small gear meshing with the large gear (7) around the large gear (7). (5), and the axis of the large gear (7) preferably coincides with the rotation axis (L). An oil groove (47) is formed in the bottom plate (2) on the side of the thrust bearing (8), and the oil groove (4) is formed in the thrust bearing (8).
A guide hole through which the lubricating oil is guided is formed in the rolling element of the thrust bearing (8) in communication with 7).

The bucket (29) has an arm structure (1).
5 and 16) are formed so as to be swingably supported at both ends.

The arm structure (15, 16) has a pin (37) in a direction perpendicular to the rotation axis (L) of the rotation axis (7) in the centrifugal direction (CD) with respect to the rotation axis (7). , 3
8), the arm structure (15,
16) is more specifically a plate structure (15, 1) on both sides.
6), the plate structure (15) on one side of the plate structure includes two plates (17, 18), and the plate structure (1) on the other side of the plate structure.
6) includes two plates (21, 22), the arm structure (15, 16) further includes a connector (25), and the connector (25) includes four plates (17, 18, 21). , 22) penetrate in the orthogonal direction, and further have an arm box (12) for mounting equipment, the arm box (12) is fixed to the rotating shaft (7), and the connecting body (25) is an arm. It penetrates the box (12). With such a structure, the above-described free displacement of the arm structure and its constraint are rationally realized.

[0026]

FIG. 1 is a perspective view of a centrifugal force test apparatus according to an embodiment of the present invention. The bearing base 1 is attached to a bottom plate 2 on the ground as shown in FIG. The electric motor 3 is supported by a support 4 inside the bearing base 1. A small gear 5 is attached to an output shaft of the electric motor 3. The small gear 5 is a large gear 6
Are engaged. The rotation shaft 7 is connected to the large gear 6. The rotation shaft 7 and the large gear 6 share a rotation axis L. The large gear 6 is vertically supported by a thrust bearing 8. The rotating shaft 7 is radially supported by an upper radial bearing 9 and a lower radial bearing 11. Large gear 6
It is preferable that a plurality of other small gears are arranged in mesh with the large gear.

An arm box 12 is fixed to the upper end of the rotating shaft 7. The arm box 12 is driven to rotate integrally with the rotation shaft 7. Arm box 12 may be a welded structure.
The arm box 12, as shown in FIG.
14. One side arm forming body 15 is joined to arm box 12 at one side surface 13. The other arm forming body 16 is joined to the arm box 12 at the other side surface 14. The one arm forming body 15 and the other arm forming body 16 extend in the centrifugal direction CD.

The one-side arm forming body 15 is formed of one-side first arm forming element 17 and one-side second arm forming element 18. The one-side first arm forming element 17 and the one-side second arm forming element 18 are separated from each other by both-side first spacers 19 interposed therebetween. One side first arm forming element 17 and one side second arm forming element 1
8 extends in the centrifugal direction CD.

The other arm forming body 16 is formed of a first arm forming element 21 on the other side and a second arm forming element 22 on the other side. The other-side first arm forming element 21 and the other-side second arm forming element 22 are separated from each other by two-sided second spacers 23 interposed therebetween. The other side first arm forming element 21 and the other side second arm forming element 2
2 extends in the centrifugal direction CD.

The one arm forming body 15 and the other arm forming body 16 are separated by an inter-arm spacer. One side first arm forming element 17 and the other side first arm forming element 21 are connected to connecting bolt 25 and tightening nut 2.
6 and 26, the one-side arm forming body 15 and the other-side arm forming body 16 are strongly joined to both side surfaces 13 and 14 by the tightening.

As described above, the arm formed by the one-side arm forming body 15 and the other-side arm forming body 16 is joined to the both side surfaces 13 and 14 by the holding structure. The connecting bolt 25 is connected to one side first arm forming element 17, one side second arm forming element 18, and the other side first arm forming element 2.
1, through the through holes (not shown) opened in the second arm forming element 22 on the other side. The diameter of the connecting bolts 25 is appropriately smaller than the diameter of those through holes. The connection bolt 25 penetrates the arm box 12 with a margin.

As shown in FIG. 1, the central portions of both ends of the arm forming elements 17, 18, 21, 22 are
A bulging portion 5 bulging in the vertical direction (the direction of the rotation axis L).
1 is formed. The connecting bolt 25 is connected to the bulging portion 25.
Penetrates with some margin. Connecting bolt 2
The reference numeral 5 also penetrates the vertical extension 52 of the arm box 12 with a margin.

The arm box 12 and the one-side arm forming body 15 are rotatably connected by a first arm pin 37 as shown in FIGS. The arm box 12 and the other-side arm forming body 16 are rotatably connected by a second arm pin 38.

One side first arm forming element 17, one side second arm forming element 18, and the other side first arm forming element 2
It is important that each of the first and second arm forming elements 22 is a single plate material. Such a sheet material is provided as a rolled steel sheet. One side arm forming body 15 and the other side arm forming body 16 are plane-symmetric with respect to a vertical plane including a first center line 27 orthogonal to the rotation axis L of the rotation shaft 7 and pointing in the centrifugal direction.

With respect to the vertical plane including the second center line 28 orthogonal to the first center line 27 orthogonal to the rotation axis L of the rotating shaft 7, the one-side arm forming body 15 and the other-side arm forming body 16 Each is plane symmetric. Therefore, the one-side arm forming body 15 and the other-side arm forming body 16 are designed in principle so as to balance themselves with respect to centrifugal force.

The buckets 29, 31 on both sides are
5 are connected to the one-side arm forming body 15 and the other-side arm forming body 16 respectively. Bucket 29 on both sides,
31 is a bucket base 32 (see FIG. 1)
And both side branch portions 3 branching from the bucket base 32 in the same body
3 and a bucket base 34 which is integrally connected to both side branch portions 33.

Each of the bucket bases 32 has an end of the first side arm forming element 17 and a second side of the second arm forming element 17, respectively.
Between the end of the arm forming element 18 and between the end of the other side first arm forming element 21 and the other side second arm forming element 2
2 between the two ends. Hanging pins 35 are passed through the ends and the respective bucket bases 32. The pin axis of the suspension pin 35 is parallel to the second center line 28.

A spherical bearing or a self-aligning roller bearing (not shown) is interposed between the suspension pin 35 and the bucket base 32, and is provided between the one arm forming body 15 and the other arm forming body 16. For the arm to be formed, both buckets 2
9, 31 allow their rotation in three-dimensional directions. The side branch portions 33 are connected to a bucket base 34 via bucket pins 36, and a rotational movement between the bucket base 34 and the bucket pins 36 is allowed to some extent.

Therefore, the two-side branch portion 33 and the bucket base 34 form a parallelogram parallel link mechanism. A spherical bearing or a self-aligning roller bearing (not shown) is also provided between the bucket pin 36 and the bucket base 34. A spherical bearing or a self-aligning roller bearing (not shown) is provided between the rotating shaft 7 and the upper radial bearing 9 and between the rotating shaft 7 and the lower radial bearing 11.

An oil reservoir 41 is provided at the bottom of the bearing base 1. The oil reservoir 41 forms a part of a closed space forming an oil passage through which lubricating oil circulates. The lubricating oil in the oil sump 41 is sucked by the oil pump 42, passes through the first nozzle pipe 43, and jets out toward the upper radial bearing 9. From upper radial bearing 9 to lower radial bearing 1
The oil passage toward 1 is covered with a rubber bellows 44. The lubricating oil that has lubricated the upper radial bearing 9 falls gravitationally and lubricates the lower radial bearing 11. Lower radial bearing 11
Is lubricated by the rotating large gear 6 below the lower radial bearing 11 and is splashed off by the lubricating oil, and returns to the oil sump 41 in the closed space and stays there. Second nozzle pipe 4 branched at the outlet side of oil pump 42
It is preferable to inject the lubricating oil directly from 5 to the large gear 6. A filter, a check valve, a pressure gauge, a thermometer and the like are attached before and after the oil pump 42.

FIG. 4 shows the lubrication of the thrust bearing 8. The lubricating oil is splashed in the centrifugal direction together with the air by the rolling elements 46 forming the thrust bearing 8, and a negative pressure is generated at the center portion. An oil film is effectively formed on the surface.
An oil passage hole 48 is formed at the center of the lower part of the main body of the thrust bearing 8, and the lubricating oil passes through the oil passage hole 48 and is sucked into the rotation region of the rolling element.

As shown in FIG. 5, a plurality of radially extending oil grooves 47 are formed on the upper surface of the bottom plate 2 disposed below the bearing surface of the thrust bearing 8. The lubricating oil in the lubricating oil reservoir 41 penetrates between the lower surface of the lower portion of the main body of the thrust bearing 8 and the upper surface of the bottom plate 2, is further guided by the oil groove 47, passes through the oil passage hole 48, and rotates as described above. Sucked into the area. An oil film is formed between the bearing surface of the thrust bearing 8 and the bottom plate 2, and the thrust bearing 8 is automatically adjusted so as to share the rotation axis L defined by the upper and lower two radial bearings 9 and 11 as a center line. Be hearted.

As shown in FIG. 1, the first arm pin 3
The axis of the 7 and the second arm pin 38 is on a plane including the pin axis of the suspension pins 35 on both sides. Connection bolt 25
Are four one-side first arm forming elements 17 and one-side second arm forming elements 17.
Arm forming element 18, other side first arm forming element 21,
The second arm forming elements 22 on the other side are bundled together. The arm formed by being bundled in this manner is the second center line 2
The bending (displacement) in the direction 8 is effectively prevented.

The arm formed of the one arm forming body 15 and the other arm forming body 16 is allowed to rotate around the first arm pin 37 and the second arm pin 38 with respect to the arm box 12, Is connected so as to be capable of relative rotational displacement, but the connecting bolt 25 penetrates through the vertical vertical end of the centrifugal extension 52 of the arm box 12 with a margin, and the arm forming body 15 , 16 whose relative rotational displacement with respect to the arm box 12 is only allowed in a certain small rotational angle range. In this manner, the arm is restricted from a large displacement with respect to the arm box 12, but a small displacement is allowed.

FIGS. 1 and 2 show a state where both buckets 29 and 31 driven to rotate by the electric motor 3 are rotated at a high speed and rise in a substantially horizontal direction from the vertical direction.
The centrifugal force generated in the two buckets 29 and 31 is transmitted to the arms, but is only held between the one arm forming body 15 and the other arm forming body 16 forming a single arm. The centrifugal force is not transmitted to the arm box 12.

As shown in FIG. 3, the centrifugal force acting on the one-side arm forming body 15 and the centrifugal force acting on the other-side arm forming body 16 are opposite to each other on a straight line, and as a whole, It has been canceled. Such a centrifugal force is not transmitted to the arm box 12, and further, no bending moment acts on the arm itself or the rotating shaft 7.

As described above, in the arm structure, the extension in the centrifugal direction is free with respect to the arm box, and the displacement in the rotation direction is allowed with respect to the arm box. Such an arm structure itself forms a connectionless structure capable of smoothly flowing a flow of stress based on centrifugal force. The connectionless structure does not have a seam that blocks the flow of stress like welding. Arm forming elements 17, 18, 21, 22
The through-hole through which the connecting bolt 25 for bundling the arm and the arm pins 37 and 38 for supporting the arm structure rotatably with respect to the arm box does not block such a flow of stress. As a result, the arm box is released from the centrifugal force, and does not exert an excessive force on the rotating shaft supporting structure that supports the arm box.

The arm forming member is a single-piece rolled steel plate, having no welded portion, and utilizing the material strength as it is.
Stress concentration is kept small. An arm box that is not subjected to centrifugal force may have a low rigidity, resulting in a large space inside the box. Two-sided branch portion 33 and bucket base 34 forming a three-dimensional quadrilateral parallel link mechanism
The three-dimensional structure prevents stress concentration three-dimensionally, and does not transmit excessive bending stress to the arm structure.

The bending moment does not act on the rotating shaft connected to the arm that does not receive the bending moment. As a result, the rigidity of the bearing stand is increased, and a gear with a small rated torque can be used. All members such as a gear box for accommodating gears and an electric motor mount can be simply integrated with the bearing stand to make the whole compact.

The rotating shaft is stably supported in the radial direction by the upper radial bearing 9 and the lower radial bearing 11.
The position of the rotation axis L is determined. The rotating shaft in which the position of the rotating axis L is stable is supported by the thrust bearing 8 sharing the rotating axis L, and the arm box, the arm, and the bucket are kept while the rotating axis is stabilized. Can be supported.

A plurality of small gears 5 and large gears 6 are accommodated in one shaft box, and the inside of the shaft box is formed as an oil reservoir.
Under such lubrication conditions, the large gear 6 that is supported by meshing with the plurality of small gears 5 does not receive a large bending moment. The motor is mounted directly on the gearbox, the configuration of the rotary drive mechanism is simple as a whole, and maintenance and inspection are easy. In the case of a plurality of small gears, the transmission force between the gears is smaller than that of a single small gear, and both the large and small gears can be reduced. Furthermore, the bending moment of the shaft transmitted to the large gear is canceled, the bending rigidity of the bearing stand and the rotating shaft may be small, and the rigidity is substantially increased with the same size of the bearing stand and the rotating shaft. Power transmission is possible.

An oil film is formed on the lower surface of the thrust bearing 8. The thrust bearing is automatically aligned with respect to the two radial bearings due to the play operation of the oil film, and the work of centering adjustment is unnecessary. The large gravity of the rotating body acts on the bottom plate 2 on the ground via the thrust bearing, and the mass of the rotating body does not deform the bearing base, thereby suppressing the generation of high stress.

The lubricating oil for lubricating the upper radial bearing 9 is as follows:
After flowing down to the lower radial bearing 11 and lubricating it, it is centrifugally bounced by the fan effect of the large gear to generate a negative pressure near the center thereof. Wet the tooth surface. The oil in the oil pool is
Due to the centrifugal force of the thrust bearing 8, the gas flows from the center to the periphery, a negative pressure is generated at the center, the suction is performed at the center of the thrust bearing, and the centrifugal exhaust is performed along the oil groove.

The flexible pipe that covers the oil passage from the upper radial bearing to the lower radial bearing does not have a high pressure therein, so that it is easy to manufacture and easy to prevent oil leakage. The flexible tube is easy to remove and the internal shaft is easy to inspect.

[0055]

According to the centrifugal force test apparatus of the present invention, distortion and stress concentration do not occur in a joint such as a weld due to centrifugal force applied to the arm structure. The centrifugal force acting on the arm structure does not act on the central device mounting structure associated with the arm structure. The centrifugal force acting on the arm structure is not transmitted to the rotating shaft, and the rotation mechanism is further smoothed by hydraulic lubrication.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing an embodiment of a centrifugal force experimental device according to the present invention.

FIG. 2 is a plan sectional view of FIG. 1;

FIG. 3 is an analysis diagram showing a centrifugal force action.

FIG. 4 is a sectional view showing a thrust bearing.

FIG. 5 is a sectional plan view of an end face of FIG. 1;

FIG. 6 is a plan view showing a known centrifugal device.

FIG. 7 is a front sectional view of FIG. 6;

FIG. 8 is an analysis diagram showing a centrifugal force action of a known device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 2 ... Bottom plate 3 ... Motor 6 ... Gear 7 ... Rotating shaft 8 ... Thrust bearing 9 ... Upper radial bearing 11 ... Lower radial bearing 12 ... Equipment mounting structure 15,16 ... Arm structure 15 ... One side arm forming body Reference Signs List 16: Other arm forming body 17, 18, 21, 22: Plate extending in the centrifugal direction 17: One side first arm forming element 18: One side second arm forming element 19: First spacer 21: Other side first arm Forming element 22 ... other side second arm forming element 23 ... second spacer 29, 31 ... bucket 32 ... bucket base 33 ... branching part 34 ... bucket base 37, 38 ... swing shaft 41 ... oil sump 47 ... oil groove 46 ... rolling element 48 ... oil through hole L ... rotation axis center line CD ... centrifugal direction

Claims (15)

[Claims] A rotating shaft, an arm structure supported by the rotating shaft and rotating in the same manner as the rotating shaft, and a bucket swingably supported by an end of the arm structure. A centrifugal force experiment device in which the arm structure receiving the force freely extends in a centrifugal direction with respect to the rotation axis. 2. The centrifugal force experiment apparatus according to claim 1, wherein the arm structure has no connection portion that connects in a centrifugal direction. 3. The centrifugal force experiment apparatus according to claim 1, wherein the arm structure is formed of a plate extending in the centrifugal direction. 4. The centrifugal force test apparatus according to claim 3, wherein the plate is a rolled steel plate. 5. The centrifugal force experiment apparatus according to claim 1, further comprising an arm box as a device mounting structure, wherein the arm structure freely extends in a centrifugal direction with respect to the arm box. 6. The arm structure according to claim 5, wherein the arm structure is rotatably supported by a pin in a direction perpendicular to the centrifugal centrifugal direction and a rotation axis of the rotation shaft with respect to the arm box. Centrifugal force experimental device. 7. The centrifugal force experiment apparatus according to claim 6, wherein the arm structure is restrained in a certain angle range around the pin with respect to the arm box. 8. The bucket according to claim 1, wherein the bucket comprises: a bucket base; a branch part branching from the bucket base; and a bucket base part united at an end of the branch part. A centrifugal force experimental device, wherein a base and the bucket base have a four-node link structure. 9. The centrifugal force experiment apparatus according to claim 8, wherein the four nodes of the four-node link structure are formed by spherical bearings. 10. The lubricating oil circulation device according to claim 1, further comprising: a bearing structure that supports the rotating shaft; and a lubrication oil circulation device, wherein the lubrication oil circulation device includes an oil reservoir in a circulation oil passage thereof. The bearing structure includes: an upper radial bearing that supports the rotating shaft; a lower radial bearing that supports the rotating shaft; a thrust bearing that supports the rotating shaft; and a bottom plate that supports the thrust bearing, A centrifugal force test apparatus in which the space between the thrust bearing and the bottom plate communicates with the oil reservoir, and the thrust bearing is floatable by an oil film. 11. The centrifugal force test according to claim 10, further comprising: a prime mover; and a gear interposed between the prime mover and the rotating shaft, wherein the gear is disposed in the circulating oil passage. apparatus. 12. The gear according to claim 11, further comprising: a small gear connected to the motor side; a large gear connected to the rotary shaft side; and another gear meshing with the large gear around the large gear. A centrifugal force experiment device comprising: a small gear; and an axis of the large gear coincides with the axis of rotation. 13. An oil groove according to claim 11, wherein an oil groove is formed in said bottom plate on a side of said thrust bearing.
A centrifugal force experimental device, wherein the thrust bearing is provided with a guide hole communicating with the oil groove to guide lubricating oil to a rolling element of the thrust bearing. 14. The centrifugal force experiment device according to claim 1, wherein the bucket is formed of two buckets that are swingably supported at both ends of the arm structure. 15. The arm structure according to claim 1, wherein the arm structure is rotatably supported by pins in the centrifugal direction with respect to the rotation axis and in a direction orthogonal to a rotation axis of the rotation axis. The structure includes a plate structure on both sides, a plate structure on one side of the plate structure includes two plates, a plate structure on the other side of the plate structure includes two plates, and the arm structure includes: Further comprising a connecting body, wherein the connecting body penetrates the four plates in the orthogonal direction, and further includes an arm box on which a device is mounted, wherein the arm box is fixed to the rotating shaft, A centrifugal force experiment device in which the coupling body penetrates the arm box.