Positioning swivel table device

Abstract

To provide a rotary positioning turn table device which can constantly maintain a state where no gap exists when a rotary table is stopped and has a simple structure.SOLUTION: A positioning turn table device includes: a rotary table having a slide surface; a device body having a holding surface which faces the slide surface of the rotary table and is perpendicular to a center axis in a vertical direction and configured to hold the slide surface of the rotary table with the holding surface; an oil groove which is formed on at least one of the holding surface and the slide surface so as to extend on a circumference around the center axis; a hydraulic mechanism which supplies an oil to the oil groove and applies a predetermined oil pressure; and a drive mechanism which is disposed at the device body and applies drive force to the rotary table. The above problem is solved by the positioning turn table device.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a positioning and rotating table device. [Background technology]

[0002] Patent Document 1 (JP 2020-60248 A) and Patent Document 2 (JP 5128314 A) disclose circular table devices that can ensure the rotation angle of a rotating disk-shaped rotary table with high precision when the table rotates. The circular table devices disclosed in these patent documents are devices that rotate a rotary table around a vertical axis using a drive mechanism such as a servo motor that rotates around an axis perpendicular to the vertical direction.

[0003] Patent Document 1 discloses a so-called barrel cam type circular table device. In a barrel cam type circular table device, cam followers are arranged intermittently around the circumference of a rotating rotary table, and a cam shaft is arranged which is connected to a motor and has a spiral cam groove that fits with the cam followers. The cam shaft rotates, causing the cam followers to move in the cam groove, thereby rotating the rotary table.

[0004] Patent Document 2 also discloses a circular table device in which bearings are arranged on the circumference inside a rotating rotary table, and the rotary table is rotated by a ball reducer, which is a drive mechanism that rotates around a worm gear that extends along an axis perpendicular to the vertical direction. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2020-60248 [Patent Document 2] Patent No. 5128314 specification Summary of the Invention [Problem to be solved by the invention]

[0006] For example, in conventional rotary table devices as exemplified by Patent Documents 1 and 2, a thrust bearing is placed below the rotary table to reduce frictional forces caused by vertical loads. In particular, thrust bearings for the rotary table of rotary table devices naturally have large sizes because they must support large loads, which increases the cost of the bearing parts.

[0007] Furthermore, if the thrust bearing is pressed by the clamping mechanism when the rotary table is stopped, deformation due to the pressing force is unavoidable. If the thrust bearing is deformed, it will lead to deformation of the upper surface of the table, making it impossible to achieve high-precision positioning.

[0008] In conventional circular table mechanisms such as those described in Patent Documents 1 and 2, the cam grooves and cam followers are fitted together so that there is no gap between them. If a gap were to form, it would lead to a decrease in positioning accuracy.

[0009] In general, it is not easy to always maintain a state in which there is no gap between the cam groove and the cam follower, both when the cam is turning and when the cam is stopped.

[0010] On the other hand, the overwhelming majority of rotary table operations require precision angle when stopped, and fabricating the cam groove and cam follower so that there is no gap when the table is stopped is easier than maintaining a constant gap when the table is rotating or stopped.

[0011] That is, to ensure high rotation angle accuracy and high positional accuracy both when the rotary table is rotating and when it is stopped, high accuracy is required in all processes, including design, parts processing, and assembly, which results in the problem of high costs.For example, if an index table device is realized using the rotation mechanism of a conventional circular table device as in Patent Documents 1 and 2, achieving high accuracy in all processes, including design, parts processing, and assembly, requires a lot of effort, resulting in high costs.

[0012] Therefore, there is a demand for a rotary positioning table device with a simple structure that can always maintain a state where there is no gap when stopped. [Means for solving the problem]

[0013] The problems are solved by a positioning swivel table device comprising: a rotary table having a sliding surface; a device body having a holding surface that faces the sliding surface of the rotary table and is perpendicular to a vertical central axis and holds the sliding surface of the rotary table with the holding surface; an oil groove formed in at least one of the holding surface or the sliding surface so as to extend circumferentially around the central axis; a hydraulic mechanism that can supply oil to the oil groove to apply a predetermined oil pressure; and a drive mechanism that is disposed in the device body and applies a driving force to the rotary table. [Effects of the Invention]

[0014] According to the present invention, a rotary positioning and turning table device with a simple structure can be realized that can always maintain a state where there is no gap when the rotary table is stopped. [Brief explanation of the drawings]

[0015] [Figure 1] 1 shows a positioning and rotating table device 1 according to an embodiment of the present invention. [Figure 2A] 2 is a cross-sectional view of the positioning swivel table device 1 according to the embodiment of the present invention, showing the cross section AA in FIG. [Figure 2B]1 is a cross-sectional view of a positioning swivel table apparatus 1 according to an embodiment of the present invention, showing cross section BB in FIG. [Figure 3A] 3 is a diagram showing an oil groove 33 of the positioning swivel table device 1 according to the embodiment of the present invention. FIG. [Figure 3B] 10 is a diagram showing an example in which an oil reservoir 33a is arranged in an oil groove 33 of a positioning swivel table apparatus 1 according to an embodiment of the present invention. FIG. [Figure 3C] 10 is a diagram showing an example in which an oil reservoir 33b is arranged in an oil groove 33 of a positioning swivel table apparatus 1 according to an embodiment of the present invention. FIG. [Figure 4A] 2B is an enlarged view of the hydraulic mechanism 6 in the cross-sectional view of the positioning swivel table device 1 shown in FIG. 2A, showing a state in which the piston cylinder 62 is retracted from the oil chamber 61. FIG. [Figure 4B] 2B is an enlarged view of the hydraulic mechanism 6 in the cross-sectional view of the positioning swivel table device 1 shown in FIG. 2A, showing a state in which the piston cylinder 62 has entered the oil chamber 61. FIG. [Figure 5] 2 is an enlarged cross-sectional view of a cam groove 51 and a cam follower 52 as an example of a drive mechanism 5 of the positioning and turning table apparatus 1 according to the embodiment of the present invention. FIG. [Figure 6] 1 is an enlarged cross-sectional view of a cam groove 51 and a spherical cam follower 53 as an example of a drive mechanism 5 of a positioning and turning table apparatus 1 according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] [Embodiment Mode] (Positioning swivel table device 1) A positioning and swivel table apparatus 1 according to an embodiment of the present invention will be described with reference to Figures 1 to 4. Figure 1 shows the positioning and swivel table apparatus 1 according to an embodiment of the present invention. Figure 2A is a cross-sectional view of the positioning and swivel table apparatus 1 according to an embodiment of the present invention, showing the cross section AA in Figure 1, and Figure 2B is a cross-sectional view of the positioning and swivel table apparatus 1 according to an embodiment of the present invention, showing the cross section BB in Figure 1.

[0017] The positioning swivel table device 1 comprises a rotary table 2, a device main body 3, a drive mechanism 5, and a hydraulic mechanism 6. The positioning swivel table device 1 has a positioning state and a non-positioning state. In the positioning state, the rotary table 2 is stopped and positioned at a predetermined position with high precision, and is held and fixed. The rotary table 2 is a positioning table with a disk-shaped surface that is set horizontally. It is arranged to be rotatable around the center of the disk shape.

[0018] The predetermined position is a position rotated a predetermined angle from a predetermined reference axis around the axis of the rotation center on the surface of the turntable 2. The non-positioning state is a state other than the positioning state, and includes a state (operating state) in which the turntable 2 is actually rotating to position it at the predetermined position, a state in which the turntable 2 is not actually rotating but is preparing to start rotation, and a state in which the turntable 2 has stopped rotating and is preparing to enter the positioning state (preparation state).

[0019] (Rotary table 2) The rotary table 2 can rotate continuously, but when in the positioning operation state, it rotates through a maximum range of 180 degrees as shown by the arrow in Figure 1. The center of the disk-shaped surface is defined as the vertical central axis and the rotation center of the rotary table. The disk-shaped surface is the uppermost surface in the vertical direction, and a workpiece can be clamped on the disk-shaped surface.

[0020] The turntable 2 has a sliding surface 2a. The sliding surface 2a is typically a surface formed on the opposite side of the disk-shaped surface, and is a surface that is parallel to the disk-shaped surface and extends in the horizontal direction.

[0021] (Device body 3) The device body 3 has a holding surface 3a, which is a surface that faces the sliding surface 2a of the turntable 2 and is set horizontally perpendicular to the vertical central axis. The holding surface 3a is, for example, a doughnut-shaped surface, and a rotation axis mechanism that defines the rotation axis of the turntable 2 is inserted into a hole in the center of the doughnut, and is held by, for example, a bearing, thereby ensuring the rotation of the turntable 2.

[0022] The sliding surface 2a of the turntable 2 is supported and held by the holding surface 3a of the device body 3. As a result, the turntable 2 is rotatably held by the device body 3 so that the sliding surface 2a of the turntable 2 slides on the holding surface 3a of the device body 3.

[0023] Next, oil groove 33 will be described with reference to Figures 3A to 3C. Figure 3A is a diagram showing oil groove 33 of positioning swivel table apparatus 1 according to an embodiment of the present invention. Figure 3B is a diagram showing an example in which oil reservoir 33a is arranged in oil groove 33 of positioning swivel table apparatus 1 according to an embodiment of the present invention. Figure 3C is a diagram showing an example in which oil reservoir 33b is arranged in oil groove 33 of positioning swivel table apparatus 1 according to an embodiment of the present invention.

[0024] As shown in Fig. 4A, the holding surface 3a has an oil groove 33 formed circumferentially around the central axis, extending circumferentially over the entire circumference. The oil groove 33 is drilled on the holding surface 3a as a groove with a uniform depth. The oil groove 33 is arranged on the holding surface 3a over the entire circumference of the turntable 2. As will be described later, oil (lubricating oil) is supplied to the oil groove 33, and the oil (lubricating oil) is supplied to the entire sliding surface 2a of the turntable 2 and the holding surface 3a of the device body 3 through the oil groove 33.

[0025] As shown in FIG. 4, the oil groove 33 typically has a uniform width, but does not necessarily have to have a uniform width across the entire area as long as oil (lubricant) can be supplied to the entire area between the sliding surface 2a of the turntable 2 and the holding surface 3a of the device body 3. The oil groove 33 may have a wide oil reservoir 33a in a portion thereof. An example of a wide oil reservoir 33a is the circular oil reservoir 33a shown in FIG. 4B, which may be disposed in various locations along the oil groove 33. The oil reservoir 33a is typically circular, but the shape is not limited as long as the volume of the oil reservoir 33a is defined as a large portion. For example, the oil reservoir 33b may have a long, narrow shape as shown in FIG. 4C.

[0026] Typically, oil grooves 33 are disposed only on the holding surface 3a. However, as long as they are disposed circumferentially around the central axis, they may be partially disposed on the sliding surface 2a. That is, oil grooves 33 can be disposed alternately on the sliding surface 2a and the holding surface 3a, thereby disposing oil grooves 33 circumferentially around the central axis along the entire circumference.

[0027] The oil groove 33 has an opening over the entire circumference, and the opening is always located between the sliding surface 2a of the turntable 2 and the holding surface 3a of the device body 3. If the oil groove 33 is located on the holding surface 3a, the sliding surface 2a of the turntable 2 will be in contact with the opening of the oil groove 33, and if the oil groove 33 is located on the sliding surface 2a, the holding surface 3a will also be in contact with the opening of the oil groove 33.

[0028] (Hydraulic mechanism 6) Next, hydraulic mechanism 6 will be described with reference to Figures 2A, 4A, and 4B. Figure 4A is an enlarged view of the hydraulic mechanism 6 in the cross-sectional view of positioning swivel table apparatus 1 shown in Figure 2A, showing a state in which piston cylinder 62 has retracted from oil chamber 61. Figure 4B is an enlarged view of the hydraulic mechanism 6 in the cross-sectional view of positioning swivel table apparatus 1 shown in Figure 2A, showing a state in which piston cylinder 62 has advanced into oil chamber 61.

[0029] The device main body 3 is equipped with a hydraulic mechanism 6 that supplies oil (lubricating oil) to the oil groove 33. The hydraulic mechanism 6 is equipped with an oil chamber 61, a piston cylinder 62, and an oil conduit 63. The oil chamber 61 and the oil groove 33 are fluidly connected by the oil conduit 63. The oil conduit 63 supplies oil to the oil groove 33, while also being equipped with a check valve 63a that prevents the oil supplied to the oil groove 33 from flowing back.

[0030] The oil chamber 61 is disposed at the tip of the piston cylinder 62 so that the piston cylinder 62 is inserted into the oil chamber 61. The oil supply source and the oil chamber 61 are fluidly connected by an oil conduit 64. The oil chamber 61 is filled with oil. The oil conduit 64 supplies oil from the oil supply source to the oil chamber 61, and is equipped with a check valve 64a that prevents the oil supplied to the oil chamber 61 from flowing back into the oil supply source.

[0031] The piston cylinder 62 of the hydraulic mechanism 6 operates to repeatedly move forward and backward within the oil chamber 61. As shown in Fig. 4A, as the piston cylinder 62 retracts from the oil chamber 61, the volume of the oil chamber 61 expands and the oil pressure in the oil chamber 61 drops. To compensate for this, oil is introduced into the oil chamber 61 from the oil supply source.

[0032] 4B, when the piston cylinder 62 is pushed into the oil chamber 61 and advances, the volume of the oil chamber 61 is compressed and the oil pressure in the oil chamber 61 increases. Here, the check valve 64a prevents the oil supplied to the oil chamber 61 from flowing back to the oil supply source.

[0033] Next, the piston cylinder 62 retracts from the oil chamber 61, and more oil is introduced into the oil chamber 61 from the oil supply source. However, here, the check valve 63a prevents the oil supplied to the oil groove 33 from flowing back into the oil chamber 61.

[0034] When rotating the turntable 2, the hydraulic mechanism 6 increases the hydraulic pressure in the oil chamber 61 by the back-and-forth movement of the piston cylinder 62 at the start of the rotation, and supplies oil to the oil groove 33 at a predetermined hydraulic pressure. That is, by pushing the tip of the piston cylinder 62 into the oil chamber 61, the oil in the oil chamber 61 is introduced into the oil groove 33 through the oil conduit 63. At this time, the pressure of the oil pushing into the oil groove 33 pushes the sliding surface 2a of the turntable 2 up against the holding surface 3a of the device body 3, and the sliding surface 2a of the turntable 2 is separated from the holding surface 3a of the device body 3. That is, when the hydraulic mechanism 6 is operated, an oil film is formed between the sliding surface 2a and the holding surface 3a by the oil supplied to the oil groove 33. As oil is supplied to the oil groove 33, the turntable 2 rises slightly by the amount of the oil film. Oil is supplied to the oil groove 33, forming an oil film between the sliding surface 2a and the holding surface 3a, so that the sliding surface 2a and the holding surface 3a are in a non-contact state when viewed microscopically. When the turntable 2 rotates in this state, strictly speaking, the sliding surface 2a and the holding surface 3a move relative to each other without contacting each other, but in this specification, even in this state, the sliding surface 2a and the holding surface 3a are held in contact with each other via the oil film that has formed between them, and it is expressed that the sliding surface 2a slides against the holding surface 3a when the turntable 2 rotates.

[0035] (Drive mechanism 5) Next, the drive mechanism 5 will be described with reference to Figures 2B, 5, and 6. Figure 5 is an enlarged cross-sectional view of cam groove 51 and cam follower 52 as an example of drive mechanism 5 of positioning and swivel table apparatus 1 according to an embodiment of the present invention. Figure 6 is an enlarged cross-sectional view of cam groove 51 and spherical cam follower 53 as an example of drive mechanism 5 of positioning and swivel table apparatus 1 according to an embodiment of the present invention.

[0036] The device main body 3 includes a motor 4 and a drive mechanism 5. The motor 4 provides a drive force to the drive mechanism 5, and the drive mechanism 5 applies the drive force received from the motor 4 to the turntable 2. This drive force causes the turntable 2 to rotate around its central axis.

[0037] The drive mechanism 5 is connected to the motor 4 and includes a drive shaft 50 that extends rotatably around a central axis of rotation perpendicular to the vertical direction. The drive shaft 50 has a cam groove 51 on its periphery. The cam groove 51 is typically a spiral cam groove having a predetermined width defined between threads.

[0038] The rotary table 2 is equipped with cam followers 52 that fit into the cam grooves 51. A plurality of cam followers 52 are arranged circumferentially around the center of rotation of the rotary table 2. The number of cam followers can be determined based on the ratio of the rotary table rotation angle to the drive shaft rotation angle and the reduction ratio.

[0039] Cam follower 52 has a tapered shape that is thickest at its base and tapers toward the center of rotation of drive shaft 50. That is, for example, cam follower 52 is typically shaped like a truncated cone, as shown in Figure 5, and its cross section is tapered.

[0040] In this case, the taper angle of cam groove 51 can be set to match the shape of cam follower 52. The angle of the upper entrance of cam groove 51 can be set to be gentle, and the angle can be set to be steeper depending on the depth direction of cam groove 51, so that the inclination angle of the tapered shape can have multiple inclination angles toward the rotation center of drive shaft 50.

[0041] For example, typically in a non-positioning state, when oil is supplied to oil groove 33, an oil film formed between sliding surface 2a and holding surface 3a causes turntable 2 to rise, and cam follower 52 moves away from cam groove 51 by a gap corresponding to the oil film. On the other hand, in a positioning state, oil is stopped from being supplied to oil groove 33, the oil film formed between sliding surface 2a and holding surface 3a disappears, sliding surface 2a and holding surface 3a come into contact, and cam follower 52, which had risen by the amount of the oil film, approaches cam groove 51.

[0042] The width of the base of cam follower 52 (diameter in the case of a typical truncated cone shape) is set so that it forms a tight fit with the width of cam groove 51 when the supply of oil to oil groove 33 is stopped, the oil film formed between sliding surface 2a and holding surface 3a disappears, and sliding surface 2a and holding surface 3a are in contact. In the positioned state, cam groove 51 should be in contact with cam follower 52 without any gap when turntable 2 is fixed.

[0043] The clamping mechanism 31 includes a clamping head 31a. The clamping head 31a has, for example, a hollow doughnut shape. The turntable 2 includes a flange 2b that protrudes in the radial direction at least partially, preferably over the entire circumference. The turntable 2 is inserted into the hollow portion of the clamping head 31a, vertically above the flange 2b.

[0044] In a positioning state where oil is stopped from flowing to the oil groove 33, the sliding surface 2a and the holding surface 3a are in contact with each other. In this state, the clamp mechanism 31 moves the clamp head 31a toward the sliding surface 2a, and the clamp head 31a applies a pressing force to the sliding surface 2a. The pressing force applied by the clamp head 31a presses the sliding surface 2a against the holding surface 3a, bringing the turntable 2 into a state (clamped state) in which the turntable 2 cannot rotate.

[0045] Contrary to the clamped state, in the non-positioned state, the clamp mechanism 31 moves the clamp head 31a away from the sliding surface 2a and releases the pressing force of the clamp head 31a on the sliding surface 2a in preparation for rotation of the turntable 2. By releasing the pressing force from the clamp head 31a, the sliding surface 2a is no longer restricted in movement relative to the holding surface 3a, and the turntable 2 is placed in a rotatable state (unclamped state).

[0046] When the clamp mechanism 31 is in the unclamped state, the clamp head 31a releases the pressing force on the sliding surface 2a, and therefore oil is supplied to the oil groove 33 at a predetermined oil pressure by the hydraulic mechanism 6, forming an oil film between the sliding surface 2a and the holding surface 3a, creating a gap between the cam groove 51 and the cam follower 52, eliminating resistance to rotational motion and enabling smooth rotation.

[0047] That is, in the present invention, when the hydraulic mechanism 6 stops supplying oil to the oil groove 33, the oil film between the sliding surface 2a and the holding surface 3a disappears, the width of the cam groove 51 matches the width of the cam follower 52, the so-called backlash gap disappears, and highly accurate positioning becomes possible. In this state where the hydraulic mechanism 6 stops supplying oil to the oil groove 33 and the oil film between the sliding surface 2a and the holding surface 3a disappears, the clamp mechanism 31 presses the sliding surface 2a of the turntable 2 against the holding surface 3a and fixes it.

[0048] When oil is supplied to the oil groove by the hydraulic mechanism 6, an oil film is formed between the sliding surface 2a and the holding surface 3a, the sliding surface 2a rises from the holding surface 3a by the thickness of the oil film, a gap is formed between the width of the cam groove 51 and the width of the cam follower 52, this gap acts as backlash, the cam groove 51 and the cam follower 52 mesh smoothly, there is no resistance to the rotational motion and smooth rotation is possible. In other words, the relationship between the tapered shape of the cam follower 52 and the cam groove 51 is determined so as to correspond to the presence or absence of a gap between the width of the cam groove 51 and the width of the cam follower 52 in accordance with the thickness of the oil film between the sliding surface 2a and the holding surface 3a depending on whether or not oil is supplied to the oil groove 33 by the hydraulic mechanism 6.

[0049] The present invention makes it possible to reduce costs, greatly reduce the amount of deformation of the rotary table, and also reduce deformation of the upper surface of the rotary table.

[0050] The tapered shape of the cam follower 52 may be a shape that linearly narrows toward the center of the drive shaft 50, such as the truncated cone shape as described above, that is, a shape that does not have a tapered cross section. For example, the tapered shape may be a curved shape that narrows toward the center of the drive shaft 50. Furthermore, in this case, the curved surface may particularly be a spherical surface.

[0051] When the tapered shape is spherical, as shown in Figure 6, a spherical hole may be drilled in the turntable 2 and a spherical cam follower 53 such as a steel ball may be attached to the turntable. In this case, the diameter of the spherical cam follower such as a steel ball may be read as the width of the base of the truncated cone shaped cam follower 52. The spherical cam follower 53 also has a spherical curved surface, and therefore has the same effect as a curved surface that is thickest at the base and tapers towards the center of rotation of the drive shaft 50.

[0052] Even in this case, the supply of oil to the oil groove 33 is stopped, the oil film formed between the sliding surface 2a and the holding surface 3a disappears, and the sliding surface 2a and the holding surface 3a are in contact with each other, and the width of the cam groove 51 is set to be in a state of tight fit. [Explanation of symbols]

[0053] 1 Positioning swivel table 2 Rotating Tables 2a Sliding surface 3. Device body 3a Holding surface 31 Clamping mechanism 31a Clamp head 32 bearings 33 Oil groove 4 motors 5 Drive mechanism 50 drive shaft 51 Cam groove 52 Cam Followers 6 Hydraulic mechanism 61 Hydraulic chamber 62 Piston cylinder 63 Oil conduit

Claims

1. a rotary table having a sliding surface; an apparatus main body having a holding surface that faces the sliding surface of the rotary table and is perpendicular to a central axis in a vertical direction, and that holds the sliding surface of the rotary table with the holding surface; an oil groove formed on at least one of the retaining surface and the sliding surface so as to extend circumferentially around the central axis; a hydraulic mechanism capable of supplying oil to the oil groove to apply a predetermined hydraulic pressure; a driving mechanism that is disposed in the device body and applies a driving force to the rotary table, the drive mechanism includes a drive shaft connected to a motor and having a cam groove on its periphery, and a cam follower disposed on the rotary table and fitted into the cam groove; When oil is supplied to the oil groove by the hydraulic mechanism, the sliding surface rises from the holding surface by the amount of the oil film thickness between the sliding surface and the holding surface, creating a gap between the width of the cam groove and the width of the cam follower.

2. 2. The positioning and rotating table device according to claim 1, The hydraulic mechanism supplies oil to the oil groove, and in a state in which an oil film is formed between the sliding surface and the holding surface by the oil, the sliding surface of the rotary table is held by the holding surface, and the rotary table is rotated around the central axis by the driving force.

3. 3. The positioning and rotating table device according to claim 1, The cam follower has a tapered shape toward the center of rotation of the drive shaft.

4. 4. The positioning and rotating table device according to claim 1, When the hydraulic mechanism stops supplying oil to the oil groove, the oil film between the sliding surface and the holding surface disappears, and the gap between the width of the cam groove and the width of the cam follower disappears.

5. 5. The positioning and rotating table device according to claim 1, a clamping mechanism that fixes the rotary table to the device body when the hydraulic mechanism stops supplying oil to the oil groove and there is no oil film between the sliding surface and the holding surface;

6. 6. The positioning and rotating table device according to claim 1, the hydraulic mechanism includes a piston cylinder, an oil chamber disposed at a tip of the piston cylinder and filled with the oil, and an oil conduit fluidly connecting the oil groove and the oil chamber, A positioning swivel table device in which the oil in the oil chamber is introduced into the oil groove through the oil conduit by pushing the tip of the piston cylinder into the oil chamber.

7. 4. The positioning and turning table device according to claim 3, wherein the tapered shape is a curved surface.

Images