JP2006153162A - Device with oil seal, and oil seal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a device with an oil seal, sufficiently sealing between a rotary shaft and a housing. <P>SOLUTION: The housing 14 with oil 7 poured, the rotary shaft 44 passing through the inside and outside of the housing 14, and the annular oil seal 50 intervened between the housing 14 and the rotary shaft 44, have a first groove part 50b recessed along the peripheral direction in a peripheral surface brought into contact with the housing 14, a second groove part 50d recessed along a circumferential direction in an inner peripheral surface brought into contact with the rotary shaft 44, and a communicating hole 50e connecting the first groove part 50b and the second groove part 50d. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a device with an oil seal having a rotating shaft that passes through a housing filled with oil.

As an apparatus with an oil seal, an apparatus in which an annular oil seal is interposed between a rotating shaft and, for example, a housing that houses the rotating shaft is known. In addition, there is also a type of sealing between two mechanical members that are arranged concentrically and move relatively by using a tough and elastic synthetic resin seal ring and a strain ring made of an elastic rubber material (for example, , See Patent Document 1). In a seal structure using two oil seals of a seal ring and a strain ring, an annular groove is formed on the inner peripheral surface of the seal ring, and the outer peripheral surface becomes lower toward the center in the width direction of the ring. A recess having such an inclination along the circumferential direction is formed. Furthermore, the groove | channel of an internal peripheral surface and the recessed part of an outer peripheral surface are connected by the radiation hole formed radially. For example, when the two mechanical members are a shaft and a housing, the shaft is inserted into the seal ring so that the inner peripheral surface of the seal ring is in contact with the outer peripheral surface of the shaft, and the outer periphery of the seal ring inserted into the shaft A strain ring is fitted into a recess provided on the surface, and the strain ring presses the housing. In the seal structure of the seal ring and the strain ring, when a pressurized fluid exists on one side across the seal ring, the strain ring is inclined on the other side of the recess by the pressurized fluid located on one side of the seal ring. Pressed against the surface. For this reason, between the strain ring and the two inclined surfaces of the recess, the contact pressure between the inclined surface on one side where the pressurized fluid exists and the strain ring is different from that on the other inclined surface where the pressurized fluid does not exist. Less than the contact pressure with the ring. For this reason, the pressurized fluid that has entered the groove provided on the inner peripheral surface of the seal ring flows through the radiation hole in the outer peripheral direction of the seal ring. At this time, the pressurized fluid that has reached the strain ring enters along the inclined surface on one side where the pressurized fluid exists and has a small contact pressure. For this reason, the pressurized fluid does not enter the other side where the pressurized fluid does not exist, and the sealed state is maintained.
Japanese Patent No. 2523006

  However, when sealing between two mechanical members with two oil seals, the number of members constituting the oil seal is increased and the number of assembly steps is increased as compared with the case of sealing with one oil seal. Parts management and management associated with assembly work are also required, resulting in high costs. Moreover, since both oil seals are fine members, the work of attaching two oil seals to a mechanical member in combination is complicated. Furthermore, since it is used for sealing a pressurized fluid, it is difficult to assemble due to friction between the strain ring and the machine member when assembled to other machine members in a state where two oil seals are combined. It is not possible to confirm whether it is assembled in a proper state. For this reason, when the strain ring is strongly pressed to either side of the two inclined surfaces when the two oil seals are combined and assembled to another mechanical member, a good sealing state can be maintained. There was a problem that there was no drowning.

  The present invention has been made in view of the above problems, and an object thereof is to propose a device with an oil seal and an oil seal capable of better sealing between a rotating shaft and a housing. It is.

  The main invention is an apparatus with an oil seal, comprising: a housing into which oil has been injected; a rotating shaft penetrating into and out of the housing; and an annular oil seal interposed between the housing and the rotating shaft. The oil seal includes a first groove portion that is recessed along the circumferential direction on the outer peripheral surface that contacts the housing, and a second groove portion that is recessed along the circumferential direction on the inner peripheral surface that contacts the rotating shaft, An apparatus with an oil seal having a communication hole for communicating the first groove portion and the second groove portion.

  Other features of the present invention will be clarified by the description of the present specification and the accompanying drawings.

  According to the present invention, it is possible to better seal between the rotating shaft and the housing.

  At least the following will be made clear by the description of the present specification and the accompanying drawings.

  In a device with an oil seal, comprising: a housing into which oil has been injected; a rotating shaft that penetrates into and out of the housing; and an annular oil seal interposed between the housing and the rotating shaft. A first groove that is recessed along the circumferential direction on an outer peripheral surface that contacts the housing; a second groove that is recessed along the circumferential direction on an inner peripheral surface that contacts the rotating shaft; and the first groove A device with an oil seal having a communication hole that communicates with the second groove portion.

  According to such an apparatus with an oil seal, the first groove portion is provided on the outer peripheral surface of the oil seal that contacts the housing, and the second groove portion is provided on the inner peripheral surface of the oil seal that contacts the rotating shaft. Therefore, when the oil seal is pressed by the oil injected into the inside of the housing, the oil enters the first groove portion and the second groove portion. For this reason, since the frictional heat generated by the rotation of the rotating shaft is suppressed by the oil that has entered the first groove portion and the second groove portion, it is possible to suppress damage to the oil seal due to the frictional heat. Further, since the first groove portion and the second groove portion are communicated with each other through the communication hole, the oil that has entered the first groove portion and the second groove portion passes through the communication hole, and the oil is filled in the first groove portion and the second groove portion. And the force which presses a 1st groove part to the 2nd groove part side and a 2nd groove part to the 1st groove part side generate | occur | produces with the filled oil. And since the pressing force by the oil that has entered the first groove portion and the second groove portion acts in opposite directions to cancel each other, the pressing force that presses the oil seal against the housing and the rotating shaft is suppressed. For this reason, since the frictional force between the oil seal and the rotating shaft is reduced, it is possible to prevent seizure of the oil seal due to frictional heat and damage to the oil seal due to excessive load. Therefore, it is possible to rotate the rotating shaft well for a long period of time, and it is possible to improve the rotational performance and reliability of the device with an oil seal. In addition, since the oil seal is composed of one member, it has a simple structure and can easily interpose the oil seal of one member between the housing and the rotating shaft, thereby reducing the work man-hours. Thus, the cost can be reduced.

In such an apparatus with an oil seal, it is desirable that the oil flows into the first groove portion before the second groove portion when the rotating shaft rotates.
According to such an apparatus with an oil seal, since the oil is guided to the outer peripheral side by the rotation of the rotating shaft, it is possible to first enter from the first groove portion on the housing side. For this reason, since the pressing force by the oil hardly occurs until the second groove portion is filled with the oil, the rotating shaft can be smoothly rotated.

In such an apparatus with an oil seal, it is preferable that the width of the oil seal in the outer peripheral surface in contact with the housing in the rotation axis direction is narrower than the width in the rotation shaft direction in the inner peripheral surface in contact with the rotation shaft.
According to such an apparatus with an oil seal, the width in the rotation axis direction on the outer peripheral surface of the oil seal is narrower than the width in the rotation axis direction on the inner peripheral surface, so that the outer peripheral surface side, that is, the first groove portion is provided. On the side, the oil flows more easily than the inner peripheral surface side, that is, the side on which the second groove portion is provided. For this reason, it is possible to allow oil to flow into the first groove portion before the second groove portion.

In such an apparatus with an oil seal, the oil seal is composed of two types of elastic members having different rigidity, and the elastic member having low rigidity is used on the outer peripheral surface side in contact with the housing, and is in contact with the rotating shaft. It is desirable that the elastic member having high rigidity is used on the inner peripheral surface side.
According to such an apparatus with an oil seal, since the outer peripheral surface side of the oil seal has low rigidity and the inner peripheral surface side has high rigidity, the outer peripheral surface side, i.e., the first groove portion side, is closer to the inner peripheral surface side, i.e., the first. Oil tends to flow in from the side where the two grooves are provided. For this reason, it is possible to allow oil to flow into the first groove portion before the second groove portion.

In such an apparatus with an oil seal, the communication hole is preferably provided along the radial direction of the oil seal.
According to such an apparatus with an oil seal, the communication hole of the oil seal is provided in the radial direction of the rotating shaft. For this reason, even in the communication hole, the pressing force by the oil that has entered the first groove portion and the second groove portion acts in the radial direction of the rotating shaft, that is, in the direction perpendicular to the peripheral surface of the rotating shaft, and cancels each other. Is possible.

In the device with an oil seal, it is preferable that the diameter of the communication hole is smaller than the width of the first groove portion and the width of the second groove portion.
According to such an apparatus with an oil seal, the oil filled in the first groove and the oil filled in the second groove press the portion where the communication hole is not provided in the inner peripheral wall of each groove. Therefore, it is possible to generate a pressing force on each of the first groove portion side and the second groove portion side, thereby canceling each other's pressing force and generating a frictional force acting between the rotating shaft and the oil seal. It is possible to reduce.

In such an apparatus with an oil seal, it is preferable that the oil that has flowed into the first groove portion flows into the second groove portion through the communication hole.
According to such an apparatus with an oil seal, the pressing force by the oil is not generated until the oil flowing in from the first groove portion is filled in the second groove portion, and the first groove portion is filled with the oil after the first groove portion is filled with the oil. Since the pressing force by the oil that has entered the groove and the second groove acts so as to cancel each other, it is possible to prevent a large frictional force from acting on the oil seal and the rotating shaft.

In such an apparatus with an oil seal, it is desirable that a pressure acting in a direction from the second groove portion side toward the first groove portion side is generated by the oil flowing into the second groove portion.
According to such an apparatus with an oil seal, the oil flowing into the second groove portion generates a pressure acting in the direction from the second groove portion side to the first groove portion side. It is possible to suppress the pressing force that acts.

In the apparatus with an oil seal, the input shaft and the input shaft of the work table device configured such that an input shaft provided with a cam and an output shaft to which a cam follower engaged with the cam is fixed are accommodated in the housing. It is desirable that the oil seal is interposed between at least one of the output shafts and the housing.
Since the work table device is required to rotate smoothly at high speed, when an oil seal is interposed between at least one of the input shaft and the output shaft of the work table device and the housing, Since heat generated by friction is small and damage to the oil seal is suppressed, it is possible to realize a high-performance work table device that rotates smoothly at a high speed over a long period of time.

Further, a first groove portion recessed along the circumferential direction on the outer peripheral surface of the annular oil seal, a second groove portion recessed along the circumferential direction on the inner peripheral surface, and the first groove portion and the first groove portion An oil seal having a communication hole that communicates with the two groove portions.
According to such an oil seal, since the oil is interposed between the inner peripheral surface and the object in contact with the outer peripheral surface by the groove portions provided on the inner peripheral surface and the outer peripheral surface, the lubricating effect and friction caused by the oil are reduced. It is possible to obtain a cooling effect such as heat. In addition, since the first groove portion and the second groove portion are communicated with each other through the communication hole, the oil that has entered the first groove portion and the second groove portion is filled through the communication hole and presses in opposite directions. For this reason, the pressing force due to the oil that has entered the first groove portion and the second groove portion cancels each other, and the pressing force that presses the oil seal against an object that contacts the inner peripheral surface and the outer peripheral surface is suppressed. For this reason, it is possible to reduce the frictional force generated between the oil seal and the object in contact with the inner and outer peripheral surfaces.

=== Configuration of device with oil seal ===
As an embodiment of a device with an oil seal according to the present invention, a working table device that transmits a rotational motion input from an input shaft to a rotary table via a cam mechanism will be described as an example. First, an outline of the work table device will be described.

  FIG. 1 is an external view of a work table device 10 according to the present embodiment, FIG. 2 is a cross-sectional view in a plane perpendicular to an axis when the rotary table rotates, and FIG. It is A sectional drawing.

  As shown in the figure, the work table device 10 of the present embodiment includes a rotary table 12 that holds a workpiece W and a housing 14 that rotatably supports the rotary table 12. Then, the workpiece W held on the rotary table 12 is rotated at a high speed (for example, 500 rpm) by rotating the rotary table 12 at a high speed in order to perform cutting with the cutting tool T1 or the like abutted from the outside. It is possible.

  On the upper surface of the turntable 12, slide grooves 12 a for sliding blocks constituting a chuck for holding the workpiece W are provided radially from the center of the turntable 12. A cross roller bearing 30 is used as a bearing structure of the rotary table 12 and the housing 14.

  A cylindrical turret 9 as an output shaft is suspended from the lower surface side of the rotary table 12, and a plurality of cam followers arranged radially at equal intervals in the circumferential direction below the outer peripheral surface of the turret 9. 8 is provided.

  The cross roller bearing 30 is provided at the upper part of the housing 14 and is disposed inside the support ring 28 and a support ring 28 fixed to the inner periphery of the opening 14a through which the turret 9 to which the cam follower 8 is attached can be inserted. The turret 9 having an outer peripheral surface facing the inner peripheral surface of the support ring, a plurality of rolling elements 26 interposed between the support ring 28 and the turret 9, and a holder 66 for holding the rolling element 26 It consists of and.

  The above-described support ring 28 has two annular members 28a and 28b. In the annular members 28a and 28b, the edge on the turret 9 side is chamfered at 45 ° over the entire circumference. These annular members 28a and 28b are overlapped with each other and fixed with bolts with a slight gap therebetween, and a second V-shaped groove 56 opened to the turret 9 side is formed by each chamfered portion. Yes.

  The turret 9 is formed with a first V-shaped groove 58 that is open to the support ring 28 side over the entire circumference at a position facing the second V-shaped groove 56.

  A plurality of rolling elements 26 formed in a cylindrical shape are interposed between the first V-shaped groove 58 and the second V-shaped groove 56. The rolling elements 26 have a pair of flat end surfaces 26 b at both ends of a cylindrical rolling surface 26 a, and are arranged at equal intervals along the circumferential direction of the turret 9. These rolling elements 26 are provided in an inner track portion that is provided in the inner turret 9 and forms the first V-shaped groove 58, and an outer track portion that is provided in the outer support ring 28 and forms the second V-shaped groove 56. It comes into contact and rolls. Further, the rolling elements 26 are arranged so as to be inclined so that the rolling axis is directed to the rotation axis of the turret 9, and the adjacent rolling elements 26 are arranged so that the rolling axes are orthogonal to each other. An annular gap is set between the turret 9 and the support ring 28, and a thin cylindrical holder 66 is provided in the gap, and a rolling element is provided on the peripheral surface of the holder 66. A plurality of pocket holes for individually mounting 26 are formed.

  An input shaft 44 as a rotating shaft for inputting a driving force to the rotary table 12 is rotatably supported with respect to the housing 14 by a pair of bearings 46. A cam 48 is provided on the input shaft 44. The cam 48 has a cam surface 48a whose phase is displaced in the axial direction as the input shaft 44 rotates, and the cam surface 48a and the cam follower 8 of the turret 9 are engaged with each other.

  The cam mechanism in the work table device 10 of the present embodiment basically includes an input shaft 44 provided with a cam 48, a turret 9 to which a cam follower 8 engaged with the cam 48 is fixed, a cam 48 and a cam follower 8. The housing 14 that supports both ends of the input shaft 44 through a pair of bearings 46 that can be locked in the axial direction of the input shaft 44 and a bearing that is fitted to the housing 14. 46 and a first flange 38 and a second flange 40 for locking the bearing 46 in the axial direction of the input shaft 44, and the oil 7 is injected into the housing 14 to such an extent that the input shaft 44 is immersed. Yes.

  The work table device 10 according to the present embodiment includes an input shaft 44 provided with a cam 48 and a turret 9 in which a plurality of cam followers 8 are projected at equal intervals on the outer peripheral portion. The input shaft 44 and the turret 9 Are supported by the housing 14 in a torsional relationship orthogonal to each other. The cam 48 and the cam follower 8 are accommodated in the housing 14, and the cam 48 and the cam follower 8 are engaged with each other.

  The cam 48 is provided with ribs 48b having a trapezoidal cross section on the outer periphery of the input shaft 44 with a preset meandering shape. The cam surfaces 48a on both sides of the rib 48b are displaced in the axial direction as the input shaft 44 rotates. Therefore, the turret 9 is rotated along the meandering shape of the rib 48b when the cam follower 8 is brought into sliding contact with the cam surface 48a and the cam 48 rotates.

  In the housing 14 that supports the input shaft 44, a pair of insertion holes 32 for supporting a pair of bearings 46 so as to be movable in the axial direction together with the input shaft 44 at least on the inner wall portion of the portion that supports the input shaft 44. , 34 are formed. At least one of the pair of insertion holes 32 and 34 is formed with a diameter that allows the input shaft 44 provided with the cam 48 to be inserted into the housing 14. In the present embodiment, the input shaft 44 provided with the cam 48 is inserted into the insertion hole 32 on the opposite side (reverse drive side) to the side (drive side) where the input shaft 44 and the motor 22 as a drive source are connected. It is made possible. The pair of insertion holes 32, 34 are formed in a stepped manner with communication holes 32 a, 34 a communicating between the inside and the outside of the housing 14, and at outer portions of the respective insertion holes 32, 34 with a larger diameter than the communication holes 32 a, 34 a. Recesses 32b and 34b are provided.

  A bearing 46 is fitted into the drive-side insertion hole 34 from the inside of the housing 14, and a second flange 40 is fitted from the outside. The 2nd flange 40 has the cylindrical part 40a inserted by the communicating hole part 34a, and the ring part 40b formed in the outer diameter larger than the cylindrical part 40a. The second flange 40 is fixed to the housing 14 by fitting the ring portion 40b into the recess 34b and tightening it with a bolt. The second flange 40 is provided with a through hole 40 c at the center, and the input shaft 44 extends outside the housing 14 through the through hole 40 c and is connected to the motor 22 through the coupling 36. The portion on the outside of the through hole 40 c is formed so that its inner diameter is slightly larger than the outer diameter of the input shaft 44. That is, the through hole 40c is formed so that the inner diameter is different between the portion located on the inner side of the housing 14 and the portion located on the outer side, and the inner diameter of the portion 40d located on the inner side is the input The inner diameter of the portion 40 e that is formed to be sufficiently larger than the outer diameter of the shaft 44 and located on the outer side is formed to be slightly larger than the outer diameter of the input shaft 44. An oil seal 50 for preventing leakage of the oil 7 injected into the housing 14 is provided between the inner peripheral surface of the inner portion 40d of the through hole 40c and the outer peripheral surface of the input shaft 44. Is provided. Further, an annular contact portion 40 f that comes into contact with the outer ring 46 a of the bearing 46 that is disposed inside the housing 14 is provided on the surface facing the inside of the second flange 40.

  A first flange 38 having a fitting hole 38c into which the bearing 46 is fitted is fixed to the insertion hole 32 on the non-driving side. The first flange 38 includes a cylindrical portion 38a that is fitted into the communication hole portion 32a, and a ring portion 38b that has an outer diameter larger than that of the cylindrical portion 38a. The first flange 38 is fixed to the housing 14 by the ring portion 38b being fitted into the recess 32b and tightened with a bolt.

  The fitting hole 38a has four holes with different inner diameters in a concentric manner such that the inner diameter decreases sequentially from the inside toward the outside in a state where the first flange 38 is fixed to the housing 14. That is, the cross section is formed in a stepped shape. Here, the hole portion having the largest inner diameter and located on the innermost side is referred to as a first hole portion 38d, and is sequentially referred to as a second hole portion 38e, a third hole portion 38f, and a fourth hole portion 38g. .

  A bearing 46 is fitted in the first hole 38d, and a step formed by the inner diameter difference between the first hole 38d and the second hole 38e is in contact with the outer ring 46a of the bearing 46. The third hole 38f has an oil seal 50 between the outer peripheral surface of the input shaft 44 and the inner peripheral surface of the third hole 38f for preventing leakage of the oil 7 injected into the housing 14. Is provided. The fourth hole 38g is formed to have an inner diameter slightly larger than the outer diameter of the input shaft 44, and the input shaft 44 supported by the bearing 46 passes therethrough.

  4 is a longitudinal sectional view for explaining the structure of the oil seal, and FIG. 5 is a sectional view taken along line BB in FIG.

  The work table device 10 of this embodiment includes oil seals 50 on both end sides of the input shaft 44. Since the structure of these oil seals 50 is the same, the oil seal 50 provided on the non-driving side will be described here.

  The oil seal 50 provided on the non-driving side is interposed between the input shaft 44 and the third hole 38 f of the first flange 38. The oil seal 50 is formed in an annular shape with, for example, acrylonitrile-butadiene-rubber having high oil resistance. Here, in the present embodiment, the oil seal 50 is interposed between the input shaft 44 and the first flange 38, but the first flange 38 is fixed in close contact with the housing 14, so that the first The flange 38 and the housing 14 are considered as one body, and the oil seal 50 can be regarded as being interposed between the input shaft 55 and the housing. In the following description, the axial direction when the oil seal 50 is attached to the input shaft 44 is defined as the width direction of the oil seal 50.

  The oil seal 50 has a first groove portion 50b having a semicircular cross section along the circumferential direction on the outer peripheral surface 50a, and a rectangular cross section along the circumferential direction on the inner peripheral surface 50c. The second groove 50d is recessed. The oil seal 50 is provided with one communication hole 50e that allows the first groove portion 50b and the second groove portion 50d to communicate in the diametrical direction. Here, the diameter of the communication hole 50e is smaller than the diameter of the first groove 50b and the width of the second groove 50d. Further, the width of the first groove portion 50b is formed wider than the width of the second groove portion 50d. The centers in the width direction of the first groove portion 50b, the second groove portion 50d, and the communication hole 50e coincide with the centers in the width direction of the oil seal 50.

  In the state where the oil seal 50 is assembled to the work table device 10, the outer peripheral surface 50a is in contact with the inner peripheral surface of the third hole 38f of the first flange 38, and the inner peripheral surface 50c is the input shaft. 44 is in contact with the outer peripheral surface. Therefore, an annular outer peripheral space 51 is formed between the first flange 38 and the oil seal 50 by the first hole 50b of the oil seal 50 and the inner peripheral surface of the third hole 38f. An annular inner peripheral space 52 is formed between the oil seal 50 and the input shaft 44 by the second groove portion 50d and the outer peripheral surface of the input shaft 44, and the outer peripheral space 51 and the inner peripheral space 52 are connected to the communication hole 50e. It is communicated at. At this time, since the width of the first groove portion 50b is formed wider than the width of the second groove portion 50d, it contacts the inner peripheral surface of the third hole portion 38f of the first flange 38 at the side portion of the first groove portion 50b. The width to be narrowed is smaller than the width that contacts the outer peripheral surface of the input shaft 44 at the side portion of the second groove portion 50d.

  6A is a diagram for explaining the state of the oil seal when the work table device is stopped, and FIG. 6B is a diagram for explaining the state of the oil seal when oil flows into the outer peripheral space. FIG. 6C is a diagram for explaining a state of the oil seal when the outer peripheral space and the inner peripheral space are filled with oil.

  As shown in FIG. 6A, in the unused work table apparatus 10, the oil 7 injected into the housing 14 is stored so as to press the inner side surface 50f of the oil seal 50 outward in the axial direction. . At this time, oil does not flow into the outer peripheral space 51, the inner peripheral space 52, and the communication hole 50e.

  When the input shaft 44 starts to rotate, the oil 7 on the side surface 50f side of the oil seal 50 flows out in a direction away from the input shaft 44 along the side surface 50f. The oil that flows along the side surface 50f reaches the inner peripheral surface of the third hole 38f, and begins to flow between the inner peripheral surface of the third hole 38f and the outer peripheral surface of the oil seal 50. At this time, the width contacting the side of the first groove 50b, that is, the outer peripheral surface 50a and the inner peripheral surface of the third hole 38f is equal to the side of the second groove 50d, that is, the outer periphery of the inner peripheral surface 50c and the input shaft 44. Since the width of the first groove 50b is narrower than the width contacting the surface, the oil flowing along the side surface 50f of the oil seal 50 flows from the first groove 50b before the second groove 50d. To do. The oil that has flowed into the first groove 50b, that is, the outer peripheral space 51 from between the inner peripheral surface of the third hole 38f and the outer peripheral surface of the oil seal 50, passes through the communication hole 50e. Also flows into the circumferential space 52.

  When the oil that has flowed in this way fills the outer peripheral space 51, the inner peripheral space 52, and the communication hole 50e, the first groove 50b of the oil seal 50 is surrounded by the oil filled in the outer peripheral space 51 around the third hole 38f. It is pressed in the direction from the surface side toward the input shaft 44. Further, the second groove 50d of the oil seal 50 is pressed in the direction from the input shaft 44 side toward the peripheral surface of the third hole 38f by the oil filled in the inner peripheral space 52. For this reason, forces acting in opposite directions are generated so as to sandwich the first groove portion 50b and the second groove portion 50d of the oil seal 50 in the diameter direction of the oil seal 50. That is, even when the oil filled in the first groove 50b presses the oil seal 50 in the direction toward the input shaft 44, when the oil is filled in the first groove 50b, the second groove 50d is also filled with oil. Since it is full, the oil seal 50 is pressed away from the input shaft 44 by the oil filled in the second groove 50d. For this reason, the pressing force by the oil on the first groove portion 50b side and the pressing force by the oil on the second groove portion 50d side cancel each other, so that the contact surface pressure of the oil seal 50 to the input shaft 44 is reduced, and the oil seal 50 It is possible to suppress wear.

  That is, since the frictional force between the oil seal 50 and the input shaft 44 is reduced, it is possible to prevent seizure of the oil seal 50 due to frictional heat and damage of the oil seal 50 due to excessive load. Therefore, the input shaft 44 can be rotated well for a long period of time, and the rotational performance and reliability of the work table device 10 can be improved. Further, since the oil seal 50 is composed of one member, it has a simple structure, and the one-member oil seal 50 can be easily interposed between the first flange 38 and the input shaft 44. Therefore, it is possible to reduce the work man-hours and the cost.

  According to the work table device 10 of the present embodiment, since the oil is guided to the outer peripheral side by the rotation of the input shaft 44, it is possible to first enter the first groove portion 50b on the housing 14 side. For this reason, almost no pressing force is generated by the oil until the second groove portion 50d is filled with the oil, so that the input shaft 44 can be smoothly rotated. In particular, in the present embodiment, since the width of the first groove portion 50b is formed wider than the width of the second groove portion 50d, the rigidity on the outer peripheral surface 50a side of the oil seal 50 is lower than the inner peripheral surface 50c side. A structure in which oil is more likely to flow in from the outer peripheral surface 50a side is realized.

  Further, since the first groove portion 50b and the second groove portion 50d are communicated with each other through the communication hole 50e, the oil that has flowed into the first groove portion 50b flows into the second groove portion 50d through the communication hole 50e. For this reason, it is possible to make the oil which flowed in from the 1st groove part 50b flow in into the 2nd groove part 50d. After the second groove portion 50d is filled with oil, the pressing force due to the oil flowing into the first groove portion 50b and the second groove portion 50d acts so as to cancel each other, so that the oil seal 50 and the input shaft 44 are greatly affected. It is possible to prevent a large frictional force from acting.

  Furthermore, since the communication hole 50 e is provided along the radial direction of the oil seal 50, the communication hole 50 e of the oil seal 50 is provided in the radial direction of the input shaft 44. Therefore, even in the communication hole 50e, the pressing force by the oil that has entered the first groove portion 50b and the second groove portion 50d acts in the radial direction of the input shaft 44, that is, in the direction perpendicular to the peripheral surface of the input shaft 44. It is possible to cancel each other.

  Further, since the diameter of the communication hole 50e is smaller than the width of the first groove part 50b and the width of the second groove part 50d, the outer peripheral space 51 is filled even around the part where the communication hole 50e is provided. Since the oil and the oil filled in the inner peripheral space 52 press the portions where the communication holes 50e are not provided in the inner peripheral walls of the groove portions 50b and 50d, the first groove portion 50b side and the second groove portion 50d. It is possible to generate a pressing force on each side, thereby canceling each other's pressing force and reducing a frictional force acting between the input shaft 44 and the oil seal 50.

  In the present embodiment, an example in which one communication hole 50e is provided has been described. However, a plurality of communication holes 50e may be provided.

  Further, according to the work table device 10 of the present embodiment, when the oil seal 50 is interposed between at least one of the input shaft 44 and the turret 9 and the housing 14, the oil seal 50 is interposed. Since the heat generated by friction is small in the portion thus formed and damage to the oil seal 50 is suppressed, it is possible to realize a high-performance work table apparatus 10 that rotates smoothly at a high speed over a long period of time.

  In the present embodiment, the width at which the side portion of the first groove portion 50b is in contact with the inner peripheral surface of the third hole portion 38f is greater than the width at which the side portion of the second groove portion 50d is in contact with the outer peripheral surface of the input shaft 44. By adopting a narrow configuration, the rigidity on the first groove portion 50b side is lowered and the oil is more likely to flow in from the outer peripheral surface 50a side. For example, the oil seal 50 is replaced with two types of elastic members having different stiffnesses. By using a member having low rigidity among the two types of elastic members on the outer peripheral side of the oil seal, it is possible to realize a configuration in which oil more easily flows from the outer peripheral surface side.

The external view of the table apparatus for work in this embodiment. Sectional drawing in a plane perpendicular | vertical to the axis | shaft at the time of a rotation table rotating. AA sectional drawing of FIG. The longitudinal cross-sectional view for demonstrating the structure of an oil seal. BB sectional drawing in FIG. FIG. 6A is a diagram for explaining a state of an oil seal when the work table device is stopped. FIG. 6B is a diagram for explaining a state of the oil seal when oil flows into the outer peripheral space. FIG. 6C is a diagram for explaining the state of the oil seal when the outer peripheral space and the inner peripheral space are filled with oil.

Explanation of symbols

7 Oil 10 Work table device (device with oil seal)
14 Housing 44 Input shaft (rotary shaft)
50 Oil seal 50b 1st groove part 50d 2nd groove part 50e Communication hole

Claims (10)

In an apparatus with an oil seal, comprising: a housing into which oil has been injected; a rotating shaft that penetrates into and out of the housing; and an annular oil seal interposed between the housing and the rotating shaft.
The oil seal includes a first groove that is recessed along the circumferential direction on the outer peripheral surface that contacts the housing, and a second groove that is recessed along the circumferential direction on the inner peripheral surface that contacts the rotating shaft. A device with an oil seal having a communication hole for communicating the first groove portion and the second groove portion. In the apparatus with an oil seal according to claim 1,
The oil-sealed device is characterized in that the oil flows into the first groove portion before the second groove portion by rotating the rotating shaft. In the apparatus with an oil seal according to claim 1 or 2,
The device with an oil seal, wherein a width of the oil seal in an outer peripheral surface in contact with the housing in the rotation axis direction is narrower than a width in the rotation axis direction of an inner peripheral surface in contact with the rotation shaft. In the apparatus with an oil seal in any one of Claims 1 thru | or 3,
The oil seal is composed of two types of elastic members having different rigidity,
The elastic member having low rigidity is used on the outer peripheral surface side in contact with the housing,
The device with an oil seal, wherein the elastic member having high rigidity is used on an inner peripheral surface side that contacts the rotating shaft. In the apparatus with an oil seal in any one of Claims 1 thru | or 4,
The device with an oil seal, wherein the communication hole is provided along a radial direction of the oil seal. In the apparatus with an oil seal in any one of Claims 1 thru | or 5,
The diameter of the said communicating hole is smaller than the width | variety of the said 1st groove part, and the width | variety of a 2nd groove part, The apparatus with an oil seal characterized by the above-mentioned. In the apparatus with an oil seal in any one of Claims 1 thru | or 6,
The oil-sealed device, wherein the oil that has flowed into the first groove portion flows into the second groove portion through the communication hole. In the apparatus with an oil seal in any one of Claims 1 thru | or 7,
A device with an oil seal, wherein pressure that acts in a direction from the second groove portion side toward the first groove portion side is generated by the oil flowing into the second groove portion. In the apparatus with an oil seal in any one of Claims 1 thru | or 8,
At least one of the input shaft and the output shaft of a work table device in which an input shaft provided with a cam and an output shaft to which a cam follower engaged with the cam is fixed are accommodated in the housing. An apparatus with an oil seal, characterized in that the oil seal is interposed between one side and a housing.   A first groove portion recessed along the circumferential direction on the outer peripheral surface of the annular oil seal, a second groove portion recessed along the circumferential direction on the inner peripheral surface, and the first groove portion and the second groove portion An oil seal having a communication hole for communicating with the oil seal.

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