JP5182028B2 - Torque limiter - Google Patents

Description

  The present invention relates to a torque limiter.

  Conventional torque limiters include those described in Japanese Patent Application Laid-Open No. 55-010191 (Patent Document 1). In this torque limiter, the inner peripheral surface of the cylindrical member is fitted on the outer peripheral surface of the shaft member, pressure oil is supplied to the hydraulic passage of the cylindrical member, and the inner peripheral surface of the cylindrical member is reduced in diameter by the pressure oil of the hydraulic passage. Then, the inner peripheral surface is pressed against the outer peripheral surface of the shaft member, and the shaft member and the cylindrical member are frictionally coupled to transmit torque. The shear tube seals the pressure oil in the hydraulic passage, while the shaft member is fixed with a locking member that is locked to the end of the shear tube.

  A load of a predetermined value or more is applied to the shaft member or the cylindrical member, the inner peripheral surface of the cylindrical member slips with respect to the outer peripheral surface of the shaft member, and the position of the shaft member around the axis changes with respect to the cylindrical member. Then, the end of the shear tube is cut by the locking member, and the pressure oil in the hydraulic passage is discharged to the outside. As a result, the inner peripheral surface of the cylindrical member cannot press the outer peripheral surface of the shaft member, and the frictional coupling between the shaft member and the cylindrical member is released, thereby blocking torque transmission. Further, when the shaft member or the cylindrical member is subjected to a load of a predetermined value or more and the inner peripheral surface of the cylindrical member slides with respect to the outer peripheral surface of the shaft member, the shaft member and the cylindrical member are seized. In order to prevent this, lubricating oil is applied between the shaft member and the cylindrical member.

In the conventional torque limiter, the release torque is not constant and is likely to be unstable due to the unstable lubrication state by the applied lubricating oil. For example, the lubricating oil weakens the force with which the cylindrical member clamps the shaft member, and even during normal torque load, the cylindrical member rotates relative to the shaft member, and the release torque (torque at which the torque limiter begins to idle) May be lower than the desired (design value) release torque. Also, the hydraulic pressure release time becomes longer, and the sliding surface may become galling.
JP-A-55-010191 (FIG. 1)

  Accordingly, an object of the present invention is to provide a torque limiter in which variation from a desired value of the release torque is small and the hydraulic pressure release time is short.

In order to solve this problem, the torque limiter of the present invention is
A shaft member;
A cylindrical member radially facing the shaft member;
A hydraulic expansion chamber provided in one of the shaft member and the cylindrical member;
A piston member provided in the hydraulic pressure expansion chamber so as to be movable in a radial direction and capable of pressing the other member of the shaft member and the cylindrical member;
A sealed liquid passage extending from the hydraulic expansion chamber;
A hydraulic passage releasing member that releases the sealed state of the hydraulic passage by a relative movement in the circumferential direction between the shaft member and the cylindrical member ;
The surface of the piston member on the other member side in the radial direction is
A cylindrical partial surface consisting of a part of the cylindrical surface;
When the relative rotation of the one member relative to the other member is located upstream of the cylindrical partial surface in the relative rotational direction, the distance from the cylindrical surface increases toward the upstream of the relative rotational direction. With an increasing slope
The have is characterized in Rukoto.

  According to the present invention, since the one member is frictionally engaged with the other member by the piston member, the size, number, arrangement, and the like of the piston member are adjusted based on the specifications. Thus, conditions that are not easily affected by the lubricating oil can be easily selected, and the force from the piston member can be adjusted easily and accurately. Therefore, variation from the desired value of the release torque is reduced.

  In addition, according to the present invention, the piston member is configured to frictionally engage the one member with the other member. Therefore, the size, number, arrangement, etc. of the piston member can be set regardless of the specifications of the torque limiter. By adjusting, it is possible to reduce the hydraulic pressure release time when the power transmission is canceled. For example, in the case of a large torque limiter, the volume of each hydraulic expansion chamber can be reduced by increasing the number of hydraulic expansion chambers and piston members, and the liquid filled in each hydraulic expansion chamber can be reduced. Can be reduced, and the hydraulic pressure release time can be reduced. Therefore, even when the torque limiter is large, it is possible to suppress galling of the friction engagement surfaces of the shaft member and the cylindrical member.

Further , according to the present invention , the distance from the cylindrical surface increases as the surface on the other member side in the radial direction of the piston member goes upstream in the relative rotational direction and upstream in the relative rotational direction. It has an inclined surface that becomes larger. Accordingly, when the one member rotates relative to the other member, the upstream end of the surface of the piston member on the other member side is pressed against the other member pressed by the piston. Contactless. Therefore, the piston member and the other member can be prevented from being galled.

  According to the torque limiter of the present invention, the variation of the release torque from the desired value is reduced. Further, according to the torque limiter of the present invention, the hydraulic pressure release time can be shortened when the power transmission is released, and the friction engagement surface can be prevented from being galled during the relative rotation of the other member with respect to the one member. .

  The present invention will be described in detail below with reference to the drawings.

  FIG. 1 is a half sectional view in the axial direction of a torque limiter according to an embodiment of the present invention.

  The torque limiter includes a shaft member 1 as one member, a cylindrical member 2 as the other member, a plurality of piston members 9, a locking member 16, a ball bearing 5, and a ball bearing 6.

  The outer peripheral surface of the shaft member 1 has a plurality of recesses 30 and a recess opening passage 31. The concave portion is a chamber that opens outward in the radial direction. The recess constitutes a hydraulic expansion chamber as an example of a hydraulic expansion chamber. The plurality of recesses 30 are positioned on the outer peripheral surface of the shaft member 1 in a double row in the axial direction and in a double row in the circumferential direction, and have a substantially circular shape when viewed from above in the radial direction. The bottom surface of the recess 30 is a part of a cylindrical surface. The recess opening passage 31 is open to each recess 30. The recess opening passage 31 communicates with an oil drain hole of the shear valve 35, and one end portion of the shear valve 35 and one end portion of the oil drain hole are axially extended from one axial end surface of the shaft member 1. It protrudes outward. The recess opening passage 31 and the oil drain hole constitute an oil passage 47 as an example of a liquid passage.

  Each piston member 9 has a substantially circular shape when viewed from the outside in the radial direction. Each piston member 9 is fitted in the recess 30. Each piston member 9 is movable in the radial direction with respect to the recess 30.

  FIG. 2 is a perspective view showing a part of the shaft member 1 and the piston member 9 fitted in the recess 30 of the shaft member 1.

  As shown in FIG. 2, the piston member 9 has a side surface corresponding to the side surface of the recess 30. The side surface portion of the piston member 9 is fitted into the side surface portion of the recess 30. The side surface portion of the piston member 9 and the side surface portion of the recess 30 are in a state where there is no gap. The piston member 9 is movable in the radial direction of the shaft member 1. In FIG. 2, a dotted line 37 indicates the opening of the recess opening passage 31. As shown in FIG. 2, the recess opening passage 31 opens at the approximate center of the bottom surface of each recess 30.

  Referring to FIG. 1 again, the cylindrical member 2 is composed of a first cylindrical member 10 and a second cylindrical member 11. The first tubular member 10 has a substantially cylindrical inner peripheral surface 21 that forms a friction engagement surface, and has a substantially cylindrical outer peripheral surface 23. The inner peripheral surface 21 is in contact with the radially outer surface of the piston member 9 constituting the friction engagement surface of the shaft member 1.

  The locking member 16 is fixed to one end portion in the axial direction of the inner peripheral surface of the first cylindrical member 10 with a bolt. The locking member 16 extends inward in the radial direction. The radially inner end of the locking member 16 extends in the radial direction along one axial end surface of the shaft member 1. The locking member 16 locks the one end of the shear valve 35. The locking member 16 and the shear valve 35 constitute a hydraulic pressure passage releasing member. The second cylindrical member 11 has a substantially cylindrical inner peripheral surface 24, and the substantially cylindrical inner peripheral surface 24 contacts the substantially cylindrical outer peripheral surface 23 of the first cylindrical member 10. It touches.

  As shown in FIG. 1, the radially outer surface of the piston member 9 is in contact with the inner peripheral surface 21 of the first cylindrical member 10. An outer surface in the radial direction of the piston member 9 constitutes a friction engagement surface. In the state where the radially outer surface of the piston member 9 is in contact with the inner peripheral surface 21 of the first cylindrical member 10, the radially inner surface of the piston member 9 is the recess 30. Located at a distance from the bottom surface. The inner surface of the piston member 9 in the radial direction, the bottom surface of the recess 30, the side surface of the recess 30, the recess opening passage 31 and the oil drain hole of the shear valve 35 together constitute a sealed chamber.

  FIG. 3 shows a state where a part of the torque limiter of the present embodiment is cut by a cutting plane that is perpendicular to the central axis of the shaft member 1 and passes through the center of the opening 37 on the recess 30 side of the recess opening passage 31. It is sectional drawing. In FIG. 3, an arrow A is an arrow indicating the direction of relative rotation of the shaft member 1 with respect to the first cylindrical member 10.

  As shown in FIG. 3, the radially outer surface 50 of the piston member 9 has a cylindrical partial surface 50 and an inclined surface 52. The said cylindrical partial surface 50 consists of a part of cylindrical surface. Further, the inclined surface 52 is located upstream of the cylindrical partial surface 50 in the circumferential direction in the circumferential direction. The inclined surface 52 has a linear shape in the cross-sectional view of FIG. In addition, the inclined surface 52 is formed by the cylindrical surface (specifically, the cylindrical partial surface 50 and the circumferential and axial extension surfaces of the cylindrical partial surface 50 as it goes upstream in the relative rotational direction. The distance from the configured cylindrical surface) is large.

  The piston member 9 has an annular O-ring engagement groove on a side surface, and an O-ring 55 is fitted in the O-ring engagement groove. The O-ring 55 prevents oil in the recess 30 from passing between the side surface of the piston member 9 and the side surface of the recess 30.

  Referring again to FIG. 1, the ball bearing 5 is fitted and fixed to the inner ring 60 that is fitted and fixed to the outer circumferential surface of the shaft member 1 and the inner circumferential surface of the second cylindrical member 11. And an outer ring 61, and a plurality of balls 62 arranged between the raceway surface of the inner ring 60 and the raceway surface of the outer ring 61. The ball bearing 6 includes an inner ring 64 that is fitted and fixed to the outer peripheral surface of the shaft member 1, an outer ring 65 that is fitted and fixed to the inner peripheral surface of the first cylindrical member 10, and an inner ring 64. And a plurality of balls 66 arranged between the raceway surface of the outer ring 65 and the raceway surface of the outer ring 65. The ball bearings 5 and 6 are configured to support the shaft member 1 so as to be rotatable with respect to the cylindrical member 2 when the shaft member 1 rotates relative to the cylindrical member 2.

  When the shaft member 1 rotates relative to the cylindrical member 2 between the radially outer surface of each piston member 9 and the inner peripheral surface 21 of the first cylindrical member 10, Turbine oil, traction oil or the like as lubricating oil for preventing the piston member 9 and the first cylinder member 10 from seizing is disposed. A part of this lubricating oil enters between the inclined surface 52 and the first cylindrical member 10, so that the effect of preventing the above-mentioned galling and the effect of preventing the seizure are promoted.

  In the above configuration, when a load less than a predetermined value is applied to the shaft member 1 or the cylindrical member 2 (the load in a range where torque is transmitted), the shaft member 1 or the cylindrical member 2 is sealed after being injected into the recess 30 via a coupler (not shown). The piston member 9 and the first cylindrical member 10 are pressed by pressing the radially outer surface 50 of the piston member 9 against the inner peripheral surface 21 of the first cylindrical member 10 with oil for hydraulic expansion. It is designed to be frictionally coupled. In this way, the shaft member 1 and the cylindrical member 2 are frictionally coupled to transmit torque between the shaft member 1 and the cylindrical member 2.

  On the other hand, the shaft member 1 or the cylinder member 2 is subjected to a load greater than a predetermined value (a load larger than the range in which torque is transmitted), and the radially outer surface 50 of the piston member 9 is the first cylinder. When slipping with respect to the inner peripheral surface 21 of the member 10 and the positions of the shaft member 1 and the cylindrical member 2 about the axis change, the locking member 16 cuts one end portion of the shear valve 35 and the oil passage The oil for hydraulic expansion in 47 is discharged to the outside through a shear valve 35 with one end cut off. In this way, the force of the radially outer surface 50 of the piston member 9 pressing the inner peripheral surface 21 of the first cylindrical member 10 is released, and the frictional coupling between the shaft member 1 and the cylindrical member 2 is achieved. The torque transmission is cut off. In this way, when an overload occurs in the shaft member 1 or the cylindrical member 2, the transmission of torque is interrupted to protect the expensive machine connected to the torque limiter device.

  According to the torque limiter of the above embodiment, since the shaft member 1 is frictionally engaged with the cylindrical member 2 by the piston member 9, the size, number, arrangement, and the like of the piston member 9 are determined based on the specifications. By adjusting, it is possible to easily select conditions that are not easily affected by the lubricating oil, and it is possible to easily adjust the force from the piston member 9. Therefore, variation from the desired value of the release torque is reduced. For example, in the present embodiment, by disposing the piston members 9 in two rows in the axial direction and in eight rows in the circumferential direction, variation from the desired value of the release torque can be reduced.

  Further, according to the torque limiter of the above embodiment, the piston member 9 is configured to frictionally engage the shaft member 1 with the cylindrical member 2, so that the size, number, and number of piston members can be determined regardless of the specifications of the torque limiter. By adjusting the arrangement and the like, the hydraulic pressure release time when power transmission is released can be reduced. For example, in this embodiment, by increasing the number of the recesses 30 and the piston members 9, the volume of each recess 30 is reduced, and the amount of liquid filled in each recess 30 is reduced. Therefore, the hydraulic pressure release time can be shortened, and the galling of the respective frictional engagement surfaces of the shaft member and the cylindrical member can be suppressed.

  Further, according to the torque limiter of the above embodiment, the surface 50 on the other member side in the radial direction of the piston member 9 is located upstream of the relative rotation direction of the shaft member 1 with respect to the tubular member 2 in the relative rotation direction. There is an inclined surface 52 whose distance from the cylindrical surface increases as it goes upstream. Therefore, when the cylindrical member 2 rotates relative to the shaft member 1, the upstream end of the surface 50 on the other member side is a member that is pressed by the piston member 9 as another member. It becomes non-contact with respect to the 1st cylinder member 10. Therefore, the piston member 9 and the first cylinder member 10 can be prevented from being galled.

  In the torque limiter of the above embodiment, the piston member 9 forms part of the shaft member 1, but in the present invention, the piston member may form part of a cylindrical member. In this case, the inner peripheral surface of the cylindrical member has a concave portion that opens inward in the radial direction, a part of the piston member is fitted into the concave portion, and the piston member is caused by the hydraulic pressure of oil for hydraulic expansion, Needless to say, it is pressed inward in the radial direction. In this case, for example, a configuration in which the shear valve is fitted into a shear valve engagement hole formed on the outer peripheral surface of the cylindrical member and extending in the radial direction can be employed.

  Further, in the torque limiter of the above-described embodiment, the cylindrical member 2 includes the first cylindrical member 10 having the inner peripheral surface 21 that contacts the piston member 9 and the inner peripheral surface that contacts the outer peripheral surface 23 of the first cylindrical member 10. In the present invention, the cylindrical member may be an integral member, although the second cylindrical member 11 having the surface 24 is used.

  In the torque limiter of the above embodiment, the side surface of the recess 30 and the side surface of the piston member 9 are sealed by the O-ring 55. However, in this invention, the side surface of the recess and the side surface of the piston member are It does not have to be sealed with an O-ring. In this case, for example, the side surface of the recess is tapered in the radial direction and slightly divergent toward the bottom surface of the recess, and the side surface shape of the piston member is preferably a tapered shape corresponding to the side surface shape of the recess. . This is because when the piston member is pressed in the opening direction of the recess by the liquid pressure of the liquid sealed in the recess, the portion having a larger outer diameter on the side surface of the piston member In this case, the inner diameter is pressed to the smaller side, so that the sealing between the side surface of the concave portion and the side surface of the piston member can be made excellent, and liquid leakage from the concave portion can be surely prevented. .

  In the torque limiter of the above embodiment, as shown in FIG. 3, the shape of the bottom surface of the recess 30 is a cylindrical shape. However, in this invention, the shape of the bottom surface of the recess is the same as that shown in FIG. As shown in the drawing corresponding to FIG. 3 in the torque limiter, the radial cross section may have a linear shape, and the shape of the bottom surface of the concave portion may be any shape. More specifically, in the torque limiter of the above embodiment, the shape of the recess 30 and the shape of the piston member 9 are substantially circular when viewed from the outside in the radial direction. The shape of the piston member may be a shape other than a substantially circular shape when viewed from the outside or the inside in the radial direction. For example, in the present invention, the shape of the recess and the shape of the piston member may be a substantially elliptical shape, a substantially polygonal shape, or the like when viewed from the outside or the inside in the radial direction.

  In the torque limiter of the above embodiment, the inclined surface 52 has a linear shape in the radial cross section. In the present invention, the inclined surface is a distance from the cylinder as it goes upstream. As long as the shape is large, the cross section in the radial direction may not have a linear shape, and may have any shape such as a parabolic shape. Further, in the present invention, the distance from the cylinder does not increase toward the upstream side of the surface on the other member side in the radial direction of the piston member, and the piston member is positioned at a distance from the cylinder. A surface to be formed may be formed.

  In the torque limiter of the above embodiment, the outer surface in the radial direction of the piston member 9 has the cylindrical partial surface 51 formed of a part of the cylindrical surface and the inclined surface 52. Then, all the surfaces on the other member side in the radial direction of the piston member may be part of the cylindrical surface.

  Further, in the torque limiter of the above embodiment, the radially outer surface of the piston member 9 constitutes a friction engagement surface, and the radially outer surface of the piston member 9 is directly connected to the other member. The inner peripheral surface 21 of the first cylindrical member corresponding to the friction engagement surface is pressed. However, in the present invention, a cylindrical member forming a part of one member is disposed between the piston member and the friction engagement surface of the other member, and the other member side in the radial direction of the piston member 9 is disposed. The structure which presses the surrounding surface of the cylindrical member may be sufficient. Then, a cylindrical member forming a part of one member and the other member may be frictionally engaged.

  In the torque limiter of the above embodiment, the hydraulic expansion chamber is a hydraulic expansion chamber, and the liquid filled in the hydraulic expansion chamber is oil, but in the present invention, the hydraulic expansion chamber is filled. The liquid may be any liquid other than oil.

  In the present invention, one shear valve or a plurality of shear valves may be provided at equal intervals in the circumferential direction. In the present invention, a plurality of shear valves may be provided at unequal intervals in the circumferential direction. Further, in the present invention, the number of liquid passages may be one or more, and the shape of the liquid passage is such that all the liquid in the hydraulic pressure expansion chamber is in a state where the cylindrical member rotates relative to the shaft member. Any shape may be used as long as it can be discharged to the outside. Moreover, in this invention, all the recessed parts 30 may be connected by the liquid channel.

  In the present invention, one or a plurality of piston members may be provided. When a plurality of piston members are provided, the plurality of piston members are, for example, equidistant or in at least one of the axial direction and the circumferential direction. Multiple rows can be provided at non-equal intervals. When a plurality of piston members are provided, for example, a plurality of piston members may be staggered on the cylindrical surface. Thus, in this invention, when providing a plurality of piston members, the plurality of piston members may be arranged in any manner.

  Furthermore, in this invention, while providing one annular recessed part in the circumferential direction, you may make it provide one piston member which has a cylindrical shape in which a part fits in the annular recessed part.

It is a half sectional view of the axial direction of the torque limiter of one embodiment of the present invention. It is a perspective view which shows a part of shaft member and the piston member fitted in the recessed part of the shaft member. It is sectional drawing when a part of torque limiter of this embodiment is cut | disconnected by the cut surface which passes along the center of an opening by the side of the recessed part of a recessed part opening channel | path perpendicularly to the central axis of a shaft member. It is a figure corresponding to Drawing 3 in the torque limiter of a modification.

DESCRIPTION OF SYMBOLS 1 Shaft member 2 Cylindrical member 9 Piston member 30 Recessed part 31 Recessed opening passage 47 Oil passage 50 The surface of the piston member on the radially outer side 51 Partial cylinder surface 52 Inclined surface A The relative rotation of the shaft member with respect to the first tubular member Direction arrow

Claims (1)

A shaft member;
A cylindrical member radially facing the shaft member;
A hydraulic expansion chamber provided in one of the shaft member and the cylindrical member;
A piston member provided in the hydraulic pressure expansion chamber so as to be movable in a radial direction and capable of pressing the other member of the shaft member and the cylindrical member;
A sealed liquid passage extending from the hydraulic expansion chamber;
A hydraulic passage releasing member that releases the sealed state of the hydraulic passage by a relative movement in the circumferential direction between the shaft member and the cylindrical member ;
The surface of the piston member on the other member side in the radial direction is
A cylindrical partial surface consisting of a part of the cylindrical surface;
When the relative rotation of the one member relative to the other member is located upstream of the cylindrical partial surface in the relative rotational direction, the distance from the cylindrical surface increases toward the upstream of the relative rotational direction. With an increasing slope
The have a torque limiter, wherein Rukoto.

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