1. A timepiece component, having:

a rotating body that can rotate around a rotating shaft;

a sliding surface provided on the rotating body, facing the surface to be opposed of the counterpart member while being inclined, and sliding with respect to the surface to be opposed by rotation of the rotating body; and

one or more groove portions extending in a direction intersecting the sliding direction on the sliding surface and capable of holding lubricating oil.

2. The timepiece component according to claim 1, wherein the sliding surface is inclined with respect to a rotation center line of the rotating body.

3. The timepiece part according to claim 2, wherein an inclination angle of the sliding surface with respect to the rotation center line on a plane including the rotation center line is 1 degree or more and 5 degrees or less.

4. The timepiece part according to any one of claim 1 to claim 3, wherein a depth of the groove portion from the sliding surface is 0.1 μm or more and 3.0 μm or less.

5. The timepiece component according to any one of claim 1 to claim 4, wherein a groove width of the groove portion in a direction orthogonal to an extending direction of the sliding surface is 1 μm or more and 20 μm or less.

6. A cartridge, comprising:

the timepiece part according to any one of claims 1 to 5; and

the counterpart member having the opposed surface,

by the rotation of the rotating body, a part of the sliding surface slides while contacting or point-contacting with the opposed surface line.

7. A timepiece provided with the movement according to claim 6.

Background

In a timepiece component provided in a timepiece, a component having a sliding surface that faces a facing surface of a counterpart member and slides with respect to the facing surface as it rotates is sometimes used.

For example, an escape wheel provided in a mechanical timepiece includes a sliding surface that slides with a pallet stone attached to an escape fork as the escapement wheel rotates. Conventionally, such a configuration has been proposed: since the drop drill is made of a high-hardness material such as ruby or ceramic, a lubricating oil is retained on the sliding surface in order to reduce wear of the sliding surface.

Patent document 1 describes an escape wheel: the rim mounted on the hub is provided with a plurality of teeth arranged in a radial shape, the finger-shaped body of the teeth comprises a first part arranged on one side close to the rim and a second part which is arranged on one side close to the front end part of the finger-shaped body and has a thickness smaller than that of the first part, and the boundary of the two parts is a raised part forming the oil retaining part.

Patent document 2 describes an electroformed part: on the surface of the electroformed body, fine vertical steel bar-like irregularities extending in a direction perpendicular to the sliding direction at the sliding portion are formed, and the sliding portion has high lubricating oil retaining properties.

Patent document 3 describes a timepiece component in which at least 3 layers of precision mechanical components are stacked, the precision mechanical components having a sliding portion that contacts another component at a portion substantially parallel to the stacking direction, and at least a portion of the sliding portion having a recess.

[ Prior Art document ]

[ patent document ]

[ patent document 1 ] Japanese Kokai publication No. 2007-506073;

[ patent document 2 ] Japanese patent laid-open No. 2016-176714;

[ patent document 3 ] Japanese patent application laid-open No. 2010-91544.

Disclosure of Invention

[ problem to be solved by the invention ]

In a timepiece component having a sliding surface that faces a facing surface of a counterpart member and slides with the facing surface as the counterpart member rotates, it is desired to suppress wear of the sliding surface and reduce energy required for rotation of the timepiece component. In the techniques described in the above patent documents, since the lubricating oil is retained on the sliding surface, the wear of the sliding surface caused by the sliding between the sliding surface and the opposed surface is suppressed, but there is room for improvement in reducing the energy required for rotation.

The purpose of the present application is to reduce the energy required for the rotation of a rotating body while suppressing wear of a sliding surface in a timepiece component having the sliding surface that faces a facing surface with respect to a counterpart member and slides with the facing surface as the counterpart member rotates.

[ MEANS FOR solving PROBLEMS ] A method for solving the problems

A timepiece component according to a first aspect includes: a rotating body that can rotate around a rotating shaft; a sliding surface provided on the rotating body, facing the surface to be opposed of the counterpart member while being inclined, and sliding with respect to the surface to be opposed by rotation of the rotating body; and one or more groove portions extending in a direction intersecting the sliding direction on the sliding surface and capable of retaining lubricating oil.

In this timepiece component, since the sliding surface provided on the rotating body faces the opposed surface of the counterpart member while being inclined, the sliding surface comes into linear or spot contact with the opposed surface when the sliding surface slides against the opposed surface by the rotation of the rotating body.

Further, the sliding surface is provided with a groove portion in a direction orthogonal to the sliding direction, and the groove portion can hold the lubricating oil.

As a result, the sliding surface comes into linear or spot contact with the opposed surface, and friction is reduced by the lubricating oil retained by the groove portion, whereby the sliding resistance of the sliding surface is reduced. That is, the wear of the sliding surface when the sliding surface slides against the opposed surface can be suppressed, and the energy required for the rotation of the rotating body can be reduced.

In a second aspect, the sliding surface is inclined with respect to a rotation center line of the rotating body in the first aspect.

Thus, the following configuration is realized: even if the rotating body rotates, the sliding surface moves in the circumferential direction of rotation while maintaining a state of being inclined with respect to the rotation center line.

A third aspect is the second aspect wherein an inclination angle of the sliding surface with respect to the rotation center line on a plane including the rotation center line is 1 degree or more and 5 degrees or less.

The inclination angle is 1 degree or more, so that, for example, even when the rotation center line is inclined with respect to a designed value, the sliding surface can reliably maintain a state of sliding in linear or dot contact with the opposed surface.

Further, the inclination angle is 5 degrees or less, so that the positional deviation of the leading end portion of the sliding surface (that is, the portion that slides in contact with the surface to be opposed) can be suppressed, and the relative positional relationship between the sliding surface and the surface to be opposed can be maintained.

A fourth aspect is the first to third aspects, wherein a depth of the groove portion from the sliding surface is 0.1 μm or more and 3.0 μm or less.

The grooves have a depth of 0.1 μm or more, and can reliably hold the lubricating oil.

Further, since the depth of the groove portion is 3.0 μm or less, the groove portion does not become excessively deep, and the amount of the lubricating oil remaining in the groove portion and being unusable and wasted can be reduced.

A fifth aspect is the sliding surface of any one of the first to fourth aspects, wherein a groove width of the groove portion in a direction orthogonal to an extending direction of the sliding surface is 1 μm or more and 20 μm or less.

The groove width of the groove part is more than 1 μm, so that the lubricating oil can be reliably kept.

Further, the groove width of the groove portion is 20 μm or less, so that the sliding surface can smoothly slide with respect to the opposed surface.

A movement according to a sixth aspect is a movement including the timepiece component according to any one of the first to fifth aspects and the counter member including the opposed surface, wherein a part of the sliding surface slides while being in contact with or in point contact with the opposed surface line by rotation of the rotating body.

In this movement, since the timepiece component according to any one of the first to fifth aspects is provided, when a part of the sliding surface slides while being in contact with the opposite surface line or in point contact with the opposite surface line by the rotation of the rotating body, it is possible to reduce the energy required for the rotation while suppressing the wear of the sliding surface.

A timepiece according to a seventh aspect includes the movement according to the sixth aspect.

The timepiece includes a movement of a sixth aspect having the timepiece components of any one of the first to fifth aspects. Therefore, when a part of the sliding surface slides while being in contact with the opposing surface line or in point contact by the rotation of the rotating body, the abrasion of the sliding surface can be suppressed, and the energy required for the rotation can be reduced.

[ Effect of the invention ]

In the present application, it is possible to reduce the energy required for the rotation of the rotating body while suppressing wear of the sliding surface.

Drawings

Fig. 1 is a plan view showing a movement including an escape wheel and a pallet fork of the first embodiment.

Fig. 2 is a sectional view showing the escape wheel and the bearing of the first embodiment.

Fig. 3 is a plan view showing a state in which the sliding surface of the escape wheel and the opposed surface of the pallet stone of the first embodiment face each other.

Fig. 4 is an enlarged plan view showing a state in which the sliding surface of the escape wheel and the opposed surface of the pallet stone of the first embodiment face each other.

Fig. 5 is an enlarged perspective view of the escape wheel according to the first embodiment in the vicinity of the sliding surface.

Fig. 6 is a cross-sectional view taken along line 6-6 of fig. 4, showing a state in which the sliding surface of the escape wheel of the first embodiment is opposed to the opposed surface of the pallet stone.

Fig. 7 is an enlarged view of the escape wheel of the first embodiment in the vicinity of the sliding surface, as viewed in the direction of arrow 7 in fig. 5.

Fig. 8 is an enlarged cross-sectional view taken along line 8-8 of fig. 7, showing the escape wheel of the first embodiment in the vicinity of the sliding surface.

Fig. 9 is an explanatory view showing an enlarged view of the escape wheel tip of the escape wheel according to the first embodiment.

Fig. 10 is an explanatory view showing an enlarged view of an escape wheel tip portion of the escape wheel according to the first embodiment.

Fig. 11 is a coordinate diagram showing a relationship between a tenon gap of the escape wheel and a tilt angle of the rotation axis in the first embodiment.

Fig. 12 is a coordinate diagram showing a relationship between the size of the escape wheel and the inclination angle of the sliding surface in the first embodiment.

Fig. 13 is a coordinate diagram showing a relationship between an oil film surface depth and a groove width in the groove portion of the escape wheel according to the first embodiment.

Fig. 14 is a front view of a timepiece illustrating the technique of the present disclosure.

Detailed Description

The timepiece component of the first embodiment and the timepiece 22 using the timepiece component will be described in detail with reference to the drawings.

Timepiece 22 shown in fig. 14 is an automatic winding mechanical watch, and includes movement 24 shown in fig. 1 inside. Movement 24 includes an escape wheel 26 and a pallet fork 28. The escape wheel 26 is an example of a timepiece component, and the pallet 28 is an example of a counterpart.

The escape wheel 26 has a plurality of arms 32 radially extending in an inclined manner with the rotation axis 30 as a center. The plurality of arms 32 are disposed at a predetermined angle in the circumferential direction of the rotary shaft 30. The surface of each arm 32 on the side where the tip end extends is a sliding surface 42.

As shown in fig. 2, the rotation shaft 30 is inserted through a bearing 34 provided in the timepiece 22. Thereby, the escape wheel 26 is rotatably held in the direction of the arrow R1 shown in fig. 1.

As shown in fig. 1, the pallet 28 is swingably held in the direction of arrow Y1 and the direction opposite thereto, that is, in the direction of arrow Y2, about the pallet shaft 36. The pallet 28 is rocked by changing the rotation of a predetermined angle in the direction of the arrow Y1 and the rotation of a predetermined angle in the direction of the arrow Y2 by a pendulum drill, not shown.

The pallet fork 28 has 2 square pieces 38, and the inlet shoe 40A is held by one of the square pieces 38 and the outlet shoe 40B is held by the other. In the following, the pallet-stone 40 will be described as the pallet-stone 40 only, without distinguishing the inlet-stone 40A from the outlet-stone 40B.

Pallet-stone 40, as also shown in fig. 3 and 4, is provided with an opposed surface 44. The opposed surface 44 is a surface that may be opposed to the sliding surface 42 of any one of the arms 32 depending on the rotation angle of the escape wheel 26.

The escape wheel 26 receives a rotational driving force of a driving source, not shown, in the direction of an arrow R1. Rotation of the escape wheel 26 in the direction of arrow R1 is temporarily prevented by abutment of one of the arms 32 against the inlet tile 40A or the outlet tile 40B. For example, as shown in fig. 1, one of the arms 32 abuts on the outlet shoe 40B, and can take a state in which the rotation in the arrow R1 direction is prevented. Here, if the pallet 28 is rotated in the direction of arrow Y1 by a pendulum, not shown, the pallet 40B is separated from the arm 32, and the escape wheel 26 can be rotated in the direction of arrow R1.

On the way the output shoe 40B moves away from the arm 32, the sliding surface 42 slides with respect to the opposed surface 44 of the output shoe 40B, and at the same time the escape wheel 26 rotates.

The escape wheel 26 rotates in the direction of the arrow R1, and at the same time, the pallet 28 rotates in the direction of the arrow Y1 by a predetermined angle, and the pallet 40A abuts on the arm 32 of the escape wheel 26 (an arm different from the arm with which the pallet 40B contacts) in a state where the rotation angle of the escape wheel 26 is at the predetermined angle. Thereby, the rotation of the escape wheel 26 is again prevented. Subsequently, if the pallet 28 rotates in the direction of the arrow Y2, the pallet 40A moves away from the arm 32, and thus the escape wheel 26 can rotate again in the direction of the arrow R1.

As such, the sliding surface 42 also slides with respect to the opposed surface of the inlet shoe 40A on the way of the inlet shoe 40A away from the arm 32, and at the same time, the escape wheel 26 also rotates.

If the escape wheel 26 rotates by a predetermined angle in the direction of the arrow R1, the exit shoe 40B abuts on the arm 32 of the escape wheel 26 (an arm different from the arm with which the entrance shoe 40A contacts), and rotation of the escape wheel 26 is prevented. The escape wheel 26 is a timepiece component that depicts a certain time by performing such intermittent rotation (rotation at a certain angle and stop of rotation).

In the technique of the present disclosure, as shown in fig. 5, 6, 9, and 10, the sliding surface 42 of the escape wheel 26 is inclined at an inclination angle θ 1 with respect to the rotation center line CL-1. Here, as shown in fig. 5, a plane PL including a rotation center line CL-1 is considered, and an angle of the sliding surface 42 on the plane PL with respect to the rotation center line CL-1 (in fig. 5, a reference line CL-2 parallel to the rotation center line CL-1) is taken as an inclination angle θ 1 of the sliding surface 42. In the present embodiment, the inclination angle θ 1 is 1 degree or more and 5 degrees or less. In fig. 6, 9, and 10, the inclination angle θ 1 is shown larger than the actual value in order to clarify the inclination of the sliding surface 42.

In contrast, as shown in fig. 6, opposed surface 44 of pallet-stone 40 is parallel to rotation center line CL-1 of escape wheel 26. Therefore, the sliding surface 42 of the escape wheel 26 faces the opposed surface 44 of the pallet 28 according to the rotation angle of the escape wheel 26, but in such a facing state, the sliding surface 42 is inclined with respect to the opposed surface 44.

In a state where the sliding surface 42 faces the opposed surface 44, the escape wheel tip end portion 26T of the sliding surface 42 contacts the opposed surface 44. In this contact state, the escape wheel 26 rotates in the direction of the arrow R1, and the sliding surface 42 slides while making linear or point-like contact with the opposed surface 44.

As shown in fig. 4 to 8, a plurality of groove portions 46 are formed in the sliding surface 42. Each groove 46 is a direction intersecting the direction in which the sliding surface 42 slides with respect to the opposed surface 44 (the direction of arrow S1). In particular, in the present embodiment, as shown in fig. 7, if the sliding surface 42 is viewed from the front, the extending direction of the groove portion 46 is the direction that coincides with the thickness direction (the direction of the arrow T1) of the escape wheel 26, and is the direction orthogonal to the sliding direction (the direction of the arrow S1).

As shown in fig. 6, since the sliding surface 42 is inclined with respect to the opposed surface 44, a wedge gap WG is formed between the sliding surface 42 and the opposed surface 44 in a state where the sliding surface 42 slides with respect to the opposed surface 44. Further, lubricating oil 48 is applied to the sliding surface 42. In a state where the escape wheel tip portion 26T of the sliding surface 42 is in contact with the opposed surface 44, the lubricating oil 48 can be temporarily stored in the gap WG. The lubricating oil 48 functions to reduce friction when the sliding surface 42 slides against the opposed surface 44.

As shown in fig. 8, a part of the lubricating oil 48 applied to the sliding surface 42 is retained in each groove portion 46. In other words, the groove portion 46 is a recessed portion that is provided so as to be able to hold the lubricating oil 48 in this manner. Even when the amount of the lubricant 48 decreases due to repeated sliding of the sliding surface 42 with respect to the opposed surface 44, the groove portion 46 maintains the state of holding the lubricant 48.

The "retention" of the lubricating oil 48 described here means a state in which the lubricating oil 48 remains in the groove portion 46 without leaking from the groove portion 46 due to viscosity, surface tension, or the like. Therefore, for example, when the lubricating oil 48 retained in the groove portion 46 is not continuous with the lubricating oil 48 on the sliding surface 42 (including a case where the lubricating oil on the sliding surface 42 disappears), the state where the lubricating oil 48 does not leak from the groove portion 46 is maintained regardless of the orientation of the sliding surface 42. Even if the lubricant oil 48 flows vertically downward in the groove portion 46 due to gravity, it does not leak to the outside of the groove portion 46. In contrast, in a state where the lubricating oil 48 retained in the groove portion 46 and the lubricating oil 48 on the sliding surface 42 are continuous, a part of the lubricating oil 48 may be exchanged between the inside of the groove portion 46 and the sliding surface 42, but even in this case, the retained lubricating oil 48 does not completely separate to the outside of the groove portion 46.

In addition, in fact, a part of the lubricating oil 48 slightly rises from the groove portion 46 due to the surface tension described above, and as shown by a two-dot chain line in fig. 8, a meniscus (meniscus)48A rising in a convex shape is sometimes formed. In this case, if the sliding surface 42 slides with respect to the opposed surface 44, the lubricating oil 48 reliably adheres to the pallet leading end portion 28T of the pallet stone 40.

In contrast, as shown by a solid line in fig. 8, the meniscus of the lubricating oil 48 formed in the groove portion 46 may be a concave meniscus 48B that is recessed into the groove portion 46. Even in this case, the pallet tip 28T (see fig. 4) of the pallet stone 40 slightly enters the groove portion 46, and thus the lubricating oil 48 adheres to the pallet tip 28T of the pallet stone 40.

As shown in fig. 7 and 8, the groove portion 46 has a predetermined groove width W1 in the sliding direction. In the present embodiment, the groove width W1 is 1 μm or more and 20 μm or less.

The groove portion 46 has a predetermined groove depth D1 from the sliding surface 42. In the present embodiment, the groove depth D1 is 0.1 μm or more and 3.0 μm or less.

Next, the operation of the present embodiment will be described.

As shown in fig. 5 and 6, the sliding surface 42 of the escape wheel 26 is inclined at an inclination angle θ 1 with respect to the rotation center line CL-1. In contrast, the opposed surface 44 of the pallet 28 is parallel to the rotation center line CL-1. Therefore, the sliding surface 42 is inclined at the inclination angle θ 1 with respect to the facing surface 44 in a state of facing the facing surface 44. When the sliding surface 42 slides on the opposed surface 44 due to rotation of the escape wheel 26 in the direction of the arrow R1 (see fig. 1 to 3), the sliding surface 42 slides in linear or dot contact with the opposed surface 44.

The lubricating oil 48 is retained in the groove portion 46 provided in the sliding surface 42. Due to the lubricating oil 48, the friction of sliding when the sliding surface 42 slides on the opposed surface 44 is reduced, and the resistance to sliding is also reduced.

Thus, in the present embodiment, even if the sliding surface 42 slides on the opposed surface 44, wear of the sliding surface 42 can be suppressed and energy required for rotation of the escape wheel 26 can be reduced, as compared with a structure in which the sliding surface 42 is not inclined and a structure in which the lubricating oil 48 is not retained by the groove portions 46.

In the present embodiment, the sliding surface 42 is inclined at a predetermined inclination angle θ 1 with respect to the rotation center line CL-1 of the escape wheel 26. Therefore, even if the escape wheel 26 rotates, the sliding surface 42 can be maintained in a state of being inclined at a constant inclination angle θ 1 with respect to the rotation center line CL-1.

As shown in fig. 2, the rotation shaft 30 of the escape wheel 26 is inserted into a bearing 34 penetrating the timepiece 22, and a gap GP is generated between the outer periphery of the rotation shaft 30 and the inner periphery of the bearing 34. This gap is a so-called "tenon gap", and the rotation shaft 30 is sometimes inclined with respect to the original rotation center line CL-1 of the escape wheel 26 as shown by a two-dot chain line in fig. 2 due to the gap GP. In the present embodiment, as such, the lower limit value of the inclination angle θ 1 is determined in such a manner that: even if the rotation axis 30, i.e., the actual rotation center line CL-1, is inclined with respect to the designed rotation center line, the sliding surface 42 can be maintained in linear or spot contact with the opposed surface 44.

In fig. 11, the relationship of the inclination of the rotation shaft 30 and the clearance GP (tenon clearance) in the case where the shaft length L1 is 1mm, 2mm, 3mm, and 4mm, respectively, is shown. As shown in fig. 2, the axial length L1 is the length of the entire rotating shaft 30 in the rotating shaft 30.

Specifically, in the escape wheel 26 of the timepiece 22, the maximum value of the gap GP is about 10 μm, the minimum value of the axial length L1 of the bearing 34 is about 1mm, and the maximum inclination angle of the rotary shaft 30 in this case is 0.57 degrees as can be seen from fig. 11. As described above, the lower limit of the inclination angle θ 1 may be set to 1 degree so that the sliding surface 42 can be maintained in linear or point contact with the opposed surface 44 even when the rotation shaft 30 is inclined.

As such, the upper limit value of the inclination angle θ 1 is not limited from the viewpoint of maintaining the state in which the sliding surface 42 is in linear or spot contact with the opposed surface 44. However, if the inclination angle θ 1 is made too large, the thickness of the escape wheel tip 26T becomes thin, and the strength decreases. Therefore, from the viewpoint of ensuring the strength of the escape wheel tip 26T, the upper limit value is preferably set to the inclination angle θ 1.

As shown in fig. 9 and 10, the escape wheel tip portion 26T of the sliding surface 42 may have a curved shape due to a limit in manufacturing accuracy, and the curvature radius R of the curved shape may vary in a range of 0 μm or more and 20 μm. In fig. 9 and 10, the escape wheel tip 26T shown by a solid line is a case where the radius of curvature R is relatively small (as R = R1), and the escape wheel tip 26T shown by a two-dot chain line is a case where the radius of curvature R is large (as R = R2). Fig. 9 shows a case where the inclination angle θ 1 of the sliding surface 42 is relatively small, and fig. 10 shows a case where the inclination angle θ 1 of the sliding surface 42 is relatively large. In fig. 9 and 10, the inclination angle in the drawings is shown to be larger than the actual inclination angle.

As can be seen from both fig. 9 and 10, the larger the radius of curvature R of the escape wheel tip 26T, the larger the influence on the dimension L2 of the escape wheel 26. As can be seen from a comparison between fig. 9 and 10, the dimension L2 becomes larger as the inclination angle θ 1 becomes larger, and this tendency becomes more remarkable as the curvature radius R becomes larger. The dimension L2 is a length from the position of the escape wheel tip 26T (see a reference line L3 shown in fig. 9 and 10) to the actual escape wheel tip 26T when the radius of curvature R =0 (zero) is measured in each arm 32.

Fig. 12 shows the relationship between the dimension L2 and the inclination angle θ 1 in the case where the radius of curvature R of the escape wheel tip 26T is 20 μm, 10 μm, 5 μm, and 2 μm. Here, if the allowable value of the dimensional variation due to the curvature radius R is 2 μm, as is clear from fig. 12, when the curvature radius R is 20 μm, the inclination angle θ 1 corresponding to the dimension L2 of 2 μm is 5.71 degrees. Therefore, if the upper limit value of the inclination angle θ 1 is set to 5 degrees, the variation of the dimension L2 when the curvature radius R is large can be reduced.

As shown in fig. 8, as long as the lubricating oil 48 can be retained in the groove portion 46, the groove width W1 of the groove portion 46 (i.e., the opening width of the groove portion 46 in the direction orthogonal to the extending direction of the groove portion 46) is not limited. However, if the groove width W1 is excessively increased, the pallet tip end portion 28T comes into contact with the groove portion 46 so as to drop when the sliding surface 42 slides on the opposed surface 44, and thus becomes resistance to sliding. When the minimum value of the curvature radius of the pallet front end 28T is set to 20 μm, the resistance when the sliding surface 42 slides on the opposed surface 44 can be reduced by setting the maximum value of the groove width W1 of the groove portion 46 to 20 μm.

As long as the lubricating oil 48 can be retained in the groove portion 46, the groove depth D1 from the sliding surface 42 of the groove portion 46 is not limited. For example, if the lower limit of the groove depth D1 is set to 0.1 μm, the lubricating oil 48 can be retained in the groove portion 46.

However, if the groove portion 46 is made too deep, the lubricating oil 48 accumulates in the vicinity of the groove bottom portion 46B of the groove portion 46 in the groove portion 46, and the amount of the lubricating oil 48 that is not supplied between the sliding surface 42 and the opposed surface 44 increases. For example, as shown in fig. 8, in the groove portion 46, when the meniscus 48B of the lubricating oil 48 is concave, the lubricating oil 48 in the range shown by the one-dot chain line N1 may not be used.

Fig. 13 shows a relationship between the oil film surface depth D2 and the groove width W1 of the lubricating oil 48 retained in the groove portion 46. The oil film surface depth D2 is the depth of the deepest portion measured from the sliding surface 42 in the concave meniscus 48B of the lubricating oil 48 retained in the groove portion 46 as shown in fig. 8. The deepest portion appears at the center within the range of the groove width W1.

Further, the sliding surface 42 may be subjected to a so-called oil retaining treatment. The oil retaining treatment is a treatment for increasing the contact angle θ 2 (see fig. 8) of the lubricating oil 48 at the sliding surface 42 (including the groove portion 46), and the lubricating oil 48 is easily retained on the sliding surface 42 (including the groove portion 46) by the oil retaining treatment. As an example, the contact angle θ 2 in the case where the oil retention treatment is not performed is 30 degrees, as opposed to 70 degrees in the case where the oil retention treatment is performed.

As described above, the maximum value of the groove width W1 of the groove portion 46 can be set to 20 μm in relation to the opposed surface 44 of the pallet stone 40. In this case, the oil film surface depth is 2.7 μm according to FIG. 13. That is, even if the groove depth D1 of the groove portion 46 is made deeper than 2.7 μm, the lubricant oil 48 which cannot be used is generated. In consideration of this, if the upper limit of the groove depth D1 of the groove portion 46 is set to 3 μm, the amount of the lubricating oil 48 that cannot be used can be reduced.

In the technique of the present disclosure, the number of the groove portions 46 is not limited, and only 1 groove may be formed in the sliding surface 42, for example. In the above, as shown in fig. 7, the sliding surface 42 is viewed from the front, and the extending direction of the groove portion 46 is a direction along the thickness direction (the direction of the arrow T1) of the escape wheel 26, but the extending direction of the groove portion 46 may be inclined with respect to the thickness direction of the escape wheel 26. The groove 46 may not have a constant depth and a constant groove width along the extending direction.

In the technique of the present disclosure, the manufacturing method of the escape wheel 26 is not limited, but the escape wheel can be manufactured by, for example, an electroforming method. In this case, a conductive film is formed on one surface of a silicon wafer to form a substrate, and a photoresist layer is formed on the substrate. By providing a tapered portion corresponding to the inclination of the sliding surface 42 in the photoresist layer, the escape wheel 26 having the sliding surface inclined with respect to the rotation center line CL-1 is obtained when the escape wheel 26 is manufactured by electroforming.

In the above, the escape wheel 26 is exemplified as an example of the timepiece component, but the timepiece component is not limited to this, and may be various gears, cams, and the like provided inside the timepiece. The movement is not limited to a structure including the escape wheel 26 and the pallet 28. For example, the technique of the present disclosure may be applied to a mechanism that transmits rotational force by meshing a plurality of gears, or the like.

[ notation ] to show

22 clock

24 movement

26 escape wheel (an example of a rotating body)

Front end of 26T escape wheel

28 escape fork (an example of the counterpart)

Front end of 28T pallet fork

30 rotating shaft

32 arm

34 bearing

36 escape pinion

40 pallet stone

42 sliding surface

44 opposite side of quilt

46 groove part

46B groove bottom

48 lubricating oil

Center line of rotation of CL-1

Plane with PL including center line of rotation

D1 groove depth (depth from sliding surface)

Angle of inclination of theta 1

W1 slot width.