Abstract:
A sliding component has a multi-layer structure having a sliding portion configured to undergo sliding contact with a surface of another component different from the sliding component. A lubricating oil retaining/supplying structure retains a lubricating oil and supplies the lubricating oil to the sliding portion during sliding contact between the sliding portion and the surface of another component irrespective of a contact angle between the sliding portion and the surface of the another component.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a U.S. national stage application of International Application No. PCT/JP2009/052732 filed Feb. 18, 2009, claiming an earliest priority date of Feb. 21, 2008, and published in a non-English language. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a sliding component used as a timepiece component such as a cogwheel or a bearing. 
     2. Background Information 
     As a method of manufacturing a sliding component of high dimensional precision such as a small cogwheel, there is employed a technique combining photolithography and electroforming (See, for example, Patent Document 1). A sliding component involves generation of friction due to a mutual action between itself and a component held in contact therewith. If the regions of these components in contact with each other lack wear resistance, these components will be worn early. The efficiency of a mechanism using the sliding component is markedly affected by wear. In view of this, in order to achieve an increase in wear resistance, a lubricating oil is used. However, being a liquid, the lubricating oil does not remain at the sliding portion but there is danger of its being dispersed over the entire sliding component or to other components. In view of this, some sliding components adopt a structure which retains the lubricating oil at the sliding portion (See, for example, Patent Document 2).
     Patent Document 1: JP-A-2006-64575   Patent Document 2: JP-T-2007-506073   

     In the structure disclosed in Patent Document 1, the sliding portion is smooth, so that any lubricating oil used does not remain at the sliding portion but is quite likely to be dispersed. 
     The structure disclosed in Patent Document 2 adopts a lubricating oil retaining structure, so that the possibility of the lubricating oil being dispersed is low.  FIG. 31  is a partial sectional view showing a sliding process between an escape tooth  501  of an escape wheel &amp; pinion and a pallet  210  of a pallet fork constituting the mating component as disclosed in Patent Document 2. 
     The escape tooth  501  retains a lubricating oil  410  at a lubricating oil retaining portion  521 , so that the lubricating oil  410  is not dispersed but remains at the sliding portion. As shown in  FIGS. 31(   a ) and  31 ( d ), when the escape tooth  501  and the pallet  210  are held in contact with each other in a straight state, the lubricating oil  410  is supplied to the sliding portion, so that lubrication property is to be expected. 
     Also in a case in which the escape tooth  501  and the pallet  210  are held in contact with each other while inclined as shown in  FIGS. 31(   b ) and  31 ( e ), the lubricating oil  410  is supplied to the sliding portion, so that lubrication property is to be expected. However, in a case in which the escape tooth  501  and the pallet  210  are held in contact with each other while inclined as shown in  FIGS. 31(   c ) and  31 ( f ), there is a possibility of the lubricating oil  410  not being supplied from the lubricating oil retaining portion  521 . 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a sliding component of high wear resistance having a lubricating oil retaining structure for supplying a lubricating oil independently of the angle between itself and the mating component. Another object is to provide a timepiece equipped with the sliding component. 
     According to the present invention, there is provided a sliding component in which at least three layers are stacked together and which has a sliding portion sliding on another component on an outer peripheral surface substantially parallel to the direction in which the layers are stacked, characterized in that there is formed a recess in a sliding portion of at least one internally situated layer between an uppermost layer and a lowermost layer of the at least three layers stacked together. According to this invention, the recess constituting a lubricating oil retaining portion is not situated on one side of the stacking direction, so that it is possible to reliably supply the lubricating oil without being much affected by the contact angle between the sliding component and the mating component, making it possible to obtain a sliding component of high wear resistance. 
     In the sliding component of the present invention, the recess may be formed by causing at least one internally situated layer between the uppermost and the lowermost layers of the at least three layers stacked together to recede. 
     The sliding component of the present invention is characterized in that there are provided a plurality of recesses as mentioned above in the stacking direction. According to this invention, the sliding component is less subject to the influence of the contact angle between itself and the mating component, making it possible to supply the lubricating oil more reliably. 
     The sliding component of the present invention is characterized in that the recess is formed over the entire periphery of the outer peripheral surface. According to this invention, it is possible to augment the amount of lubricating oil retained in the recess. 
     The sliding component of the present invention may be of a structure in which at least three layers formed of at least two different kinds of materials are stacked together. In this connection, the material of one layer of the layers may be of higher heat conductivity than the material of the other layers. 
     The sliding component of the present invention is characterized in that at least one of protrusion layers protruding with respect to the layer forming the recess has a curved surface at a crossing portion between a surface substantially perpendicular to the stacking direction and a surface substantially parallel thereto. 
     The sliding component of the present invention is characterized in that the at least three layers comprise a predetermined layer, and a first opposing layer and a second opposing layer which are opposed to the predetermined layer in the thickness direction of the predetermined layer, that the recess is formed by causing the predetermined layer to recede from the outer peripheral surface of the first opposing layer or the second opposing layer, and that at least one of the first opposing layer and the second opposing layer has a curved surface at a crossing portion between a surface substantially perpendicular to the stacking direction and a surface substantially parallel thereto. 
     The sliding component of the present invention is characterized in that at least one of the first opposing layer and the second opposing layer has the curved surface on the former of a predetermined layer side where the predetermined layer is formed and aside opposite to the predetermined layer side. 
     The sliding component of the present invention is characterized in that at least one of the first opposing layer and the second opposing layer has the curved surface on the latter of a predetermined layer side where the predetermined layer is formed and a side opposite to the predetermined layer side. 
     The sliding component of the present invention is characterized in that at least one of the first opposing layer and the second opposing layer has the curved surface on both of a predetermined layer side where the predetermined layer is formed and a side opposite to the predetermined layer side. 
     The sliding component of the present invention is characterized in that it is used as a timepiece component. 
     A timepiece according to the present invention is characterized in that it is equipped with a sliding component according to the present invention. 
     According to the present invention, there is provided a sliding component manufacturing method comprising the steps of: forming a photosensitive material layer on an upper surface of a conductive substrate; exposing the photosensitive material via a mask pattern arranged above the photosensitive material; developing the photosensitive material to form a cavity consisting of the photosensitive material and an exposed surface of the conductive substrate; depositing at least two or more kinds of material layers on the exposed surface of the conductive substrate in the cavity by electroforming; extracting the deposited Material layers from the cavity; and selectively removing a part of the surfaces of the material layers. 
     According to the present invention, it is possible to provide a sliding component of superior wear resistance having a lubricating oil retaining structure, and a timepiece employing this sliding component as a timepiece component to thereby achieve an increase in maintenance period. Further, according to the manufacturing method of the present invention, it is possible to easily manufacture a sliding component of superior wear resistance having a lubricating oil retaining structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  A plan view schematically showing the configuration of a front train wheel side of a movement. 
         FIG. 2  A schematic partial sectional view showing a portion extending from a barrel drum to a pallet fork. 
         FIG. 3  A schematic partial sectional view showing a portion extending from an escape wheel &amp; pinion to a balance with hairspring. 
         FIG. 4  A diagram showing an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 5  An enlarged partial view of an escape tooth and a pallet. 
         FIG. 6  A diagram showing a sliding process of an escape tooth and a pallet. 
         FIG. 7  A diagram showing a lubricating oil supply function of an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 8  A diagram showing a manufacturing process for an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 9  A diagram showing a manufacturing process for an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 10  A diagram showing a manufacturing process for an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 11  A diagram showing a manufacturing process for an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 12  A diagram showing a manufacturing process for an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 13  A diagram showing a manufacturing process for an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 14  A diagram showing a lubricating oil supply function of an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 15  A diagram showing a manufacturing process for an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 16  A diagram showing a manufacturing process for an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 17  A diagram showing a lubricating oil supply function of an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 18  A diagram showing a manufacturing process for an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 19  A diagram showing a manufacturing process for an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 20  A diagram showing a manufacturing process for an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 21  A diagram showing a manufacturing process for an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 22  A diagram showing a lubricating oil supply function of an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 23  A diagram showing a manufacturing process for an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 24  A diagram showing a manufacturing process for an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 25  A partial enlarged view of an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 26  A diagram showing a lubricating oil supply function of an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 27  A diagram showing a lubricating oil supply function of an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 28  A diagram showing a lubricating oil supply function of an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 29  A diagram showing a lubricating oil supply function of an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 30  A diagram showing a lubricating oil supply function of an escape wheel &amp; pinion having a structure according to the present invention. 
         FIG. 31  A diagram showing a lubricating oil supply function of a conventional escape wheel &amp; pinion. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     First Embodiment 
     In the following, a first embodiment of the present invention will be described with reference to the drawings. 
       FIG. 1  is a plan view schematically showing the configuration of a movement front train wheel side of a movement of a timepiece  1 ,  FIG. 2  is a schematic partial sectional view showing a portion extending from a barrel drum  2  to an escape wheel &amp; pinion  100  of the timepiece  1 , and  FIG. 3  is a schematic partial sectional view showing a portion from the escape wheel &amp; pinion  100  to a balance with hairspring  10  of the timepiece. 
     Here, the timepiece  1  is a two-hand type mechanical timepiece. However, the timepiece may also be an electronic control type mechanical timepiece, a quartz type timepiece, etc. 
     The timepiece  1  is equipped with a movement barrel  2  equipped with a mainspring  2 B, a barrel cogwheel  2 A, a barrel arbor  2 C, and a barrel cover  2 D. An external end of the mainspring  2 B is fixed to the barrel cogwheel  2 A, and an internal end thereof is fixed to the barrel arbor  2 C. The barrel arbor  2 C is supported by a main plate  3  and a train wheel bridge  4 , and is fixed in position by a ratchet wheel screw so as to rotate integrally with a ratchet wheel  5 . The ratchet  5  is in mesh with a click  7  so as to rotate clockwise but not to rotate counterclockwise. The method of winding the mainspring  2 B is the same as the self-winding and the manual winding of an ordinary mechanical timepiece, so that a description thereof will be omitted. 
     The rotation of the barrel cogwheel  2 A is increased in speed via a speed increasing train wheel  11  composed of a center wheel &amp; pinion  12 , a third wheel &amp; pinion  13 , and a second wheel &amp; pinion  14 , and is then transmitted to the balance with hairspring  10  via an escape wheel &amp; pinion  100  and a pallet fork  200 . 
     A cannon pinion  15  is fixed to the second wheel &amp; pinion  12  of the speed increasing train wheel  11 , and a minute hand  8  is fixed to the cannon pinion  15 . Based on the rotation of the cannon pinion  15 , an hour wheel  16  is rotated via the rotation of a minute wheel (not shown). An hour hand  9  is fixed to the hour wheel  16 . That is, the indicator hands  8 ,  9  are connected to the speed increasing train wheel  11 , and the barrel cogwheel  2 A and the cogwheels of the wheels &amp; pinions  12  through  14  used in the speed increasing train wheel  11  are used as cogwheels driving the indicator hands  8 ,  9  of the timepiece  1 . Thus, high dimensional precision and wear resistance are required of each timepiece component. 
     The timepiece  1  has various train wheels; in the following description, for the sake of simplicity, the escape wheel &amp; pinion  100  will be taken as an example. It should be noted, however, that the escape wheel &amp; pinion is only taken as an example to facilitate the understanding of the present invention. 
       FIG. 4(   a ) shows the escape wheel &amp; pinion (sliding component)  100  having a structure according to the present invention. The escape wheel &amp; pinion  100  has a plurality of escape teeth  101  in the outer periphery thereof, and an axial hole  102  extending in the thickness direction at the center thereof. The escape wheel &amp; pinion  100  is a component used as a timepiece component of the mechanical timepiece shown in  FIGS. 1 through 3 . 
       FIG. 4(   b ) is an enlarged view of the portion of an escape tooth  101  enclosed by a circle C in  FIG. 4(   a ). The escape tooth  101  has a stop surface  111 , an impact surface  112 , and a back surface  113 , and a crossing ridge between the stop surface  111  and the impact surface  112  constitutes a rocking corner  114 , and a crossing ridge between the impact surface  112  and the back surface  113  constitutes a let-off corner  115 . The stop surface  111 , the impact surface  112 , and the back surface  113  constitute a part of an outer peripheral surface substantially parallel to the thickness direction of the escape wheel &amp; pinion  100 , and the impact surface  112  including the rocking corner  114  and the let-off corner  115  constitute a sliding portion sliding on a pallet  210  described below. The escape wheel &amp; pinion  100  of the structure of the present invention has a multi-layer structure in which at least three layers are stacked together in the thickness direction; for example, in this embodiment, it is composed of a first metal layer  121  (first opposing layer) and a third metal layer  123  (second opposing layer) which are formed of the same material, and a second metal layer  122  which is between the first and second metal layers  121 ,  123  and which is formed of a material different therefrom. 
     Examples of the material of the first and third metal layers  121 ,  123  include metals such as nickel (Ni), cobalt (Co), platinum (Pt), rhodium (Rh), chromium (Cr), and palladium (Pd), alloys such as Ni-tungsten (W) and Ni-boron (B), and composites obtained as eutectoid, in the matrix of one of the above-mentioned metals, of particles or fibers of ceramics such as alumina (Al 2 O 3 ) or silicon carbide (SiC), or a resin such as polytetrafluoroethylene (PTFE), or some other organic or inorganic substance. Examples of the material of the second metal layer  122  include metals such as copper (Cu), gold (Au), zinc (Zn), silver (Ag), iron (Fe), and tin (Sn), alloys such as Cu—Au and Cu—Ag, or a composite obtained as eutectoid of the particles or fibers as mentioned above in the matrix of one of the above metals. In the manufacturing process described below, in order to form a recess  150  in the second metal layer  122  through etching, there is adopted a combination of materials allowing selective etching of the second metal layer  122  only, or a combination of materials involving a difference in etching rate. Since the escape wheel &amp; pinion  100  is a sliding component, it is desirable for the first and third metal layers  121 ,  123  which come into contact with the mating component to be formed of a hard material. 
       FIG. 4(   c ) is a sectional view of the escape wheel &amp; pinion  100  taken along the line X-X of  FIG. 4(   b ). In the escape wheel &amp; pinion  100  having the structure of the present invention, the outer dimension of the second metal layer  122  is smaller than the outer dimension of the first and third metal layers  121 ,  123 . The outer peripheral surface of the second metal layer  122  is receded from the outer peripheral surface of the escape wheel &amp; pinion  100  (the outer peripheral surfaces of the first and third metal layers  121 ,  123 ). Thus, in this embodiment, the escape wheel &amp; pinion  100  has, at least in a part of the sliding portion, a recess  150  extending over the entire periphery of the outer peripheral surface of the escape wheel &amp; pinion  100  and not open in the thickness direction. The recess  150  serves to retain a lubricating oil. 
     In this embodiment, the thickness T 0  of the escape wheel &amp; pinion  100  is 100 μm. The thickness T 0  is set to 10 μm to 1 mm according to the component to be manufactured. The thickness T 1  of the first metal layer  121  and the thickness T 3  of the third metal layer  123  range from 1 μm to 900 μm. It is not necessary for the thickness T 1  and the thickness T 3  to be of the same value. The thickness T 2  of the second metal layer  122  is set to 500 nm to 500 μm. The depth W 1  of the recess  150  is set to 1 μm to 1 mm. The thickness T 2  and the depth W 1  determining the size of the recess  150  are determined as appropriate according to the viscosity and surface tension of the lubricating oil. 
     The escape wheel &amp; pinion  100  slides on a pallet fork  200 . More specifically, escape teeth  101  of the escape wheel &amp; pinion  100  slide on pallets  210  of the pallet fork  200 .  FIG. 5(   a ) is a partial enlarged view of an escape tooth  101 , and  FIG. 5(   b ) is a partial enlarged view of a pallet  210  of the pallet fork  200 . Like the escape tooth  101 , the pallet  210  is composed of a stop surface  211 , an impact surface  212 , a back surface  213 , a rocking corner  214 , and a let-off corner  215 . 
     The process in which the escape tooth  101  slides on the pallet  210  will be described with reference to  FIG. 6 . In  FIG. 6(   a ), the rocking corner  114  of the escape tooth  101  is in contact with the stop surface  211  of the pallet  210 , with the pallet fork stopping the escape wheel &amp; pinion  101 . 
     When the pallet fork moves in the direction of the arrow, a state is attained in which the rocking corner  114  of the escape tooth  101  and the rocking corner  214  of the pallet  210  are held in contact with each other as shown in  FIG. 6(   b ), and then the rocking corner  114  of the escape tooth  101  slides on the impact surface  212  of the pallet  210  as shown in  FIG. 6(   c ). 
     A state is attained in which the rocking corner  114  of the escape tooth  101  and the let-off corner  215  of the pallet  210  are held in contact with each other as shown in  FIG. 6(   d ); and then, as shown in  FIG. 6(   e ), the let-off corner  215  of the pallet  210  slides on the impact surface  112  of the escape tooth  101 . 
     When the let-off corner  115  of the escape tooth  101  and the let-off corner  215  of the pallet  210  are brought into contact with each other as shown in  FIG. 6(   f ), the escape tooth  101  and the pallet  210  are separated from each other. 
     In the sliding process shown in  FIG. 6 , friction occurs between the escape tooth  101  and the pallet  210 , so that a lubricating oil is applied in order to achieve an improvement in terms of wear resistance.  FIG. 7  is a sectional view taken along the line Y-Y of  FIG. 6(   e ). As shown in  FIGS. 7(   a ) and  7 ( d ), the recess  150  serves to retain a lubricating oil  410 . 
     The recess  150  is provided over the entire periphery of the escape wheel &amp; pinion  100 , so that, in all of the states of the sliding process illustrated with reference to  FIG. 3 , it is possible to supply the lubricating oil  410  to the sliding portion. Further, in the escape wheel &amp; pinion  100 , the recess  150  constituting the lubricating oil retaining portion thereof is not situated on one side in the stacking direction but substantially at the center, so that even when the pallet  210  is inclined as shown in  FIGS. 7(   b ),  7 ( e ),  7 ( c ), and  7 ( f ), it is possible to supply the lubricating oil  410  to the sliding portion. 
     In the escape wheel &amp; pinion  100 , the lubricating oil  410  is supplied from the recess  150  to the sliding portion more reliably, whereby an improvement in terms of sliding property is achieved. As a result, the escape wheel &amp; pinion  100  is improved in terms of wear resistance, and the service life of the components becomes longer than that in the prior art. 
     Further, the recess  150  is provided in the entire periphery of the escape wheel &amp; pinion  100 , so that the oil retaining amount is larger than that of an escape wheel &amp; pinion of a conventional structure. A mechanical timepiece requires maintenance for oiling the sliding components every several years; by using a sliding component of the structure of the present invention, it is possible to elongate the inter-maintenance period as compared with the prior art. 
     In the following, a method of manufacturing an escape wheel &amp; pinion  100  of the structure of the present invention will be described with reference to  FIGS. 8 through 11 .  FIGS. 8 through 11  are partial sectional views illustrating a manufacturing process for the escape wheel &amp; pinion  100 . Here, the portion around which one escape wheel &amp; pinion  100  is formed is schematically shown in section. 
       FIG. 8(   a ) is a diagram illustrating a process for forming a conductive substrate. An electrode material  602  is formed on a substrate  601 . The substrate  601  is formed of silicon, quartz, sapphire or the like. The electrode material  602  consists of Cu, Au, Cr, Ti or the like. It is also possible to form the substrate  601  of a metal such as stainless steel or Ti. In the case in which the substrate  601  is formed of a metal, there is no need to form the electrode material  602 . The thickness of the substrate  601  is set to 100 μm to 1 mm so that it can support itself in the processes described below. The thickness of the electrode material  602  is set to 10 nm to 10 μm. 
       FIG. 8(   b ) is a diagram illustrating a resist forming process. A photo resist  603  is deposited on the electrode material  602 . The photo resist  603  may be of either the negative type or the positive type. The photo resist  603  is formed by spin coating, dip coating or the like. When using a dry film resist as the photo resist  603 , it is formed on the electrode material  602  by a laminating method. The thickness of the photo resist  603  is not less than the thickness T 0  of the escape wheel &amp; pinion  100 . In the following, the case will be described in which the photo resist  603  is of the negative type. 
       FIG. 8(   c ) is a diagram illustrating a developing process. Using a photo mask with a contour pattern of the escape wheel &amp; pinion  100 , the photo resist  603  is irradiated with ultraviolet rays, thereby curing the portion of the resist other than that used for electroforming of the escape wheel &amp; pinion  100 . The uncured resist portion is removed, whereby the electroforming mold is completed. A side surface  631  of a photo resist  603 K has a configuration corresponding to the contour of the escape wheel &amp; pinion  100 . A side surface  632  of a photo resist  603 L has a configuration corresponding to that of the axial hole  102 . 
       FIGS. 8(   d ) through  9 ( a ) are diagrams illustrating an electroforming process. The first metal layer  121 , the second metal layer  122 , and the third metal layer  123  are stacked together in that order such that the second metal layer  122  is between the first and third metal layers  121 ,  123 . The electroformed product grows solely from the bottom surface. 
       FIG. 8(   d ) is a diagram illustrating a metal layer electroforming process. The first metal layer  121  is deposited on the mold portion on the electrode material  602  other than the photo resists  603 K,  603 L to a thickness of T 1 . 
       FIG. 8(   e ) is a diagram illustrating a metal electroforming process. The second metal layer  122  is deposited on the second metal layer  122  to a thickness of T 2 . The sum total of the thickness T 1  and the thickness T 2  is smaller than the thickness T 0 . 
       FIG. 9(   a ) is a diagram illustrating a metal electroforming process. The third metal layer  123  is deposited on the second metal layer  122  to a thickness of not less than T 3  so that the thickness of the electroformed product may be not less than the thickness T 0  of the escape wheel &amp; pinion. However, in the case in which the grinding/polishing process shown in  FIG. 9(   b ) to be performed thereafter is omitted, the third metal layer  123  is deposited to a thickness T 3  so that the thickness of the electroformed product may become T 0 . 
       FIG. 9(   b ) is a diagram illustrating the grinding/polishing process. Through grinding, the third metal layer  123  and the photo resists  603 K,  603 L are cut such that the thickness of the escape wheel &amp; pinion  100  becomes T 0 , thereby effecting flattening. Polishing is further performed to form the surface of the third metal layer  123  as a mirror surface. 
       FIG. 9(   c ) is a diagram illustrating a resist removal process. The photo resists  603 K,  603 L are removed by etching, physical force or the like. 
       FIG. 9(   d ) is a diagram illustrating a recess forming process. An electroformed product is immersed in an etching liquid which effects etching on the second metal layer  122  but which does not effect etching on the first and third metal layers  121 ,  123 . Etching is effected only on the second metal layer  122  to form the recess  150  having a depth W 1 . For example, in the case in which Ni is deposited on the first and third metal layers  121 ,  123  and in which Cu is deposited on the second metal layer  122 , it is possible to effect etching solely on the Cu by using an ammonium persulfate solution as the etching liquid. 
       FIG. 9(   e ) is a diagram illustrating an electroformed product separating process. The substrate  601  and the electrode  602  are removed by etching, physical force or the like. 
     The processes shown in  FIGS. 9(   c ) through  9 ( e ) after the grinding/polishing may also be performed by the following steps. 
       FIG. 10(   a ) is a diagram illustrating a substrate/electrode removal process. The substrate  601  and the electrode  602  are removed by etching or the like. 
       FIG. 10(   b ) is a diagram illustrating a resist removal process. The photo resists  603 K,  603 L are removed by etching, physical force or the like. 
       FIG. 10(   c ) is a diagram illustrating a recess forming process. An electroformed product is immersed in an etching liquid which effects etching on the second metal layer  122  but which does not effect etching on the first and third metal layers  121 ,  123 . Etching is effected only on the second metal layer  122  to form the recess  150  of the depth W 1 . 
     When an improvement in functions such as corrosion resistance, lubrication property, and heat resistance is to be achieved, and when the oil retaining property is to be improved by increasing wettability, there is added a plating process shown in  FIGS. 11(   a ) and  11 ( b ) after the process shown in  FIG. 9(   e ) or  FIG. 10(   c ). A metal film  650  is formed by plating all over the separated electroformed product. Examples of the material of the metal film  650  include metals such as Ni, Co, Rh, and Cr, alloys such as Ni—W and Ni—Co, and composites such as Ni—Al 2 O 3  and Ni-PTFE. The thickness T 4  of the metal film  650  is set to 100 nm to 100 μm. The thickness, however, is to be such as will not cause the recess  150  to be filled up. 
     As described above, according to the manufacturing method of the present invention, it is possible to easily manufacture the sliding component shown in  FIG. 4 . 
       FIG. 12  is a diagram illustrating an electroforming process performed in the case in which there is used, as the material of the first metal layer  121 , a composite obtained through eutectoid reaction of particles of Al 2 O 3 , SiC or the like in the metal matrix of Ni, Co or the like.  FIG. 12(   a ) is a diagram illustrating an electroforming process for the first metal layer  121 . As shown in  FIG. 12(   a ), a part of the eutectoid composite particles is not completely confined in the metal matrix but is exposed on the upper surface. The exposed composite particles are completely confined in the metal layer  122  in the electroforming process for the second metal layer  122  shown in  FIG. 12(   b ). In the case in which the composite particles of the first metal layer  121  consist of a substance of rough surface, eutectoid reaction of the composite particles occurs in the interface of the metal layers  121 ,  122 , thereby increasing the force with which the two metal layers are held in intimate contact with each other. This effect is the same with the intimate contact force between the second metal layer  122  and the third metal layer  123  in the casein which a composite is used as the material of the second metal layer  122 . A similar effect is also obtained in the case in which the substance that undergoes eutectoid reaction consists of fibers of tungsten carbide (WC) or the like. 
     In the case in which there is used, as the material of the second metal layer  122 , a composite obtained through eutectoid reaction of particles of PTFE, acrylic resin or the like in the metal matrix of Ni, Cu or the like, the recess can also be formed by the process shown in  FIG. 13 .  FIG. 13(   a ) shows the state after the resist removal process in the case in which there is used, as the material of the second metal layer  122 , a composite obtained through eutectoid reaction of particles of PTFE, acrylic resin or the like in the metal matrix of Ni, Cu or the like. As shown in  FIG. 13(   a ), a part of the composite particles appears through eutectoid reaction in the sliding surface. By removing the composite particles thus appearing through eutectoid reaction in the sliding surface by heat treatment, organic solvent or the like, it is possible to form the recess  150  shown in  FIG. 13(   b ). In this case, the recess  150  is not formed over the entire periphery of the outer peripheral surface but is solely formed in the portion where the composite particles appearing through eutectoid reaction are removed. The recess  150  serves to retain the lubricating oil. 
     In some cases, the escape wheel &amp; pinion  100  involves generation of friction heat during sliding, and the temperature of the sliding portion increases to reduce the hardness of the material forming the escape wheel &amp; pinion  100 , making it subject to wear. However, in the present invention, by using a material of high heat conductivity for the second metal layer  122 , it is possible to improve the heat conductivity of the entire escape wheel  6  pinion  100 , and it becomes hard for the temperature of the first and third metal layers  121 ,  123  to rise, so that the layers become resistant to wear. In an example of such combination of metals, Ni is used for the first and third metal layers  121 ,  123 , and Cu is used for the second metal layer  122 . 
     Further, by adopting the configuration shown in  FIG. 14 , it is possible to achieve a further improvement in terms of wear resistance. The escape wheel &amp; pinion  100  shown in  FIG. 14  has curved surfaces  161 A,  163 A at crossing portions between the outer peripheral surfaces of the first and third metal layers  121 ,  123  and the surfaces not in contact with the second metal layer  122 . It is not necessary for the curvature R 11   a  of the curved surface  161 A and the curvature R 13   a  of the curved surface  163 A to be of the same value. As shown in  FIGS. 7(   b ),  7 ( e ),  7 ( c ), and  7 ( f ), in the case in which the escape tooth  101  and the pallet  210  are in contact with each other while inclined, there is a possibility of a corner abutting to cause an increase in frictional force. On the other hand, when the configuration as shown in  FIG. 14  is adopted, as shown in  FIG. 14(   b ), through formation of the curved surfaces  161 A,  163 A, even when the escape tooth  101  and the pallet  210  are held in contact with each other while inclined, no corner abuts, and satisfactory lubrication property is attained, so that the frictional force is reduced, and an improvement in terms of wear resistance is achieved. Further, due to the formation of the curved surfaces  161 A,  163 A, the Hertz contact pressure at the time of sliding is reduced, so that an improvement in terms of wear resistance is achieved. 
     A method of manufacturing the escape wheel &amp; pinion  100  having the structure shown in  FIG. 14  will be described below with reference to  FIGS. 15 and 16 . 
       FIGS. 15(   a ) and  15 ( c ) are diagrams illustrating a barrel polishing process. After the process of  FIG. 10(   b ), the electroformed product is polished with a barrel to form the curved surfaces  161 A,  163 A. The radius of the curved surfaces  161 A,  163 A can be adjusted according to the barrel polishing condition. As shown in  FIG. 15(   c ), according to the barrel polishing condition, also the crossing portions between the inner peripheral surfaces of the first and third metal layers  121 ,  123  and the surfaces not in contact with the second metal layer  122  are also polished, thereby forming curved surfaces  161 B,  163 B. It is not necessary for the curvatures R 11   a , R 13   a , the curvature R 11   b  of the curved surface  161 B, and the curvature R 13   b  of the curved surface  163 B to be of the same value. 
       FIGS. 15(   b ) and  15 ( d ) are diagrams illustrating a recess forming process. An electroformed product is immersed in an etching liquid which effects etching on the second metal layer  122  but does not effect etching on the first and third metal layers  121 ,  123 . Etching is effected only on the second metal layer  122  to form the recess  150  of the depth W 1 . 
     The process illustrated in  FIGS. 15(   c ) and  15 ( d ) can also be performed by the following process. 
       FIG. 16(   a ) is a diagram illustrating a wet etching process. An electroformed product is immersed in an etching liquid which effects etching on the first and third metal layers  121  and  123  but does not effect etching on the second metal layer  122 . Etching is effected only on the first and third metal layers  121  and  123  to form curved surfaces  161 A,  161 B,  163 A, and  163 B. For example, in the case in which Cr is deposited on the first and third metal layers  121 ,  123  and in which Cu is deposited on the second metal layer, it is possible to effect etching solely on the Cr by using a potassium ferricyanide solution as the etching liquid. 
       FIG. 16(   b ) is a diagram illustrating a recess forming process. An electroformed product is immersed in an etching liquid which effects etching on the second metal layer  122  but does not effect etching on the first and third metal layers  121 ,  123 . Etching is effected solely on the second metal layer  122  to form the recess  150  of the depth W 1 . 
     In the case in which the escape wheel &amp; pinion  100  has the curved surfaces  161 B,  163 B, it is possible to mitigate the stress when a shaft is driven into the axial hole  102 , thereby preventing breakage. 
     Further, also by adopting the configuration shown in  FIG. 17 , it is possible to achieve an improvement in terms of wear resistance. The escape wheel &amp; pinion  100  has curved surfaces  161 C,  163 C at the crossing portions between the outer peripheral surfaces of the first and third metal layers  121 ,  123  and the surfaces in contact with the second metal layer  122 . It is not necessary for the curvature R 11   c  of the curved surface  161 C and the curvature R 13   c  of the curved surface  163 C to be of the same value. The curved surfaces  161 C,  163 C are formed so as to extend from the recess  150  to the sliding surface, so that the lubricating oil  410  can be easily supplied from the recess  150  to the sliding portion as shown in  FIG. 17 . Thus, it is possible to achieve an improvement in lubrication property and in wear resistance. 
     A method of manufacturing the escape wheel &amp; pinion  100  of the structure shown in  FIG. 17  will be described below with reference to  FIGS. 18 through 21 . 
       FIG. 18(   a ) is a diagram illustrating a sacrifice layer electroforming process. After the step of  FIG. 8(   c ), a first sacrifice layer  141  is deposited on the mold portion on the electrode material  602  other than the photo resists  603 K,  603 L. The electroformed product only grows from the bottom surface. The sacrifice layer  141  is formed of Au, Cr, Ni, Cu or the like. The thickness of the first sacrifice layer  141  is set to 10 nm to 10 μm. 
       FIG. 18(   b ) is a diagram illustrating a metal layer electroforming process. The first metal layer  121  is deposited on the first sacrifice layer  141  to a thickness T 1 . The second metal layer  122  is deposited thereon to a thickness T 2 . The third metal layer  123  is deposited thereon to a thickness of not less than T 3  so that the thickness of the electroformed product may exceed the thickness T 0  of the escape wheel &amp; pinion  100 . 
       FIG. 18(   c ) is a diagram illustrating a grinding/polishing process. Through grinding, the third metal layer  123  and the photo resists  603 K,  603 L are cut so that the escape wheel &amp; pinion  100  may attain the thickness T 0  to thereby effecting flattening. Further, polishing is performed to finish the surface of the third metal layer  123  as a mirror surface. 
       FIG. 18(   d ) is a diagram illustrating a sacrifice layer electroforming process. The second metal layer  142  is deposited on the third metal layer  123 . The second sacrifice layer  142  is formed of Au, Cr, Ni, Cu or the like. The thickness of the second sacrifice layer  142  is set to 10 nm to 10 μm. 
       FIG. 18(   e ) is a diagram illustrating a substrate/electrode removal process. The substrate  601  and the electrode  602  are removed by etching or the like. 
       FIG. 18(   f ) is a diagram illustrating a resist removal process. The photo resists  603 K,  603 L are removed by etching, physical force or the like. 
       FIG. 18(   g ) is a diagram illustrating a recess forming process. An electroformed product is immersed in an etching liquid which effects etching on the second metal layer  122  but does not effect etching on the first and third metal layers  121 ,  123  and the first and second sacrifice layers  141 ,  142 . Etching is effected only on the second metal layer  122  to form the recess  150  of the depth W 1 . For example, in the case in which Ni is deposited on the first and third metal layers  121 ,  123 , in which Cu is deposited on the second metal layer  122 , and in which Cr is deposited on the first and second sacrifice layers  141 ,  142 , it is possible to effect etching solely on the Cu by using an ammonium persulfate solution as the etching liquid. 
       FIGS. 18(   h ) and  18 ( j ) are diagrams illustrating a barrel polishing process. The electroformed product is polished with a barrel to form the curved surfaces  161 C,  163 C. The radius of the curved surfaces  161 C,  163 C can be adjusted according to the barrel polishing condition. As shown in  FIG. 17 , in the case of a configuration which has no curved surfaces at the crossing portions between the outer peripheral surfaces of the first and third metal layers  121 ,  123  and the surfaces not in contact with the second metal layer  122 , the radius of the curved surfaces  161 C,  163 C is set to be not more than the thickness of the first and second sacrifice layers  141 ,  142 . As shown in  FIG. 18(   j ), depending upon the barrel polishing condition, the crossing portions between the inner peripheral surfaces of the first and third metal layers  121 ,  123  and the surfaces not in contact with the second metal layer  122  are polished to thereby form curved surfaces  161 D,  163 D. It is not necessary for the curvatures R 11   c , R 13   c , the curvature R 11   d  of the curved surface  161 D, and the curvature R 13   d  of the curved surface  163 D to be of the same value. 
       FIGS. 18(   i ) and  18 ( k ) are diagrams illustrating a sacrifice layer removal process. An electroformed product is immersed in an etching liquid which effects etching on the first and second sacrifice layers  141 ,  142  but does not effect etching on the first and third metal layers  121 ,  123 , and the second metal layer  122 . Etching is effected only on the first and second sacrifice layers  141 ,  142  to remove the sacrifice layers. For example, in the case in which Ni is deposited on the first and third metal layers  121 ,  123 , in which Cu is deposited on the second metal layer  122 , and in which Cr is deposited on the first and second sacrifice layers  141 ,  142 , it is possible to effect etching solely on the Cr by using a potassium ferricyanide solution as the etching liquid. 
     The process shown in  FIGS. 18(   b ) through  18 ( d ) can also be performed by the process illustrated in  FIGS. 19(   a ) and  19 ( b ). 
       FIG. 19(   a ) is a diagram illustrating a metal layer electroforming process. The first metal layer  121  is deposited on the first sacrifice layer  141  to a thickness T 1 . The second metal layer  122  is deposited thereon to a thickness T 2 . The third metal layer  123  is deposited thereon to a thickness T 3 . The sum total of the thickness of the first sacrifice layer and the thickness T 1 , the thickness T 2 , and the thickness T 3  is smaller than the thickness of the photo resists  603 K,  603 L. 
       FIG. 19(   b ) is a diagram illustrating a sacrifice layer electroforming process. The second metal layer  142  is deposited on the third metal layer  123 . 
     The process shown in  FIGS. 18(   g ) through  18 ( j ) can also be performed by the process illustrated in  FIGS. 20(   a ) and  20 ( b ). 
       FIG. 20(   a ) is a diagram illustrating a wet etching process. An electroformed product is immersed in an etching liquid which effects etching on the first and third metal layers  121  and  123  but does not effect etching on the second metal layer  122  and the first and second sacrifice layers  141 ,  142 . Etching is effected only on the first and third metal layers  121  and  123  to thereby form the curved surfaces  161 C,  161 D,  163 C, and  163 D. For example, in the case in which Ni is deposited on the first and third metal layers  121 ,  123 , in which Cr is deposited on the second metal layer, and in which Cu is deposited on the first and second sacrifice layers  141 ,  142 , it is possible to effect etching solely on the Ni by using a nickel selective etching liquid —NC (manufactured by Nippon Chemical Industry Kabushiki Kaisha) as the etching liquid.  FIG. 20(   b ) is a diagram illustrating a sacrifice layer removal process. An electroformed product is immersed in an etching liquid which effects etching on the first and second sacrifice layers  141 ,  142  but does not effect etching on the first and third metal layers  121 ,  123  and the second metal layer  122 . Etching is effected only on the first and second sacrifice layers  141 ,  142  to remove the sacrifice layers. 
     The process shown in  FIGS. 18(   d ) through  18 ( j ) can also be performed by the process shown in  FIGS. 21(   a ) through  21 ( e ). 
       FIG. 21(   a ) is a diagram illustrating a resist removal process. The photo resists  603 K,  603 L are removed by etching, physical force or the like. 
       FIG. 21(   b ) is a diagram illustrating a recess forming process. An electroformed product is immersed in an etching liquid which effects on the second metal layer  122  but does not effect etching on the first and third metal layers  121 ,  123  and the first and second sacrifice layers  141 ,  142 . Etching is effected only on the second metal layer  122  to form the recess  150  of the depth W 1 . 
       FIG. 21(   c ) is a diagram illustrating a wet etching process. An electroformed product is immersed in an etching liquid which effects etching on the first and third metal layers  121  and  123  but does not effect etching on the second metal layer  122  and the first and second sacrifice layers  141 ,  142 . Etching is effected only on the first and third metal layers  121  and  123  to thereby form the curved surfaces  161 C,  161 D,  163 C, and  163 D. 
       FIG. 21(   d ) is a diagram illustrating an electroformed product separating process. The substrate  601  and the electrode  602  are removed by etching, physical force or the like. 
       FIG. 21(   e ) is a diagram illustrating a sacrifice layer removal process. An electroformed product is immersed in an etching liquid which effects on the first and second sacrifice layers  141 ,  142  but does not effect etching on the first and third metal layers  121 ,  123  and the second metal layer  122 . Etching is effected only on the first and second sacrifice layers  141 ,  142  to remove the sacrifice layers. 
     By using the configuration as shown in  FIG. 22 , it is possible to achieve a further improvement in terms of wear resistance. The escape wheel &amp; pinion  100  shown in  FIG. 22  has the curved surfaces  161 A,  161 C,  163 A, and  163 C. It is not necessary for the curvatures R 11   a , R 11   c , R 13   a , and R 13   c  to be of the same value. Due to the provision of the configuration shown in  FIG. 14 , through the formation of the curved surfaces  161 A,  163 A as shown in  FIG. 22(   b ), no corner abuts even when the escape tooth  101  and the pallet  210  are held in contact with each other while inclined, and a satisfactory lubrication property is provided, so that the frictional force is reduced, and an improvement in terms of wear resistance is achieved. Further, through the formation of the curved surfaces  161 A,  161 C,  163 A, and  163 C, the Hertz contact pressure at the time of sliding is reduced, so that an improvement in terms of wear resistance is achieved. 
     Further, due to the provision of the configuration shown in  FIG. 17 , the curved surfaces  161 C,  163 C are formed so as to extend from the recess  150  to the sliding surface, so that the lubricating oil  410  is easily supplied from the recess  150  to the sliding portion. Thus, an improvement is achieved in terms of lubrication property and wear resistance. 
     Further, in the case in which the curved surfaces  161 A and  161 C, and  163 A and  163 C, are connected with each other and in which the entire outer peripheral surface of the escape wheel &amp; pinion  100  is a curved surface, it slides on the pallet  210  while in point contact therewith, so that an improvement is achieved in terms of lubrication property and wear resistance. 
     A method of manufacturing the escape wheel &amp; pinion  100  of the structure shown in  FIG. 22  will be described below with reference to  FIG. 23 . 
       FIGS. 23(   a ) and  23 ( b ) are diagrams illustrating a barrel polishing process. After the process of  FIG. 10(   c ), the electroformed product is polished with a barrel to form the curved surfaces  161 A,  161 C,  163 A, and  163 C. The radius of the curved surfaces  161 A,  161 C,  163 A, and  163 C can be adjusted according to the barrel polishing condition. As shown in  FIG. 23(   b ), the curved surfaces  161 B,  161 D,  163 B, and  163 D are formed depending upon the barrel polishing condition. It is not necessary for the curvatures R 11   a , R 11   b , R 11   c , R 11   d , R 13   a , R 13   b , R 13   c , and R 13   d  to be of the same value. 
     The process shown in  FIG. 23(   b ) can also be performed by the following process. 
       FIG. 24(   a ) is a diagram illustrating a wet etching process. An electroformed product is immersed in an etching liquid which effects etching on the first and third metal layers  121  and  123  but does not effect etching on the second metal layer  122 . Etching is effected only on the first and third metal layers  121  and  123  to thereby form the curved surfaces  161 A,  161 B,  161 C,  161 D,  163 A,  163 B,  163 C, and  163 D. 
     In the case in which the escape wheel &amp; pinion  100  has the curved surfaces  161 B,  161 D,  163 B, and  163 D, it is possible to mitigate the stress when driving a shaft into the axial hole  102 , thereby preventing breakage. 
     Second Embodiment 
       FIG. 25  is a partial enlarged view of an escape wheel &amp; pinion  700  having a structure according to the present invention. The escape wheel &amp; pinion  700  has a multi-layer structure in which n layers (n is an integer of 4 or more) are stacked together in the thickness direction; for example, it is composed of first, third, . . . metal layers  711 ,  713 , . . . which are formed of the same material as the first and third metal layers  121 ,  123  of the first embodiment and of a larger outer dimension, and second, fourth, . . . metal layers  712 ,  714 , . . . which are, for example, formed of the same material as the second metal layer  122  and of a smaller outer dimension. 
     In the second embodiment described above, the effect of the first embodiment is further enhanced. In the following, a case will be described in which n is an odd number and in which the uppermost layer and the lowermost layer are metal layers of a larger outer dimension. In this case, the uppermost layer and the lowermost layer are metal layers that do not undergo etching, so that even when etching is effected on the metal layers to reduce the outer dimension in order to form a recess, there is advantageously no variation in the thickness TO of the escape wheel &amp; pinion  700 . 
     Here, suppose n=2 m+1 (m is an integer of 2 or more). The sliding component  700  has (m+1) first, third, . . . metal layers of a larger outer dimension and m second, fourth, . . . metal layers of a smaller outer dimension, with these metal layers being alternately stacked together in the thickness direction. 
     In the escape wheel &amp; pinion  700 , the outer dimension of the second, fourth, . . . metal layers  712 ,  714 , . . . is smaller than the outer dimension of the first, third, . . . metal layers  711 ,  713 , . . . ). The outer peripheral surfaces of the second, fourth, . . . metal layers  712 ,  714 , . . . are recessed from the outer peripheral surface of the escape wheel &amp; pinion  700  (the outer peripheral surfaces of the first, third, . . . metal layers  711 ,  713 , . . . ). Thus, in this embodiment, the escape wheel &amp; pinion  700  has, dispersed in the thickness direction, m recesses  750  that are not open in the thickness direction of the escape wheel &amp; pinion  100 , at least in a part of the sliding portion, over the entire periphery of the outer peripheral surface of the escape wheel &amp; pinion  700 . The recesses  750  serve to retain the lubricating oil. 
       FIG. 26  is a sectional view showing the sliding process between an escape tooth  701  of the escape wheel &amp; pinion  700  and a pallet  210  of the pallet fork  200  when m=3. As shown in  FIGS. 26(   a ) and  26 ( d ), when the escape tooth  701  and the pallet  210  are in contact with each other in a straight state, there are a plurality of places to which the lubricating oil  410  is supplied, so that there is supplied more lubricating oil  410  than in the first embodiment, with the lubricating oil being delivered uniformly. 
     As shown in  FIGS. 26(   b ),  26 ( e ),  26 ( c ), and  26 ( f ), in the case in which the escape tooth  701  and the pallet  210  are in contact with each other while inclined, when a plurality of recesses  750  are distributed over a wide range, the distance D 1  from the contact point between the escape tooth  701  and the pallet  210  to the closest recess  750  is smaller than the distance D 1  from the contact point between the escape tooth  101  and the pallet  210  to the recess  150  in the example shown in  FIGS. 7(   b ),  7 ( e ),  7 ( c ), and  7 ( f ), so that the lubricating oil  410  can be supplied reliably. 
     Further, when the pallet  210  has surface irregularities as shown in  FIG. 27 , when there is only one recess  150  as in the case of  FIG. 27(   a ), there is a possibility of the lubricating oil  410  not being supplied properly. In contrast, when a plurality of recesses  750  are distributed in the thickness direction as shown in  FIG. 27(   b ), the lubricating oil  410  can be supplied reliably. 
     Further, as shown in  FIG. 28 , when there are provided curved surfaces  761 A,  769 A at the crossing portions between the outer peripheral surfaces of metal layers  711 ,  799  of the escape wheel &amp; pinion  700  and the surfaces not in contact with layers  712 ,  716 , the resultant wear resistance is superior to that in the case of  FIGS. 26(   b ),  26 ( e ),  26 ( c ), and  26 ( f ). It is not necessary for the curvature R 71   a  of the curved surface  761 A and the curvature R 79   a  of the curved surface  769 A to be of the same value. As shown in  FIGS. 26(   b ),  26 ( e ),  26 ( c ), and  26 ( f ), when the escape tooth  701  and the pallet  210  are in contact with each other while inclined, there is a possibility of a corner abutting to cause an increase in frictional force. In contrast, by using the configuration as shown in  FIG. 28 , due to the provision of the curved surfaces  761 A,  769 A as shown in  FIG. 28(   b ), no corner abuts even when the escape tooth  701  and the pallet  210  are held in contact with each other while inclined, and satisfactory lubrication property is provided, so that an improvement in terms of wear resistance is achieved. 
     As shown in  FIG. 29 , in a case in which there are provided curved surfaces  761 C,  769 C at the crossing portions between the outer peripheral surfaces of the metal layers  711 ,  799  of the escape wheel &amp; pinion  700  and the surface in contact with the layers  712 ,  716  and in which there are provided curved surfaces  763 C,  765 C at the crossing portions between the outer peripheral surfaces of the metal layers  713 ,  715  and the surface in contact with the upper and lower metal layers, the wear resistance is superior to that in the case of  FIGS. 26 and 27(   b ). It is not necessary for the curvature R 71   c  of the curved surface  761 C, the curvature R 73   c  of the curved surface  763 C, the curvature R 75   c  of the curved surface  765 C, and the curvature R 79   c  of the curved surface  769 C to be of the same value. Since the portion extending from the recess  750  to the sliding surface is a curved surface, the lubricating oil  410  can be easily supplied from the recess  750  to the sliding portion as shown in  FIG. 29 , and the lubrication property is improved, whereby an improvement in terms of wear resistance is achieved. 
     Further, when, as shown in  FIG. 30 , there are provided curved surfaces  761 A,  761 C,  763 C,  765 C,  769 C,  769 A, and  769 C, the wear resistance is further enhanced. It is not necessary for the curvatures R 71   a , R 71   c , R 73   c , R 75   c , R 79   a , and R 79   c  to be of the same value. As shown in  FIG. 30(   b ), even when the escape tooth  701  and the pallet  210  are held in contact with each other while inclined, no corner abuts, and satisfactory lubrication property is provided, so that the frictional force is reduced, and the wear resistance is enhanced. Further, since there is no corner, the Hertz contact pressure at the time of sliding is reduced, thereby achieving an improvement in terms of wear resistance. Further, the portion from the recess  750  to the sliding surface is a curved surface, the lubricating oil  410  can be easily supplied from the recess  750  to the sliding portion as shown in  FIG. 30 , and an improvement is achieved in terms of lubrication property and wear resistance. Further, in the case in which the entire outer peripheral surface of the escape wheel &amp; pinion  700  is a curved surface, it slides on the pallet  210  while in point contact therewith, so that an improvement is achieved in terms of lubrication property and wear resistance. 
     Further, since the escape wheel &amp; pinion  700  has a plurality of recesses  750  for retaining the lubricating oil, so that the amount of lubricating oil  410  retained is large. Thus, the inter-maintenance period of can be made longer than that in the first embodiment. 
     The thickness T 0  of the escape wheel &amp; pinion  700  is the same as the thickness T 0  in the first embodiment. The thicknesses T 1  through T 2   m+ 1 of the metal layers are the same as the thicknesses T 1 , T 3  in the first embodiment. It is not necessary for the thicknesses T 1  through T 2   m+ 1 to be of the same value. The thicknesses T 2  through T 2   m  are the same as the thickness T 2  in the first embodiment. It is not necessary for the thicknesses T 2  through T 2   m  to be of the same value. The depth W 1  of the recess W 1  is the same as the depth W 1  in the first embodiment. 
     The method of manufacturing the escape wheel &amp; pinion  700  is the same as that in the first embodiment. However, the electroforming process shown in  FIGS. 8(   d ) through  9 ( f ),  FIG. 12 ,  FIG. 18(   b ), and  FIG. 19(   a ) is conducted until the n-th layer is stacked. In this connection, the thickness as measured up to the (n−1)th layer is smaller than the thickness T 0 . 
     While in the above embodiments described above an escape wheel &amp; pinion is taken as an example of the sliding component, this should not be construed restrictively; the present invention is also applicable to timepiece components such as a center, third, and second wheel &amp; pinion, a ratchet wheel, a movement barrel, a click, and a crown wheel of a mechanical timepiece. 
     Further, the present invention is applicable not only to timepiece components but also to sliding components such as a cogwheel of an endoscope advancing/retreating apparatus, and a gear of a drive apparatus of a toy vehicle. 
     According to the present invention, it is possible to provide a sliding component having a lubricating oil retaining structure and that is superior in wear resistance, and a timepiece whose inter-maintenance period is prolonged by using this sliding component as a timepiece component. Further, according to the manufacturing method of the present invention, it is possible to easily manufacture a sliding component having a lubricating oil retaining structure and that is superior in wear resistance.