Powder lubrication method for a wave gear device

Abstract

In the inner space (9) of the outer gear (3) of the invention's wave gear device (1), a powder supply mechanism (10) is assembled with a press-formed product (12) in which solid lubricant powder is pre-solidified. During operation of the wave gear device (1), the powder supply mechanism (10) wears the press-formed product (12) using a friction plate (13) to supply a small amount of solid lubricant wear powder (11) from the press-formed product (12) for a long period. Loss torque caused by the efficiency reduction due to the invasion of a large amount of solid lubricant powder into the gap of the contact portion (C) of the high-speed rotating wave generator (4) and the like can be suppressed. Thus, the high efficiency state of the powder-lubricated wave gear device can be maintained and its long service life can be achieved.

Description

Technical Field

[0001] This invention relates to a wave gear device, and more particularly to a powder lubrication method for a wave gear device that uses powder of a solid lubricant to lubricate contact surfaces, etc. Background Technology

[0002] The inventors of this invention have proposed a powder lubrication method in Patent Documents 1 and 2, which lubricates the contact surfaces of components of a wave gear device by using tiny powders of a solid lubricant sealed or filled inside the device. Regarding the wave gear device described in Patent Document 1, tiny powders of an ion-bonded compound with a layered structure are filled into the internal space of the external gear as a solid lubricant. When the wave gear device is in operation, the filled tiny powders are flattened between the contact surfaces of the lubricated objects and move to both contact surfaces to form a thin surface film. Furthermore, they are compressed and further subdivided to change into a shape that easily penetrates the contact surfaces. Lubrication is maintained by the tiny powders whose shape has changed and the thin surface film formed on the contact surfaces. The moving thin surface film and the subdivided tiny powders are non-sticky, so no viscous resistance loss occurs, enabling efficient operation in low-load and high-speed rotation regions. On the other hand, the wave gear device described in Patent Document 2 has a mechanism for efficiently guiding tiny powders of solid lubricant sealed or filled inside the external gear to the part to be lubricated.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2016 / 084235

[0006] Patent Document 2: International Publication No. 2016 / 113847 Summary of the Invention

[0007] Here, the experiments conducted by the inventors of the present invention have shown that the service life of a wave gear device lubricated by micro-powders of solid lubricant largely depends on the amount of micro-powders used; if an appropriate amount of powder is not ensured, the service life will be shortened.

[0008] However, when using fine powders of solid lubricants with a layered structure, these fine powders are introduced into the gaps between the contact surfaces due to cleavage forces, resulting in them being compressed thinner. This leads to a temporary reduction in efficiency due to torque loss during further subdivision. The magnitude and frequency of this efficiency reduction are influenced by various factors, including the atmosphere during the operation of the wave gear device, the characteristics of the fine powders used (load capacity, coefficient of friction, cohesiveness, etc.), the filling amount, and particle size. In particular, when a large amount of fine powder is supplied to the gaps between the contact surfaces of a high-speed rotating wave generator, the efficiency reduction due to torque loss becomes significant, hindering the stable operation of the wave gear device.

[0009] The purpose of this invention is to provide a powder lubrication method for a wave gear device, which can continuously supply an appropriate amount of powder to the lubrication target parts such as the contact surface of the wave generator, so as to suppress the efficiency reduction caused by the loss of torque due to the supply of a large amount of solid lubricant powder to the lubrication target parts.

[0010] In addition, the present invention aims to provide a wave gear device having a powder supply mechanism capable of continuously supplying an appropriate amount of powder to the lubrication target area in order to suppress the efficiency reduction caused by the loss of torque due to the supply of a large amount of solid lubricant powder to the lubrication target area.

[0011] The powder lubrication method for the wave gear device of the present invention is characterized in that,

[0012] A pressurized solid lubricant powder is placed inside the wave gear device.

[0013] When the wave gear device operates, the friction plate comes into frictional contact with the pressurized molded product, generating solid lubricant wear powder.

[0014] The generated solid lubricant wear powder is used to lubricate the lubrication target parts of the wave gear device.

[0015] Furthermore, the wave gear device of the present invention is characterized in that...

[0016] The wave gear device comprises: a rigid internal gear; a flexible external gear disposed inside the internal gear; a wave generator disposed inside the external gear; and a powder supply mechanism disposed inside the external gear.

[0017] The powder supply mechanism comprises: a pressurized molded article of solid lubricant powder; a friction plate that rubs against the pressurized article to generate solid lubricant abrasive powder; and a pressing member that presses the friction plate against the pressurized article to maintain the state of frictional contact.

[0018] As solid lubricant powders, molybdenum disulfide (MoS2), tungsten disulfide (WS2), graphite, carbon nanotubes (CNT), onion carbon (OLC), etc. can be used.

[0019] When the wave gear device is used as a speed reducer, the wave generator is a rotary input component, and the external gear is a fixed component or a speed-reducing rotary output component. In this case, a friction plate is disposed on one of the wave generator and the external gear, and a pressure-molded part is disposed on the other. Furthermore, a spring component is used to press at least one of the friction plate and the pressure-molded part against the other component.

[0020] In this invention, the press-molded solid lubricant powder is preferably a lightly press-molded product with a pressed density of less than 50% of its true density. Furthermore, the press-molded product is preferably a simple shape such as a cylinder or a ring.

[0021] In this invention, the friction plate can be made of steel, stainless steel, copper alloy, aluminum alloy, ceramics, etc., with a hardness of Hv60 or higher or a Mohs hardness of 2 or higher. Furthermore, a material that makes it difficult for solid lubricant powder to move is preferred as the friction plate material. The surface roughness of the friction surface of the friction plate is preferably 12S or lower, and it can have a fine surface-based shape.

[0022] Invention Effects

[0023] In this invention, instead of filling the interior of the wave gear device with fine powder of solid lubricant, a press-molded article formed by pre-solidifying the solid lubricant powder is disposed inside the wave gear device. During operation of the wave gear device, the press-molded article wears down, resulting in a stable, long-term generation of minute amounts of solid lubricant wear powder. This suppresses the efficiency reduction caused by torque loss due to the large amount of solid lubricant powder supplied to the gap between the contact surfaces of the lubricated object. Therefore, a stable, high-efficiency state of the wave gear device can be maintained, and its lifespan extended. Attached Figure Description

[0024] Figure 1A This is a schematic longitudinal sectional view showing an example of the wave gear device to which the present invention is applied.

[0025] Figure 1B yes Figure 1A A schematic longitudinal sectional view of the wave gear device, showing a semi-longitudinal section of the initial state on the left and a semi-longitudinal section of the final state of the press-molded part reduced due to wear on the right.

[0026] Figure 2A This is a schematic longitudinal sectional view showing another example of the wave gear device to which the present invention is applied.

[0027] Figure 2B yes Figure 2A A schematic longitudinal sectional view of the wave gear device, showing a semi-longitudinal section of the initial state on the left and a semi-longitudinal section of the final state of the press-molded part reduced due to wear on the right. Detailed Implementation

[0028] Hereinafter, embodiments of the wave gear device to which the present invention is applied will be described with reference to the accompanying drawings. Furthermore, the following embodiments represent one example of the present invention and are not intended to limit the present invention to these embodiments.

[0029] (Implementation Method 1)

[0030] Figure 1A This is a schematic longitudinal sectional view showing an example of the wave gear device to which the present invention is applied. The wave gear device 1, referred to as a cup-shaped device, includes: a rigid internal gear 2 in the shape of an annulus; a flexible external gear 3 in the shape of a cup; and a wave generator 4 with an elliptical profile. The external gear 3 is coaxially disposed inside the internal gear 2. The wave gear device 1 is configured in a vertical position with its axis 1a pointing in the vertical direction and the wave generator 4 located on the upper side.

[0031] The external gear 3 has a cylindrical body 3a that can flex in the radial direction, and external teeth 3b are formed on the outer peripheral surface of the cylindrical body 3a at the open end. A diaphragm 3c extending inward in the radial direction is formed from the opposite end of the cylindrical body 3a. A rigid annular boss 3d is formed on the inner peripheral edge of the diaphragm 3c. The boss 3d is clamped between the annular pressing member 7b and the output shaft 7a, and in this state, the three parts are coaxially fastened and fixed by a plurality of fastening bolts 7c.

[0032] The wave generator 4 includes: a rigid wave plug 4a; and a wave bearing 4b (wave generator bearing), which is mounted on the outer peripheral surface of the elliptical profile. The wave generator 4 is mounted on the inner side of the portion of the cylindrical main body 3a of the external gear 3 where the external teeth 3b are formed.

[0033] In this example, the wave gear device 1 is used as a speed reducer. For example, the internal gear 2 is fixed to the device housing 5, which is located on the upper side and serves as a fixed component. The wave generator 4 is connected to the input shaft 6, such as the motor rotation shaft, which is located on the upper side. The external gear 3 is coaxially connected to the output shaft 7a located on the lower side. The high-speed rotation input to the wave generator 4 is significantly reduced by the internal gear 2 and the external gear 3, and the reduced rotation is output from the external gear 3 via the output shaft 7a.

[0034] Here, a powder supply mechanism 10 is assembled inside the cylindrical main body 3a of the external gear 3 and in the inner space 9 formed between the diaphragm 3c and the wave generator 4. Solid lubricant wear powder supplied from the powder supply mechanism 10 is supplied to the lubrication target area inside the wave gear device 1 to lubricate the aforementioned lubrication target area.

[0035] The main lubrication points of the wave gear device 1 are: the contact portion (tooth portion) A between the internal gear 2 and the external gear 3; the contact portion B between the inner circumferential surface 3f of the cylindrical main body 3a of the external gear 3 and the outer circumferential surface 4c of the wave generator 4; and the contact portion C inside the wave generator 4. The contact portion C inside the wave generator 4 includes: the contact portion between the wave plug 4a and the wave bearing 4b; and the contact portion between the components of the wave bearing 4b (inner ring, outer ring, and balls). Each contact surface of contact portion B (inner circumferential surface 3f, outer circumferential surface 4c) and each contact surface of contact portion C inside the wave generator 4 communicates with the inner space 9 of the external gear 3. Each contact surface of contact portions B and C is lubricated by solid lubricant abrasive powder 11 supplied from the powder supply mechanism 10. Additionally, contact portion A is also lubricated by solid lubricant abrasive powder 11 that passes through contact portions B and C and winds into contact portion (tooth portion) A.

[0036] The powder supply mechanism 10 includes: a press-molded article 12 of solid lubricant powder; a friction plate 13 that rubs against the press-molded article 12 to generate solid lubricant abrasive powder 11; and a molding pressing part 14 that presses the press-molded article 12 and the friction plate 13 relative to each other to maintain their rub-contact state. Additionally, it includes: a first guide plate 15 that agitates the solid lubricant abrasive powder 11 generated by the press-molded article 12 and guides it toward contact portions B and C of the lubrication target area; and a second guide plate 16 that guides the solid lubricant abrasive powder 11 passing through contact portions B and C toward contact portion A.

[0037] To explain in more detail, the disc-shaped friction plate 13 is coaxially fixed to the inner end face 4d of the waveform plug 4a of the wave generator 4, facing the inner space 9. In this example, it is fixed by bolts 17 that fasten the waveform plug 4a to the input shaft 6. The end face of the friction plate 13 facing the inner space 9 is designated as the friction surface 13a. A press-molded article 12, formed as an annular solid lubricant powder of a fixed thickness, is coaxially disposed on the lower side of the friction surface 13a. In this example, the press-molded article 12 is pressed onto the friction surface 13a by the molding pressing part 14 along the direction of the axis 1a.

[0038] The molding pressing part 14 includes: a molding holding member 21, which holds the pressurized molding 12 in a state that can move in a direction relative to the friction surface 13a; a molding pressing plate 22, which presses the pressurized molding 12 held in the molding holding member 21 against the friction surface 13a; and a large-diameter outer helical spring 23 and a small-diameter inner helical spring 24, which press the pressurized molding 12 against the friction surface 13a by means of the molding pressing plate 22.

[0039] The molded article holding member 21 is coaxially fixed to the central shaft portion 7d of the output shaft 7a, which passes through the central opening of the boss 3d of the external gear 3 and extends into the inner space 9. The molded article pressing plate 22 includes an annular protrusion 22a disposed on the lower side of the molded article holding member 21 and pressing the pressurized molded article 12 held in the molded article holding member 21 against the friction surface 13. In addition, the molded article pressing plate 22 is supported by a cylindrical shaft portion 21a formed in the center of the molded article holding member 21 and is in a state that can slide in the direction of the axis 1a. This sliding molded article pressing plate 22 is pressed toward the friction surface 13a by a large-diameter outer helical spring 23 and a small-diameter inner helical spring 24. The outer helical spring 23 is configured in a compressed state between the molded pressing plate 22 and the diaphragm 3c of the external gear 3, and the inner helical spring 24 is configured in a compressed state between the molded pressing plate 22 and the end face 7e of the output shaft 7a exposed at the center opening of the boss 3d of the external gear 3.

[0040] Next, the first guide plate 15 of the powder supply mechanism 10 is installed within the inner space 9, surrounding the friction plate 13 and the pressure-molded article 12, on the inner end face 4d of the plug of the wave generator 4. The first guide plate 15 includes: an inverted frustum-shaped cylindrical portion 15a that extends from the lower side to the upper side along the direction of the axis 1a; and a disc-shaped portion 15b that extends from the upper end of the cylindrical portion 15a toward the inner side in the radial direction, the inner circumferential portion of the disc-shaped portion 15b being coaxially fixed to the inner end face 4d of the plug. Openings 15c are formed at equal angular intervals on the outer circumferential edge of the disc-shaped portion 15b connected to the upper end of the cylindrical portion 15a in the circumferential direction.

[0041] Furthermore, the second guide plate 16 is coaxially fixed to the outer end face 4e of the plug on the opposite side of the inner space 9 of the waveform plug 4a. The second guide plate 16 is disc-shaped, and its outer periphery extends to the vicinity of the outer ring of the waveform bearing 4b of the wave generator 4. In addition, an annular end face portion 5a extending from the outer periphery to the contact portion A (tooth portion) is formed on the device housing 5 at a position adjacent to the upper side of the second guide plate 16.

[0042] Figure 1BThis is a schematic longitudinal sectional view of the wave gear device. The left side shows a semi-longitudinal section of the initial state, and the right side shows a semi-longitudinal section of the final state, where the remaining portion has been reduced due to wear of the pressure-molded part 12. Referring also to this figure, when the wave gear device 1 is operating, the friction plate 13 and the wave plug 4a of the wave generator 4 are integrated and rotate at high speed. The pressure-molded part 12, held in place by the molding pressing part 14 mounted on the output shaft 7a, is integrated with the output shaft 7a and rotates at a reduced speed. As a result, the pressure-molded part 12 is formed into a frictional contact state where it is pressed against the friction surface 13a of the friction plate 13 by elastic force. Due to wear of the friction surface 13a, the pressure-molded part 12 generates solid lubricant wear powder 11.

[0043] Solid lubricant abrasive powder 11 generated by the pressure-molded article 12 is guided towards the upper end of the cylindrical portion 15a by the inverted frustum-shaped cylindrical portion 15a and the disc-shaped portion 15b of the first guide plate 15, and then guided towards the contact portions B and C through the opening 15c. Additionally, solid lubricant abrasive powder 11 scattered from the lower end of the cylindrical portion 15a outwards is guided towards the contact portions B and C along the outer frustum-shaped peripheral surface of the rapidly rotating inverted frustum-shaped cylindrical portion 15a.

[0044] Solid lubricant abrasive powder 11 is supplied to the internal contact part B (wave generator bearing 4b) and the contact part C (the contact part between the wave generator 4 and the external gear 3) to lubricate the aforementioned parts. Furthermore, a portion of the solid lubricant abrasive powder 11 supplied to the wave generator bearing 4b passes through the track portion of the wave generator bearing 4b and moves upward. Additionally, a portion of the solid lubricant abrasive powder 11 supplied between the wave generator 4 and the external gear 3 passes between them and moves upward.

[0045] A second guide plate 16, integrally formed with the wave generator 4 and rotating at high speed, is disposed on the upper side of the wave generator bearing 4b. Solid lubricant wear powder 11 passing through the upper side is guided to the outer peripheral side by the high-speed rotating second guide plate 16 and supplied to the contact part A (the tooth surface of the outer and inner teeth).

[0046] exist Figure 1B A comparison of the left and right semi-longitudinal sections reveals that the thickness of the press-molded article 12 gradually decreases due to wear caused by frictional contact with the friction plate 13. The press-molded article 12 is constantly pressed against the friction surface 13a of the friction plate 13 by elastic force, thus continuously generating a fixed amount of solid lubricant wear powder 11. Consequently, the solid lubricant wear powder 11 is continuously supplied to the contact portions B and C of the lubricated object at approximately a fixed amount.

[0047] Here, as a solid lubricant powder for molding the pressure-molded article 12, molybdenum disulfide (MoS2), tungsten disulfide (WS2), graphite, carbon nanotubes (CNT), onion carbon (OLC), etc., can be used.

[0048] The pressure-molded article 12 is preferably a simple cylindrical or annular shape. Furthermore, it is best to be a lightly pressure-molded article, with a pressed powder density preferably less than 50% of the true density. Regarding the true density, it is 4.8 in the case of molybdenum disulfide, 7.5 in the case of tungsten disulfide, 2.2 in the case of graphite, and 1.74 in the case of onion carbon.

[0049] As for the material of the friction plate 13, if the hardness is Hv60 or higher (Mohs hardness is 2), steel, stainless steel, copper alloy, aluminum alloy, or ceramic can be used. The friction plate 13 is preferably made of a material that makes it difficult for the solid lubricant wear powder to move. If ranked from materials that are easy to move, the order is steel, stainless steel, copper alloy, aluminum alloy, and ceramic. Furthermore, the surface roughness of the friction surface 13a is preferably 12S or lower, and it may also have a fine shape based on surface texture.

[0050] In this example, a pair of helical springs 23 and 24 are used to generate the pressing force that presses the molded article 12 against the friction plate 13. Various types of springs can be used to generate the pressing mechanism that produces the fixed pressing force. For example, helical springs, coil springs, conical springs, etc., can be used; however, compression helical springs, which allow for flexible design of spring constants, are easier to handle. Multiple spring components can be used.

[0051] As explained above, during the operation of the wave gear device 1, by causing the pressure-molded part 12 to wear, a small amount of solid lubricant wear powder 11 can be stably generated over a long period and supplied to the lubricated part. This suppresses the efficiency reduction caused by the loss torque resulting from the supply of a large amount of solid lubricant powder to the gap between the contact surfaces of the lubricated part, especially in the contact portion of the high-speed rotating wave generator 4. Therefore, the wave gear device 1 can maintain a stable and efficient state and achieve a long service life.

[0052] (Implementation Method 2)

[0053] Regarding the powder supply mechanism 10 of the wave gear device 1 in Embodiment 1 described above, a pressure-molded article 12 is mounted on the side of the output shaft 7a (external gear 3) that rotates at a reduced speed, and a friction plate 13 is mounted on the side of the wave plug 4a of the high-speed rotating wave generator 4. A powder supply mechanism with a structure in which the pressure-molded article 12 is mounted on the high-speed rotating wave plug 4a and the friction plate 13 is mounted on the output shaft 7a (external gear 3) that rotates at a reduced speed can be used instead of the powder supply mechanism 10.

[0054] Figure 2A This is a schematic longitudinal sectional view of a wave gear device assembled with this type of powder supply mechanism. The basic structure of the wave gear device 100 is the same as that of the wave gear device 1, so the same reference numerals are used for corresponding parts and their descriptions are omitted.

[0055] The powder supply mechanism 110 includes: a press-molded article 112 of solid lubricant powder; a friction plate 113 that rubs against the press-molded article 112 to generate solid lubricant abrasive powder 111; and a molding pressing part 114 that presses the press-molded article 112 and the friction plate 113 relative to each other to maintain their rub-contact state. Additionally, it includes: a first guide plate 15 that agitates the solid lubricant abrasive powder 111 generated by the press-molded article 112 and guides it toward contact portions B and C of the lubrication target area; and a second guide plate 16 that guides the solid lubricant abrasive powder 111 passing through contact portions B and C toward contact portion A.

[0056] A disc-shaped friction plate 113 is mounted on the output shaft 7a fixed to the external gear 3. The friction plate 113 includes a disc portion 113b disposed in the inner space 9; and a mounting shaft portion 113c protruding from the center of the disc portion 113b toward the opposite side of the inner space 9. The mounting shaft portion 113c passes through the central opening of the boss 3d of the external gear 3 and is coaxially fixed to the output shaft 7a. The end face of the disc portion 113b facing the inner space 9 is designated as the friction surface 113a. The friction plate 113 and the output shaft 7a (external gear 3) are integrally formed and rotate at reduced speed.

[0057] The molding pressing part 114 includes: a molding holding member 121, which holds the pressurized molding 112 in a state that can move in a direction relative to the friction surface 113a; a molding pressing plate 122, which presses the pressurized molding 112 held in the molding holding member 121 against the friction surface 113a; and a coil spring 123, which presses the pressurized molding 112 against the friction surface 113a by means of the molding pressing plate 122.

[0058] The molded article holding member 121 is coaxially fixed to the input shaft 6, which is fixed to the waveform plug 4a of the wave generator 4, in the inner space 9. The molded article pressing plate 122 has an annular protrusion 122a disposed on the upper side of the molded article holding member 121, which presses the pressurized molded article 112 held in the molded article holding member 121 against the friction surface 113a. In addition, the molded article pressing plate 122 is supported by a pressing plate guide shaft 121a formed in the center of the molded article holding member 121, and is in a state that can slide in the axial direction. This sliding molded article pressing plate 122 is pressed toward the friction surface 113a by a coil spring 123. The coil spring 123 is disposed in a compressed state between the molded article pressing plate 122 and the inner end face 4f of the center side of the waveform plug 4a.

[0059] Figure 2B This is a schematic longitudinal sectional view of the wave gear device. A semi-longitudinal section showing the initial state is shown on the left, and a semi-longitudinal section showing the final state, with the remaining portion reduced due to wear of the pressure-molded part 112, is shown on the right. The description will also refer to this figure. When the wave gear device 100 is in operation, the friction plate 113 is integrally formed with the output shaft 7a (external gear 3) and rotates at reduced speed. The pressure-molded part 112, which is mounted on the wave plug 4a (input shaft 6) side of the wave generator 4, is integrally formed with the wave plug 4a and rotates at high speed. The pressure-molded part 112 is formed into a frictional contact state where it is pressed against the friction surface 113a of the friction plate 113 by elastic force. Solid lubricant wear powder 111 is generated in the pressure-molded part 112 due to wear of the friction surface 113a.

[0060] Solid lubricant abrasive powder 111 generated by the pressure molding article 112 is guided towards the upper end of the cylindrical portion 15a by the inverted frustum-shaped cylindrical portion 15a and the disc-shaped portion 15b of the first guide plate 15, and then guided towards the contact portions B and C through the opening 15c. In addition, solid lubricant abrasive powder 111 scattered from the lower end of the cylindrical portion 15a to the outer periphery is guided towards the contact portions B and C along the outer periphery of the frustum-shaped cylindrical portion 15a which is rotating at high speed.

[0061] Solid lubricant abrasive powder 111 is supplied to the internal contact part B (wave generator bearing 4b) and contact part C (the contact part between wave generator 4 and external gear 3) to lubricate the aforementioned parts. Furthermore, a portion of the solid lubricant abrasive powder 111 supplied to the wave generator bearing 4b passes through the track portion of the wave generator bearing 4b and moves upward. Additionally, a portion of the solid lubricant abrasive powder 111 supplied between the wave generator 4 and the external gear 3 passes between them and moves upward.

[0062] A second guide plate 16, integrally formed with the wave generator 4 and rotating at high speed, is disposed on the upper side of the wave generator bearing 4b. Solid lubricant wear powder 111 passing through the upper side is guided to the outer peripheral side by the high-speed rotating second guide plate 16 and supplied to the contact part A (the tooth surface of the external and internal teeth).

[0063] exist Figure 2B A comparison of the left and right semi-longitudinal sections reveals that the pressure-molded article 112 wears down due to frictional contact with the friction plate 113, causing its thickness to gradually decrease. The pressure-molded article 112 is constantly pressed against the friction surface 113a of the friction plate 113 by elastic force, thus continuously generating a fixed amount of solid lubricant wear powder 111. Consequently, the contact portions B, C, and A of the lubricated objects are continuously supplied with approximately a fixed amount of solid lubricant wear powder 111.

Claims

1. A powder lubrication method for a wave gear device, characterized in that, The wave gear device includes: a rigid internal gear; a flexible external gear disposed inside the internal gear; and a wave generator disposed inside the external gear. A pressurized molded product of solid lubricant powder and a friction plate are disposed inside the external gear and in the internal space formed between the external gear and the wave generator. The friction plate is mounted on one of the wave generator and the external gear, and the pressure-molded article is mounted on the other. A spring component is used to press at least one component of the friction plate and the pressure-molded article against the other component to maintain a frictional contact between them. When the wave gear device is in operation, the friction plate causes the pressurized molded product to wear, generating solid lubricant wear powder. The generated solid lubricant abrasive powder is guided toward the lubrication target area of ​​the wave gear device, and the lubrication target area of ​​the wave gear device is lubricated by the solid lubricant abrasive powder guided toward the lubrication target area.

2. The powder lubrication method for the wave gear device according to claim 1, characterized in that, The solid lubricant powder is at least one of molybdenum disulfide, tungsten disulfide, graphite, carbon nanotubes, and onion carbon.

3. The powder lubrication method for the wave gear device according to claim 2, characterized in that, The pressure-molded product is a lightweight pressure-molded product with a pressed powder density of less than 50% of its true density.

4. The powder lubrication method for the wave gear device according to claim 3, characterized in that, The friction plate is made of steel, stainless steel, copper alloy, aluminum alloy, or ceramic with a hardness of Hv60 or higher or a Mohs hardness of 2 or higher. The surface roughness of the friction surface of the friction plate is below 12S.

5. The powder lubrication method for the wave gear device according to claim 1, characterized in that, The wave generator is a rotary input component, and the external gear is a fixed component or a rotary output component.

6. A wave gear device, characterized in that, The wave gear device includes: a rigid internal gear; a flexible external gear disposed inside the internal gear; a wave generator disposed inside the external gear; and a powder supply mechanism disposed inside the external gear within the internal space formed between the external gear and the wave generator. The powder supply mechanism comprises: a pressurized molded article of solid lubricant powder; a friction plate that rubs against the pressurized article to generate solid lubricant abrasive powder; a spring member that presses the friction plate against the pressurized article to maintain frictional contact; and a guide member that guides the solid lubricant abrasive powder generated by the pressurized article in a direction toward the lubrication target area of ​​the wave gear device. The wave generator is a rotary input component, and the external gear is either a fixed component or a rotary output component. The friction plate is disposed on one of the wave generator and the external gear, and the pressure-molded article is disposed on the other. The spring component is used to press at least one of the friction plate and the pressure-molded article onto the other component.

7. The wave gear device according to claim 6, characterized in that, The solid lubricant powder is at least one of molybdenum disulfide, tungsten disulfide, graphite, carbon nanotubes, and onion carbon.

8. The wave gear device according to claim 7, characterized in that, The pressure-molded product is a lightweight pressure-molded product with a pressed powder density of less than 50% of its true density.

9. The wave gear device according to claim 6, characterized in that, The press-molded product is cylindrical or annular.

10. The wave gear device according to claim 8, characterized in that, The friction plate is made of steel, stainless steel, copper alloy, aluminum alloy, or ceramic with a hardness of Hv60 or higher or a Mohs hardness of 2 or higher. The surface roughness of the friction surface of the friction plate is below 12S.

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