Patent Description:
A thrust pad is designed to guarantee the formation of an axial gap between static and dynamic components without direct contact, to reduce surface abrasion, and to prolong service life. In a wind power sliding bearing gearbox, a planet-gear axial thrust pad is usually mounted between a planet gear and a planet carrier. The thrust pad is secured on the planet carrier through a bolt.

During the operation process of the wind power gearbox, temperatures of components inside the gearbox, such as the planet gear, a rotating stand, and the thrust pad, fluctuate greatly. At an ambient temperature of <NUM>, the thrust pad is pre-tightened through the bolt. During operation, the internal temperature of the gearbox rises. Because the coefficient of thermal expansion of the material of the thrust pad is greater than the coefficient of thermal expansion of the material of the bolt, the thrust pad expands in the radial direction. The connection stiffness between the thrust pad and the bolt decreases. The pre-tightening force of the bolt decreases. The expansion of the thrust pad in the axial direction and the clamping force of the bolt lead to the plastic deformation of the thrust pad. When the internal temperature of the gearbox decreases again, the thrust pad cannot rebound to its original size in the axial direction, and the pre-tightening force of the bolt also decreases.

Under the alternate fluctuation of temperature rise and fall, the pre-tightening force of the bolt decreases by <NUM>% to <NUM>%. After a period of use, the planet-gear thrust pad is no longer firmly attached to the planet carrier, thereby resulting in the failure of the gearbox.

Further relevant technologies are also known from <CIT> (<NUM>-<NUM>-<NUM>) which relates to elastic support of thrust bearing, <CIT> (<NUM>-<NUM>-<NUM>) which relates to axial plain bearing and bearing segment for the same, <CIT> (<NUM>-<NUM>-<NUM>) which relates to improvements in or relating to bearings.

The present disclosure provides a gearbox, which at least solves the problem of the mounting of the bolt, which is easy to loosen. In the case where the thrust pad has little to no plastic deformation, it guarantees that the tightening torque of a bolt that can be borne by the thrust pad is increased and that the pre-tightening force of the bolt is compensated for. Therefore, a shortcoming that the mounting of the bolt is easy to loosen is overcome. The thrust pad is fully secured on a carrying member, avoiding the failure of the gearbox.

The above problem is solved by a gearbox according to claim <NUM>. Further improvements are provided in the dependent claims.

Also provided is a gearbox. The gearbox includes a thrust pad, a carrying member, and the preceding fastening apparatus of a thrust pad. The fastening apparatus of a thrust pad is configured to connect the thrust pad to the carrying member. The thrust pad is provided with a first recess and a communication hole communicating with the first recess, the carrying member is provided with a threaded hole, an aperture of the communication hole is greater than an aperture of the threaded hole, the fastening apparatus comprises a bolt and a connection structure, an end cap of the bolt is disposed in the first recess, a screw of the bolt passes through the connection structure and is threaded into the threaded hole, and the connection structure is able to be clamped between the end cap and the carrying member. The connection structure comprises a flange pad and a bushing body, the flange pad is disposed in the first recess, the bushing body is disposed in the communication hole, the flange pad is clamped between the end cap and a bottom of the first recess, and a reserved gap A is formed between the bushing body and one of the carrying member or the flange pad.

In some possible embodiments, the flange pad and the bushing body are integrally structured, and the reserved gap A is formed between the bushing body and the carrying member, or the flange pad and the bushing body are separably structured, and the reserved gap A is formed between the bushing body and one of the carrying member or the flange pad.

In some possible embodiments, when the reserved gap is formed between the bushing body and the flange pad, one end of the bushing body abuts against the carrying member, and the reserved gap A is formed between another end of the bushing body and the flange pad.

According to the invention, the thrust pad further comprises a second recess, the first recess and the second recess communicate with two sides of the communication hole respectively, an area of a bottom of the first recess and an area of a bottom of the second recess are each greater than an opening area of the communication hole, and an opening of the second recess faces the carrying member.

In some possible embodiments, the connection structure and the bolt are integrally structured, the connection structure is connected to an end of the end cap facing the screw, the end cap abuts against the bottom of the first recess, the connection structure is disposed in the communication hole, and the reserved gap A is formed between the carrying member and an end of the connection structure facing away from the end cap.

In some possible embodiments, the size of the reserved gap A is greater than or equal to <NUM>.

The technical solutions in embodiments of the present disclosure are further described in detail hereinafter in conjunction with the drawings. Apparently, the embodiments described below are part, not all, of embodiments of the present disclosure.

In the description of the present disclosure, unless otherwise expressly specified and limited, the term "connected to each other", "connected" or "secured" is to be construed in a broad sense, for example, as securely connected, detachably connected or integrated; mechanically connected or electrically connected; directly connected to each other or indirectly connected to each other via an intermediary; or internal connection between two components or interaction relations between two components. For those of ordinary skill in the art, specific meanings of the preceding terms in the present disclosure may be construed based on specific situations.

In the present disclosure, unless otherwise expressly specified and limited, when a first feature is described as "above" or "below" a second feature, the first feature and the second feature may be in direct contact or be in contact via another feature between the two features. Moreover, when the first feature is described as "on", "above", or "over" the second feature, the first feature is right on, above, or over the second feature, the first feature is obliquely on, above, or over the second feature, or the first feature is simply at a higher level than the second feature. When the first feature is described as "under", "below", or "underneath" the second feature, the first feature is right under, below, or underneath the second feature, the first feature is obliquely under, below, or underneath the second feature, or the first feature is simply at a lower level than the second feature.

This embodiment provides a gearbox. As shown in <FIG>, the gearbox includes a thrust pad <NUM>, a carrying member <NUM>, and a fastening apparatus of the thrust pad. The fastening apparatus <NUM> of a thrust pad is configured to connect the thrust pad <NUM> to the carrying member <NUM>. The carrying member <NUM> may be a rotating stand. The carrying member <NUM> may be set according to needs and is not limited. This embodiment provides a fastening apparatus of a thrust pad. As shown in <FIG>, the thrust pad <NUM> is provided with a first recess <NUM> and a communication hole <NUM> communicating with the first recess <NUM>. The carrying member <NUM> is provided with a threaded hole <NUM>. The aperture of the communication hole <NUM> is greater than the aperture of the threaded hole <NUM>. The fastening apparatus <NUM> includes a bolt <NUM> and a connection structure. An end cap <NUM> of the bolt <NUM> is disposed in the first recess <NUM>. A screw <NUM> of the bolt <NUM> passes through the connection structure and is threaded into the threaded hole <NUM>. The connection structure is able to be clamped between the end cap <NUM> and the carrying member <NUM>.

The carrying member <NUM> is provided with the threaded hole <NUM> to be connected to the bolt <NUM> in a threaded manner so as to mount and carry the thrust pad <NUM>. The bolt <NUM> presses and secures the thrust pad <NUM> on the carrying member <NUM> through the connection structure. The connection structure is used for bearing the tightening torque of the bolt <NUM> directly, preventing the thrust pad <NUM> from directly bearing the full tightening torque of the bolt <NUM>. Therefore, it guarantees that the thrust pad <NUM> has little to no plastic deformation, preventing the thrust pad <NUM> from being crushed, improving the tightening torque of the bolt <NUM> that can be borne by the thrust pad <NUM>, and compensating for the pre-tightening force loss of the bolt <NUM>. The arrangement of the connection structure increases the function area of the bolt <NUM>. Therefore, a greater pre-tightening force of the bolt <NUM> can be applied, thereby enabling various components that are connected to each other to be sufficiently stable and firm without looseness, overcoming the shortcoming that the existing mounting of the bolt <NUM> is easy to loosen. The thrust pad <NUM> is fully secured on the carrying member <NUM>, avoiding the failure of the gearbox.

The carrying member <NUM> may be a planet carrier or a gear. The thrust pad <NUM> is disposed between the planet carrier and the gear. The thrust pad <NUM> is connected to one of the planet carriers or the gear through the fastening apparatus of a thrust pad.

In an embodiment, the coefficient of thermal expansion of the thrust pad <NUM> may be the same as, greater than, or less than the coefficient of thermal expansion of the material of the bolt <NUM>. The material of the thrust pad <NUM> is not limited, improving the applicability of the fastening apparatus <NUM>.

In an embodiment, the connection structure is disposed between the thrust pad <NUM> and the bolt <NUM>. The thrust pad <NUM> is in indirect contact with the bolt <NUM> through the connection structure.

In an embodiment, not part of the invention, as shown in <FIG>, the connection structure includes a flange pad <NUM> and a bushing body <NUM> that are connected to each other. The flange pad <NUM> is disposed in the first recess <NUM>. The bushing body <NUM> is disposed in the communication hole <NUM>. The flange pad <NUM> is clamped between the end cap <NUM> and the bottom of the first recess <NUM>. A reserved gap A is formed between the bushing body <NUM> and the carrying member <NUM>. The bolt <NUM> applies a force to the bushing. After the bolt <NUM> is tightened, the reserved gap A is eliminated. A lower end face of the bushing is in contact with the carrying member <NUM> to press the thrust pad <NUM> and secure the thrust pad <NUM> on the carrying member <NUM>. In design, the size tolerance of the bushing body <NUM> is controlled. In an original state, the lower end face of the bushing body <NUM> and a surface of the carrying member <NUM> form the gap, that is, the reserved gap A. The size of the reserved gap A is greater than or equal to <NUM>. The size of the reserved gap A is related to the magnitude of the tightening torque of the bolt <NUM> and is optionally determined by calculation to guarantee sufficient stable connection. The tightening torque of the bolt <NUM> is designated by adjusting the size of the reserved gap A, guaranteeing a sufficient clamping force and no looseness. Moreover, the bushing body <NUM> is supported between the bolt <NUM> and the carrying member <NUM>. The thrust pad <NUM> is not in direct contact with the bolt <NUM> so that the thrust pad <NUM> has little to no plastic deformation, preventing the thrust pad <NUM> from being crushed. Additionally, the bolt <NUM> acts directly on the flange pad <NUM> and the bushing body <NUM> to be connected to the carrying member <NUM>. The contact area between the flange pad <NUM> and the thrust pad <NUM> is relatively increased. Therefore, a greater pre-tightening force of the bolt <NUM> can be applied, guaranteeing that various components are connected stably without looseness.

Optionally, the flange pad <NUM> and the bushing body <NUM> are each provided with a through hole to facilitate the passage of the screw <NUM>. The first recess <NUM> is a circular recess. The outer diameter of the flange pad <NUM> is less than the inner diameter of the first recess <NUM> so that the flange pad <NUM> is accommodated in the first recess <NUM>.

In an embodiment, the flange pad <NUM> and the bushing body <NUM> are integrally structured. For example, a flange bushing may be purchased, which is convenient and reliable. In other embodiments, the flange pad <NUM> and the bushing body <NUM> are separably structured. The flange pad <NUM> and the bushing body <NUM> may be connected through, for example, bonding, welding or fastener connection. The connection may be set according to needs and is not limited.

This embodiment provides a fastening apparatus of a thrust pad. The fastening apparatus in this embodiment is the basically same as the structure in embodiment one, with no repetition of identical parts. A difference between this embodiment and the preceding embodiment lies in that, as shown in <FIG>, the thrust pad <NUM> further includes a second recess <NUM>. The first recess <NUM> and the second recess <NUM> communicate with two sides of the communication hole <NUM> respectively. The area of the bottom of the first recess <NUM> and the area of the bottom of the second recess <NUM> are each greater than the opening area of the communication hole <NUM>. An opening of the second recess <NUM> faces the carrying member <NUM>. The connection structure includes a flange pad <NUM> and a bushing body <NUM>. The flange pad <NUM> is disposed in the first recess <NUM>. The bushing body <NUM> is disposed in the communication hole <NUM>. The flange pad <NUM> is clamped between the end cap <NUM> and the bottom of the first recess <NUM>. A reserved gap A is formed between the carrying member <NUM> and the bushing body <NUM>.

On the basis of embodiment one, the structure of the thrust pad <NUM> is modified. The first recess <NUM> and the second recess <NUM> form an annular cantilever structure <NUM> with a certain thickness at the periphery of the communication hole <NUM>. The thrust pad <NUM> forms a structure having an elastic rebound and may maintain the elastic deformation with a first amplitude. When temperatures fluctuate, the thrust pad <NUM> has enough elasticity and stability, further improving the firmness of securing the thrust pad <NUM> on the carrying member <NUM>.

This embodiment provides a fastening apparatus of a thrust pad. The fastening apparatus in this embodiment is the basically same as the structure in embodiment one. The same part is not repeated. A difference between this embodiment and the preceding embodiment lies in that, as shown in <FIG>, the connection structure includes a flange pad <NUM> and a bushing body <NUM>. The flange pad <NUM> is disposed in the first recess <NUM>. The bushing body <NUM> is disposed in the communication hole <NUM>. The flange pad <NUM> is clamped between the end cap <NUM> and the bottom of the first recess <NUM>. One end of the bushing body <NUM> abuts against the carrying member <NUM>. A reserved gap A is formed between the other end of the bushing body <NUM> and the flange pad <NUM>.

Optionally, the flange pad <NUM> may be a metal pad with a certain thickness. An upper surface of the metal pad and a lower surface of the metal pad are in contact with the end cap <NUM> of the bolt <NUM> and the thrust pad <NUM> respectively. The lower surface of the pad <NUM> and an upper surface of the bushing form the gap. The bolt <NUM> is not in direct contact with the thrust pad <NUM> and the bushing body <NUM> and acts directly on the pad <NUM>. After the gap is consumed, the lower surface of the pad <NUM> is in contact with the bushing body <NUM> and presses the thrust pad <NUM>. The existence of the pad <NUM> may get a greater pre-tightening force of the bolt <NUM> to be borne, guaranteeing that various components are connected stably without looseness. Moreover, the bushing body <NUM> is supported between the pad <NUM> and the carrying member <NUM>, preventing the thrust pad <NUM> from being crushed.

This embodiment provides a fastening apparatus of a thrust pad. The fastening apparatus in this embodiment is the basically same as the structure in embodiment one. The same part is not repeated. A difference between this embodiment and the preceding embodiments lies in that, as shown in <FIG>, the thrust pad <NUM> further includes a second recess <NUM>. The first recess <NUM> and the second recess <NUM> communicate with two sides of the communication hole <NUM> respectively. The area of the bottom of the first recess <NUM> and the area of the bottom of the second recess <NUM> are each greater than the opening area of the communication hole <NUM>. An opening of the second recess <NUM> faces the carrying member <NUM>. The connection structure includes a flange pad <NUM> and a bushing body <NUM>. The flange pad <NUM> is disposed in the first recess <NUM>. The bushing body <NUM> is disposed in the communication hole <NUM>. The flange pad <NUM> is clamped between the end cap <NUM> and the bottom of the first recess <NUM>. A reserved gap A is formed between the flange pad <NUM> and the bushing body <NUM>.

On the basis of embodiment three, the structure of the thrust pad <NUM> is modified. The first recess <NUM> and the second recess <NUM> form an annular cantilever structure <NUM> with a certain thickness at the periphery of the communication hole <NUM>. The thrust pad <NUM> forms a structure having an elastic rebound and may maintain the elastic deformation with a certain amplitude. When temperature fluctuates, the thrust pad <NUM> has enough elasticity and stability, further improving the firmness of securing the thrust pad <NUM> on the carrying member <NUM>.

This embodiment provides a fastening apparatus of a thrust pad. The fastening apparatus in this embodiment is the basically same as the structure in embodiment one. The same part is not repeated. A difference between this embodiment and the preceding embodiments lies in that, as shown in <FIG>, the connection structure and the bolt <NUM> are integrally structured. The connection structure is connected to an end of the end cap <NUM> facing the screw <NUM>. The end cap <NUM> abuts against the bottom of the first recess <NUM>. The connection structure is disposed in the communication hole <NUM>. A reserved gap A is formed between the carrying member <NUM> and an end of the connection structure facing away from the end cap <NUM>.

The connection structure and the bolt <NUM> are integrated to form a non-standard bolt <NUM>. The end cap <NUM> of the bolt <NUM> is in direct contact with the thrust pad <NUM>. The connection structure is located between the screw <NUM> and the end cap <NUM> to form a shoulder <NUM> with a plane. An end face of the shoulder <NUM> and a surface of the carrying member <NUM> form the reserved gap A. The bolt <NUM> is tightened. After the gap is consumed, the end face of the shoulder <NUM> is in contact with the carrying member <NUM> and presses the thrust pad <NUM>. The shoulder <NUM> is supported on the surface of the carrying member <NUM>, increasing the contact area between the bolt <NUM> and the carrying member <NUM> and thrust pad <NUM>, bearing a greater pre-tightening force of the bolt <NUM>, guaranteeing that various components are connected stably without looseness, and preventing the thrust pad <NUM> from being crushed.

This embodiment provides a fastening apparatus of a thrust pad. The fastening apparatus in this embodiment is the basically same as the structure in embodiment one. The same part is not repeated. A difference between this embodiment and the preceding embodiment lies in that, as shown in <FIG>, the connection structure includes a bushing body <NUM>. The bushing body <NUM> passes through the communication hole <NUM>. The screw <NUM> passes through the bushing body <NUM>. Two ends of the bushing body <NUM> abut against the end cap <NUM> and the carrying member <NUM> respectively. A reserved gap A is formed between the end cap <NUM> and the bottom of the first recess <NUM>.

An upper surface of the bushing body <NUM> and a lower surface of the bushing body <NUM> are in contact with the end cap <NUM> of the bolt <NUM> and the carrying member <NUM> respectively. The height of the bushing body <NUM> is greater than the depth of the communication hole <NUM> so that the reserved gap A is formed between a lower end face of the end cap <NUM> of the bolt <NUM> and the bottom of the first recess <NUM> of the thrust pad <NUM>. The bolt <NUM> is not in direct contact with the thrust pad <NUM> and acts directly on the bushing body <NUM>. After the gap is consumed, a lower end surface of the bolt <NUM> is in contact with the thrust pad <NUM>, pressing the thrust pad <NUM>. The tightening torque of the bolt <NUM> is designated by adjusting the size of the gap, guaranteeing that various components are connected stably without looseness. Moreover, the bushing body <NUM> is supported between the end cap <NUM> of the bolt <NUM> and the carrying member <NUM> so as to carry part of the tightening torque of the bolt <NUM>, preventing the thrust pad <NUM> from being crushed.

This embodiment provides a fastening apparatus of a thrust pad. The fastening apparatus in this embodiment is the basically same as the structure in embodiment one with no repetition of identical parts. A difference between this embodiment and the preceding embodiments lies in that, as shown in <FIG>, the connection structure includes a bushing body <NUM>. The bushing body <NUM> passes through the communication hole <NUM>. The screw <NUM> passes through the bushing body <NUM>. One end of the bushing body <NUM> abuts against the carrying member <NUM>. The end cap <NUM> abuts against the bottom of the first recess <NUM>. A reserved gap A is formed between the other end of the bushing body <NUM> and the end cap <NUM>.

The height of the bushing body <NUM> is less than the depth of the communication hole <NUM> so that a lower end face of the end cap <NUM> of the bolt <NUM> and an upper surface of the bushing body <NUM> form the gap. In an original state, the bolt <NUM> is in direct contact with the thrust pad <NUM>. The bolt <NUM> is tightened. After the thrust pad <NUM> is deformed and the gap is consumed, the lower end face of the end cap <NUM> of the bolt <NUM> is in contact with the bushing, pressing the thrust pad <NUM>. The tightening torque of the bolt <NUM> is designated by adjusting the size of the gap, guaranteeing that various components are connected stably without looseness. Moreover, the bushing body <NUM> is supported between the end cap <NUM> of the bolt <NUM> and the carrying member <NUM> so as to carry part of the tightening torque of the bolt <NUM>, preventing the thrust pad <NUM> from being crushed.

Claim 1:
A gearbox, comprising a thrust pad (<NUM>), a carrying member (<NUM>), and a fastening apparatus (<NUM>), wherein the fastening apparatus (<NUM>) is configured to connect the thrust pad (<NUM>) to the carrying member (<NUM>), the thrust pad (<NUM>) is provided with a first recess (<NUM>) and a communication hole (<NUM>) communicating with the first recess (<NUM>), the carrying member (<NUM>) is provided with a threaded hole (<NUM>), an aperture of the communication hole (<NUM>) is greater than an aperture of the threaded hole (<NUM>), the fastening apparatus comprises a bolt (<NUM>) and a connection structure, an end cap (<NUM>) of the bolt (<NUM>) is disposed in the first recess (<NUM>), a screw (<NUM>) of the bolt (<NUM>) passes through the connection structure and is threaded into the threaded hole (<NUM>), and the connection structure is able to be clamped between the end cap (<NUM>) and the carrying member (<NUM>), characterised in that
the thrust pad (<NUM>) further comprises a second recess (<NUM>), the first recess (<NUM>) and the second recess (<NUM>) communicate with two sides of the communication hole (<NUM>) respectively, an area of a bottom of the first recess (<NUM>) and an area of a bottom of the second recess (<NUM>) are each greater than an opening area of the communication hole (<NUM>), and an opening of the second recess (<NUM>) faces the carrying member (<NUM>); and wherein
the connection structure comprises a flange pad (<NUM>) and a bushing body (<NUM>), the flange pad (<NUM>) is disposed in the first recess (<NUM>), the bushing body (<NUM>) is disposed in the communication hole (<NUM>), the flange pad (<NUM>) is clamped between the end cap (<NUM>) and a bottom of the first recess (<NUM>), and a reserved gap (A) is formed between the bushing body (<NUM>) and one of the carrying member (<NUM>) or the flange pad (<NUM>).