Gearbox

Abstract

The present application relates to a gearbox comprising: an input shaft (15) supported in first and second bearing holes in first and second walls by first and second roller bearings located on both axial sides of a first gear (18); a second gear engaged with the first gear (18); a bushing comprising first and second sections secured to the first wall and comprising: first and second sections mounted within the first and second bearing holes, and an intermediate section connecting both the first and second sections, the intermediate section comprising a notch (46) allowing the first gear and the second gear to mesh; a first and resilient pressure plate assembly (20a, 20b), the first section axially engaged with the bearing outer ring of the first roller bearing (12) via the first resilient pressure plate assembly to receive an axial force from the bearing outer ring; the second section is axially engaged with a bearing outer ring of the second roller bearing via a second resilient platen assembly to receive an axial force from the bearing outer ring.

Description

Technical Field

[0001] The present application relates to a gearbox, in particular a gearbox for a ship unloader. Background Art

[0002] In the planetary differential reducer or gearbox of the current ship unloader, the helical pinion on the motor shaft of the lifting / opening and closing stage motor (or another input shaft driven by it) meshes and drives the two helical driven gears to rotate at the same time, so as to drive the two rollers of the ship unloader to move at the same time. The bearings supporting the motor shaft are usually a pair of spherical roller bearings that are cross-positioned or called X-type arrangement. The two bearings are respectively supported on the outer housing wall and the inner middle partition wall of the gearbox, and are respectively directly supported in the bearing seats provided by the housing wall and the middle partition wall. During the operation of the gearbox, the axial force generated by the meshing of the helical gears on the motor shaft is directed to and transmitted to one of the two bearings according to the different force directions, and finally borne by the corresponding bearing seat. For a gearbox with this structure, both bearing seats need to be designed to withstand axial forces, and additional reinforcement design is required, resulting in a complex housing structure, heavy weight and high cost. Utility Model Content

[0003] The purpose of this application is to improve the gearbox structure so that no matter what the direction of the axial force received by the motor shaft is, the axial force is borne by the housing wall of the gearbox.

[0004] This object is achieved by the gearbox of the present application. The gearbox comprises: an input shaft defining an axial direction, on which a first gear is arranged and supported by a first roller bearing and a second roller bearing respectively located on both sides of the first gear in the axial direction; a second gear meshing with the first gear; and a first wall formed with a first bearing hole and a second wall formed with a second bearing hole; and further comprises: a bushing comprising a cylindrical body and a flange extending radially outward from a first end of the cylindrical body and fixed to the first wall, the cylindrical body comprising: a first section, which is installed in the first bearing hole and engages with a first roller bearing housed inside to receive an axial force from an outer ring of the first roller bearing; a second section, which is installed in the second bearing hole in a clearance fit manner and engages with a second roller bearing housed inside to receive an axial force from an outer ring of the second roller bearing; and an intermediate section connecting the first section and the second section and extending axially across the first gear, the intermediate section comprising a notch radially penetrating the intermediate section to allow the first gear and the second gear to mesh;

[0005] a first elastic pressure plate assembly, the first section being axially engaged with a bearing outer ring of the first roller bearing via the first elastic pressure plate assembly; and

[0006] The second section is axially engaged with the bearing outer ring of the second roller bearing via the second elastic pressure plate assembly.

[0007] In one embodiment, the first roller bearing and the second roller bearing are spherical roller bearings or tapered roller bearings.

[0008] In one embodiment, the first roller bearing and the second roller bearing are arranged face to face, and the gear box also includes: a first end cover, which is fixed to the first end of the bushing, wherein the first elastic pressure plate assembly is axially arranged between the first end cover and the bearing outer ring of the first roller bearing; a second end cover, which is fixed to the second section, wherein the second elastic pressure plate assembly is axially arranged between the second end cover and the bearing outer ring of the second roller bearing.

[0009] In one embodiment, each of the first and second elastic pressure plate assemblies includes: a pressure plate directly engaging a corresponding end cover and an elastic element sandwiched between the pressure plate and a bearing outer race of a corresponding bearing.

[0010] In one embodiment, the first end cover includes a first body to which the first end is fixed and a first protrusion extending axially from the first body to abut against the pressure plate of the first elastic pressure plate assembly; the second end cover includes a second body to which the second section is fixed and a second protrusion extending axially from the second body to abut against the pressure plate of the second elastic pressure plate assembly.

[0011] In one embodiment, the first section and the middle section of the bushing form: a first outer step surface for being axially spaced apart from the first wall, and / or a first inner step surface for axially facing the bearing outer ring of the first roller bearing.

[0012] In one embodiment, the second section and the middle section of the bushing form a second outer step surface for being axially spaced apart from the second wall and / or a second inner step surface for axially facing the bearing outer ring of the second roller bearing.

[0013] In one embodiment, the bushing is a one-piece piece; and / or the bushing is a metal piece.

[0014] In one embodiment, the first gear is a driving gear, the second gear includes one or two or more second gears, and correspondingly the gap is one or two or more gaps.

[0015] In one embodiment, the gearbox is a gearbox for a ship unloader, and the input shaft is a shaft driven by a lifting and / or opening and closing motor.

[0016] According to the gearbox of the present application, a first gear is arranged on the input shaft, and is supported in the first bearing hole and the second bearing hole on the first wall and the second wall respectively through two roller bearings located on both sides of the first gear in the axial direction. The gearbox also includes a bushing fixed to the first wall, the bushing having a first section installed in the first bearing hole, a second section installed in the second bearing hole, and an intermediate section connecting the first section and the second section and extending axially across the first gear, the intermediate section including a notch radially penetrating the intermediate section to allow the first gear to mesh with the corresponding second gear. The gearbox also includes a first elastic pressure plate assembly, the first section of the bushing is axially engaged with the bearing outer ring of the first roller bearing via the first elastic pressure plate assembly to receive the axial force from the bearing outer ring; and a second elastic pressure plate assembly, the second section of the bushing is axially engaged with the bearing outer ring of the second roller bearing via the second elastic pressure plate assembly to receive the axial force from the bearing outer ring.

[0017] This structure ensures that no matter what the direction of the axial force on the input shaft is, the axial force is transmitted to the bearing seat provided by the gearbox housing wall or to the housing wall, and the intermediate partition wall does not bear the axial force and does not need to be strengthened. There is no need to increase the weight of the gearbox, saving costs. In addition, an elastic pressure plate assembly is set between the end cover and the bearing of the gearbox. For the bearing on the side that does not bear the axial force, the elastic force from the corresponding elastic pressure plate assembly has a pre-tightening effect on it, so it will not slip. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a partial cross-sectional view of the gearbox for the ship unloader of the present application.

[0019] Figure 2 yes Figure 1 A partial enlarged view of the part within the dotted box.

[0020] Figure 3 It is along Figure 1 A cross-sectional view of line AA.

[0021] Figure 4 and 5 These are perspective views of the common bushing of the present application from two different angles.

[0022] Figure 6 is a side view of the common bushing.

[0023] Figure 7 It is along Figure 6 A cross-sectional view along line BB. DETAILED DESCRIPTION

[0024] Figure 1It is a partial cross-sectional view of the gearbox for ship unloader of the present application. The figure shows the housing 10 of the gearbox and the input shaft (or it can be directly the output shaft of the motor, collectively referred to as the input shaft of the gearbox) 15 driven by a motor (for example, here the lifting / opening and closing stage motor of the ship unloader), and the input shaft 15 is supported by two (first and second) bearings 12 and 14 arranged face to face. The bearings 12 and 14 are roller bearings capable of bearing both axial force and radial force, such as, but not limited to, spherical roller bearings or tapered roller bearings, preferably tapered roller bearings. The bearings 12 and 14 are supported by the housing wall 11 of the gearbox and the intermediate partition wall 13 inside the gearbox, respectively.

[0025] The input shaft 15 is provided with a driving gear 18 in the form of an integral helical gear. Of course, this integral gear can be replaced by a pinion fixed to the input shaft 15. The driving gear 18 can simultaneously mesh and drive two helical driven gears 17 and 19. When driven to rotate, the driven gears 17 and 19 respectively drive the support shafts 17a and 19a to rotate (in this gearbox for the ship unloader, each of the support shafts 17a and 19a drives the sun gear of the corresponding planetary transmission stage of the gearbox to rotate, and then the planetary carrier output shaft of the planetary transmission stage drives the roller to drive the roller to work). In the illustrated example, the driven gear 17 is an intermediate idler gear for driving the helical gear 17b on the support shaft 17a to achieve the purpose of changing the rotation direction so that the rotation directions of the support shafts 17a and 19a and the corresponding rollers are the same. It can be understood by those skilled in the art that, depending on the expected rotation direction of the roller, the driving gear 18 can directly drive the helical gear 17b, and an idler gear can also be provided between the driven gear 19 and the driving gear 18.

[0026] In the gearbox of the present application, two bearings 12 and 14 are supported in corresponding bearing holes 22 and 24 formed on the housing wall 11 and the intermediate partition wall 13 through a common bushing 30 (hereinafter referred to as "bushing"). For convenience, hereinafter, "axial (direction)" will be used to refer to the direction in which the central axis or rotation axis of the input shaft 15 extends, "circumferential (direction)" refers to the direction around the central axis or rotation axis of the input shaft 15, and "radial (direction)" extends perpendicular to the axial direction. In the axial direction, the first direction refers to the direction from the second bearing 14 toward the first bearing 12 along the axial direction, and the second direction refers to the direction opposite to the first direction. The first side or end refers to the side or end close to the first bearing 12 in the axial direction, and the second side or end refers to the side or end close to the second bearing 14 in the axial direction.

[0027] Reference below Figure 2-7The gearbox of the present application including the bushing 30 is described in detail. The bushing 30 can be made of metal material or any other rigid material capable of transmitting axial force. The bushing 30 is shown as a single piece in the figure, but the present application is not limited thereto, and it can be an assembly including multiple separately formed parts.

[0028] In general, reference Figure 2 In the axial direction, on opposite sides of the driving gear 18, first and second stop portions 21a and 21b are arranged respectively. The first and second stop portions 21a and 21b may be provided by an integrally formed shoulder of the input shaft 15 or may be separately arranged shaft rings. The inner rings of the first bearing 12 and the second bearing 14 arranged face to face axially abut against the first and second stop portions 21a and 21b respectively, thereby positioning the corresponding bearings on one axial side or direction toward the driving gear 18. The first and second end covers 25a and 25b axially abut against the outer rings of the first bearing 12 and the second bearing 14 via the elastic pressure plate assemblies 20a and 20b respectively, thereby positioning the corresponding bearings on the other axial side or direction away from the driving gear 18. The first end cover 25a is fastened or fixed to the first end surface 31a or (e.g.) the first end surface 31a of the bushing 30. Figure 1 and 2 The second end cover 25b is fastened or fixed to the opposite second end surface 31b of the bushing 30 (as shown) from the recessed portion of the first end surface 31a. The bushing 30 itself is fixed to the first end surface 11a (or the recessed portion thereof) of the housing wall 11 and can be axially displaced relative to the intermediate partition wall 13.

[0029] Specifically, each of the elastic pressure plate assemblies 20a and 20b includes pressure plates 26a and 26b and elastic elements 28a and 28b disposed between the pressure plates 26a and 26b and the outer rings of the first and second bearings 12 and 14. The elastic elements may be, but are not limited to, springs. Specifically, one end of the elastic elements 28a and 28b abuts against the outer rings of the corresponding bearings, and the other end is received in a hole formed in the corresponding pressure plate. For each of the elastic pressure plate assemblies 20a and 20b, the elastic element is compressed between the pressure plate and the corresponding outer ring of the bearing. When the bearing is subjected to an axial force in the direction of the pressure plate, the outer ring of the bearing further compresses the elastic element and transmits the axial force to the corresponding pressure plate. When the axial force disappears, the bearing (specifically the outer ring of the bearing) can be returned to its original position by the elastic element. Due to the pressure preload effect of the elastic element, the problem of movement of the bearing when it is not subjected to the axial force is eliminated. For example, each elastic pressure plate assembly may include a plurality of elastic elements evenly spaced and arranged around the input shaft 15. In addition, as shown in the figure, the pressure plates 26a and 26b of each elastic pressure plate assembly 20a and 20b include an outer ring portion with a larger thickness and an inner ring portion with a smaller thickness. The inner ring portion includes a central hole concentric with the input shaft 15, and holes for receiving the elastic elements 28a and 28b are formed on the outer ring portion with a larger thickness.

[0030] The first and second end covers 25a and 25b respectively include annular bodies 32a and 32b and annular protrusions 34a and 34b protruding from the inner circumference of the annular bodies 32a and 32b. When the annular bodies 32a and 32b are fastened to the first end surface 31a and the second end surface 31b of the bushing 30, the annular protrusions 34a and 34b axially abut the pressure plates 26a and 26b of the elastic pressure plate assemblies 20a and 20b, respectively.

[0031] The bushing 30 is installed in the corresponding bearing holes 22 and 24 formed on the housing wall 11 and the intermediate partition wall 13, and is installed on the radially outer side of the two bearings 12 and 14 of the gearbox around them. The bushing 30 generally includes a cylindrical body 40 and a flange 50 extending radially outward from the first end of the cylindrical body 40. The first end surface 31a and the second end surface 31b of the bushing 30 are defined by the flange 50 and the cylindrical body 40, respectively. The flange 50 can have, but is not limited to, a non-circular outer profile. In the axial direction, the bushing 30 can include a first section and a second section for being installed in the first bearing hole 22 and the second bearing hole 24, respectively, and an intermediate section axially connecting the first section and the second section.

[0032] Specific reference Figure 4-7The bushing 30 defines an inner peripheral surface 41 and an outer peripheral surface 43 opposite in the radial direction, and the outer peripheral surface 43 is defined by the cylindrical body 40. The bushing 30 includes two notches 46 that penetrate the thickness of the bushing 30 to allow the driving gear 18 to engage with the driven gears 17 and 19. It can be understood that the number of notches and the position along the circumferential direction depend on the number of driven gears and the circumferential positioning relative to the driving gear. The number of driven gears can also be one or more than two. The present application does not limit the shape and size of the notch when the above functions can be met.

[0033] The outer peripheral surface 43 includes a first outer annular portion 42a and a second outer annular portion 42b which respectively form a clearance fit with the first bearing hole 22 on the box wall 11 and the second bearing hole 24 on the intermediate partition wall 13 in the radial direction, and an outer intermediate portion 42c (only in Figure 2 The outer middle portion 42c is axially connected between the first outer annular portion 42a and the second outer annular portion 42b. Two notches are arranged circumferentially on the outer middle portion 42c.

[0034] The first outer annular portion 42a of the outer peripheral surface 43 has a reduced outer diameter or is recessed relative to the outer middle portion 42c and is located between the flange 50 and the outer middle portion 42c in the axial direction, thereby forming a first outer stepped surface 51a ( Figure 5 and 7 ). Figure 2 The flange 50 of the bushing 30 is fastened to the first end surface 11a of the housing wall 11, and the opposite second end surface 11b of the housing wall 11 is slightly axially spaced apart from the first outer stepped surface 51a (eg Figure 2 The second outer annular portion 42b of the outer peripheral surface 43 terminates at the second end surface 31b of the bushing 30, has a reduced outer diameter or is recessed relative to the outer middle portion 42c, and thus forms a second outer stepped surface 51b with the outer middle portion 42c. Figure 2 The second end of the second outer annular portion 42 b (or the bushing 30 ) terminates in the second bearing hole 24 of the intermediate partition wall 13 and the second outer step surface 51 b is slightly axially spaced apart from the intermediate partition wall 13 .

[0035] The inner peripheral surface 41 includes a first inner annular portion 44a and a second inner annular portion 44b that respectively accommodate or face the first bearing 12 and the second bearing 14, and an inner middle portion 44c is axially connected between the first inner annular portion 44a and the second inner annular portion 44b. Two notches 46 are formed on the inner middle portion 44c. The first inner annular portion 44a and the second inner annular portion 44b of the inner peripheral surface 41 have an increased inner diameter relative to the inner middle portion 44c, and extend from the first end surface 31a and the second end surface 31b of the bushing 30 to the inner middle portion 44c, respectively. As a result, the first inner annular portion 44a and the second inner annular portion 44b form first and second inner step surfaces 53a and 53b ( Figure 7 ).

[0036] It can be understood that the first section of the bushing 30 has a first inner annular portion 44a and a first outer annular portion 42a; the second section of the bushing 30 has a second inner annular portion 44b and a second outer annular portion 42b; and the middle section of the bushing 30 has the above-mentioned two notches 46, and has an inner middle portion 44c and an outer middle portion 42c.

[0037] Figure 2 Also shown are a plurality of first bolts 61 ( Figure 5 and 7 61a for the first bolt 61), a plurality of second bolts 63 ( Figure 4 and 7 The hole 63a for the second bolt 63 is shown in FIG. Figure 4 , 5 7 also shows bolt holes 67 a for third bolts used to connect the flange 50 of the bushing 30 to the housing wall 11 .

[0038] During the operation of the gearbox as described in detail above, when the input shaft 15 has an axial force toward the first end due to the meshing of the helical gears, the axial force is sequentially transmitted from the driving gear 18 through the first stopper 21a, the inner ring of the first bearing 12, the outer ring of the first bearing 12, the first elastic pressure plate assembly 20a, the first end cover 25a, the bushing 30, and finally transmitted to the housing wall 11. When the input shaft 15 has an axial force toward the second end, the axial force is sequentially transmitted from the driving gear 18 through the second stopper 21b, the inner ring of the second bearing 14, the outer ring of the second bearing 14, the second elastic pressure plate assembly 20b, the second end cover 25b, the bushing 30, and finally transmitted to the housing wall 11. Therefore, using the gearbox of the present application, no matter what the rotation direction of the lifting / opening and closing stage motor is, no matter what the direction of the axial force applied to the input shaft 15 is, the axial force will eventually be transmitted to the box wall 11 via the bushing 30, and the intermediate partition wall 13 will not bear any axial force, nor will any reinforcement design be required, thereby avoiding increasing the weight of the gearbox and increasing costs.

[0039] In addition, the present application preferably uses tapered roller bearings, which eliminates the defect that only one row of rollers is loaded and thus the bearing life is reduced when using double-row spherical roller bearings, and the defect that the other row of rollers that is not loaded may slip. The use of tapered roller bearings also reduces or eliminates the axial movement problem caused by the large internal clearance of spherical roller bearings. The gearbox includes an elastic pressure plate assembly for the bearing, so the bearing on the side that does not bear the axial force is still preloaded by the spring pressure of the corresponding elastic pressure plate assembly, and no slipping occurs.

[0040] Although the present invention is described with reference to the gearbox for ship unloaders shown in the figure, it is obvious that the gearbox of the present application is not limited to the gearbox for ship unloaders. In addition, without departing from the principles of the present application, ordinary technicians in the field can make variations and improvements to the details shown in the figure and described above, and these variations and improvements fall within the scope of protection of the present application. The scope of protection of the present application is limited only by the attached claims.

Claims

1. A gear box, comprising: An axial input shaft (15) is defined on which a first gear (18) is disposed and supported by a first roller bearing (12) and a second roller bearing (14) respectively located on both sides of the first gear (18) in the axial direction; a second gear meshing with the first gear (18); and A first wall having a first bearing hole (22) formed therein and a second wall having a second bearing hole (24) formed therein; It is characterized by further comprising: A bushing (30) comprising a cylindrical body (40) and a flange (50) extending radially outward from a first end of the cylindrical body and fixed to the first wall, the cylindrical body (40) comprising: a first section installed in the first bearing hole (22) and engaging with a first roller bearing (12) housed therein to receive an axial force from an outer ring of the first roller bearing; a second section installed in the second bearing hole (24) in a clearance fit manner and engaging with a second roller bearing (14) housed therein to receive an axial force from an outer ring of the second roller bearing; and an intermediate section connecting the first section and the second section and extending axially across the first gear, the intermediate section comprising a notch (46) radially penetrating the intermediate section to allow the first gear and the second gear to mesh; a first elastic pressure plate assembly (20a), the first section being axially engaged with the bearing outer ring of the first roller bearing (12) via the first elastic pressure plate assembly (20a); and A second elastic pressure plate assembly (20b), the second section is axially engaged with the bearing outer ring of the second roller bearing (14) via the second elastic pressure plate assembly (20b).

2. The gearbox according to claim 1, characterized in that: The first roller bearing (12) and the second roller bearing (14) are spherical roller bearings or tapered roller bearings.

3. The gearbox according to claim 2, characterized in that: The first roller bearing (12) and the second roller bearing (14) are arranged face to face, and the gear box further comprises: a first end cover (25a) fixed to a first end of the bushing (30), wherein the first elastic pressure plate assembly (20a) is axially arranged between the first end cover (25a) and the bearing outer ring of the first roller bearing (12); A second end cover (25b) is fixed to the second section, wherein the second elastic pressure plate assembly (20b) is axially arranged between the second end cover (25b) and the bearing outer ring of the second roller bearing (14).

4. The gearbox according to claim 3, characterized in that: Each of the first elastic pressure plate assembly (20a) and the second elastic pressure plate assembly (20b) includes: a pressure plate directly engaged with a corresponding end cover and an elastic element sandwiched between the pressure plate and the bearing outer ring of the corresponding bearing.

5. The gearbox according to claim 4, characterized in that: The first end cover (25a) includes a first body (32a) to which the first end is fixed and a first protrusion (34a) extending axially from the first body to abut against the pressure plate of the first elastic pressure plate assembly (20a); the second end cover (25b) includes a second body (32b) to which the second section is fixed and a second protrusion (34b) extending axially from the second body to abut against the pressure plate of the second elastic pressure plate assembly (20b).

6. The gearbox according to any one of claims 1 to 5, characterized in that: The first section and the middle section of the bushing (30) form: a first outer step surface (51a) for being axially spaced apart from the first wall, and / or a first inner step surface (53a) for axially facing the bearing outer ring of the first roller bearing (12).

7. The gearbox according to claim 6, characterized in that: The second section and the middle section of the bushing (30) form: a second outer step surface (51b) for being axially spaced apart from the second wall, and / or a second inner step surface (53b) for axially facing the bearing outer ring of the second roller bearing (14).

8. The gearbox according to any one of claims 1 to 5, characterized in that: The bushing is a one-piece piece; and / or the bushing is a metal piece.

9. The gearbox according to any one of claims 1 to 5, characterized in that: The first gear is a driving gear, the second gear includes one or two or more second gears, and correspondingly the gap is one or two or more gaps.

10. The gearbox according to any one of claims 1 to 5, characterized in that: The gearbox is a gearbox for a ship unloader, and the input shaft (15) is a shaft driven by a lifting and / or opening and closing motor.

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