Railway Locomotive, and Gearbox and Axle-hung Box Coupling Device Thereof FIELD OF THE TECHNOLOGY [0001] The present invention relates to a connection technology for railway locomotive components and, in particular, to a railway locomotive, and a gearbox and axle-hung box coupling device thereof BACKGROUND [0002] In an axle hung locomotive in the prior art, a motor can elastically hang on the frame of a locomotive, and can transmit output power of the motor to a wheel set via a gearbox and axle-hung box coupling device. Specifically, as shown in FIG.1, FIG.1 is a schematic structural diagram of a gearbox and axle-hung box coupling device in the prior art, the coupling device can comprise a gearbox 11 and an axle-hung box 12, wherein, the gearbox 11 is mounted between the motor and the axle-hung box 12, with one end connected to the motor and the other end rigidly coupled to the axle-hung box 12 via a mounting sear 29; the axle-hung box 12 is provided on an axle, and can transmit output power of the motor to a wheel set via the axle, and the wheel set directly acts on the steel rails. [0003] The above prior art has the following technical disadvantages: during the running of a locomotive, the axle-hung box will vibrate along with the wheel set, since the wheel set has a different vibration frequency with the motor, and the gearbox suffers from the vibration at different frequencies, which often causes gearbox body to develop cracks and gearbox to leak oil, and thereby significantly influences the driving safety of a locomotive railway. SUMMARY [0004] The present invention seeks to provide a railway locomotive, and a gearbox and axle-hung box coupling device thereof, aiming to solve the problem that gearbox develops cracks and leaks oil due to suffering from vibration from the wheel set and the motor, and prevent the gearbox from developing cracks and leaking oil. [0005] One aspect of the present invention provides a gearbox and axle-hung box coupling device, the coupling device comprises a gearbox and an axle-hung box, and the gearbox and the axle-hung box are connected together, further comprises: 5460513_1 (GHMatters) P92320.AU [0006] A rubber coupler, fixed to the gearbox; the rubber coupler comprises an outer body, a rubber pad and an inner axle sleeve, wherein a central hole is provided on the outer body, the inner axle sleeve penetrates through the central hole, and the rubber pad is provided between an outer wall of the inner axle sleeve and an inner wall of the central hole; [00071 A locating clamp, provided between the axle-hung box and the rubber coupler, a locating hole and a locating edge are provided on the locating clamp, the locating hole is opposite to an axle hole of the inner axle sleeve, and an outer wall of the outer body of the rubber coupler is locked by the locating edge; and [0008] A coupling bolt, penetrating through a first bolt hole on the axle-hung box, the locating hole on the locating clamp and the axle hole in the inner axle sleeve of the rubber coupler in turn, so as to couple and fix the axle-hung box and the gearbox. [0009] In the above gearbox and axle-hung box coupling device, a plurality of second bolt holes are provided on the outer body, and a plurality of mounting bolts penetrate through the plurality of second bolt holes respectively, so as to fix the rubber coupler on the gearbox. [0010] The above gearbox and axle-hung box coupling device further comprises: a locked spacer, and the locked spacer is provided between the plurality of the mounting bolts. [00111 In the above gearbox and axle-hung box coupling device, a reinforcing rib is provided on the locating edge of the locating clamp. [0012] The above gearbox and axle-hung box coupling device further comprises: an adjusting spacer, and the adjusting spacer is provided between the locating clamp and the axle-hung box. [0013] In the above gearbox and axle-hung box coupling device, the locating clamp is made of cast steel. [0014] Another aspect of the present invention provides a railway locomotive, comprises a motor, a gearbox and axle-hung box coupling device, an axle and a wheel set; the wheel set is mounted on the axle, the gearbox and axle-hung box coupling device is connected to the motor and the axle, respectively; the gearbox and axle-hung box coupling device adopts the gearbox and axle-hung box coupling device according to the present invention; a gearbox of the gearbox and axle-hung box coupling device is connected to the motor, and an axle-hung box of the gearbox and axle-hung box coupling device is mounted on the axle. [0015] According to various aspects of the present invention, the railway locomotive, and the gearbox and axle-hung box coupling device thereof can effectively absorb the high-frequency vibration in different directions through arranging components such as a rubber coupler and a 2 locating clamp between the gearbox and the axle-hung box, prevent the gearbox from developing structural cracks which cause oil leakage, and reliably ensure the driving safety of a locomotive. [0015a] In another aspect, there is provided a gearbox and axle-hung box coupling device for coupling a gear box to an axle-hung box for a railway locomotive the coupling device comprising: a rubber coupler, capable of fixing to a gearbox; said rubber coupler comprising an outer body, a rubber pad and an inner axle sleeve, wherein a central hole is provided on said outer body, said inner axle sleeve penetrates through said central hole, and said rubber pad is provided between an outer wall of said inner axle sleeve and an inner wall of said central hole; a locating clamp, locatable between an axle-hung box and said rubber coupler, the locating clamp having a locating hole and a locating edge said locating hole being opposite to an axle hole of said inner axle sleeve, and an outer wall of said outer body of said rubber coupler being locked by said locating edge; and a coupling bolt, capable of penetrating through a first bolt hole on said axle-hung box, said locating hole on said locating clamp and said axle hole in said inner axle sleeve of said rubber coupler in turn, so as to couple and fix said axle-hung box and said gearbox. [0015b] In yet another aspect, there is provided a railway locomotive, comprising a motor, a gearbox and axle-hung box coupling device according to any one of the preceding claims, an axle and a wheel set; said wheel set being mounted on said axle, said gearbox being connected to the motor and said axle-hung box being connected to said motor; wherein said gearbox and axle-hung box coupling device is connected between and to the gearbox and the axle-hung box. BRIEF DESCRIPTION OF THE DRAWINGS [0016] In order to describe the technical solutions in embodiments of the present invention or the prior art more clearly, accompanying drawings for the embodiments of the present invention or for the prior art are introduced briefly hereinafter. Obviously, the accompanying drawings are only some embodiments of the present invention and persons skilled in the art can obtain other drawings according to the accompanying drawings without any creative work. [0017] FIG. 1 is a schematic structural diagram of a gearbox and axle-hung box coupling device in the prior art; [0018] FIG.2 is a front view of a gearbox and axle-hung box coupling device according to an 3 5460513_1 (GHMatters) P92320.AU embodiment of the present invention; [0019] FIG.3 is a top view of a gearbox and axle-hung box coupling device according to an embodiment of the present invention; [0020] FIG.4 is a sectional view taken along the line A-A in FIG.3; [0021] FIG.5 is a top view of the rubber coupler in FIG.2; [0022] FIG.6 is a sectional view taken along the line B-B in FIG.5; [0023] FIG. 7 is a top view of the locating clamp in FIG.2; [0024] FIG. 8 is a side view of the locating clamp in FIG.2; [0025] FIG. 9 is a half sectional view of FIG.7. [0026] Reference Numerals 11-gearbox 12- axle-hung box 13-rubber coupler 14-locating clamp 15-coupling bolt 16-outer body 17-rubber pad 18-inner axle sleeve 19- central hole 20-locating hole 21-locating edge 22-axle hole 23-first bolt hole 24-second bolt hole 25-mounting bolt 26- reinforcing rib 27-locked spacer 28-adjusting spacer 29- mounting seat DETAILED DESCRIPTION [0027] In order to make the technical solutions and merits of the embodiments of the 3a 5460513_1 (GHMatters) P92320.AU present invention clearer, a clear and complete description of the technical solutions in embodiments of the present invention is given with reference to the accompanying drawings. Apparently, the embodiments described herein are only a part rather than all of the embodiments of the present invention, and all other embodiments derived by persons skilled in the art from the embodiments of the present invention without making any creative effort shall fall within the protection scope of the present invention. [0028] The main technical solutions of the present invention lie in that: the rigid coupling manner between the gearbox and the axle-hung box is modified into an elastic coupling, for example, a rubber coupler, a locating clamp and a coupling bolt can be used for connection. The above elastic coupling can effectively absorb the high-frequency vibration in different directions, remain the location of the gearbox, and solve the problem that gearbox develops cracks and leaks oil. [0029] Hereinafter, the technical solutions of the present invention will be described in detail by reference to the accompanying drawings and specific embodiments. [0030] FIG.2 is a front view of a gearbox and axle-hung box coupling device according to an embodiment of the present invention, FIG.3 is a top view of a gearbox and axle-hung box coupling device according to an embodiment of the present invention, and FIG.4 is a sectional view taken along the line A-A in FIG.3. As shown in FIGS 2-4, the gearbox and axle-hung box coupling device according to this embodiment can comprise a gearbox 11, an axle-hung box 12, a rubber coupler 13, a locating clamp 14 and a coupling bolt 15. [003 1] The rubber coupler 13 is fixed on the gearbox 11; the rubber coupler 13 can comprise an outer body 16, a rubber pad 17 and an inner axle sleeve 18, the inner axle sleeve 18 penetrates through a central hole 19 provided on the outer body 16, and the rubber pad 17 is provided between an outer wall of the inner axle sleeve 18 and an inner wall of the central hole 19. Wherein, the inner axle sleeve 18 comprises an axle hole 22, and a bolt can penetrates through the axle hole 22; the rubber pad 17 is provided to closely attach on the outer wall of the inner axle sleeve 18 and the inner wall of the central hole 19, and can absorb the high-frequency vibration in different directions. [0032] A locating clamp 14 is provided between the axle-hung box 12 and the rubber coupler 13, a locating hole 20 and a locating edge 21 are provided on the locating clamp 14, the locating hole 20 is opposite to the axle hole 22 of the inner axle sleeve 18, and the outer wall of the outer body 16 of the rubber coupler 13 is locked by the locating edge 21. Wherein, the locating hole 4 20 also can be configured to be penetrated by the bolt; the locating clamp 14 is pressed tightly with the inner axle sleeve 18, and located via two sides of the outer body 16 locked by the locating edge 21, on one hand, this can fix the rubber coupler 13 and further effectively reduce the vibration being absorbed by rubber pad 17 and maintain location of the gearbox, on the other hand, the locating clamp 14 is equivalent to isolate the axle-hung box 12 and the gearbox 11, such that the axle-hung box 12 and the gearbox 11 can vibrate independently. Relative to the double vibration influences from the axle-hung box 12 and the motor suffered by the gearbox 11 in the prior art, this can greatly reduce the vibration degree of the gearbox 11, and thereby solve the problem that gearbox body develops cracks and leaks oil. [0033] A coupling bolt 15 penetrates through a first bolt hole 23 on the axle-hung box 12, the locating hole 20 on the locating clamp 14 and the axle hole 22 in the inner axle sleeve 18 of the rubber coupler 13 in turn, so as to couple and fix the axle-hung box 12 and the gearbox 11. When the gearbox 11 and the axle-hung box 12 are connected and assembled, the coupling bolt 15 can fix the axle-hung box 12 and the gearbox 11, and the coupling bolt 15 can ensure the locating coupling between the gearbox 11 and the axle-hung box 12. [0034] Specifically, refers to FIGS.5-6 for the structure of the rubber coupler 13, FIG.5 is a top view of the rubber coupler in FIG.2 and FIG.6 is a sectional view taken along the line B-B in FIG.5. A plurality of second bolt holes 24 are provided on the outer body 16 of the rubber coupler, and a plurality of mounting bolts 25 (refer to FIGS.2-3) penetrate through the plurality of second bolt holes 24 respectively, so as to fix the rubber coupler on the gearbox. For example, in this embodiment, the rubber coupler can be fixed on the gearbox via four mounting bolts 25. [00351 Specifically, refers to FIGS.7-9 for the structure of the locating clamp 14, FIG. 7 is a top view of the locating clamp in FIG.2, FIG. 8 is a side view of the locating clamp in FIG.2, and FIG. 9 is a half sectional view of FIG.7. The locating clamp can be made of cast steel materials, for example, ZG150-450. Wherein, a locating hole 20 is provided on the middle of the locating clamp, and the locating hole 20 can be round, and opposite to the axle hole of the inner axle sleeve for being penetrated by a bolt. Two locating edges 21 can be provided on the locating clamp, for being locked on the side edges of the outer body of the rubber coupler. Furthermore, a reinforcing rib 26 can be provided on the locating edge 2 of the locating clamp, for enhancing intensity of the locating clamp. [0036] Further, with reference to FIGS.2-4, locked spacer 27 is provided between the plurality 5 of the mounting bolts 25 so as to prevent the mounting bolts 25 from being loosened. For example, in this embodiment, four mounting bolts 25 can be provided, two locked spacers 27 are provided correspondingly, and each of the locked spacers 27 is provided between two mounting bolts 25. Furthermore, an adjusting spacer 28 can be provided between the locating clamp 14 and the axle-hung box 12, the adjusting spacer 28 can compensate deviation caused by machining of the gearbox 11 and the axle-hung box 12, preventing additional assembly stress being produced when the gearbox is mounted. [0037] According to this embodiment, the gearbox and axle-hung box coupling device can effectively absorb the high-frequency vibration in different directions through arranging components such as a rubber coupler and a locating clamp between the gearbox and the axle-hung box, prevent the gearbox from developing structural cracks which cause oil leakage, and provide technical assurance on the safe and reliable driving of a locomotive; moreover, the system is simple in structure, easy to mount and light in weight. [0038] Another embodiment of the present invention provides a railway locomotive, the locomotive can comprise a motor, a gearbox and axle-hung box coupling device, an axle and a wheel set. Wherein, the wheel set is mounted on the axle, and the gearbox and axle-hung box coupling device is connected to the motor and the axle, respectively. In this embodiment, the gearbox and axle-hung box coupling device can adopt the gearbox and axle-hung box coupling device provided in any of the embodiments of the present invention; the gearbox of the gearbox and axle-hung box coupling device is connected to the motor, and the axle-hung box of the gearbox and axle-hung box coupling device is mounted on the axle. This can greatly reduce the vibration influence suffered by the gearbox and prevent the gearbox from developing cracks which cause oil leakage. [0039] Finally, it should be noted that the above embodiments are merely provided for describing the technical solutions of the present invention, but not intended to limit the present invention. It should be understood by persons skilled in the art that although the present invention has been described in detail with reference to the foregoing embodiments, modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent replacements can be made to some technical features in the technical solutions; however, such modifications or replacements do not cause the essence of corresponding technical solutions to depart from the spirit and scope of the embodiments of the present invention. 6 5460513_1 (GHMatters) P92320.AU [0040] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention. [0041] It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country. 57 5460513_1 (GHMatters) P92320.AU