Gearbox

Abstract

The utility model provides a gearbox which comprises a box body, a rear end cover and a gear shifting mechanism, the rear end cover is fixed at the rear end of the box body, and an oil cylinder cavity is formed in the rear end cover. The gear shifting mechanism comprises an oil cylinder end cover arranged on the rear end cover and used for sealing the oil cylinder cavity, a gear shifting rod arranged in the oil cylinder cavity in a penetrating mode, a piston fixedly arranged on the gear shifting rod in a sleeving mode and located in the oil cylinder cavity, a check block located on the outer side of the rear end cover and fixed to the gear shifting rod, and a reset spring arranged between the check block and the oil cylinder end cover. And a built-in oil duct is arranged in the rear end cover and is communicated with the oil cylinder cavity. The reset spring part of the gear shifting mechanism is arranged on the outer side of the box body of the gearbox, the external space is reasonably utilized, the situation that the internal installation space of the gearbox is insufficient, and the reset function of a gear shifting rod after oil drainage and pressure relief of an oil cylinder cannot be achieved is avoided, and reliability, stability and high efficiency of power gear shifting are guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of gearboxes, in particular to a gearbox with an external return spring. Background Art

[0002] In the existing technology, the internal structure of the fully automatic power shift transmission is complex and has many parts, which to a certain extent affects the setting of the control cylinder, shift lever and shift fork, resulting in insufficient installation space for the control cylinder assembly and the inability to meet the requirements of the shift lever returning to its original position after the cylinder is drained and depressurized, thereby affecting the reliability, stability and efficiency of the power shift.

[0003] Therefore, it is necessary to provide a gearbox to overcome the above-mentioned defects. Utility Model Content

[0004] The purpose of the utility model is to provide a gearbox.

[0005] According to one aspect of the present invention, a gearbox is provided, comprising:

[0006] Box,

[0007] The rear end cover is fixed to the rear end of the box body, and a cylinder cavity is provided in the rear end cover.

[0008] A shift mechanism, comprising a cylinder end cover provided on the rear end cover and used to seal the cylinder cavity, a shift rod passing through the cylinder cavity, a piston sleeved and fixed on the shift rod and located in the cylinder cavity, a stopper located outside the rear end cover and fixed to the shift rod, and a return spring disposed between the stopper and the cylinder end cover;

[0009] A built-in oil channel is provided in the rear end cover and is communicated with the oil cylinder cavity.

[0010] Preferably, a threaded hole is axially provided at the end of the shift rod, and the stopper is locked and fixed to the end of the shift rod by a bolt that cooperates with the threaded hole.

[0011] Preferably, the piston includes a cylindrical portion mounted on the shift rod and a main body portion extending radially outward from the cylindrical portion, the main body portion is located on the side of the cylindrical portion away from the stop block, and a piston sleeve is provided at the end of the cylinder cavity away from the stop block, and the main body portion is placed in the piston sleeve.

[0012] Preferably, a first annular groove is formed on the main body, and a first sealing ring is provided in the first annular groove.

[0013] Preferably, one end of the cylinder portion close to the stopper is connected to the shift rod via a thread, and one end of the cylinder portion away from the stopper is sleeved on the shift rod and sealed to the shift rod via an O-ring.

[0014] Preferably, the shift lever is provided with a self-locking nut, and the self-locking nut is located between the piston and the cylinder end cover.

[0015] Preferably, the cylinder end cover includes a sleeve portion and a mounting portion extending radially outward from the outer circumferential surface of the sleeve portion, the mounting portion is fixed to the rear end cover by bolts, the sleeve portion partially extends into the cylinder cavity and opens a second annular groove, a second sealing ring is provided in the second annular groove, and sealing is achieved by the second sealing ring and the inner wall of the cylinder cavity.

[0016] Preferably, the sleeve portion is arranged in a stepped shape, including a small cylinder for sleeve-mounting the reset spring and a large cylinder for supporting the reset spring, a step surface is formed between the small cylinder and the large cylinder, and the reset spring is supported on the step surface.

[0017] Preferably, the stopper comprises a sleeve portion for sleeved with the reset spring and a supporting portion for supporting the reset spring, wherein the supporting portion is located at an end portion of the sleeve portion and extends radially outward from the sleeve portion.

[0018] Preferably, the shift lever is provided with a shift fork, and the shift fork is located in the box.

[0019] Compared with the prior art, the gearbox provided by the present invention has the following beneficial effects:

[0020] Due to the adoption of the above technical solution, the utility model has the advantages of simple structure, ingenious design and low cost. The return spring part of the shift mechanism is arranged on the outside of the gearbox housing, which rationally utilizes the external space and avoids insufficient installation space inside the gearbox, which makes it impossible to realize the shift lever return function after the oil cylinder is drained and the pressure is released, thereby ensuring the reliability, stability and efficiency of the power shifting. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0022] Figure 1 A perspective view of the gearbox of the present invention;

[0023] Figure 2 This is a front view of the gearbox of the present invention;

[0024] Figure 3 for Figure 2 Cross-sectional view of the BB surface;

[0025] Figure 4 for Figure 3 The enlarged view of point C;

[0026] Figure 5 A cross-sectional view of the gearbox of the present invention;

[0027] Figure 6 It is a three-dimensional diagram of the oil cylinder end cover of the utility model;

[0028] Figure 7 A three-dimensional diagram of the piston of the present invention;

[0029] Figure 8 It is a three-dimensional diagram of the stopper of the present utility model.

[0030] Among them, 1. housing, 11. synchronizer, 2. rear end cover, 21. cylinder cavity, 22. built-in oil channel, A. shift mechanism, 3. cylinder end cover, 31. sleeve part, 311. second annular groove, 312. small cylinder, 313. large cylinder, 314. step surface, 32. mounting part, 4. shift lever, 5. piston, 51. cylinder part, 52. main body, 521. first annular groove, 6. block, 61. sleeve part, 62. supporting part, 7. return spring, 8. shift fork, 9. self-locking nut, 101. shift lever bushing, 102. piston bushing, 103. first sealing ring, 104. second sealing ring, 105. third sealing ring, 106. O-ring, 107. fixing bolt, a. compression chamber, b. hydraulic chamber. DETAILED DESCRIPTION

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] To simplify the drawings, only the parts relevant to the present invention are schematically shown in each figure. They do not represent the actual structure of the product. In addition, to simplify the drawings and facilitate understanding, in some figures, only one of the components with the same structure or function is schematically depicted or labeled. In this document, "one" not only means "only one" but also "more than one."

[0033] It should be further understood that the term "and / or" used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0034] It should be noted that, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they can refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this utility model based on the specific circumstances.

[0035] In addition, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without inventive work.

[0037] See also Figures 1 to 4 This embodiment discloses a transmission, comprising a housing 1, a front cover (not shown), a rear cover 2, and a shift mechanism. The front cover is fixed to the front end of the housing 1, and the rear cover 2 is fixed to the rear end of the housing 1. The rear cover 2 defines a cylinder chamber 21 and a built-in oil passage 22 communicating with the cylinder chamber 21. The shift mechanism comprises a cylinder end cover 3, a shift rod 4, a piston 5, a stopper 6, a return spring 7, and a shift fork 8.

[0038] See also Figure 5 One end of the cylinder chamber 21 is open, and the cylinder end cover 3 is located at this opening and fixed to the rear end cover 2, sealing the cylinder chamber 21. A through-hole for the shift rod 4 is provided at the other end of the cylinder chamber 21, and a shift rod bushing 101 is located within this through-hole. The shift rod 4 is inserted into the cylinder chamber 21, and the piston 5 is fixedly mounted on the shift rod 4 and located within the cylinder chamber 21. A stopper 6 is located outside the rear end cover 2 and fixed to the shift rod 4. A return spring 7 is interposed between the stopper 6 and the cylinder end cover 3.

[0039] A threaded hole is axially provided at the end of the shift rod 4 , and the stopper 6 is locked and fixed to the end of the shift rod 4 by means of a fixing bolt 107 that cooperates with the threaded hole.

[0040] See also Figure 7 The piston 5 includes a barrel portion 51 that is sleeved on the shift lever 4 and a body portion 52 that extends radially outward from the barrel portion 51. The body portion 52 is located on the side of the barrel portion 51 away from the stopper 6. A piston sleeve 102 is provided at the end of the cylinder chamber 21 away from the stopper 6, and the body portion 52 is disposed within the piston sleeve 102.

[0041] The main body 52 defines a first annular groove 521, within which a first sealing ring 103 is positioned, sealing against the inner wall of the piston bushing 102. The end of the barrel 51 proximal to the stopper 6 is threadedly connected to the shift rod 4. The end of the barrel 51 distal to the stopper 6 is sleeved onto the shift rod 4 and sealed therewith via an O-ring 106. The shift rod 4 is equipped with a self-locking nut 9, located between the piston 5 and the cylinder end cap 3. This nut locks the threaded connection between the piston 5 and the shift rod 4, preventing it from loosening.

[0042] See also Figure 6 The cylinder end cover 3 includes a sleeve portion 31 and a mounting portion 32 extending radially outward from the outer circumferential surface of the sleeve portion 31. The mounting portion 32 is fixed to the rear end cover 2 by bolts. The sleeve portion 31 partially extends into the cylinder cavity 21 and defines a second annular groove 311. A second sealing ring 104 is provided in the second annular groove 311, and a seal is achieved between the second sealing ring 104 and the inner wall of the cylinder cavity 21. The sleeve portion 31 is arranged in a stepped shape, including a small cylinder 312 for the return spring 7 to be sleeved and a large cylinder 313 for supporting the return spring 7. A step surface 314 is formed between the small cylinder 312 and the large cylinder 313, and the return spring 7 is supported on the step surface 314. A third sealing ring 105 is provided at the contact point between the inner ring of the small cylinder 312 and the shift lever 4. Both the first sealing ring 103 and the third sealing ring 105 are Gly rings.

[0043] See also Figure 8 The stopper 6 includes a sleeve portion 61 for sleeved with the return spring 7 and a supporting portion 62 for supporting the return spring 7. The supporting portion 62 is located at the end of the sleeve portion 61 and extends radially outward from the sleeve portion 61. A mounting groove is provided in the middle of the sleeve portion 61 for the shift lever 4 to be lifted into.

[0044] The shift fork 8 is disposed within the housing 1. One end of the shift fork 8 is connected to the shift lever 4, and the other end is connected to the synchronizer 11 mounted on the output shaft within the housing 1. On the side of the main body 52 near the shift fork 8, a compression chamber a is formed between the main body 52, the piston bushing 102, and the side wall of the rear end cover 2. On the side of the main body 52 near the stopper 6, a hydraulic chamber b is formed by the main body 52, the cylinder chamber 21, and the cylinder end cover 3. The built-in oil passage 22 of the rear end cover 2 leads to the hydraulic chamber b, injecting hydraulic oil into it, controlling the piston 5 to push forward, thereby driving the shift fork 8 to move on the synchronizer 11. At this time, the return spring 7 is compressed. After the hydraulic chamber b is depressurized, the return spring 7 pushes the stopper 6 outward, which in turn drives the shift lever 4 outward, thereby driving the shift fork 8 back to its initial position on the synchronizer 11.

[0045] It will be apparent to those skilled in the art that various modifications and variations can be made to the exemplary embodiments described above without departing from the spirit and scope of the present invention. Therefore, it is intended that the present invention cover modifications and variations of the present invention that fall within the scope of the appended claims and their equivalents.

Claims

1. A gearbox, characterized in that: include: Box; A rear end cover, the rear end cover is fixed to the rear end of the box body, and a cylinder cavity is provided in the rear end cover; A shift mechanism, comprising a cylinder end cover provided on the rear end cover and used to seal the cylinder cavity, a shift rod passing through the cylinder cavity, a piston sleeved and fixed on the shift rod and located in the cylinder cavity, a stopper located outside the rear end cover and fixed to the shift rod, and a return spring disposed between the stopper and the cylinder end cover; A built-in oil channel is provided in the rear end cover and is communicated with the oil cylinder cavity.

2. The gearbox according to claim 1, wherein: A threaded hole is axially provided at the end of the shift rod, and the stopper is locked and fixed to the end of the shift rod by means of a bolt that cooperates with the threaded hole.

3. The gearbox according to claim 2, wherein: The piston includes a cylindrical portion mounted on the shift rod and a main body portion extending radially outward from the cylindrical portion. The main body portion is located on the side of the cylindrical portion away from the block. A piston sleeve is provided at the end of the cylinder cavity away from the block, and the main body portion is placed in the piston sleeve.

4. The gearbox according to claim 3, wherein: A first annular groove is formed on the main body, and a first sealing ring is provided in the first annular groove.

5. The gearbox according to claim 4, characterized in that One end of the cylinder portion close to the stop block is connected to the shift rod through a thread, and one end of the cylinder portion away from the stop block is sleeved on the shift rod and sealed with the shift rod through an O-ring.

6. The gearbox according to claim 5, characterized in that The shift rod is provided with a self-locking nut, and the self-locking nut is located between the piston and the oil cylinder end cover.

7. The gearbox according to claim 6, wherein: The cylinder end cover includes a sleeve portion and a mounting portion extending radially outward from the outer circumferential surface of the sleeve portion. The mounting portion is fixed to the rear end cover by bolts. The sleeve portion partially extends into the cylinder cavity and opens a second annular groove. A second sealing ring is provided in the second annular groove, and sealing is achieved by the second sealing ring and the inner wall of the cylinder cavity.

8. The gearbox according to claim 7, wherein: The sleeve portion is arranged in a stepped shape, including a small cylinder for sleeved by the reset spring and a large cylinder for supporting the reset spring. A step surface is formed between the small cylinder and the large cylinder, and the reset spring is supported on the step surface.

9. The gearbox according to claim 8, wherein: The stopper comprises a sleeve portion for sleeved with a reset spring and a supporting portion for supporting the reset spring. The supporting portion is located at an end of the sleeve portion and extends radially outward from the sleeve portion.

10. The gearbox according to claim 1, wherein: The shift lever is provided with a shift fork, and the shift fork is located in the box body.

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