Off-gear prevention mechanism of gearbox

Abstract

An out-of-gear preventing mechanism of a gearbox comprises a locking air cylinder and a shifting fork shaft which is fixed to a gearbox shell, a telescopic lock shaft is arranged in a piston cavity of the locking air cylinder and is perpendicular to the gearbox, a piston head is formed by the portion, located in the piston cavity, of the telescopic lock shaft, and the telescopic lock shaft extends out of a shaft body of the locking air cylinder to be arranged in a shaft hole of the gearbox shell in a penetrating mode. An arc-shaped annular groove is formed in the cylindrical surface of a shaft body of the telescopic lock shaft; one end of the compression spring abuts against the piston head, and the other end abuts against the end of the shaft hole. A plurality of arc-shaped grooves are formed in the shifting fork shaft; the telescopic lock shaft is provided with a locking position and an unlocking position, and when the telescopic lock shaft is located at the unlocking position, the arc-shaped annular groove is aligned with the shifting fork shaft, so that the shifting fork shaft can freely and axially move; when the telescopic lock shaft is located at the locking position, the cylindrical surface of the shaft body of the telescopic lock shaft is matched with the arc-shaped groove of the shifting fork shaft in a convex-concave mode so that the axial position of the shifting fork shaft can be locked. According to the utility model, the position of the shifting fork shaft after shifting can be locked, and the out-of-gear phenomenon caused by vibration is avoided.

Description

TECHNICAL FIELD

[0001] The utility model belongs to gearbox technical field, concretely relates to a gearbox anti -skipping gear mechanism. BACKGROUND

[0002] At present, the mud pump gearbox for oil field needs to be manually or remotely controlled to shift gears according to the change of load size. Since the working condition on site is relatively poor, the vibration and impact are very large. After the gear shifting is completed, the meshing sleeve (installed on the shift lever) is affected by the vibration and impact, the shift lever has axial movement, and there is often a poor meshing or gear skipping situation, thereby causing the meshing teeth to be damaged or the gearbox to be unable to work normally.

[0003] In the prior art, in order to prevent the axial movement of the shift lever and the meshing sleeve after the gear shifting is completed, the meshing sleeve teeth are designed as tapered teeth, and a steel ball and a spring are added to the shift lever, which reduces the probability of gear skipping to a certain extent. However, in actual application, especially in hard geological conditions (such as rock layers), the axial movement of the meshing sleeve caused by vibration is already greater than the locking force of the tapered teeth and the steel ball, and there is still a risk of gear skipping. SUMMARY

[0004] The utility model aims at providing a gearbox anti -skipping gear mechanism, which is improved in mechanical structure and used in cooperation with the gearbox, thereby solving the problem of shift lever gear skipping of the gearbox under vibration and impact working conditions.

[0005] In order to achieve the above-mentioned purpose, the utility model adopts the technical scheme of a gearbox anti -skipping gear mechanism, which comprises a locking cylinder, the locking cylinder is fixedly connected to a gearbox shell, a telescopic lock shaft is arranged in a piston cavity of the locking cylinder, the telescopic lock shaft is perpendicular to a shift fork shaft in the gearbox for gear shifting, the part of the telescopic lock shaft located in the piston cavity forms a piston head of the locking cylinder, the shaft body of the telescopic lock shaft extending out of the locking cylinder is arranged in a shaft hole of the gearbox shell, and a circular-arc annular groove is arranged on the shaft body cylindrical surface of the telescopic lock shaft.

[0006] A compression spring is arranged, one end of the compression spring abuts against the piston head, and the other end of the compression spring abuts against a stepped surface at the end of the shaft hole;

[0007] A plurality of circular-arc grooves corresponding to the gear positions of the gearbox are arranged on the shift fork shaft, and the shape of the circular-arc grooves is consistent with the shape of the shaft body cylindrical surface of the telescopic lock shaft.

[0008] The telescopic lock shaft has a locking position and an unlocking position, when the telescopic lock shaft is in the unlocking position, the circular-arc annular groove is aligned with the shift fork shaft, so that the shift fork shaft can freely move axially, and when the telescopic lock shaft is in the locking position, the shaft body cylindrical surface of the telescopic lock shaft is in convex-concave cooperation with the circular-arc groove of the shift fork shaft, so as to lock the axial position of the shift fork shaft.

[0009] Further, the locking cylinder comprises a cylinder shell and a cylinder cover, one end of the cylinder shell is fixedly connected with the end surface of the gearbox shell, the other end of the cylinder shell is fixedly connected with the cylinder cover, an intake and exhaust pipeline is connected with the cylinder cover, and the intake and exhaust pipeline is connected with a compressed gas source.

[0010] Further, an electromagnetic valve is arranged on the intake and exhaust pipeline.

[0011] Further, two or more than two shift fork shafts are arranged on the gearbox shell, and the number of the circular-arc annular grooves on the telescopic locking shaft is equal to the number of the shift fork shafts.

[0012] In the technical scheme, the distance between the shaft center of the shift fork shaft and the shaft center of the telescopic locking shaft is less than the sum of the radius of the shift fork shaft and the radius of the telescopic locking shaft, and the radial dimension of the overlapping part of the shift fork shaft and the telescopic locking shaft is equal to the depth of the circular-arc groove or the circular-arc annular groove.

[0013] In the technical scheme, the compression spring is sleeved on the shaft body of the telescopic locking shaft.

[0014] In the technical scheme, the outer circular surface of the piston head is provided with a magnet, the cylinder body of the locking cylinder is externally provided with a magnetic switch capable of detecting the magnet, the magnetic switch comprises an unlocking position magnetic switch and a locking position magnetic switch, and the unlocking position magnetic switch and the locking position magnetic switch monitor the unlocking position and the locking position of the telescopic locking shaft, respectively.

[0015] Specifically, the magnet is a rubber magnetic ring arranged in a ring-shaped mounting groove on the outer circular surface of the piston head.

[0016] Further, a safety distance is left between the outer diameter surface of the rubber magnetic ring and the groove opening of the ring-shaped mounting groove.

[0017] Further, a sealing ring is further arranged on the outer circular surface of the piston head and in contact with the inner wall of the piston cavity.

[0018] The utility model discloses a locking structure of a shift fork shaft, which is used in cooperation with a gearbox.

[0019] The utility model discloses a locking structure of a shift fork shaft, which is used in cooperation with a gearbox. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0021] Figure 1 It is a structure schematic view of the gear box anti-shift-out mechanism in the unlocking state.

[0022] Figure 2 It is a structure schematic view of the gear box anti-shift-out mechanism in the locking state. Figure 1 It is a B-B view in the figure.

[0023] Figure 3 It is a structure schematic view of the gear box anti-shift-out mechanism in the unlocking state.

[0024] Figure 4 It is a B-B view in the figure. Figure 3

[0025] Marked in the figure: 1, first shift fork shaft, 2, second shift fork shaft, 3, cylinder shell, 4, locking position magnetic switch, 5, unlocking position magnetic switch, 6, cylinder cover, 7, intake and exhaust pipeline, 8, electromagnetic valve, 9, piston head, 10, rubber magnetic ring, 11, compression spring, 12, telescopic lock shaft, 13, circular arc annular groove, 14, gear box shell, 1401, shaft hole, 15, circular arc groove, 16, neutral position, 17, 1st gear position, 18, 2nd gear position, 19, sealing ring. DETAILED DESCRIPTION

[0026] The present application will be further described in detail below in combination with the drawings and embodiments, but it is not as a basis for any limitation on the application.

[0027] As shown in Figure 1 , 3 , the gear box anti-shift-out mechanism is installed on the gear box shell 14, which can lock the shift fork shaft gear shifting position of the gear box to avoid the axial movement of the shift fork shaft in the gear position after gear shifting and shift out. In this embodiment, two parallel arranged shift fork shafts are arranged in the gear box shell 14, which are the first shift fork shaft 1 and the second shift fork shaft 2. Each shift fork shaft drives the corresponding meshing sleeve to realize gear shifting operation by axial movement (as shown by the arrow in Figure 2 , 4 . Utilizing the shift fork shaft to realize gear shifting belongs to the conventional technology in the field of gear box, which is not within the scope of structural improvement of the present application, so it is not described in detail.

[0028] As shown in Figure 2 , 4 ​As shown, in the embodiment, three arc-shaped grooves 15 are arranged on the cylindrical surface of the first shift fork shaft 1 and the second shift fork shaft 2, and the three arc-shaped grooves 15 are arranged along the axial direction of the shift fork shaft. Each arc-shaped groove 15 indicates a gear position of the gearbox. For example, the middle arc-shaped groove 15 corresponds to the neutral position 16, and the two arc-shaped grooves 15 at the ends correspond to the 1st gear position 17 and the 2nd gear position 18, respectively.

[0029] The locking cylinder includes a cylinder shell 3 and a cylinder cover 6. The telescopic locking shaft 12 is arranged in the piston cavity of the locking cylinder as a piston rod. One end of the cylinder shell 3 is fixed to the end face of the gearbox shell 14, and the end face of the cylinder shell 3 and the gearbox shell 14 is sealed by a sealing ring. The other end of the cylinder shell 3 is sealingly connected to the cylinder cover 6, thereby forming a piston cavity in the cylinder shell 3. The cylinder cover 6 is provided with a threaded air inlet hole. One end of the intake and exhaust pipeline 7 is connected to the threaded air inlet hole through an air pipe joint. The other end of the intake and exhaust pipeline 7 is connected to the electromagnetic valve 8, and the electromagnetic valve 8 is connected to a compressed air source. The intake and exhaust of the locking cylinder are realized by the opening and closing of the electromagnetic valve 8. The telescopic locking shaft 12 is movably arranged in the shaft hole 1401 in the gearbox shell 14, and the telescopic locking shaft 12 is perpendicular to the first shift fork shaft 1 and the second shift fork shaft 2. One end of the telescopic locking shaft 12 towards the locking cylinder is a piston head 9 located in the piston cavity of the locking cylinder. The cylindrical surface of the piston head 9 is provided with a sealing ring 19 capable of sealing with the inner wall of the piston cavity. The cylindrical surface of the telescopic locking shaft 12 is provided with an arc-shaped annular groove 13 away from the piston head 9. The number of arc-shaped annular grooves 13 is the same as the number of shift fork shafts and corresponds to the positions. In the embodiment, two arc-shaped annular grooves 13 are provided, and the distance between the two arc-shaped annular grooves 13 is equal to the distance between the first shift fork shaft 1 and the second shift fork shaft 2.

[0030] The shaft hole 1401 of the gearbox housing 14 is in communication with the moving hole where the first shift shaft 1 and the second shift shaft 2 are located and partially overlaps, so that part of the cylindrical surface of the first shift shaft 1 and the second shift shaft 2 can enter the shaft hole 1401, and the distance of the part of the cylindrical surface of the first shift shaft 1 and the second shift shaft 2 entering the shaft hole 1401 is equal to the depth of the circular arc annular groove 13. Therefore, when the two circular arc annular grooves 13 of the telescopic lock shaft 12 are aligned with the first shift shaft 1 and the second shift shaft 2, the first shift shaft 1 and the second shift shaft 2 can move freely in the axial direction; after the first shift shaft 1 and the second shift shaft 2 complete gear shifting, the telescopic lock shaft 12 is controlled to extend, so that the circular arc groove 15 can be engaged with the cylindrical surface of the telescopic lock shaft 12, thereby achieving locking of the corresponding shift shaft.

[0031] The specific working process is as follows:

[0032] As shown in Figure 1 , 2 , when the gearbox needs to shift gears, the closing electromagnetic valve 8 is controlled, there is no compressed gas in the intake and exhaust pipeline 7, the compression spring 11 is in a relaxed state, the telescopic lock shaft 12 is pushed back to the right end and contacts the cylinder head 6, so that the telescopic lock shaft 12 is fixed in its unlocked position, at this time, the two circular arc annular grooves 13 of the front section of the telescopic lock shaft 12 are respectively aligned with the first shift shaft 1 and the second shift shaft 2, at this time, the first shift shaft 1 and the second shift shaft 2 can move freely in the axial direction, thereby achieving gear shifting operation.

[0033] As shown in Figure 3 , 4 , when the gearbox completes gear shifting, the first shift shaft 1 and the second shift shaft 2 are respectively in their respective axial positions, at this time, the centers of the circular arc grooves 15 below the two shift shafts coincide with the axis of the telescopic lock shaft 12, by opening the electromagnetic valve 8, compressed gas is introduced into the intake pipeline 7, under the pushing of the compressed gas, the telescopic lock shaft 12 pushes the compression spring 11 to move axially, when the end surface of the piston head 9 of the telescopic lock shaft 12 contacts the bottom of the cylinder shell 3, the locking action is in place, at this time, the cylindrical surface of the front section of the telescopic lock shaft 12 enters the circular arc groove 15 below the first shift shaft 1 and the second shift shaft 2, the two shift shafts cannot move axially, thereby preventing gear shifting. Figure 4 As shown in

[0034] Further, as shown in Figure 1As shown, the piston head 9 is further provided with an annular mounting groove, and a rubber magnetic ring 10 is arranged in the annular mounting groove, and a certain safety distance is left between the outer diameter surface of the rubber magnetic ring 10 and the groove of the annular mounting groove to avoid friction between the rubber magnetic ring 10 and the inner wall of the cylinder shell 3. The outside of the cylinder shell 3 is provided with two magnetic switches capable of detecting the rubber magnetic ring 10, and the two magnetic switches are respectively a locking position magnetic switch 4 and an unlocking position magnetic switch 5. The telescopic lock shaft 12 is axially movable at two limit positions corresponding to the locking position and the unlocking position, specifically, when the piston head 9 is on the cylinder head 6, the telescopic lock shaft 12 is in the unlocking position, and when the piston head 9 is on the stepped surface at the other end of the cylinder shell 3, the telescopic lock shaft 12 is in the locking position. Therefore, when the locking position magnetic switch 4 senses the rubber magnetic ring 10 on the piston head 9, it indicates that the telescopic lock shaft 12 is in the locking position, and when the unlocking position magnetic switch 5 senses the rubber magnetic ring 10 on the piston head 9, it indicates that the telescopic lock shaft 12 is in the unlocking position. Therefore, the cooperation of the locking position magnetic switch 4 and the unlocking position magnetic switch 5 with the rubber magnetic ring 10 can sense the position of the telescopic lock shaft, and feedback the signal to the controller to realize remote control of the opening and closing of the electromagnetic valve. Alternatively, the electromagnetic valve is set to a manual mode to realize local manual control.

[0035] Further, the rubber magnetic ring 10 is mounted on the inside of the sealing ring 19 of the piston head 9, that is, the side away from the cylinder head 6, to avoid loosening of the rubber magnetic ring 10 due to the influence of the compressed air in the piston cavity.

[0036] It can be understood that the embodiment gives two fork shafts in the gearbox shell, and therefore two circular-arc annular grooves are arranged on the telescopic lock shaft. In other embodiments, one or more than two fork shafts can be arranged in the gearbox shell, and the number of the circular-arc annular grooves on the telescopic lock shaft should also be changed accordingly to be consistent with the number of the fork shafts.

[0037] In other embodiments, the compression spring can also be replaced by a plurality of small springs distributed along the circumference, which can also play a role in extruding the telescopic lock shaft to reset.

[0038] The above embodiments are only used to illustrate the technical solutions of the present application and not to limit them, and those skilled in the art should understand that the specific embodiments of the present application can be modified or replaced by equivalents according to the above embodiments, and any modification or equivalent replacement without departing from the spirit and scope of the present application is within the protection scope of the claims.

Claims

1. A gearbox anti-slip mechanism, characterized in that: The locking cylinder is fixedly connected to the gearbox housing, a retractable lock shaft is arranged in the piston cavity of the locking cylinder, the retractable lock shaft is perpendicular to the shift fork shaft in the gearbox for gear shifting, the part of the retractable lock shaft in the piston cavity forms the piston head of the locking cylinder, the shaft body of the retractable lock shaft extending out of the locking cylinder is arranged in the shaft hole of the gearbox housing, and an arc-shaped annular groove is arranged on the shaft body cylindrical surface of the retractable lock shaft; A compression spring is arranged on the piston head and abuts against the stepped surface at the end of the shaft hole; The shift fork shaft is provided with a plurality of arc-shaped grooves corresponding to the gear positions of the gearbox, and the shape of the arc-shaped grooves is consistent with the shape of the shaft body cylindrical surface of the retractable lock shaft; The retractable lock shaft has a locking position and an unlocking position, when the retractable lock shaft is in the unlocking position, the arc-shaped annular groove is aligned with the shift fork shaft to enable the axial movement of the shift fork shaft, and when the retractable lock shaft is in the locking position, the shaft body cylindrical surface of the retractable lock shaft is in convex-concave cooperation with the arc-shaped groove of the shift fork shaft to lock the axial position of the shift fork shaft.

2. A range prevention mechanism for a gearbox according to claim 1, characterised in that: The locking cylinder comprises a cylinder housing and a cylinder cover, one end of the cylinder housing is fixedly connected to the end surface of the gearbox housing, the other end of the cylinder housing is fixedly connected to the cylinder cover, an air inlet and outlet pipeline is connected to the cylinder cover, and the air inlet and outlet pipeline is connected to a compressed air source.

3. A gearbox kickdown prevention mechanism according to claim 2, characterised in that: An electromagnetic valve is arranged on the air inlet and outlet pipeline.

4. The transmission kickdown prevention mechanism of claim 1, wherein: The gearbox housing is provided with two or more shift fork shafts, and the number of the arc-shaped annular grooves on the retractable lock shaft is equal to the number of the shift fork shafts.

5. A range prevention mechanism according to any one of claims 1-4, characterized in that: The distance between the shaft center of the shift fork shaft and the shaft center of the retractable lock shaft is less than the sum of the radius of the shift fork shaft and the radius of the retractable lock shaft, and the radial dimension of the overlapping part of the shift fork shaft and the retractable lock shaft is equal to the depth of the arc-shaped groove or the arc-shaped annular groove.

6. A range prevention mechanism for a gearbox according to any one of claims 1-4, characterized in that: The compression spring is sleeved on the shaft body of the retractable lock shaft.

7. A range prevention mechanism for a gearbox according to any one of claims 1-4, characterized in that: A magnet is arranged on the outer circular surface of the piston head, a magnetic switch capable of detecting the magnet is arranged outside the cylinder body of the locking cylinder, the magnetic switch comprises an unlocking position magnetic switch and a locking position magnetic switch, and the unlocking position and the locking position of the retractable lock shaft are monitored, respectively.

8. A range prevention mechanism for a gearbox according to claim 7, characterised in that: The magnet is a rubber magnetic ring arranged in the annular mounting groove of the outer circular surface of the piston head.

9. A gearbox kickdown prevention mechanism according to claim 8, characterised in that: A safety distance is left between the outer diameter surface of the rubber magnetic ring and the groove opening of the annular mounting groove.

10. The gearbox hold-off mechanism of claim 8, wherein: A sealing ring is further arranged on the outer circular surface of the piston head and in contact with the inner wall of the piston cavity.

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