Underground tractor automatic transmission system and control method

Abstract

An underground tractor automatic transmission system and a control method. The system comprises a variable-speed transmission device, and a variable-speed reducer connected to a tractor via a variable-speed transmission shaft; the variable-speed transmission shaft is configured to allow, by means of an axial adjustment assembly, changes in the axial position; axial positions of the variable-speed transmission shaft at least comprise a first axial position and a second axial position; the output end of the variable-speed transmission shaft is provided with a first transmission member and a second transmission member; when the variable-speed transmission shaft is located at the first axial position, the variable-speed transmission shaft is connected to the variable-speed reducer by means of the first transmission member, so that the variable-speed transmission device is at a first reduction gear; when the variable-speed transmission shaft is located at the second axial position, the variable-speed transmission shaft is connected to the variable-speed reducer by means of the second transmission member, so that the variable-speed transmission device is at a second reduction gear.

Description

An automatic speed change system and control method for downhole traction devices Technical Field

[0001] This invention relates to an automatic speed change system and control method for a downhole traction device, belonging to the field of petroleum logging instruments. Background Technology

[0002] In the oil, gas, and mining industries, traction devices have become essential equipment for achieving efficient and stable operations. However, based on practical experience, some challenges remain in downhole operations. To achieve more efficient traction operations, it is necessary to develop downhole speed-changing functions, enabling the traction device to automatically adjust the reduction ratio according to the resistance level, thereby controlling speed and traction force.

[0003] In downhole operations, the resistance encountered by the traction device often changes due to the complexity and variability of the environment. Traditional traction device designs are usually based on fixed speed and traction force, which is not flexible enough to cope with the ever-changing downhole environment and cannot be adjusted according to real-time conditions.

[0004] Existing technologies have proposed gear shifting devices that include high-speed and low-speed reduction mechanisms to achieve gear switching. However, these reduction mechanisms use chain drives, requiring multiple sets of reduction mechanisms, resulting in a complex structure. Furthermore, chain drives have relatively poor stability.

[0005] In summary, how to achieve automatic speed change of the traction device downhole is a problem that urgently needs to be solved in this field. Summary of the Invention

[0006] To address the aforementioned technical problems in the existing technology, this invention proposes an automatic speed change system and control method for a downhole traction device. This system can output a speed change control signal based on the working state of the traction device through an automatic speed change control device, thereby controlling the axial displacement of the axial adjustment component and forming different connection states between the speed change transmission shaft and the variable speed reducer, thus realizing different deceleration gears and achieving automatic speed change of the traction device.

[0007] According to one aspect of the present invention, an automatic transmission system for a downhole traction device is provided, comprising:

[0008] A variable speed drive system includes a variable speed reducer connected to the traction device via a variable speed drive shaft, the variable speed drive shaft being configured to change its axial position via an axial adjustment assembly, the axial position of the variable speed drive shaft including at least a first axial position and a second axial position.

[0009] The output end of the transmission shaft is provided with a first transmission component and a second transmission component. When the transmission shaft is in a first axial position, it is connected to the variable speed reducer through the first transmission component, so that the transmission device is in a first deceleration gear. When the transmission shaft is in a second axial position, it is connected to the variable speed reducer through the second transmission component, so that the transmission device is in a second deceleration gear.

[0010] A further improvement of the present invention is that the first transmission member and the second transmission member are arranged in different positions in both the axial and radial directions of the transmission shaft.

[0011] A further improvement of the present invention is that the variable speed reducer is provided with a first mating member for engaging with the first transmission member and a second mating member for engaging with the second transmission member, wherein the axial distance between the first mating member and the second mating member is set to be smaller than the axial distance between the first transmission member and the second transmission member.

[0012] When the transmission shaft moves to the first axial position, the first transmission member engages with the first mating member, while the second transmission member separates from the second mating member; when the transmission shaft moves to the second axial position, the first transmission member separates from the first mating member, while the second transmission member engages with the second mating member.

[0013] A further improvement of the present invention is that the end of the transmission shaft is provided with a transmission disk, the first transmission component includes a plurality of transmission pins arranged circumferentially on the end face of the transmission disk, and the second transmission component includes a transmission key fixed on the end face of the transmission disk.

[0014] The first mating component includes a plurality of transmission pin holes disposed on the variable speed reducer and corresponding to the plurality of transmission pins, and the second mating component includes a transmission keyway for receiving the transmission key.

[0015] A further improvement of the present invention is that the transmission device is connected to an automatic transmission control device, which is configured to output a control signal to the axial adjustment assembly according to the working state of the traction device, thereby controlling the axial position of the transmission shaft.

[0016] A further improvement of the present invention is that the variable speed reducer includes a housing, and a plurality of planetary gear sets are arranged inside the housing; each planetary gear set includes a planetary gear carrier, planetary gears are rotatably connected to the outer periphery of the planetary gear carrier, and a sun gear is provided inside the planetary gear carrier;

[0017] A set of planetary gears connected to the transmission shaft is an input-side planetary gear set. The transmission keyway is provided on the sun gear of the input-side planetary gear set, and the transmission pin hole is provided on the planetary gear carrier of the input-side planetary gear set.

[0018] A further improvement of the present invention is that the axial adjustment assembly includes an axial movement sleeve;

[0019] The transmission shaft is rotatably mounted inside the axial movement sleeve, and the transmission shaft is provided with an axial limiting member that cooperates with the axial movement sleeve. The axial movement sleeve drives the transmission shaft to move through the axial limiting member.

[0020] A further improvement of the present invention is that the axial moving sleeve is configured to move axially under the drive of an actuating motor, the input end of the actuating motor is connected to the automatic transmission control device, and the output end of the actuating motor is engaged with the axial moving sleeve to drive the axial moving sleeve to move.

[0021] A further improvement of the present invention is that the axial moving sleeve includes an annular moving sleeve composed of a first half and a second half, and the annular moving sleeve is provided with a first bearing and a second bearing sleeved on the transmission shaft, and a limiting annular groove is defined between the first bearing and the second bearing.

[0022] The axial limiting member is constructed as an annular flange that fits into the limiting annular groove.

[0023] A further improvement of the present invention is that the axial moving sleeve is provided with a through hole, and a radial limiting rod is provided in the through hole to prevent the axial moving sleeve from rotating.

[0024] A further improvement of the present invention is that the transmission shaft is connected to the drive motor of the traction device via a coupling, and an axial compensation mechanism is provided inside the coupling.

[0025] When the transmission shaft moves axially, the coupling maintains the connection between the drive motor and the transmission shaft through the axial compensation mechanism.

[0026] A further improvement of the present invention is that the coupling includes a front end member connected to the drive motor and a rear end member connected to the transmission shaft.

[0027] The front end component is provided with a displacement compensation groove, and the inner wall of the displacement compensation groove is provided with a plurality of spline grooves; the rear end component is provided with a spline, and the spline is provided with a plurality of key bodies; the spline is confined within the displacement compensation groove, and the key bodies are confined within the spline grooves.

[0028] A further improvement of the present invention is that the key body includes a front key body and a rear key body in the circumferential direction, the radial height of the front key body is greater than the radial height of the rear key body, and the radial depth of the spline groove matches the radial height of the front key body.

[0029] A further improvement of the present invention is that the front end of the spline is a spherical shaft, and the outer surface of the front key body is arched; the radial cross-section of the key body and the spline groove are both fan-shaped surfaces with matching shapes; the rear end of the coupling is provided with a conical surface, and the end of the conical surface is provided with a rear shaft body that connects to the speed change transmission shaft.

[0030] A further improvement of the present invention is that the automatic transmission control device includes:

[0031] The control module is used to output control signals to the axial adjustment assembly to control the axial adjustment assembly to adjust the axial position of the transmission shaft.

[0032] The sampling module is used to collect data on the cable head voltage and / or power supply current of the traction device and send the collected data to the control module;

[0033] The control module compares the data information with a preset value and outputs a control signal to control the transmission shaft to be in the first deceleration gear or the second deceleration gear.

[0034] According to another aspect of the present invention, a control method for the aforementioned automatic transmission system of the downhole traction device is also provided, comprising:

[0035] Collect data on the cable head voltage and / or power supply current of the traction device;

[0036] The data information is compared with a first preset value and a second preset value.

[0037] When the data information is lower than the first preset value and higher than the second preset value, the current state remains unchanged;

[0038] When the data exceeds the first preset value, the control module sends a control signal to put the transmission shaft into the first deceleration gear.

[0039] When the data information is lower than the second preset value, the control module sends a control signal to put the transmission shaft into the second deceleration gear.

[0040] Compared with the prior art, the present invention has the following advantages.

[0041] The automatic speed control device of the present invention can output a speed control signal according to the working state of the traction device, thereby controlling the axial displacement of the axial adjustment component, forming different connection states between the speed transmission shaft and the variable speed reducer, thereby realizing different deceleration gears and realizing automatic speed change of the traction device.

[0042] Compared to traditional speed reducers, the automatic speed control device of this invention eliminates the need for components such as friction plates. Automatic speed change is achieved solely through the axial displacement of the transmission shaft, resulting in a simple motion trajectory, high stability, and rapid response. The automatic speed control device of this invention comprises fewer components, has a simple structure, and is easy to arrange. The speed reducer of this invention achieves speed change functionality with a compact and relatively simple structure. Furthermore, due to its relatively simple structure and few parts, it possesses strong structural strength and vibration resistance. Attached Figure Description

[0043] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, in which:

[0044] Figure 1 shows a schematic diagram of the structure of a speed transmission device according to an embodiment of the present invention;

[0045] Figure 2 shows a side view of a variable speed reducer according to an embodiment of the present invention;

[0046] Figure 3 is a cross-sectional view along line AA in Figure 2;

[0047] Figure 4 shows a three-dimensional structural schematic diagram of the input-side planetary gear set according to an embodiment of the present invention;

[0048] Figure 5 shows a side view of the input-side planetary gear set according to an embodiment of the present invention;

[0049] Figure 6 shows an axial sectional view of the input-side planetary gear set according to an embodiment of the present invention;

[0050] Figure 7 shows a three-dimensional structural schematic diagram of a two-stage planetary gear set according to an embodiment of the present invention;

[0051] Figure 8 shows a side view of a two-stage planetary gear set according to an embodiment of the present invention;

[0052] Figure 9 shows an axial sectional view of a two-stage planetary gear set according to an embodiment of the present invention;

[0053] Figure 10 shows a side view of the housing according to an embodiment of the present invention;

[0054] Figure 11 shows an axial sectional view of the housing according to an embodiment of the present invention;

[0055] Figure 12 shows a side view of an end cap according to an embodiment of the present invention;

[0056] Figure 13 shows a three-dimensional structural schematic diagram of a speed-changing transmission shaft according to an embodiment of the present invention;

[0057] Figure 14 shows an exploded structural diagram of a variable speed drive shaft according to an embodiment of the present invention.

[0058] Figure 15 shows an exploded structural diagram of the axial moving sleeve according to an embodiment of the present invention;

[0059] Figure 16 shows an axial cross-sectional view of an axial moving sleeve according to an embodiment of the present invention;

[0060] Figure 17 shows a schematic diagram of the connection between the variable speed drive shaft and the variable speed reducer in high speed gear according to an embodiment of the present invention.

[0061] Figure 18 shows a schematic diagram of the connection between the variable speed drive shaft and the variable speed reducer in a low speed gear according to an embodiment of the present invention.

[0062] Figure 19 shows a three-dimensional structural diagram of a coupling in an extended state according to an embodiment of the present invention;

[0063] Figure 20 shows a three-dimensional structural schematic diagram of a coupling in a retracted state according to an embodiment of the present invention;

[0064] Figure 21 shows a three-dimensional structural diagram of the front end of the coupling according to an embodiment of the present invention;

[0065] Figure 22 shows a three-dimensional structural diagram of the rear end of the coupling according to an embodiment of the present invention;

[0066] Figure 23 shows a schematic diagram of the structure of a limiting rod assembly according to an embodiment of the present invention;

[0067] Figure 24 shows a schematic diagram of the working principle of an automatic transmission control device according to an embodiment of the present invention.

[0068] Figure 25 shows a side view of a speed transmission device according to an embodiment of the present invention, illustrating a structure without a drive motor and its output shaft.

[0069] Figure 26 is a cross-sectional view of the transmission device in high gear along line AA in Figure 25;

[0070] Figure 27 is a cross-sectional view of the transmission device in low gear along line AA of Figure 25. Detailed Implementation

[0071] To make the technical solutions and advantages of the present invention clearer, exemplary embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not an exhaustive list of all embodiments. Furthermore, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0072] Figure 1 schematically shows an automatic transmission system 1000 for a downhole traction device according to an embodiment of the present invention, which includes a transmission device 100. The transmission device 100 includes a variable speed reducer 1, which is connected to a drive motor 8 of a downhole traction device (not shown) via a transmission shaft 2. An axial adjustment assembly is provided on the transmission shaft 2, which can change the axial position of the transmission shaft 2. In this embodiment, the axial position of the transmission shaft 2 includes at least a first axial position and a second axial position.

[0073] The output end of the transmission shaft 2 is provided with a first transmission member and a second transmission member. When the transmission shaft 2 is in the first axial position, it engages with the variable speed reducer 1 through the first transmission member, while the second transmission member is disengaged from the variable speed reducer 1. At this time, the transmission device 100 is in the first deceleration gear. When the transmission shaft 2 is in the second axial position, it connects to the variable speed reducer 1 through the second transmission member, while the first transmission member is disengaged from the variable speed reducer 1. At this time, the transmission device 100 is in the second deceleration gear.

[0074] According to the present invention, the first transmission member and the second transmission member are located at different positions in the axial direction and also at different positions in the radial direction. This arrangement allows the first and second transmission members to be conveniently arranged on the output end of the transmission shaft 2, thereby enabling the transmission shaft 2 to form a compact whole and saving valuable space. Simultaneously, the first and second transmission members do not interfere with each other, allowing the transmission device 100 to shift gears smoothly.

[0075] In one embodiment, the variable speed reducer 1 is provided with a first mating member that mates with the first transmission member and a second mating member that mates with the second transmission member. The axial distance between the first mating member and the second mating member is set to be less than the axial distance between the first transmission member and the second transmission member. This structure ensures that only one of the two components—the first transmission member and the first mating member, and the second transmission member and the second mating member—can engage.

[0076] Specifically, when the transmission shaft 2 moves to the first axial position, the first transmission member engages with the first mating member, and the second transmission member disengages from the second mating member. At this time, the transmission shaft transmits torque to the variable speed reducer through the first transmission member. When the transmission shaft 2 moves to the second axial position, the first transmission member disengages from the first mating member, and the second transmission member engages with the second mating member. At this time, the transmission shaft transmits torque to the variable speed reducer through the second transmission member.

[0077] In a preferred embodiment, the end of the transmission shaft 2 is provided with a transmission disk, and a first transmission component is located near the edge of the transmission disk. The first transmission component includes a plurality of transmission pins 26 arranged circumferentially and uniformly in the circumferential direction. A second transmission component includes a transmission key 27 fixed on the end face of the transmission disk. The first mating component includes a plurality of transmission pin holes 127 provided on the variable speed reducer 1, and the second mating component includes a transmission keyway 128.

[0078] In one embodiment, the downhole traction device automatic transmission system 100 further includes an automatic transmission control device 200 connected to the transmission device 100. The automatic transmission control device 200 is configured to output a transmission control signal to the axial adjustment assembly according to the operating state of the traction device, thereby controlling the axial position of the transmission shaft 2. Specifically, the automatic transmission control device 200 outputs a transmission control signal according to the operating state of the traction device, and the axial adjustment assembly receives this transmission control signal, thereby driving the transmission shaft 2 to an axial displacement to the corresponding axial position. Thus, the transmission shaft 2 forms different connection states with the variable speed reducer 1 at different axial positions, thereby forming different reduction gears.

[0079] In one embodiment, the variable speed reducer 1 includes a housing 10 with an end cap at its front end. Inside the housing 10 are several stages of planetary gear sets. Each planetary gear set includes a planetary gear carrier with planetary gears rotatably connected to its outer periphery. A sun gear meshes with the planetary gears inside the planetary gear carrier. The planetary gear carrier and sun gear in the same set are not fixedly connected; they can rotate, and the sun gear and planetary gear carrier rotate at different speeds.

[0080] In one embodiment, the planetary gear set closer to the output end is the previous stage planetary gear set, and the planetary gear set closer to the input end is the next stage planetary gear set. For example, the planetary gear set includes first-stage to n-stage planetary gear sets arranged sequentially from the output end to the input end. The i-stage planetary gear set includes an i-stage planetary carrier, an i-stage planetary gear, and an i-stage sun gear, where i is any natural number from 1 to n, and n is the number of planetary gear sets.

[0081] The output end of the planetary gear carrier is connected to the output end of the sun gear of the previous stage or the variable speed reducer. The input end of the sun gear is connected to the planetary gear carrier of the next stage or the drive pin. The housing is provided with several internal gears, wherein one side of the planetary gear meshes with the sun gear, and the other side meshes with the internal gear.

[0082] When the sun gear rotates at a high speed, it drives the planetary gears to rotate, causing the planetary gears to roll on the internal gears, thereby driving the planetary gear carrier to rotate at a lower speed, and thus outputting a lower speed to the next higher level planetary gear set.

[0083] In the automatic transmission system of the downhole traction device according to this embodiment, the i-stage sun gear is fixedly connected to the rear end of the i+1-stage planetary gear carrier and meshes with the i-stage planetary gear of the i-stage planetary gear carrier. The planetary gear carrier is a one-piece structure with a locating pin hole and a protruding shaft, which is used to fix the sun gear by an interference fit between the shaft and the hole. Several axial grooves are provided on the side wall of the planetary gear carrier, and a part of the planetary gear extends out of the planetary gear carrier through the axial grooves and meshes with the internal gear. The planetary gear carrier is rotatably connected to the planetary gears by a locating pin. A set of planetary gears connected to the transmission shaft is the input-side planetary gear set, and the locating pin of the input-side planetary gear set is provided with a limiting sleeve for axially limiting the sun gear.

[0084] In the automatic transmission system of the downhole traction device according to this embodiment, the number of planetary gears in the planetary gear set is set as needed. The planetary gears are positioned on the planetary gear carrier by locating pins. The locating pins have an interference fit with the shaft hole of the gear carrier and a transition fit or clearance fit with the shaft hole of the planetary gear. A first-stage planetary gear and an output shaft, or a second-stage planetary gear and a first-stage sun gear, or a third-stage planetary gear and a second-stage sun gear, are mounted on the planetary gear carrier; and so on, with the i-th stage planetary gear and the i+1-th stage sun gear assembled on one gear carrier. The sun gear in the output planetary gear set (i.e., the first-stage planetary gear set) is replaced by the output shaft. In the variable speed reducer 1, the planetary gears and sun gears of multiple planetary gear sets mesh with each other to form a multi-stage planetary gear set, achieving a speed reduction effect.

[0085] Figures 2 and 3 show an example of the variable speed reducer 1 when n=3. In this embodiment, the variable speed reducer 1 includes a three-stage planetary gear set, namely a first-stage planetary gear set 14, a second-stage planetary gear set 13, and a third-stage planetary gear set 12. In this embodiment, as shown in Figure 5, the sun gear 123 of the input planetary gear set 12 is provided with a transmission keyway 128 that mates with the transmission key 27, while its planetary gear carrier 121 is provided with a plurality of transmission pin holes 127 for mates with the transmission pin 26.

[0086] When the transmission shaft 2 is in the first axial position, it engages with the variable speed reducer 1 via the transmission pin 26, while the transmission key 128 is disconnected from the variable speed reducer 1. At this time, the transmission device 100 is in the first deceleration gear. When the transmission shaft 2 is in the second axial position, it connects to the variable speed reducer 1 via the transmission key 128, while the transmission pin 26 is disconnected from the variable speed reducer 1. At this time, the transmission device 100 is in the second deceleration gear.

[0087] Figures 4-6 show schematic diagrams of a three-stage planetary gear set, also known as an input-end planetary gear set. The three-stage planetary gear carrier 121 has several three-stage axial slots 126 for assembling the three-stage planetary gears 122. The axial length of the three-stage axial slots 126 is greater than the axial length of the three-stage planetary gears 122. The three-stage planetary gears 122 are located at the end of the three-stage axial slots 126 facing the end cover 11. The three-stage planetary gear locating pin 124 of the three-stage planetary gears 122 has an input-end sun gear limiting sleeve 125 for axially limiting the three-stage planetary gears 122 and the three-stage sun gear 123.

[0088] The axial distance between the third-stage planetary gear 122 and the second-stage planetary gear is greater than the axial distance between the second-stage planetary gear and the first-stage planetary gear. In other words, the axial distance between the n-stage planetary gear and the (n-1)-stage planetary gear increases with increasing n, providing space for speed-changing operations. Additionally, suitable thrust ball bearings can be installed at both ends of the third-stage planetary gear set to limit its axial displacement.

[0089] The structure of the non-input planetary gear set is described below using the second-stage planetary gear set 13 as an example. As shown in Figures 7-9, the second-stage planetary gear set 13 includes a second-stage planetary gear carrier 131, second-stage planetary gears 132, a second-stage sun gear 133, and second-stage planetary gear locating pins 134. The second-stage sun gear 133 is fixed to the rear end of the second-stage planetary gear carrier 131 and is used to mesh with the first-stage planetary gear set 14. Multiple second-stage planetary gear locating pins 134 are axially arranged through the second-stage planetary gear carrier 131, and multiple second-stage planetary gears 132 are rotatably mounted on the second-stage planetary gear carrier 131 through a second-stage planetary gear locating pin 134. The outer edge of the second-stage planetary gear 132 protrudes from the surface of the second-stage planetary gear carrier 131, and its protruding outer edge is used to mesh with the external gear ring on the inner wall of the housing 10. The portion of the second-stage planetary gear 132 located inside the second-stage planetary gear carrier 131 meshes with the embedded third-stage sun gear.

[0090] As shown in Figures 10 and 11, housing 10 is used to assemble all planetary gear sets, and its inner wall is provided with multiple sets of external gear rings for meshing with the corresponding planetary gears. The external gear rings and housing 10 are an integral structure, and there are several screw holes at the input end for fixing the end cover.

[0091] As shown in Figure 12, the end cap 11 is located at the front end of the housing 10. It is a disc-shaped structure with several screw holes and is assembled with the housing 10 by screws to ensure that the planetary gear set mechanism operates efficiently and stably in the variable speed reducer 1.

[0092] The speed reducer 1 according to the present invention can achieve speed change function through a compact and relatively simple structure. At the same time, due to its relatively simple structure and few parts, the speed reducer 1 also has strong structural strength and shock resistance.

[0093] Figures 13 and 14 show a preferred structure of the transmission shaft 2 according to the present invention. As shown, the output end of the transmission shaft 2 can be formed as a transmission disc, on which a transmission pin 26 and a transmission key 27 are provided. The transmission pin 26 and the transmission key 27 are arranged at different distances from the output end face of the transmission shaft 2 (i.e., the outer end face of the transmission disc). In the first connection state, the transmission pin 26 of the transmission shaft 2 is pinned to the nth stage planetary gear carrier 121 of the variable speed reducer 1, while the transmission key 27 is separated from the nth stage sun gear 123 of the variable speed reducer 1. In the second connection state, the transmission pin 26 of the transmission shaft 2 is separated from the nth stage planetary gear carrier 121 of the variable speed reducer 1, while the transmission key 27 is engaged with the nth stage sun gear 123 of the variable speed reducer 1.

[0094] In the illustrated embodiment, three transmission pins 26 are provided, which are used to engage with three transmission pin holes 127 provided on the n-stage planetary gear carrier 121 respectively in the first connection state. The transmission key 27 is in spline form and is used to cooperate with the transmission keyway 128 on the n-stage planetary gear carrier 121 in the second connection state.

[0095] The transmission key 27 is connected to the output end of the transmission shaft 2 via a smooth shaft. Thus, when the transmission shaft 2 extends toward the variable speed reducer 1, the transmission key 27 protrudes axially from the keyway 128 as the transmission shaft 2 extends. At this time, the smooth shaft is located within the keyway 128, thus preventing engagement between the transmission key 27 and the keyway 128. In other words, in the first connection state, only the transmission pin 26 and the transmission pin hole 127 are engaged. When the transmission shaft 2 retracts, the transmission key 27 retracts into the keyway 128, thus engaging with the keyway 128, forming the second connection state. In this second connection state, the transmission pin 26 and the transmission pin hole 127 cannot engage.

[0096] As shown in Figure 1, in one embodiment, the axial adjustment assembly includes an axial movement sleeve 3, which is configured to move axially under the drive of an actuating motor 5. A transmission shaft 2 is rotatably mounted within the axial movement sleeve 3, and the transmission shaft 2 is provided with an axial limiting member that cooperates with the axial movement sleeve 3. When the axial movement sleeve 3 moves axially, the transmission shaft 2 is driven to move axially under the action of the axial limiting member.

[0097] Preferably, the input end of the motor 5 is connected to the automatic speed control device 200, and a lead screw 6 is provided on the output shaft of the motor 5.

[0098] Figure 15 shows the structure of the axial motion sleeve 3. As shown, the axial motion sleeve 3 is provided with a threaded hole 35, and the lead screw 6 extends through the threaded hole 35. The actuation motor 5 can drive the lead screw 6 to rotate within the threaded hole 35, thereby driving the axial motion sleeve 3 to move.

[0099] As shown in Figure 15, the axial movement sleeve 3 includes an annular movement sleeve 31 composed of a first half 311 and a second half 312. Inside the annular movement sleeve 31, a first bearing 32 and a second bearing 33 are sleeved on the transmission shaft 2, and a limiting annular groove 34 is defined between the first bearing 32 and the second bearing 33. As shown in Figure 14, the axial limiting member is constructed as an annular flange 21, which can be fitted and installed within the limiting annular groove 34.

[0100] According to this embodiment, to facilitate assembly with the bearing, the flange 21 and the shaft body of the transmission shaft 2 cannot be integrally formed. Therefore, a groove is designed on the shaft body of the transmission shaft 2 for assembling the flange 21. As shown in Figure 14, the transmission shaft 2 has an annular groove 25 in the middle part of the shaft body. This groove 25 is used to assemble the annular flange 21 and to axially limit the annular flange 21 to prevent axial movement. The annular flange 21 is assembled at a position where the groove diameter is equal to the inner diameter of the two semicircles. The annular flange 21 is formed by two semicircular rings fixedly connected by bolts 24. The transmission shaft 2 has a flat key 23 at the input end (left end in Figure 14), and a pin hole 22 is provided between the flat key 23 and the annular flange 21.

[0101] When the axial movement sleeve 3 moves axially, an axial limiting relationship is formed between the axial movement sleeve 3 and the transmission shaft 2, allowing the transmission shaft 2 to reach different axial positions as the axial movement sleeve 3 moves axially. As shown in Figures 17 and 18, when the first axial position is reached, the transmission shaft 2 and the variable speed reducer 1 are in a first connection state, that is, the transmission pin 26 of the transmission shaft 2 is pin-connected to the nth stage planetary gear carrier 121 of the variable speed reducer 1, and the transmission key 27 is disengaged from the nth stage sun gear 123 of the variable speed reducer 1. When the second axial position is reached, the transmission shaft 2 and the variable speed reducer 1 are in a second connection state. The transmission pin 26 of the transmission shaft 2 is disengaged from the nth stage planetary gear carrier 121 of the variable speed reducer 1, and the transmission key 27 is engaged with the nth stage sun gear 123 of the variable speed reducer 1.

[0102] To prevent rotation of the axial motion sleeve 3, a limiting assembly 7 is provided, as shown in Figure 23. The limiting rod assembly 7 restricts the axial motion sleeve and the transmission shaft's degrees of freedom other than axial displacement, acting similarly to a guide rail, making the entire system more stable and improving its vibration resistance. The limiting assembly 7 includes a radial limiting rod 71 and a limiting rod support 72. Two through holes 36 are axially extending through the axial motion sleeve 3. A radial limiting rod 71 is axially extending through each of the through holes 36 to form a radial limiting fit with the axial motion sleeve 3. The radial limiting rod 71 is formed as a smooth cylindrical shaft, with both ends fixed to the holes in the limiting rod support 72 by interference fit. The surface of the radial limiting rod 71 forms a transition fit with the corresponding holes designed on the axial motion sleeve 3. The limiting rod support 72 includes screw holes and is fixed to the structural components of the traction device using screws. In this way, when the lead screw 6 rotates in the threaded hole 35, the limiting rod assembly 7 can prevent the axial movement sleeve 3 from rotating with the lead screw 6, and can only move axially.

[0103] In one embodiment, in order to compensate for the axial displacement of the transmission shaft 2, the present invention also provides a coupling for compensating for axial displacement while transmitting torque.

[0104] As shown in Figure 1, the transmission shaft 2 and the drive motor 8 are connected via a coupling 4. An axial compensation mechanism is provided inside the coupling 4. When the transmission shaft 2 moves axially, the coupling 4 maintains the connection between the drive motor 8 and the transmission shaft 2 through the axial compensation mechanism.

[0105] In this embodiment, the coupling is designed primarily to compensate for displacement caused by relative axial movement at both ends. It features a simple structure consisting of only two parts, resulting in a small footprint, low maintenance costs, and easy replacement. It is suitable for applications where two drive shafts require axial movement, the structure is compact, the transmitted torque is large, and the components are tightly and securely assembled, such as the connection between the motor and reducer inside a traction device. This coupling is designed as a split-type structure consisting of a front end and a rear end, both capable of transmitting torque even during normal operation with relative axial displacement.

[0106] Figures 19-23 show the structure of a coupling according to a preferred embodiment of the present invention. As shown in Figure 19, the coupling 4 includes a front coupling member 41 (which is fixed axially) and a rear coupling member 42 (which can be displaced axially). One end of the front coupling member 41 is connected to the output end of the drive motor 8, and the other end is provided with an axial displacement compensation groove 411 inside, as shown in Figure 21. The axial displacement compensation groove 411 includes a central groove 412 and spline grooves 413 radially distributed outside the central groove 412. One end of the rear coupling member 42 is provided with a spline on the outer edge of the shaft body, and the other end is connected to the input end of the transmission shaft 2. The rear coupling member 42 is slidably disposed in the axial displacement compensation groove 411, and the spline and the axial keyway 413 are radially limited. The torque output by the actuating motor 5 is transmitted through the lead screw 6 and the axial movement sleeve 3 to drive the transmission shaft 2 to move axially, thereby driving the reducer end of the coupling (i.e., the rear coupling member) to move axially, while maintaining power transmission during axial movement.

[0107] As shown in Figure 22, the spline includes several key bodies evenly distributed radially, the specific number of which can be determined according to actual needs. The key bodies include a front key body 421 and a rear key body 422. The radial height of the front key body 421 is greater than that of the rear key body 422, and the radial depth of the spline groove 413 is consistent with the radial height of the front key body 421. The front key body 421 is an arch shape with a central radial height higher than both ends. A section of shaft in the rear end 42 of the coupling used to house the arched key body is formed as a spherical shaft 423 with a central diameter larger than both ends, and this spherical shaft 423 is the same length as the arched key body.

[0108] Through the above structure, the area for transmission contact in the rear end 42 of the coupling is minimized as much as possible by using a special design of stepped and cylindrical tangential contact surfaces, thereby reducing resistance during axial movement while ensuring key strength. The special cylindrical tangential contact design, in addition to reducing the contact area, also enables the coupling to maintain smooth transmission even when there is a deflection of less than approximately 1° between the front and rear couplings. This design ensures that transmission is not affected by deflection between the input and output shafts due to external or internal factors, resulting in stronger vibration resistance and improved adaptability and reliability of the coupling.

[0109] The radial cross-section of the key and keyway 413 is a fitted sector surface. The rear end 42 of the coupling is provided with a rear shaft 424 for connecting the transmission shaft 2. The rear key 422 is connected to the rear shaft 424 via a tapered surface 425 with a gradually decreasing diameter. The front end face of the tapered surface 425 is a plane perpendicular to the central axis of the shaft, forming a flange on the shaft. The spline and flange form a T-shape. This design further ensures the reliability of the spline strength.

[0110] Preferably, the axial depth of the axial displacement compensation groove 411 is greater than one-eighth of the axial displacement distance that the coupling 4 needs to compensate for, so as to compensate for the axial displacement generated between the front end 41 and the rear end of the coupling and ensure the stability of the coupling transmission.

[0111] Figure 24 illustrates the structure and working principle of an automatic transmission control device 200 according to an embodiment of the present invention. As shown, the automatic transmission control device 200 includes a sampling module 201 and a control module 202. The sampling module 201 is used to collect data information such as the cable head voltage and / or power supply current of the traction device, and send the collected voltage and / or current data information to the control module 202.

[0112] The control module 202 outputs a low-speed control signal when the received voltage or current data exceeds a first preset value, and outputs a high-speed control signal when the received voltage or current data is lower than a second preset value. When the received voltage or current data is between the first and second preset values, the current speed is maintained. The low-speed control signal controls the motor 5 to rotate in one direction, and the high-speed control signal controls the motor 5 to rotate in the other direction.

[0113] The sampling module 201 can be implemented using a sensor in conjunction with a current and voltage sampling circuit. It is easy to understand that existing current and voltage sampling circuits in this field can be directly applied to this solution.

[0114] The control module 202 can be implemented by a control chip, a hardware circuit, or a combination of both. In this embodiment, the control module 202 consists of a hardware circuit (control circuit board) and a control chip (integrated with control software program).

[0115] The control circuit board receives signals related to cable head voltage and supply current, which directly reflect the operating status and workload of the traction device. Simultaneously, the control circuit board also receives control signals from the control software, which guide the board in precisely controlling the transmission 100. Specifically, upon receiving a control signal, the board adjusts the state of the transmission 100 according to the signal indication to ensure the traction device operates in optimal condition.

[0116] The control program is configured to determine the operating status and workload of the traction device based on the magnitude and changes in cable head voltage and supply current. When the detected cable head voltage and supply current exceed or fall below a certain threshold, the control program decides whether to trigger the operation of the transmission device 100. When the detected voltage and current values ​​exceed a certain threshold, the control program sends a control signal to the control circuit board, instructing it to adjust the state of the transmission device 100, triggering the operation of the transmission device 100, causing the motor 5 to rotate forward, thereby completing the shift from high speed to low speed.

[0117] When the working environment changes, such as a decrease in resistance to the traction device, the cable head voltage and supply current may decrease to a certain value. At this time, the control program will trigger the operation of the transmission device 100 again, controlling the motor 5 to reverse, completing the transition from low speed to high speed. This dynamic adjustment mechanism ensures that the traction device maintains optimal working condition under various working environments.

[0118] It is worth noting that after the gear shift is completed, the cable head voltage and supply current may change abruptly due to the change in the reduction ratio. According to the present invention, the control program can ignore this sudden change because the power of the traction device remains constant. Over time, the cable head voltage and supply current will gradually return to the values ​​when the traction device is operating normally, and the gear shift system will maintain the gear at the time of the completed action, preventing the gear shift system from malfunctioning due to the inevitable voltage and current changes caused by the action.

[0119] In summary, the automatic speed control device 200 achieves intelligent and automated control of the traction device by accurately monitoring the cable head voltage, power supply current, and the status of the speed transmission device 100. This control system not only improves the working efficiency of the traction device but also significantly reduces the labor intensity of operators, bringing great convenience to engineering practice. Simultaneously, the automatic speed change system for the downhole traction device according to the present invention can greatly improve the efficiency of the traction device. This design can automatically adjust the speed and power output of the traction device according to different working conditions and needs, thereby making it more adaptable to the working environment and improving working efficiency. This automatic speed change technology ensures that the traction device can achieve maximum working efficiency under various resistance conditions. The automatic switching between high and low speed gears not only increases the average speed of the traction device but also reduces construction time and labor intensity. The combination of automatic program control and manual control provides users with greater flexibility.

[0120] The working principle of the automatic speed change system of the downhole traction device according to the present invention is briefly described below.

[0121] When the gear shift signal is an acceleration signal, it is necessary to shift from a low gear to a high gear. At this time, the gear shift drive shaft 2 extends under the drive of the actuating motor 5, and the transmission pin 26 of the gear shift drive shaft 2 is inserted into the transmission pin hole 127 on the third-stage gear carrier. At this time, the torque output by the drive motor 8 is output to the third-stage gear carrier through the gear shift drive shaft 2. The third-stage sun gear in the planetary gear set mechanism becomes ineffective and becomes the driven gear; the third-stage gear carrier becomes the driving gear, realizing a lower reduction ratio transmission, and the traction device operates at high speed and lower traction force. This state is shown in Figure 26.

[0122] When the gear shift signal is a deceleration signal, it is necessary to switch from a high gear to a low gear. At this time, the gear shift drive shaft 2 retracts under the drive of the actuating motor 5, and the transmission key 27 of the gear shift drive shaft 2 meshes with the third-stage sun gear (n-stage sun gear) of the planetary gear set mechanism. At this time, the torque output by the drive motor 8 is output to the third-stage sun gear (n-stage sun gear) through the gear shift drive shaft 2, and the entire planetary gear set mechanism is in working condition. The third-stage sun gear is the driving gear of the gear shift reducer 1, realizing a high reduction ratio transmission, and the traction device operates at low speed with high traction force. This state is shown in Figure 27.

[0123] According to another aspect of the present invention, a control method for an automatic transmission system of a downhole traction device is also provided, comprising the following steps:

[0124] Collect data on the cable head voltage and / or power supply current of the traction device;

[0125] The data information is compared with a first preset value and a second preset value.

[0126] When the data information is lower than the first preset value and higher than the second preset value, the current state remains unchanged;

[0127] When the data exceeds the first preset value, the control module sends a control signal to put the transmission shaft 2 into the first deceleration gear.

[0128] When the data information is lower than the second preset value, the control module sends a control signal to put the transmission shaft 2 into the second deceleration gear.

[0129] According to the present invention, by precisely controlling speed and power output, the automatic transmission system can avoid unnecessary energy consumption. This energy-saving effect not only helps reduce operating costs but also helps reduce environmental impact. By precisely controlling speed and power output, the automatic transmission system allows the tractor to operate in optimal condition. This helps optimize the tractor's performance, improving its stability and reliability. The automatic transmission system can adjust the tractor's workload according to its usage, thereby avoiding excessive wear and damage. This helps extend the tractor's service life and reduce the frequency of maintenance and replacement. Because the system can automatically adjust speed and power output according to demand, the tractor can complete more work in less time. This helps improve work efficiency and increase production capacity. Downhole working environments are complex and variable, sometimes requiring the tractor to operate under different terrain and geological conditions. The transmission design allows the tractor to better adapt to these changes, improving its working performance.

[0130] In summary, the design of the automatic transmission system for downhole traction devices enables the traction device to maintain optimal operating conditions under different working conditions and requirements, thereby improving its efficiency, reducing energy consumption, extending service life, and optimizing performance.

[0131] Although the invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An automatic transmission system for a downhole traction device, comprising: The transmission device (100) includes a variable speed reducer (1) connected to the traction device via a transmission shaft (2), the transmission shaft (2) being configured to change its axial position via an axial adjustment assembly, the axial position of the transmission shaft (2) including at least a first axial position and a second axial position. The output end of the transmission shaft (2) is provided with a first transmission member (26) and a second transmission member (27). When the transmission shaft (2) is in the first axial position, the transmission shaft (2) is connected to the variable speed reducer (1) through the first transmission member (26), so that the transmission device (100) is in the first deceleration gear. When the transmission shaft (2) is in the second axial position, the transmission shaft (2) is connected to the variable speed reducer (1) through the second transmission member (27), so that the transmission device (100) is in the second deceleration gear.

2. The automatic transmission system according to claim 1, characterized in that, The first transmission member and the second transmission member are configured to be in different positions in both the axial and radial directions of the transmission shaft (2).

3. The automatic transmission system according to claim 2, characterized in that, The variable speed reducer (1) is provided with a first mating part for engaging with the first transmission member and a second mating part for engaging with the second transmission member, wherein the axial distance between the first mating part and the second mating part is set to be less than the axial distance between the first transmission member and the second transmission member; When the transmission shaft (2) moves to the first axial position, the first transmission member engages with the first mating member, while the second transmission member separates from the second mating member; when the transmission shaft (2) moves to the second axial position, the first transmission member separates from the first mating member, while the second transmission member engages with the second mating member.

4. The automatic transmission system according to claim 3, characterized in that, The end of the transmission shaft (2) is provided with a transmission disk. The first transmission component includes a plurality of transmission pins (26) arranged circumferentially on the end face of the transmission disk. The second transmission component includes a transmission key (27) fixed on the end face of the transmission disk. The first mating component includes a plurality of transmission pin holes (127) disposed on the variable speed reducer (1) corresponding to the plurality of transmission pins (26), and the second mating component includes a transmission keyway (128) for receiving the transmission key (27).

5. The automatic transmission system according to any one of claims 1 to 4, characterized in that, The transmission device (100) is connected to an automatic transmission control device (200), which is configured to output a control signal to the axial adjustment assembly according to the working state of the traction device, thereby controlling the axial position of the transmission shaft (2).

6. The automatic transmission system according to claim 5, characterized in that, The variable speed reducer (1) includes a housing (10), and a number of planetary gear sets are arranged inside the housing (10); each planetary gear set includes a planetary gear carrier, and planetary gears are rotatably connected to the outer periphery of the planetary gear carrier, and a sun gear is provided inside the planetary gear carrier; A set of planetary gears connected to the transmission shaft (2) is an input-side planetary gear set (12). The transmission keyway (128) is provided on the sun gear (123) of the input-side planetary gear set (12), and the transmission pin hole (127) is provided on the planetary gear carrier (121) of the input-side planetary gear set (12).

7. The automatic transmission system according to any one of claims 1 to 6, characterized in that, The axial adjustment assembly includes an axial movement sleeve (3); The transmission shaft (2) is rotatably mounted inside the axial movement sleeve (3), and the transmission shaft (2) is provided with an axial limiting member that cooperates with the axial movement sleeve (3). The axial movement sleeve (3) drives the transmission shaft (2) to move through the axial limiting member.

8. The automatic transmission system according to claim 7, characterized in that, The axial motion sleeve (3) is configured to move axially under the drive of the actuating motor (5). The input end of the actuating motor (5) is connected to the automatic transmission control device (200), and the output end of the actuating motor (5) is engaged with the axial motion sleeve (3) to drive the axial motion sleeve (3) to move.

9. The automatic transmission system according to claim 7 or 8, characterized in that, The axial movement sleeve (3) includes an annular movement sleeve (31) composed of a first half (311) and a second half (312). The annular movement sleeve (31) is provided with a first bearing (32) and a second bearing (33) sleeved on the transmission shaft (2). A limiting annular groove (34) is defined between the first bearing (32) and the second bearing (33). The axial limiting member is constructed as an annular flange (21) adapted to fit within the limiting annular groove (34).

10. The automatic transmission system according to claim 9, characterized in that, The axial movement sleeve (3) is provided with a through hole (36), and a radial limiting rod (71) is provided in the through hole (36) to prevent the axial movement sleeve (3) from rotating.

11. The automatic transmission system according to any one of claims 1 to 10, characterized in that, The transmission shaft (2) is connected to the drive motor (8) of the traction device via a coupling (4), and the coupling (4) is provided with an axial compensation mechanism. When the transmission shaft (2) moves axially, the coupling (4) maintains the connection between the drive motor (8) and the transmission shaft (2) through the axial compensation mechanism.

12. The automatic transmission system according to claim 11, characterized in that, The coupling (4) includes a front end part (41) connected to the drive motor (8) and a rear end part (42) connected to the transmission shaft (2); The front end component (41) is provided with a displacement compensation groove (411), and a plurality of spline grooves (413) are provided on the inner wall of the displacement compensation groove (411); the rear end component (42) is provided with a spline, and a plurality of key bodies are provided on the spline; the spline is confined within the displacement compensation groove (411), and the key bodies are confined within the spline grooves (413).

13. The automatic transmission system according to claim 12, characterized in that, The key body includes a front key body (421) and a rear key body (422) in the circumferential direction. The radial height of the front key body (421) is greater than the radial height of the rear key body (422). The radial depth of the spline groove (413) matches the radial height of the front key body (421).

14. The automatic transmission system according to claim 13, characterized in that, The front end of the spline is a spherical shaft (423), and the outer surface of the front key (421) is arched; the radial cross section of the key and the spline groove (413) are both fan-shaped surfaces with matching shapes; the rear end of the coupling (4) is provided with a conical surface, and the end of the conical surface is provided with a rear shaft (424) that connects to the speed transmission shaft (2).

15. The automatic transmission system according to claim 5, characterized in that, The automatic transmission control device (200) includes: The control module (202) is used to output a control signal to the axial adjustment assembly to control the axial adjustment assembly to adjust the axial position of the transmission shaft (1); The sampling module (201) is used to collect data information on the cable head voltage and / or power supply current of the traction device, and send the collected data information to the control module; The control module (202) compares the data information with a preset value and outputs a control signal to control the transmission shaft (2) to be in the first deceleration gear or the second deceleration gear.

16. A control method for an automatic transmission system according to any one of claims 1 to 15, characterized in that, include: Collect data on the cable head voltage and / or power supply current of the traction device; The data information is compared with a first preset value and a second preset value. When the data information is lower than the first preset value and higher than the second preset value, the current state remains unchanged; When the data exceeds the first preset value, the control module sends a control signal to put the transmission shaft (2) into the first deceleration gear. When the data information is lower than the second preset value, the control module sends a control signal to put the transmission shaft (2) into the second deceleration gear.

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