A compound low-speed heavy-load hydraulic motor based on gear meshing transmission

Abstract

The present invention discloses a composite low-speed heavy-duty hydraulic motor based on gear meshing transmission. The outer peripheries of the external transmission gear and the internal gear shaft are both provided with gear rings, the gear rings of the external transmission gear mesh with the gear rings of the internal gear shaft, each external transmission gear is provided with a crankshaft, the hydraulic cylinder is located on the outer periphery of the internal gear shaft, the two ends of each hydraulic cylinder are respectively connected to two adjacent external transmission gears through two crankshafts, the oil inlet of the two-position four-way solenoid valve is connected to the oil tank through the oil pump, the oil return port of the two-position four-way solenoid valve is connected to the oil tank, the two-position four-way solenoid valve is electrically connected to the control device, and the oil port A and the oil port B of the two-position four-way solenoid valve are both connected to the hydraulic cylinder. The present invention drives the external transmission gear to rotate through a double-acting hydraulic cylinder, and rotates the internal moving gear shaft through gear meshing and outputs torque. The present invention relies on multiple groups of hydraulic cylinders working simultaneously and multiple groups of reduction gears meshing transmission simultaneously to increase the reduction ratio, thereby increasing the output torque and reducing the output speed.

Description

Technical Field

[0001] The invention relates to a hydraulic motor in the field of hydraulic transmission, and in particular to a compound low-speed heavy-load hydraulic motor based on gear meshing transmission. Background Art

[0002] Gear transmission is a common form of mechanical transmission with a simple structure and high transmission efficiency. It is widely used in various engineering equipment. Under low-speed and heavy-load conditions, a hydraulic motor with high power density is required. Traditional hydraulic motors use radial piston and vane structures, which are complex, large in size and weight, and are not suitable for use in some special scenarios.

[0003] In order to solve this problem, some new hydraulic motors adopt a composite structure, combining gear transmission and hydraulic drive. These hydraulic motors drive the transmission gear to rotate through a double-acting hydraulic cylinder, and drive the gear shaft to rotate and output torque through gear meshing. They have a simple structure, small size and weight, and can be directly connected to the working mechanism to meet the ultra-low speed requirements under some special working conditions. However, the existing composite hydraulic motors still have some problems, such as unstable torque output and insufficient reduction ratio, which can be further improved. Summary of the invention

[0004] In order to solve the problems existing in the background technology, the purpose of the present invention is to design a composite low-speed heavy-duty hydraulic motor based on gear meshing transmission. The present invention provides a large torque, high-precision, composite hydraulic motor with multiple groups of hydraulic cylinders working together and multiple groups of reduction gears meshing transmission. The present invention combines multiple groups of gear transmission mechanisms and hydraulic control circuits together, significantly improving the torque of the hydraulic motor. Its technical solution is simple and reliable, compact in structure, easy to maintain, and can be used to drive various heavy-duty mechanisms.

[0005] The technical solution of the present invention is as follows:

[0006] It includes a mechanical transmission mechanism and a hydraulic control circuit, which are connected by a pipeline; the mechanical transmission mechanism includes an outer shell, an outer transmission gear, a circular inner gear shaft, a crankshaft and a hydraulic cylinder; the outer transmission gear and the inner gear shaft are both arranged inside the outer shell, and the outer peripheries of the outer transmission gear and the inner gear shaft are both provided with gear rings, and the gear rings of several outer transmission gears are meshed with the gear rings of the inner gear shaft, and each outer transmission gear is provided with a crankshaft, and several hydraulic cylinders are located on the outer periphery of the inner gear shaft, and the two ends of each hydraulic cylinder are respectively connected to two adjacent outer transmission gears through two crankshafts;

[0007] The hydraulic control circuit includes an oil pump, a control device, a two-position four-way solenoid valve and an oil tank. The oil inlet P of the two-position four-way solenoid valve is connected to the oil tank through the oil pump, the oil return port T of the two-position four-way solenoid valve is connected to the oil tank, the two-position four-way solenoid valve and the control device are electrically connected, and the oil port A and the oil port B of the two-position four-way solenoid valve are both connected to the hydraulic cylinder.

[0008] The hydraulic cylinder comprises a piston rod and a cylinder body. One end of the piston rod and one end of the cylinder body are movably connected to each other forward and backward. The other end of the piston rod and the other end of the cylinder body are respectively connected to two adjacent external transmission gears through two crankshafts. Every two hydraulic cylinders arranged opposite to each other in the hydraulic cylinders form a group. The rod chamber and the rodless chamber of one hydraulic cylinder in a group of hydraulic cylinders are respectively connected to the oil port A and the oil port B of the two-position four-way solenoid valve, and the rod chamber and the rodless chamber of the other hydraulic cylinder are respectively connected to the oil port B and the oil port A of the two-position four-way solenoid valve.

[0009] Each crankshaft is provided with a keyway and a key, the key is fixedly connected in the keyway, and the external transmission gear and the crankshaft are fixedly connected via the key.

[0010] A planetary gear bracket is arranged on the outer shell, and the planetary gear bracket is fixedly connected to the crankshaft.

[0011] The internal gear shaft is an annular structure, the inner ring of the internal gear shaft is provided with an inner gear ring, and the gear ring of the external meshing gear is meshed with the inner gear ring of the inner ring of the internal gear shaft.

[0012] The outer ring of the inner gear shaft is provided with an outer gear ring, and the gear ring of the external meshing gear is meshed in the outer gear ring of the outer ring of the inner gear shaft.

[0013] There are multiple small transmission gears evenly distributed on the outer circumference of the internal gear shaft. The crankshaft passes through the external transmission gear and is hinged to the two ends of the hydraulic cylinder. The piston rod and cylinder body of each hydraulic cylinder are connected to an external transmission gear. The axis centers of all external transmission gears form a circle, whose axis centers coincide with the axis centers of the internal gear shaft. The external transmission gears are evenly distributed on this circle with the same interval angle. The hinge points of the crankshaft and the hydraulic cylinder form a polygon. The hydraulic cylinders are arranged sequentially along this polygon. For each hydraulic cylinder, its piston rod is connected to a crankshaft, and the cylinder body is connected to the crankshaft at the adjacent points along the above polygon. The connecting holes of the external transmission gear and the hydraulic cylinder are arranged eccentrically through the crankshaft, so the thrust and pull generated by the hydraulic cylinder can be converted into torque applied to the external transmission gear.

[0014] like Figure 2As shown in the figure, the crankshaft is composed of two shaft sections, the axes of the upper and lower sections are parallel, and the distance between the two axes is constant. The upper section is hinged with two hydraulic cylinders, and the lower section is connected to the external transmission gear. A keyway is provided on the shaft, and the external transmission gear is fixed relative to the crankshaft through a key connection. A retaining ring groove is provided at the end of the crankshaft, and the axial position of the hydraulic cylinder is fixed by an elastic retaining ring. The connecting hole of the external transmission gear and the hydraulic cylinder is arranged eccentrically through the crankshaft, so the thrust and pull generated by the hydraulic cylinder can be converted into torque applied to the external transmission gear.

[0015] like Figure 3 As shown, the hydraulic control system includes a plurality of two-position four-way solenoid valves, a control device, an oil tank and a hydraulic pump. The bottom of the cavities on both sides of the hydraulic cylinder are connected to the hydraulic control circuit through the oil circuit. The number of two-position four-way solenoid valves is half the number of hydraulic cylinders, and each two-position four-way solenoid valve controls the opposite movements of two hydraulic cylinders. Each two-position four-way solenoid valve is connected to the oil pump and the oil tank respectively, so that the hydraulic oil flows from the oil pump through the two-position four-way solenoid valve and then flows into the cavity of the hydraulic cylinder through the oil circuit in sequence. Each two-position four-way solenoid valve is electrically connected to the control device. The control device coordinates and switches the working position state of each two-position four-way solenoid valve in a certain order.

[0016] The outer peripheral surface of the internal gear shaft is processed into an external tooth surface, and the outer peripheral surface of the external transmission gear is processed into an external tooth surface with the same module. The external tooth surface of the external transmission gear and the external tooth surface of the internal gear shaft form a meshing transmission pair. The axial positions of the external transmission gear and the internal gear shaft are kept fixed and can be installed to rotate, and the external transmission gear and the internal gear shaft always rotate in the same direction;

[0017] A hydraulic cylinder generates force on two adjacent external transmission gears at the same time. The end points of the crankshaft connecting the cylinder body and the piston rod are on both sides of the line formed by the axis of the two external transmission gears. Therefore, it can generate torque in the same direction on the two external transmission gears, so that the two external transmission gears rotate in the same direction, thereby satisfying the meshing transmission of multiple external transmission gears and an internal gear shaft. The movement directions of the external transmission gears and the internal gear shaft must be the same, and the linear speed at the meshing point must be the same;

[0018] Multiple hydraulic cylinders are connected in series to connect all the external transmission gears. The two hydraulic cylinders on the opposite sides work at the same time, driving all the external transmission gears and the internal gear shafts to rotate in the same direction. The positions of the hydraulic cylinders are controlled in a certain sequence, so that the motor outputs a large torque.

[0019] The crankshaft is located in the outer housing and is connected to each external transmission gear and hydraulic cylinder. The linear motion of the hydraulic cylinder is converted into rotational motion and transmitted to the external transmission gear, thereby achieving high torque and high speed output. The external transmission gear is connected to the gear shaft through meshing transmission, thereby achieving the power transmission of the hydraulic cylinder and the stability of the mechanical transmission.

[0020] The cavities of the two groups of hydraulic cylinders on the opposite sides are connected, and the cavity where the piston rod is located is connected to the other cavity of the hydraulic cylinder on the opposite side. When oil enters the cavity at one end of the piston rod, oil enters the cavity at the other end of the hydraulic cylinder on the opposite side at the same time. This makes the first hydraulic cylinder in an extended working state, while the hydraulic cylinder on the opposite side is in a shortened state. This achieves that the working states of the two hydraulic cylinders on the opposite sides are opposite, pushing the two connected external transmission gears to rotate in the same direction.

[0021] The external transmission gear and crankshaft are connected through the planetary carrier and the outer shell of the motor. The planetary carrier determines the relative positions between the external transmission gears, ensuring that the axial position of each external transmission gear remains unchanged. There is no contact between the internal gear shaft and the outer shell. The fixed-axis rotation motion of the internal gear shaft as the output motion will not drive the outer shell to rotate, and will not change the axial position of the external transmission gear.

[0022] A keyway is provided at the center of the crankshaft for connecting with the wheel shaft of the external transmission, and two retaining ring grooves are provided at the end for limiting the hinge position of the hydraulic cylinder and the crankshaft. The hinge position of the crankshaft and the hydraulic cylinder is coaxial with the eccentric shaft end of the crankshaft.

[0023] The module of the external transmission gear is the same as the number of teeth of the internal gear shaft, and the number of teeth of the external transmission wheel is smaller than that of the internal gear shaft, so that the rotation of the external transmission gear and the internal gear shaft ensures a certain reduction ratio. The internal gear shaft serves as an output element, providing low speed output and high torque output to the outside according to a certain reduction ratio.

[0024] The reduction ratio is equal to the ratio of the number of teeth on the internal gear shaft to the number of teeth on the external transmission gear.

[0025] Each hydraulic cylinder makes linear reciprocating motion on the straight line connected to the end of the crankshaft, so that all the external transmission gears rotate in the same direction. The extension and compression of the hydraulic cylinder are controlled by sequentially controlling the oil inlet and oil return of the hydraulic cylinder, as shown in the following steps:

[0026] Step 1) The hydraulic control circuit can be used to control one hydraulic cylinder in the same group of hydraulic cylinders to extend and the other hydraulic cylinder to shorten: when the hydraulic oil enters the hydraulic cylinder cavity from the cylinder body side, the oil volume on the cylinder body side increases, pushing the piston rod to extend, the hydraulic oil on the piston rod side is connected to the oil tank, and discharged through the oil circuit, thereby completing the extended working state. When the hydraulic oil is pressed into the hydraulic cylinder cavity from the piston rod side, the hydraulic oil in the cavity on the piston rod side increases, pushing the piston rod to press in, at this time the hydraulic oil on the cylinder body side is connected to the oil tank, and discharged through the oil circuit, thereby completing the shortened working state.

[0027] The extension or contraction of the hydraulic cylinder pushes the outer transmission gear to move, thereby driving the inner gear shaft to rotate;

[0028] Step 2) When one hydraulic cylinder is extended to the maximum value of the hydraulic cylinder stroke, a two-position four-way solenoid valve is used to switch the motion states of two hydraulic cylinders in the same group of hydraulic cylinders, switching the continuously extended hydraulic cylinder to a retracted state, and switching the retracted hydraulic cylinder to an extended state;

[0029] The extension and contraction of the hydraulic cylinder is controlled by a two-position four-way solenoid valve. When the solenoid valve switches the working state, the oil circuit is switched, and the oil inlet and return ends of the hydraulic cylinder are swapped, thereby completing the switching of the working state of the hydraulic cylinder.

[0030] When a hydraulic cylinder is extended to the maximum value of the hydraulic cylinder stroke, the oil in the cavity on the oil return side is completely discharged. At this time, the straight line where the hydraulic cylinder is located coincides with the straight line connecting the axes of the external transmission gears at both ends. The movement reaches the dead point, and the torque provided by the hydraulic cylinder to the crankshaft is 0. At the maximum stroke position, the length of the hydraulic cylinder is exactly equal to the sum of twice the eccentric distance of the crankshaft and the distance between the axes of the adjacent external transmission gears.

[0031] When the hydraulic cylinder is shortened to the minimum value formed by the hydraulic cylinder, the oil in the cavity on the return oil side is completely discharged. At this time, the straight line where the hydraulic cylinder is located coincides with the straight line connecting the axes of the external transmission gears at both ends. The movement reaches the dead point. The torque provided by the hydraulic cylinder to the crankshaft is 0. At the minimum stroke position, the length of the hydraulic cylinder is exactly equal to the difference between the line distance between the adjacent external transmission gear axes and twice the eccentric distance of the crankshaft.

[0032] When the hydraulic cylinder reaches the stroke limit, the mechanism reaches the dead point, and the output torque of the hydraulic cylinder at the dead point is 0. At this time, another group of hydraulic cylinders pushes the mechanism out of the dead point by applying torque to the crankshaft, keeping the gear set running.

[0033] Step 3) By continuously switching the motion states of two hydraulic cylinders in the same group of hydraulic cylinders, the hydraulic cylinders continuously push the outer transmission gear to rotate, thereby continuously driving the inner gear shaft to rotate.

[0034] The two-position three-way solenoid valve comprises oil port A, oil port B, oil port P and oil port T. Oil port P and oil port T are located on the same side of the two-position three-way solenoid valve, and oil port A and oil port B are located on the other side of the two-position three-way solenoid valve. Oil port P and oil port T of the two-position three-way solenoid valve are respectively connected to the oil pump and the oil tank through a joint, a hose, etc. Oil port A and oil port B are connected to the cavities on both sides of the hydraulic cylinder through the oil circuit in the outer shell. The two-position three-way solenoid valve is electrically connected to the control device, and the working position of each solenoid valve is switched under the control of the control device, and the movement direction of the hydraulic cylinder is further controlled, thereby controlling the fixed axis rotation of the external transmission gear and the internal gear shaft.

[0035] The present invention utilizes the bidirectional linear motion of the hydraulic cylinder to drive the fixed axis rotation of the external transmission gear, and increases the output torque by working multiple groups of hydraulic cylinders at the same time and the gear reduction ratio. When the pressure oil enters the hydraulic cylinder, the hydraulic cylinder acts on the eccentric part of the crankshaft, generates torque on the crankshaft, and drives the rotation of the gear set. The position of the hydraulic cylinder arrangement makes the movement direction of each external transmission gear the same, driving the entire mechanism to operate smoothly, output large torque, and low speed.

[0036] The beneficial effects of the present invention are as follows:

[0037] 1. The present invention combines a gear reduction transmission mechanism with a hydraulic transmission mechanism and utilizes a gear transmission with a large reduction ratio to effectively achieve the working characteristics of outputting an ultra-low speed.

[0038] 2. In the present invention, multiple groups of hydraulic cylinders are driven simultaneously, and multiple groups of transmission gears are meshed and driven simultaneously, so that large torque output can be obtained in multiples.

[0039] 3. The present invention reduces the number of two-position four-way solenoid valves by connecting the hydraulic cylinders at opposite sides in series, simplifies the control difficulty, makes the operation of the hydraulic motor more coherent and smooth, and facilitates locking.

[0040] 4. The present invention combines hydraulic cylinders and mechanical transmission gears to achieve high torque and low speed output. Multiple sets of hydraulic cylinders drive multiple external transmission gears at the same time, further increasing the output torque. With multiple sets of hydraulic cylinders working at the same time, multiple sets of reduction gears mesh and drive at the same time to increase the reduction ratio, thereby increasing the output torque and reducing the output speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 a is a schematic diagram of the initial state of the transmission mechanism of the present invention, Figure 1 b is a schematic diagram of the intermediate state of the transmission mechanism of the present invention, Figure 1 c is a schematic diagram of the second intermediate motion state of the transmission mechanism of the present invention;

[0042] Figure 2 Schematic diagram of the crankshaft connection structure in the present invention

[0043] Figure 3 Schematic diagram of a hydraulic control circuit for controlling the movement of a pair of hydraulic cylinders in the present invention

[0044] In the figure: 1. external transmission gear; 2. piston rod; 3. cylinder body; 4. internal gear shaft; 5. crankshaft; 6. oil pump; 7. control device; 8. two-position four-way solenoid valve; 9. oil tank. DETAILED DESCRIPTION

[0045] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0046] The implementation process of the embodiment of the present invention is as follows:

[0047] like Figure 1 As shown in a, it includes a mechanical transmission mechanism and a hydraulic control circuit, and the mechanical transmission mechanism and the hydraulic control circuit are connected by a pipeline; the mechanical transmission mechanism includes an outer shell, an outer transmission gear 1, a circular inner gear shaft 4, a crankshaft 5 and a hydraulic cylinder; the outer transmission gear 1 and the inner gear shaft 4 are both arranged inside the outer shell, and the outer peripheries of the outer transmission gear 1 and the inner gear shaft 4 are both provided with gear rings, and the gear rings of several outer transmission gears 1 are meshed with the gear rings of the same inner gear shaft 4 to form a meshing transmission pair, and the axial center positions of the outer transmission gear 1 and the inner gear shaft 4 remain constant during the movement of the hydraulic motor, and each outer transmission gear 1 is provided with a crankshaft 5, and several hydraulic cylinders are located on the outer periphery of the inner gear shaft 4, and the two ends of each hydraulic cylinder are respectively connected to two adjacent outer transmission gears 1 through two crankshafts 5, that is, a hydraulic cylinder is connected between two adjacent outer transmission gears 1 through the crankshaft 5, and the crankshaft 5 and the hydraulic cylinder are hinged;

[0048] like Figure 3 As shown, the hydraulic control circuit includes an oil pump 6, a control device 7, a two-position four-way solenoid valve 8 and an oil tank 9. The oil inlet P of the two-position four-way solenoid valve 8 is externally connected to the oil tank 9 through the oil pump 6, the oil return port T of the two-position four-way solenoid valve 8 is connected to the oil tank 9, the two-position four-way solenoid valve 8 and the control device 7 are electrically connected, and the oil port A and the oil port B of the two-position four-way solenoid valve 8 are both connected to the hydraulic cylinder.

[0049] The hydraulic cylinder includes a piston rod 2 and a cylinder body 3. Each group of cylinder body 3 and piston rod 2 constitutes a moving pair. One end of the piston rod 2 and one end of the cylinder body 3 can be movably connected forward and backward. The other end of the piston rod 2 and the other end of the cylinder body 3 are respectively connected to two adjacent external transmission gears 1 through two crankshafts 5. Every two hydraulic cylinders arranged opposite to each other in the hydraulic cylinder form a group. The rod chamber and rodless chamber of one hydraulic cylinder in a group of hydraulic cylinders are respectively connected to the oil port A and the oil port B of the two-position four-way solenoid valve 8, and the rod chamber and rodless chamber of the other hydraulic cylinder are respectively connected to the oil port B and the oil port A of the two-position four-way solenoid valve 8.

[0050] That is, the two-position four-way solenoid valve 8 is respectively connected to two hydraulic cylinders in a group of hydraulic cylinders, the oil port A is respectively connected to the rod chamber of one hydraulic cylinder and the rodless chamber of another hydraulic cylinder, and the oil port B is respectively connected to the rodless chamber of one hydraulic cylinder and the rod chamber of another hydraulic cylinder.

[0051] like Figure 2 As shown, each crankshaft 5 is provided with a keyway and a key, the key is fixedly connected in the keyway, and the external transmission gear 1 and the crankshaft 5 are fixedly connected via the key.

[0052] Each external transmission gear 1 is fixed relative to the crankshaft 5 via a key connection, thereby limiting the relative rotation between the external transmission gear 1 and the crankshaft 5 .

[0053] A retaining ring groove is also provided in the crankshaft 5, and the retaining ring groove is used to place an elastic retaining ring, and the axial position of the hydraulic cylinder is fixed by the elastic retaining ring.

[0054] A planetary gear support is provided on the outer shell, and the planetary gear support is fixedly connected to the crankshaft 5.

[0055] One end of the crankshaft 5 is connected to the hydraulic cylinder, and the other end is connected to the planetary gear bracket. The planetary gear bracket connects all the crankshafts 5. The planetary gear bracket is fixed relative to the outer shell to limit the axial position of all the external transmission gears 1, and the external transmission gears 1 maintain fixed-axis rotation motion.

[0056] The internal gear shaft 4 is an annular structure. The inner ring of the internal gear shaft 4 is provided with an inner gear ring. The gear ring of the external gear 20 is meshed with the inner gear ring of the inner ring of the internal gear shaft 4 .

[0057] The outer ring of the internal gear shaft 4 is provided with an outer gear ring, and the gear ring of the external meshing gear 20 is meshed with the outer gear ring of the outer ring of the internal gear shaft 4 .

[0058] The external transmission gear 1 and the internal gear shaft 4 always rotate in the same direction, the speed of each external transmission gear 1 is always the same, and the rotation of the external transmission gear 1 and the internal gear shaft 4 always maintains a certain reduction ratio.

[0059] Each two-position four-way solenoid valve 8 controls the movement position of two hydraulic cylinders at the same time. The cavities on both sides of the hydraulic cylinders are connected with the symmetrical position cavities of the opposite cylinders through oil circuits, so that the movements of the two opposite hydraulic cylinders are always opposite.

[0060] The two ends of the hydraulic cylinder and the two hinge points of the two external transmission gears 1 are always located on different sides of the axis connecting the two external transmission gears 1, so that the torque direction transmitted by the hydraulic cylinder to the external transmission gears 1 at both ends is always consistent.

[0061] The number of the external transmission gear 1, the crankshaft 5, and the hydraulic cylinders is the same, which is an even number greater than four. Two hydraulic cylinders at opposite positions form a group, and the movement paths of the two hydraulic cylinders in a group are opposite.

[0062] The rotary drive system includes a hydraulic cylinder and an external transmission gear 1. Two identical rotary drive systems are installed on the front and rear sides of the internal gear shaft 4. The external transmission gears 1 on both sides are arranged alternately on the outer periphery of the internal gear shaft 4. The two rotary drive systems work simultaneously to improve power density.

[0063] The hydraulic cylinders on opposite sides of all hydraulic cylinders are grouped together, such as Figure 1 As shown in the motion process shown in a-1c, the motion states of the hydraulic cylinders on the opposite sides are opposite, so the control of each group of hydraulic cylinders is as follows: Figure 3As shown, the left cavity of the left hydraulic cylinder is connected with the right cavity of the right hydraulic cylinder, and then connected to the oil port A of the two-position four-way solenoid valve 8 through the oil circuit; the right cavity of the left hydraulic cylinder is connected with the left cavity of the right hydraulic cylinder, and then connected to the oil port B of the two-position four-way solenoid valve through the oil circuit.

[0064] When the solenoid valve is in working condition Figure 3 As shown, the left cavity of the left hydraulic cylinder is filled with oil, and the right cavity is drained of oil, while the left cavity of the right hydraulic cylinder is drained of oil, and the right cavity is filled with oil. Therefore, at this time, the left hydraulic cylinder is in a shortened working state, and the right hydraulic cylinder is in an extended working state.

[0065] according to Figure 1 a- Figure 1 As shown in the motion state in b, all gears rotate clockwise during this process. For the set of hydraulic cylinders on the upper right and lower left, it can be seen that during the motion, the hydraulic cylinder on the upper right shortens and the hydraulic cylinder on the lower left lengthens. For the hydraulic cylinder on the upper right and the two upper and lower external transmission gears connected to it, since the hinge point of the piston rod is located on the right side of the external transmission gear above the piston rod, the piston rod moves downward relative to the external transmission gear, so the torque transmitted to the crankshaft by the hydraulic cylinder is clockwise, driving the external transmission gear to rotate clockwise; for the external transmission gear below the piston rod, since the hinge point of the cylinder body is located on the left side of the external transmission gear, the cylinder body moves upward relative to the external transmission gear, so the torque transmitted to the crankshaft by the hydraulic cylinder is clockwise, driving the external transmission gear to rotate clockwise. Similarly, for the hydraulic cylinder on the lower left and the two upper and lower external transmission gears connected to the hydraulic cylinder, the force provided by the extension of the hydraulic cylinder causes the two connected external transmission gears to rotate clockwise at the same time.

[0066] Similarly, for the set of hydraulic cylinders on the upper left and lower right, Figure 1 a- Figure 1 During the movement of b, the upper left hydraulic cylinder is in a shortened working state, and the lower right hydraulic cylinder is in an extended working state, providing clockwise torque in the same direction for the four external transmission gears. The four external transmission gears drive the internal gear shaft to rotate in the same direction, outputting large torque and low speed.

[0067] During the operation of the hydraulic motor, there is a dead point for each set of hydraulic cylinders. When the straight line where the hydraulic cylinder is located coincides with the straight line of the axis of the external transmission gear connected to it, the torque provided by the hydraulic cylinder is 0. Figure 1As shown in Figure b, the hydraulic cylinder on the upper right moves to the longest state, and the straight line where the hydraulic cylinder is located coincides with the axis connecting the upper external transmission gear and the right external transmission gear, and the torque provided by the hydraulic cylinder is 0; the hydraulic cylinder on the lower left moves to the shortest state, and the straight line where the hydraulic cylinder is located coincides with the axis connecting the upper external transmission gear and the right external transmission gear, and the torque provided by the hydraulic cylinder is 0. At this time, another group of hydraulic cylinders provides torque to push out the hydraulic cylinder at the dead point, and the gear group can continue to run clockwise.

[0068] like Figure 1 b- Figure 1 As shown in the movement process of c, when the upper left hydraulic cylinder continues to extend, the lower right hydraulic cylinder continues to shorten. Figure 1 When the hydraulic cylinders on the upper left and lower right reach the dead point, the torque provided by the two hydraulic cylinders to the external transmission gear is 0. The mechanism continues to work by relying on the hydraulic cylinders on the upper right and lower left, pushing out the two hydraulic cylinders at the dead point, and the gear set can continue to run clockwise. This reciprocating process can make the gear set run continuously, and output high torque and low speed through the internal gear shaft.

[0069] Each hydraulic cylinder switches its working state when it moves to the minimum and maximum value of the stroke, such as Figure 3 In the control system shown, when the left hydraulic cylinder moves to the shortest state and the right hydraulic cylinder moves to the longest state, the working position state of the two-position four-way solenoid valve is switched by the control device, and the right cavity of the left hydraulic cylinder starts to flow with oil, and the working state of the hydraulic cylinder changes from the previous shortened state to the extended state; the left cavity of the right hydraulic cylinder starts to flow with oil, and the working state of the hydraulic cylinder changes from the previous extended state to the shortened state.

[0070] In actual operation, the hydraulic motor runs continuously, and the four hydraulic cylinders and the external transmission gear work simultaneously. Whenever the external transmission gear rotates 90 degrees, a group of hydraulic motors switches the direction of movement to continuously provide the external transmission gear with torque in the same direction. The present invention effectively controls the working state of the hydraulic cylinder by controlling the two-position four-way solenoid valve. On the basis of the large reduction ratio provided by gear meshing, multiple groups of hydraulic cylinders work simultaneously, so that the hydraulic motor can output a larger torque.

[0071] The specific implementation of the present invention involves the coordinated action of multiple hydraulic cylinders. The working positions of multiple two-position four-way solenoid valves are controlled by a control device, and the working position states of the specified two-position four-way solenoid valves are switched in a certain time sequence.

[0072] The present invention mainly utilizes the reciprocating motion of the hydraulic cylinder to drive the gear set to operate continuously in the same direction. By having multiple sets of hydraulic cylinders work simultaneously, the output torque is greatly increased on the basis of the large reduction ratio of the gear set, and an industrial rotary mechanism with low-speed and high-torque working characteristics can be driven.

[0073] The technical solution of the present invention is not limited to the above-mentioned specific implementation cases, and all technical variations made according to the present invention fall within the protection scope of the present invention.

Claims

1. A compound low-speed heavy-duty hydraulic motor based on gear meshing transmission, Features: The invention comprises a mechanical transmission mechanism and a hydraulic control circuit, wherein the mechanical transmission mechanism and the hydraulic control circuit are connected via a pipeline; the mechanical transmission mechanism comprises an outer shell, an outer transmission gear (1), a circular inner gear shaft (4), a crankshaft (5) and a hydraulic cylinder; the outer transmission gear (1) and the inner gear shaft (4) are both arranged inside the outer shell, and the outer peripheries of the outer transmission gear (1) and the inner gear shaft (4) are both provided with gear rings, and the gear rings of a plurality of the outer transmission gears (1) are meshed with the gear rings of the inner gear shaft (4), and each outer transmission gear (1) is provided with a crankshaft (5); a plurality of hydraulic cylinders are located on the outer periphery of the inner gear shaft (4), and the two ends of each hydraulic cylinder are respectively connected to two adjacent outer transmission gears (1) via two crankshafts (5); The hydraulic control circuit comprises an oil pump (6), a control device (7), a two-position four-way solenoid valve (8) and an oil tank (9); an oil inlet P of the two-position four-way solenoid valve (8) is externally connected to the oil tank (9) via the oil pump (6); an oil return port T of the two-position four-way solenoid valve (8) is connected to the oil tank (9); the two-position four-way solenoid valve (8) and the control device (7) are electrically connected; and an oil port A and an oil port B of the two-position four-way solenoid valve (8) are both connected to a hydraulic cylinder; The hydraulic cylinder comprises a piston rod (2) and a cylinder body (3); one end of the piston rod (2) and one end of the cylinder body (3) are movably connected to each other forward and backward; the other end of the piston rod (2) and the other end of the cylinder body (3) are respectively connected to two adjacent external transmission gears (1) via two crankshafts (5); every two hydraulic cylinders arranged opposite to each other in the hydraulic cylinder form a group; the rod chamber and the rodless chamber of one hydraulic cylinder in a group of hydraulic cylinders are respectively connected to the oil port A and the oil port B of the two-position four-way solenoid valve (8); and the rod chamber and the rodless chamber of the other hydraulic cylinder are respectively connected to the oil port B and the oil port A of the two-position four-way solenoid valve (8).

2. A compound low-speed heavy-duty hydraulic motor based on gear meshing transmission according to claim 1, Features: Each crankshaft (5) is provided with a keyway and a key, the key is fixedly connected in the keyway, and the external transmission gear (1) and the crankshaft (5) are fixedly connected via the key.

3. A compound low-speed heavy-duty hydraulic motor based on gear meshing transmission according to claim 1, Features: A planetary gear bracket is provided on the outer shell, and the planetary gear bracket is fixedly connected to the crankshaft (5).

4. A compound low-speed heavy-duty hydraulic motor based on gear meshing transmission according to claim 1, Features: The internal gear shaft (4) is an annular structure, the inner ring of the internal gear shaft (4) is provided with an inner gear ring, and the gear ring of the external meshing gear (20) meshes with the inner gear ring of the inner ring of the internal gear shaft (4).

5. A compound low-speed heavy-duty hydraulic motor based on gear meshing transmission according to claim 1, Features: The outer ring of the internal gear shaft (4) is provided with an outer gear ring, and the gear ring of the external meshing gear (20) meshes with the outer gear ring of the outer ring of the internal gear shaft (4).

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