Axial plunger motor

Abstract

The utility model relates to the field of plunger motors, in particular to an axial plunger motor which comprises a shell, a transmission shaft, a movable sealing piece, a first limiting ring and a second limiting ring, the transmission shaft is arranged in the shell in a rotatable mode, the end of the transmission shaft extends out of the shell, and the transmission shaft is constructed to be used for being connected with a speed reducer; the movable sealing piece is arranged at the running fit position of the shell and the transmission shaft and is configured to prevent hydraulic oil in an inner cavity of the shell from leaking; the first limiting ring is arranged on the shell, located on the outer side of the movable sealing piece and configured to limit outward displacement of the movable sealing piece. The second limiting ring is arranged on the shell, located on the inner side of the movable sealing piece and configured to limit inward displacement of the movable sealing piece. According to the axial plunger motor, the two limiting rings are arranged to limit the axial displacement of the movable sealing piece, the situation that the movable sealing piece falls off from the preset position in the shell, so that the axial plunger motor cannot work continuously is avoided, the service life of the axial plunger motor is prolonged, and the two limiting rings are simple in structure and easy to machine and implement.

Description

TECHNICAL FIELD

[0001] The present disclosure belongs to the field of plunger motors, and particularly relates to an axial plunger motor. BACKGROUND

[0002] The axial plunger motor is a kind of hydraulic motor. When working, high-pressure oil enters the inner cylinder of the axial plunger motor, and pushes the plunger in the cylinder to reciprocate. Since the plunger is connected to the transmission shaft, the reciprocating motion of the plunger will be converted into the rotary motion of the transmission shaft and the cylinder, driving the transmission shaft to rotate and output power externally. The dynamic sealing element is arranged on the transmission shaft and is in rotary connection with the transmission shaft, so as to avoid the leakage of hydraulic oil into the housing of the axial plunger motor.

[0003] In the application of the existing axial plunger motor, the dynamic sealing element will be subjected to the pressure inside and outside the housing. When the pressure difference between the inside and outside is generated, the axial position of the dynamic sealing element is unstable, which affects the working of the axial plunger motor. When the pressure difference between the inside and outside is too large, the dynamic sealing element is prone to fall off from the preset position in the housing of the axial plunger motor, so that the motor cannot continue to work. CONTENT OF THE INVENTION

[0004] The present disclosure provides an axial plunger motor to solve the problems in the prior art.

[0005] The axial plunger motor of the present disclosure comprises:

[0006] a housing;

[0007] a transmission shaft rotatably arranged in the housing and extending out of the housing and configured to be connected to a speed reducer;

[0008] a dynamic sealing element arranged at the rotary connection between the housing and the transmission shaft and configured to prevent the leakage of hydraulic oil in the inner cavity of the housing;

[0009] a first limiting ring arranged on the housing and located outside the dynamic sealing element and configured to limit the outward displacement of the dynamic sealing element;

[0010] a second limiting ring arranged on the housing and located inside the dynamic sealing element and configured to limit the inward displacement of the dynamic sealing element.

[0011] In an embodiment of the present disclosure, the dynamic sealing element is a skeleton oil seal.

[0012] In an embodiment of the present disclosure, the radial height of the first limiting ring and / or the second limiting ring is higher than the radial height of the base of the skeleton oil seal and lower than the radial height of the spring of the skeleton oil seal.

[0013] In one embodiment of the present disclosure, the ratio of the radial height of the first limiting ring and / or the second limiting ring to the radial height of the skeleton oil seal is 1:3-2:3.

[0014] In one embodiment of the present disclosure, the shell is provided with a first annular groove and / or a second annular groove, the first limiting ring is arranged in the first annular groove, and the second limiting ring is arranged in the second annular groove.

[0015] In one embodiment of the present disclosure, the distance between the first annular groove and / or the second annular groove and the dynamic seal is 0-0.4mm.

[0016] In one embodiment of the present disclosure, the first limiting ring is in interference fit with the first annular groove; and / or,

[0017] The second limiting ring is in interference fit with the second annular groove.

[0018] In one embodiment of the present disclosure, the inside of the first annular groove is provided with a chamfer, and the angle of the chamfer is 15°-45°; and / or,

[0019] The inside of the second annular groove is provided with a chamfer, and the angle of the chamfer is 15°-45°.

[0020] In one embodiment of the present disclosure, the first limiting ring and the second limiting ring are open-type limiting rings; or,

[0021] The first limiting ring and the second limiting ring are closed-type limiting rings.

[0022] In one embodiment of the present disclosure, the first limiting ring and the second limiting ring are both metal limiting rings.

[0023] One of the beneficial effects of the axial plunger motor of the present disclosure is that when the axial plunger motor of the present disclosure is working, the dynamic seal arranged on the transmission shaft prevents the hydraulic oil in the inner cavity of the shell from leaking. In order to avoid the dynamic seal from falling off from the preset position under the pressure inside or outside, the first limiting ring is arranged outside the dynamic seal to avoid the dynamic seal from being pushed out of the shell by the low pressure in the inner cavity of the shell. At the same time, the second limiting ring is arranged inside the dynamic seal. When the pressure in the sealed cavity outside the shell rises and is higher than the pressure in the inner cavity of the shell, the second limiting ring supports the dynamic seal to avoid the dynamic seal from being pushed into the shell.

[0024] The axial plunger motor of the present disclosure achieves the purpose of limiting the double axial displacement of the dynamic seal by setting the first limiting ring and the second limiting ring. The axial plunger motor of the present disclosure can keep the axial position of the dynamic seal stable whether it is just started to work or has been working for a long time, thereby prolonging the service life of the axial plunger motor, and the structure of the two limiting rings is simple and easy to process. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a structural schematic diagram of an embodiment of the axial plunger motor of the present disclosure;

[0026] Figure 2 is a partial structural schematic diagram of the axial plunger motor and the reducer assembly of the present disclosure;

[0027] Figure 3 is a partial enlarged schematic diagram of A of Figure 1

[0028] Figure 4 is a force analysis schematic diagram of the dynamic seal of an embodiment of the axial plunger motor of the present disclosure;

[0029] Figure 5 is a force analysis schematic diagram of the dynamic seal of an embodiment of the axial plunger motor of the present disclosure without setting the second limiting ring.

[0030] Figures 1 to 5 The correspondence between the names of the components in the and the reference numerals of the accompanying drawings is as follows:

[0031] 11 housing, 12 rear cover, 111 first annular groove, 112 second annular groove;

[0032] 21 transmission shaft, 22 plunger, 23 cylinder body, 24 flow distribution disc, 211 connecting disc;

[0033] 31 dynamic seal, 32 first limiting ring, 33 second limiting ring;

[0034] 4 reducer;

[0035] a radial height of the skeleton oil seal base, b radial height of the skeleton oil seal spring;

[0036] X housing inner cavity, Y sealed cavity, F0 initial pressure of the sealed cavity, F1 pressure in the housing inner cavity, F2 pressure after the sealed cavity is raised, F f friction force received by the dynamic seal, 32 reaction force provided by the first limiting ring, 33 reaction force provided by the second limiting ring. DETAILED DESCRIPTION

[0037] ​Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. Note that the relative arrangement, numerical expressions, and numerical values of components and steps set forth in these embodiments are not limiting to the scope of the present disclosure unless otherwise specifically stated.

[0038] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the scope of the present disclosure and its applications or uses.

[0039] Techniques, methods, and apparatus known to those of ordinary skill in the relevant art can not be discussed in detail herein, but should be considered as part of the specification, where appropriate.

[0040] Note that similar reference numerals and letters indicate similar items throughout the drawings, and thus once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0041] In this document, "first", "second", and so on are used only to distinguish one item from another, and do not indicate importance and order, and a prerequisite for each other.

[0042] It should be noted that when describing the structure of the axial plunger motor and its working principle, the orientation words used herein are based on the extension direction of the transmission shaft, where the direction close to the reducer is "out", and the direction away from the reducer is "in".

[0043] In the existing axial plunger motor, the dynamic seal is subjected to pressure inside and outside the housing. When the internal and external pressures produce a pressure difference, the axial position of the dynamic seal is unstable, affecting the operation of the axial plunger motor. After the internal and external pressure difference is too large, the dynamic seal is easy to fall off from the preset position in the housing of the axial plunger motor, so that the motor cannot continue to work.

[0044] To this end, the present disclosure provides an axial plunger motor, comprising a housing, a transmission shaft, a dynamic seal, a first limiting ring and a second limiting ring.

[0045] In detail, the transmission shaft is rotatably arranged in the housing and extends out of the housing at the end portion, and is configured to connect a reducer; the dynamic seal is arranged at the rotating fit position of the housing and the transmission shaft, and is configured to prevent hydraulic oil in the cavity of the housing from leaking; the first limiting ring is arranged on the housing and located outside the dynamic seal, and is configured to limit outward displacement of the dynamic seal; and the second limiting ring is arranged on the housing and located inside the dynamic seal, and is configured to limit inward displacement of the dynamic seal.

[0046] The axial plunger motor of the present disclosure defines the axial displacement of the dynamic seal by setting the first limiting ring and the second limiting ring. When the pressure in the motor cavity is greater than the external pressure, the first limiting ring outside the first dynamic seal can prevent the pressure in the shell cavity from pushing the dynamic seal out of the shell. When the pressure in the sealed cavity between the reducer and the plunger motor gradually increases after a long period of work, the second limiting ring inside the dynamic seal can prevent the dynamic seal from being pushed into the shell when the pressure in the sealed cavity is higher than the pressure in the shell cavity.

[0047] Obviously, the axial plunger motor of the present disclosure achieves the purpose of double limiting the axial displacement of the dynamic seal by setting the first limiting ring and the second limiting ring, so that the axial position of the dynamic seal remains stable, and the dynamic seal is prevented from falling off from the preset position in the shell to make the axial plunger motor unable to continue working, thereby prolonging the service life of the axial plunger motor.

[0048] For the sake of understanding, the specific structure and working principle of the axial plunger motor provided by the present disclosure will be described in detail below with reference to Figures 1 to 5

[0049] The axial plunger motor of the present disclosure comprises a shell 11, a transmission shaft 21, a dynamic seal 31, a first limiting ring 32 and a second limiting ring 33. The transmission shaft 21 is rotatably arranged in the shell 11 and extends out of the shell 11, configured to connect the reducer 4. The dynamic seal 31 is arranged at the rotating fit position of the shell 11 and the transmission shaft 21, configured to prevent the hydraulic oil in the shell cavity X from leaking. The first limiting ring 32 is arranged on the shell 11 and located outside the dynamic seal 31, configured to limit the outward displacement of the dynamic seal 31. The second limiting ring 33 is arranged on the shell 11 and located inside the dynamic seal 31, configured to limit the inward displacement of the dynamic seal 31.

[0050] The axial plunger motor of the present disclosure sets the first limiting ring 32 outside the dynamic seal 31 to prevent the dynamic seal 31 from being pushed out of the shell 11 under the pressure of the shell cavity X. Meanwhile, the second limiting ring 33 is set inside the dynamic seal 31 to prevent the dynamic seal 31 from being pushed into the shell 11 by the increased pressure in the sealed cavity Y between the reducer 4 and the motor when the pressure in the sealed cavity Y increases and is greater than the pressure in the shell cavity X after the axial plunger motor works for a period of time.

[0051] Obviously, compared with the prior art, the axial plunger motor of the present disclosure works by setting the first limiting ring 32 and the second limiting ring 33 on both sides of the dynamic seal 31, so that the axial position of the dynamic seal 31 remains stable, and the dynamic seal is prevented from falling off from the preset position in the shell to make the axial plunger motor unable to continue working, thereby prolonging the service life of the axial plunger motor. ​

[0052] As shown in Figure 1 and Figure 3 In one embodiment of the present disclosure, the dynamic seal 31 is a skeleton oil seal.

[0053] In detail, the dynamic seal 31 of the axial plunger motor of the present disclosure is an SC type skeleton oil seal, which is composed of a rubber sealing lip, a metal skeleton and a spring.

[0054] The metal skeleton provides support, ensures the shape and rigidity of the skeleton oil seal, facilitates installation, and the SC type skeleton oil seal is further wrapped with rubber outside the metal skeleton to protect the skeleton and increase the stability of the skeleton oil seal through interference fit with the housing 11; at the same time, the rubber increases the friction of the skeleton oil seal, improves the overall sealing performance, and also provides a buffering effect on the housing 11 to reduce the wear of the skeleton oil seal on the housing 11.

[0055] The rubber sealing lip is in contact with the shaft, and there is an oil film with fluid lubrication characteristics controlled by the sealing lip blade between the rubber sealing lip and the shaft. Through the oil film effect, the leakage of hydraulic oil is prevented, and at the same time, lubrication is provided to reduce the friction between the rubber sealing lip and the transmission shaft 21.

[0056] The spring is installed on the rubber sealing lip to provide pre-tightening force to ensure that the sealing lip can be in close contact with the shaft. In this way, the SC type skeleton oil seal can prevent hydraulic oil from leaking and has good sealing performance.

[0057] In one embodiment of the present disclosure, the dynamic seal 31 can also be a TC type skeleton oil seal. Compared with the SC type skeleton oil seal, the TC type skeleton oil seal further has a dust lip in contact with the shaft outside the rubber sealing lip, which can prevent external dust, moisture and other impurities from entering the inside of the housing 11.

[0058] As shown in Figure 1 and Figure 3 In one embodiment of the present disclosure, the radial height of the first limiting ring 32 and / or the second limiting ring 33 is higher than the radial height a of the base of the skeleton oil seal and lower than the radial height b of the spring of the skeleton oil seal.

[0059] In detail, the base of the skeleton oil seal is an annular structure wrapped with rubber outside the metal skeleton. In this way, the base has a wide contact area with the housing 11, so that the skeleton oil seal will not tilt axially, and cooperates with the first limiting ring 32 and the second limiting ring 33 to limit the axial displacement of the skeleton oil seal.

[0060] The radial height of the present disclosure refers to the distance between a certain position and the reference along the radial direction pointing to the transmission shaft, with the contact surface between the skeleton oil seal and the housing 11 as the reference.

[0061] In one embodiment of the present disclosure, the radial height of the first limiting ring 32 is higher than the radial height a of the skeleton oil seal base and lower than the radial height b of the skeleton oil seal spring, so that the first limiting ring 32 can provide sufficient support for the skeleton oil seal and will not tilt the skeleton oil seal between the first limiting ring 32 and the transmission shaft 21 and cause the skeleton oil seal to fall off, and on the other hand, the first limiting ring 32 can have stability in the axial direction and will not have excessive stress area to ensure the axial limiting of the skeleton oil seal.

[0062] In one embodiment of the present disclosure, the radial height of the second limiting ring 33 is higher than the radial height a of the skeleton oil seal base and lower than the radial height b of the skeleton oil seal spring, so that the second limiting ring 33 can provide sufficient support for the skeleton oil seal and will not tilt the skeleton oil seal between the second limiting ring 33 and the transmission shaft 21 and cause the skeleton oil seal to fall off, and on the other hand, the second limiting ring 33 can have stability in the axial direction and will not have excessive stress area to ensure the axial limiting of the skeleton oil seal.

[0063] Further, in one embodiment of the present disclosure, the radial height of the first limiting ring 32 is higher than the radial height a of the skeleton oil seal base and lower than the radial height b of the skeleton oil seal spring, and the radial height of the second limiting ring 33 is higher than the radial height a of the skeleton oil seal base and lower than the radial height b of the skeleton oil seal spring, so as to ensure that the first limiting ring 32 and the second limiting ring 33 provide sufficient support for the skeleton oil seal and double limit the axial displacement of the skeleton oil seal.

[0064] Wherein, the radial height of the first limiting ring 32 and the second limiting ring 33 can be the same or different, which is not limited in the present disclosure, and those skilled in the art can determine according to the actual situation to ensure that the first limiting ring 32 and the second limiting ring 33 can stably limit the axial displacement of the skeleton oil seal.

[0065] As shown in Figure 1 and Figure 3 In one embodiment of the present disclosure, the radial height of the first limiting ring 32 and / or the second limiting ring 33 is 1:3-2:3 of the radial height of the skeleton oil seal.

[0066] In detail, the radial height of the first limiting ring 32 is 1:3-2:3 of the radial height of the skeleton oil seal. In this way, the radial height of the first limiting ring 32 will not be too low to provide sufficient support for the skeleton oil seal, thereby reducing the stability of the skeleton oil seal; nor will it be too high, so that the stress area of the first limiting ring 32 and the second limiting ring 33 will increase and will not be stable after being pressed, thereby failing to limit the outward axial displacement of the skeleton oil seal.

[0067] In one embodiment of the present disclosure, the ratio of the radial height of the second limiting ring 33 to the radial height of the skeleton oil seal is 1:3-2:3. In this way, the radial height of the second limiting ring 33 is not too low to provide sufficient support force for the skeleton oil seal, thereby reducing the stability of the skeleton oil seal; nor is it too high to increase the force area of the second limiting ring 33 itself, which is not stable enough after being subjected to pressure, thereby failing to limit the inward axial displacement of the skeleton oil seal.

[0068] Further, in one embodiment of the present disclosure, the ratio of the radial height of the first limiting ring 32 and the second limiting ring 33 to the radial height of the skeleton oil seal is 1:3-2:3. In this way, the first limiting ring 32 and the second limiting ring 33 can ensure to provide sufficient support force for the skeleton oil seal and double axial displacement limitation for the skeleton oil seal.

[0069] As shown in Figure 1 and Figure 3 In one embodiment of the present disclosure, the housing 11 is provided with a first annular groove 111 and / or a second annular groove 112, the first limiting ring 32 is arranged in the first annular groove 111, and the second limiting ring 33 is arranged in the second annular groove 112.

[0070] In detail, the present disclosure constructs the first annular groove 111 on the housing 11 to arrange the first limiting ring 32, so that the first limiting ring 32 is fixed on the housing 11, and the first limiting ring 32 and the first annular groove 111 cooperate to provide the dynamic seal 31 with inward axial support force. At the same time, the first annular groove 111 provides the first limiting ring 32 with an accurate positioning point to ensure that it can be accurately installed at the preset position, and the first annular groove 111 makes the installation and disassembly of the first limiting ring 32 more convenient for replacement or maintenance.

[0071] In one embodiment of the present disclosure, the present disclosure constructs the second annular groove 112 on the housing 11 to arrange the second limiting ring 33, so that the second limiting ring 33 is fixed on the housing 11, and the second limiting ring 33 and the second annular groove 112 cooperate to provide the dynamic seal 31 with outward axial support force. At the same time, the second annular groove 112 provides the second limiting ring 33 with an accurate positioning point to ensure that it can be accurately installed at the preset position, and the second annular groove 112 makes the installation and disassembly of the second limiting ring 33 more convenient for replacement or maintenance.

[0072] Further, in one embodiment of the present disclosure, the first annular groove 111 is configured on the shell 11 to set the first limiting ring 32, the second annular groove 112 is configured on the shell 11 to set the second limiting ring 33, the first limiting ring 32 and the second limiting ring 33 are fixed on the shell 11, and the first limiting ring 32 and the first annular groove 111 cooperate, and the second limiting ring 33 and the second annular groove 112 cooperate, so as to provide double axial support force for the dynamic seal 31, ensure the stability of the dynamic seal 31 in the axial direction, and avoid loosening of the dynamic seal 31 due to vibration or impact.

[0073] As shown in the drawings, Figure 3 in one embodiment of the present disclosure, the distance between the first annular groove 111 and / or the second annular groove 112 and the dynamic seal 31 is 0-0.4mm.

[0074] In this way, the distance between the first annular groove 111 and the dynamic seal 31 in the present disclosure is 0-0.4mm, which ensures the axial limiting effect of the first limiting ring 32 on the dynamic seal 31, avoids deformation of the dynamic seal 31 due to pressure during installation caused by too close distance, reduces the risk of damage to the dynamic seal 31, affects the sealing effect, and can also compensate for the dimensional error in the processing process.

[0075] In one embodiment of the present disclosure, the distance between the second annular groove 112 and the dynamic seal 31 is 0-0.4mm, which ensures the axial limiting effect of the second limiting ring 33 on the dynamic seal 31, avoids deformation of the dynamic seal 31 due to pressure during installation caused by too close distance, reduces the risk of damage to the dynamic seal 31, affects the sealing effect, and can also compensate for the dimensional error in the processing process.

[0076] Further, in one embodiment of the present disclosure, the distance between the first annular groove 111 and the second annular groove 112 and the dynamic seal 31 is 0-0.4mm, which is set in this way, which ensures the axial limiting effect of the first limiting ring 32 and the second limiting ring 33 on the dynamic seal 31, avoids deformation of the dynamic seal 31 due to pressure during installation caused by too close distance, affects the sealing effect, and in the working process of the transmission shaft 21, the dynamic seal 31 will expand and vibrate, and the designed gap can reduce the risk of damage to the dynamic seal 31. At the same time, such setting can also compensate for the dimensional error in the processing process.

[0077] As shown in the drawings, Figure 1 and Figure 3 in one embodiment of the present disclosure, the first limiting ring 32 and the first annular groove 111 are interference fit; and / or, the second limiting ring 33 and the second annular groove 112 are interference fit.

[0078] Thus, the present disclosure makes the outer diameter of the first retaining ring 32 slightly larger than the diameter of the first annular groove 111, and the first retaining ring 32 and the first annular groove 111 have an interference fit, ensuring that the first retaining ring 32 can be tightly fixed in the first annular groove 111 after installation. This provides a good fixing effect for the first retaining ring 32, preventing it from loosening due to vibration or impact, and also improves the sealing performance, cooperating with the dynamic seal 31 to prevent oil leakage.

[0079] In one embodiment of the present disclosure, the outer diameter of the second retaining ring 33 is slightly larger than the diameter of the second annular groove 112. The second retaining ring 33 and the second annular groove 112 are interference-fitted, ensuring that the second retaining ring 33 is tightly secured within the second annular groove 112 after installation. This provides a good securing effect for the second retaining ring 33, preventing it from loosening due to vibration or impact, and also improves sealing performance, cooperating with the dynamic seal 31 to prevent oil leakage.

[0080] Furthermore, in one embodiment of the present disclosure, the present disclosure makes the outer diameter of the first limiting ring 32 slightly larger than the diameter of the first annular groove 111, and the outer diameter of the second limiting ring 33 slightly larger than the diameter of the second annular groove 112, ensuring that the first limiting ring 32 and the second limiting ring 33 can be tightly fixed in the corresponding annular grooves after installation.

[0081] In this way, a good fixing effect is provided for the first limiting ring 32 and the second limiting ring 33, preventing the two from loosening due to vibration or impact, and further ensuring the axial stability of the dynamic seal 31; it also improves the sealing performance, reduces the gap between the first limiting ring 32 and the second limiting ring 33 and the corresponding annular groove, and can cooperate with the dynamic seal 31 to prevent oil leakage.

[0082] like Figure 1 and Figure 3 As shown, in one embodiment of the present disclosure, the inner side of the first annular groove 111 is provided with a chamfer, and the angle of the chamfer is: 15°-45°; and / or, the inner side of the second annular groove 112 is provided with a chamfer, and the angle of the chamfer is: 15°-45°.

[0083] Thus, the chamfered inner side of the first annular groove 111 serves as a guide surface when installing the first retaining ring 32 of the axial piston motor disclosed herein, helping the first retaining ring 32 to smoothly enter the first annular groove 111. This reduces resistance and friction during installation, prevents damage caused by friction between the first retaining ring 32 and the edge of the first annular groove 111, and extends the service life of the first retaining ring 32. However, if the chamfer angle is too small, it will not provide guidance and reduce friction; if the angle is too large, it will affect the stability of the first retaining ring 32 and the dynamic seal 31.

[0084] In one embodiment of the present disclosure, the inner side of the second annular groove 112 is provided with a chamfer, which can serve as a guide surface when the second limiting ring 33 is installed, helping the second limiting ring 33 to smoothly enter the second annular groove 112, reducing the resistance and friction during installation, avoiding damage caused by friction between the second limiting ring 33 and the edge of the second annular groove 112, and prolonging the service life of the second limiting ring 33. At the same time, if the angle of the chamfer is too small, it cannot play a guiding and friction-reducing role; if the angle is too large, it will affect the stability of the second limiting ring 33 and the dynamic seal 31.

[0085] Further, in one embodiment of the present disclosure, the inner side of the first annular groove 111 and the second annular groove 112 is provided with a chamfer, so that the first limiting ring 32 and the second limiting ring 33 can smoothly enter the corresponding annular groove, and the resistance and friction during installation are reduced, avoiding damage caused by friction between the first limiting ring 32 and the second limiting ring 33 and the edge of the corresponding annular groove, prolonging the service life of the first limiting ring 32 and the second limiting ring 33, and improving the stability of the first limiting ring 32, the second limiting ring 33 and the dynamic seal 31.

[0086] As shown in Figure 1 and Figure 3 In one embodiment of the present disclosure, the first limiting ring 32 and the second limiting ring 33 are open-type limiting rings; or, the first limiting ring 32 and the second limiting ring 33 are closed-type limiting rings.

[0087] In detail, the first limiting ring 32 and the second limiting ring 33 of the present disclosure are open-type limiting rings, and each of the first limiting ring 32 and the second limiting ring 33 is provided with an opening, so that the first limiting ring 32 and the second limiting ring 33 can be expanded or compressed for installation and disassembly. Such open-type limiting rings generally have good elasticity and can restore to their original shape after installation, providing good fixing effect.

[0088] In one embodiment of the present disclosure, the first limiting ring 32 and the second limiting ring 33 of the present disclosure can also be closed-type limiting rings, and the first limiting ring 32 and the second limiting ring 33 are configured as complete circles and need to be pressed in with special installation tools. Such closed-type limiting rings can provide better fixing effect and sealing performance and have higher stability.

[0089] As shown in Figure 3 In one embodiment of the present disclosure, the first limiting ring 32 and the second limiting ring 33 are both metal limiting rings.

[0090] In this way, the first limiting ring 32 and the second limiting ring 33 of the axial plunger motor of the present disclosure can have high strength and rigidity, and can withstand high load and high pressure; the metal material has good wear resistance and fatigue resistance, so that the first limiting ring 32 and the second limiting ring 33 can maintain good performance in long-term use and remain stable under repeated stress; at the same time, some metal materials (such as stainless steel and high-temperature alloy) have good high-temperature resistance, so that the first limiting ring 32 and the second limiting ring 33 can maintain stable performance in a high-temperature environment. It can be seen that the metal limiting ring can ensure the stable operation of the axial plunger motor of the present disclosure.

[0091] For better understanding, the working principle of the axial plunger motor provided by the present disclosure will be described in detail below with reference to Figures 1 to 5 an application scenario.

[0092] As shown in Figure 2 , the present disclosure provides an axial plunger motor, which comprises a housing 11, a transmission shaft 21, a dynamic seal 31, a first limiting ring 32 and a second limiting ring 33. The transmission shaft 21 is rotatably arranged in the housing 11, and the end thereof extends out of the housing 11. The dynamic seal 31 is arranged at the rotating fit position of the housing 11 and the transmission shaft 21. The first limiting ring 32 is arranged on the housing 11 and located outside the dynamic seal 31. The second limiting ring 33 is arranged on the housing 11 and located inside the dynamic seal 31.

[0093] Further, the housing 11 of the axial plunger motor of the present disclosure is provided with a first annular groove 111 and a second annular groove 112 for arranging the first limiting ring 32 and the second limiting ring 33, respectively.

[0094] The axial plunger motor of the present disclosure further comprises a rear cover 12, a distribution disc 24, a cylinder body 23 and plungers 22. The rear cover 12 is fixedly arranged on the housing 11. The distribution disc 24 is arranged on the rear cover 12. The cylinder body 23 is connected with the distribution disc 24 and is arranged obliquely in the housing 11. The plungers 22 are circumferentially distributed in the cylinder body 23. The ball head at the outer end of the plunger 22 is ball-hinged with the corresponding ball socket on the inner end connecting disc 211 of the transmission shaft 21.

[0095] Specifically, when the axial plunger motor starts to work, high-pressure oil enters the cylinder body 23 from the rear cover 12 through the distribution disc 24, and pushes the plunger 22 to reciprocate in the cylinder body 23, and then the ball-hinged connection of the connecting disc 211 is converted into the rotary motion of the transmission shaft, and the cylinder body 23 rotates together with the plunger 22 and outputs the torque of the transmission shaft 21.

[0096] As shown in Figure 5 , when the axial plunger motor just starts to work, the inner cavity X of the housing is at low pressure F1, the initial pressure in the sealed cavity Y is atmospheric pressure F0, and the friction force of the skeleton oil seal on the inner wall of the housing 11 is Ff .

[0097] At this time, F0 is much smaller than F1, and the skeleton oil seal will move to the closed cavity Y under the action of the pressure difference. Since the first limiting ring 32 is arranged in the first annular groove 111 of the shell 11, the first limiting ring 32 will exert a counterforce on the skeleton oil seal at this time , and the force acting on the skeleton oil seal at this time is as follows:

[0098]

[0099] Under the action of these forces, the skeleton oil seal remains stable.

[0100] It can be seen that if the first limiting ring 32 is not arranged on the outside of the skeleton oil seal, the pressure in the inner cavity X of the axial piston motor shell will be greater than the initial pressure in the closed cavity Y between the reducer 4 and the motor, and thus the skeleton oil seal will be pushed out of the shell 11 by the pressure in the inner cavity X of the shell.

[0101] As shown in Figure 4 , after the axial piston motor works for a long time, the motor and the reducer 4 connected to the motor transmission shaft 21 generate a lot of heat, and at this time, the pressure in the closed cavity Y will continue to rise to F2.

[0102] When F2 is much greater than F1, the skeleton oil seal will move to the inner cavity X of the shell under the action of the pressure difference. Since the second limiting ring 33 is arranged in the second annular groove 112 of the shell 11, the second limiting ring 33 will exert a counterforce F 33 on the skeleton oil seal at this time, and the force acting on the skeleton oil seal at this time is as follows:

[0103]

[0104] Under the action of these forces, the skeleton oil seal remains stable.

[0105] It can be seen that if the second limiting ring 33 is not arranged on the inside of the skeleton oil seal, after the axial piston motor works for a long time, the pressure in the closed cavity Y between the reducer 4 and the motor will rise and be greater than the pressure in the inner cavity X of the shell, and thus the skeleton oil seal will be pushed into the shell 11 by the rising pressure in the closed cavity Y.

[0106] In this way, the axial piston motor of the present disclosure achieves the purpose of double limiting the axial displacement of the skeleton oil seal by arranging the first limiting ring 32 and the second limiting ring 33, and can keep the axial position of the skeleton oil seal stable whether it is just starting to work or has been working for a long time, avoiding the skeleton oil seal from falling out of the pre-set position in the shell 11 and making the axial piston motor unable to continue to work, thereby prolonging the service life of the axial piston motor.

[0107] At the same time, the structure of the two limiting rings is simple and easy to realize.

[0108] Having described above several embodiments of the disclosure, any modifications and variations that fall within the scope of the described embodiments are also contemplated. It is also contemplated that the application covered by the claims extends to any alternative combination of claim elements not specifically disclosed above.

Claims

1. An axial piston motor, characterized in that: include: housing (11); a transmission shaft (21), the transmission shaft (21) being rotatably disposed within the housing (11), with an end portion extending out of the housing (11), and being configured to be connected to a reducer (4); A dynamic seal (31), the dynamic seal (31) being provided at a location where the housing (11) and the transmission shaft (21) are rotatably engaged, and being configured to prevent leakage of hydraulic oil from an inner cavity of the housing (11); a first limiting ring (32), the first limiting ring (32) being provided on the housing (11) and located outside the dynamic seal (31), and being configured to limit outward displacement of the dynamic seal (31); A second limiting ring (33) is provided on the housing (11) and is located inside the dynamic seal (31), and is configured to limit the inward displacement of the dynamic seal (31).

2. The axial piston motor according to claim 1, characterized in that The dynamic seal (31) is a skeleton oil seal.

3. The axial piston motor according to claim 2, characterized in that The radial height of the first limiting ring (32) and / or the second limiting ring (33) is higher than the radial height (a) of the base of the skeleton oil seal, and lower than the radial height (b) of the spring of the skeleton oil seal.

4. The axial piston motor according to claim 2, characterized in that The ratio of the radial height of the first limiting ring (32) and / or the second limiting ring (33) to the radial height of the skeleton oil seal is 1:3-2:

3.

5. The axial piston motor according to any one of claims 1 to 4, characterized in that: The housing (11) is provided with a first annular groove (111) and / or a second annular groove (112); the first limiting ring (32) is arranged in the first annular groove (111); and the second limiting ring (33) is arranged in the second annular groove (112).

6. The axial piston motor according to claim 5, characterized in that The distance between the first annular groove (111) and / or the second annular groove (112) and the dynamic seal (31) is 0-0.4 mm.

7. The axial piston motor according to claim 5, characterized in that The first limiting ring (32) is interference-fitted with the first annular groove (111); and / or, The second limiting ring (33) is interference-fitted with the second annular groove (112).

8. The axial piston motor according to claim 5, characterized in that The inner side of the first annular groove (111) is provided with a chamfer, and the angle of the chamfer is: 15°-45°; and / or, The inner side of the second annular groove (112) is provided with a chamfer, and the angle of the chamfer is 15°-45°.

9. The axial piston motor according to any one of claims 1 to 4, characterized in that: The first limiting ring (32) and the second limiting ring (33) are open-type limiting rings; or, The first limiting ring (32) and the second limiting ring (33) are closed-end limiting rings.

10. The axial piston motor according to any one of claims 1 to 4, characterized in that: The first limiting ring (32) and the second limiting ring (33) are both metal limiting rings.

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