Hydraulic motor applying plunger assembly of needle bearing

Abstract

The hydraulic motor comprises a stator, a rotor assembly, a motor front cover and a motor rear cover, the rotor assembly is connected with an output shaft, the rotor assembly comprises a rotor and a plunger assembly, the plunger assembly comprises a plunger, a spring pin and a needle bearing, the needle bearing comprises an outer ring and a needle roller, and the outer ring is connected with the motor front cover and the motor rear cover. The needle roller bearing is a roller, the needle roller is arranged between the shaft core and the outer ring, the shaft core is arranged in the center of the needle roller bearing, fixing grooves are formed in the two sides of the plunger, the two sides of the shaft core are inserted into the fixing grooves, a spring pin is further arranged at one end of the shaft core, and a roller cavity for containing the roller is formed in the plunger. A gap is formed between the roller and the inner wall of the roller cavity, rolling friction exists between the shaft core and the needle roller bearing, rolling friction exists between the bearing outer ring and the needle roller, and the hydraulic motor has the advantages that friction between the roller and other parts is changed into rolling friction from sliding friction, the friction coefficient is reduced, and therefore the starting efficiency of the hydraulic motor is improved.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic motors, and in particular to a hydraulic motor using a plunger assembly with needle roller bearings. Background Technology

[0002] As a key actuator in a hydraulic system, the hydraulic motor works by converting hydraulic energy into mechanical energy to achieve rotational motion of the output shaft. Among the many structural types of hydraulic motors, a common type mainly consists of a stator, rotor assembly, front cover, and rear cover. The rotor assembly, connected to the output shaft, plays a crucial role in transmitting power. The rotor assembly includes the rotor and a piston assembly, which comprises rollers, pistons, oil-free bearings, spring pins, piston rings, and piston baffles.

[0003] During the operation of a hydraulic motor, the plunger reciprocates within its cavity, while the rollers move in a wave-like motion along the inner wall of the rotor. This motion is driven by the pressure of hydraulic oil. When high-pressure oil enters the plunger cavity, it pushes the plunger outward, causing the rollers to roll along the inner wall of the stator. Due to the specific curved shape of the stator's inner wall, the rollers' movement causes the rotor to rotate, thus converting hydraulic energy into mechanical energy. However, the connection method between the rollers and the plunger in the current technology has significant drawbacks. Currently, an oilless bearing is used between the rollers and the plunger, and the rollers rotate relative to the oilless bearing during operation. In this process, sliding friction occurs between the rollers and the oilless bearing. Sliding friction is characterized by a high coefficient of friction, which results in a large frictional torque needing to be overcome when the hydraulic motor starts. According to the principles of mechanical motion, the greater the frictional torque overcome during startup, the more energy is required for the motor to start, and the slower the startup process becomes, directly leading to low starting efficiency.

[0004] Low starting efficiency not only affects the performance of hydraulic motors during the initial startup phase of equipment, but can also adversely impact the response speed and efficiency of the entire hydraulic system. In some work scenarios requiring high starting speeds, such as the hydraulic drive systems of certain precision machining equipment or emergency rescue equipment, the low starting efficiency of existing hydraulic motors is particularly prominent, severely limiting the overall performance and application range of the equipment. Therefore, developing a technical solution that can reduce the friction coefficient between the roller and the piston and improve the starting efficiency of hydraulic motors is an urgent practical need. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a hydraulic motor that uses a plunger assembly with needle roller bearings, so that the friction between the rollers and other components is transformed into rolling friction, thereby reducing the coefficient of friction and improving the starting efficiency of the hydraulic motor.

[0006] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: a hydraulic motor using a plunger assembly with needle roller bearings, including a stator, a rotor assembly, a motor front cover and a motor rear cover, the rotor assembly is connected to an output shaft, the rotor assembly includes a rotor and a plunger assembly, the plunger assembly includes a plunger, a spring pin and a needle roller bearing, the needle roller bearing includes an outer ring and needle rollers, the needle roller bearing is a roller, the needle rollers are disposed between the shaft core and the outer ring, the shaft core is disposed in the center of the needle roller bearing, the plunger is provided with fixing grooves on both sides, the shaft core is inserted into the fixing grooves on both sides, a spring pin is also provided at one end of the shaft core, the plunger is provided with a roller cavity for the rollers to be inserted, there is a gap between the rollers and the inner wall of the roller cavity, rolling friction occurs between the shaft core and the needle roller bearing, and rolling friction occurs between the outer ring of the bearing and the needle rollers.

[0007] A further preferred embodiment of this utility model is as follows: the plunger is cylindrical, the outer wall of the plunger is arc-shaped, both ends of the shaft are arc-shaped, and both ends of the shaft and the outer wall of the plunger are on the same curved surface.

[0008] A further preferred embodiment of this utility model is that the size of the core puller is the same as the size of the fixing groove, and the core is completely inserted into the fixing groove.

[0009] A further preferred embodiment of this utility model is that a piston ring is provided on the outer wall of the plunger.

[0010] A further preferred embodiment of this utility model is that the hydraulic oil enters the gap.

[0011] A further preferred embodiment of this utility model is: one end of the shaft is provided with a groove, and a spring pin is inserted into the groove.

[0012] The hydraulic motor using a plunger assembly with needle roller bearings as described in this claim features innovative improvements in structural design, resulting in numerous significant technical benefits. The high friction problem caused by oilless bearings between rollers and plungers in traditional hydraulic motors is effectively solved. In this solution, needle roller bearings are used as the rollers, with the needles positioned between the shaft core and the outer ring. Rolling friction occurs between the shaft core and the needle roller bearing, as does between the bearing outer ring and the needle rollers. Compared to traditional sliding friction, the coefficient of friction for rolling friction is significantly reduced, which significantly decreases the frictional torque that the hydraulic motor needs to overcome during startup. According to the principles of mechanical motion, a smaller frictional torque means less energy is required for startup, resulting in a faster startup process and thus greatly improving the startup efficiency of the hydraulic motor. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model;

[0014] Figure 2 A perspective view of the stator and rotor assembly;

[0015] Figure 3 This is a three-dimensional view of the rotor assembly;

[0016] Figure 4 A 3D view of the plunger assembly;

[0017] Figure 5 This is a cross-sectional view of the plunger assembly. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0019] like Figures 1-5 As shown, a hydraulic motor using a plunger assembly with needle roller bearings includes a stator 1, a rotor assembly 2, a front motor cover 3, and a rear motor cover 4. The rotor assembly 2 is connected to an output shaft and includes a rotor 5 and a plunger assembly 6. The plunger assembly 6 is characterized by including a plunger 7, a spring pin 8, and a needle roller bearing 9. The needle roller bearing 9 includes an outer ring 10 and needle rollers 11. The needle roller bearing 9 is essentially a roller, with the needle rollers 11 positioned between a shaft core 13 and the outer ring 10. The shaft core 13 is located at the center of the needle roller bearing 9. Fixing grooves 14 are provided on both sides of the plunger 7, and both sides of the shaft core 13 are inserted into the fixing grooves 14. A spring pin 8 is also provided at one end of the shaft core 13. The plunger 7 is provided with a roller cavity 15 into which the roller 9 can be inserted. There is a gap 20 between the roller 9 and the inner wall of the roller cavity 15. The shaft core 13 and the needle roller bearing 9 have rolling friction, and the outer ring 10 of the bearing and the needle roller 11 have rolling friction.

[0020] The hydraulic motor using a plunger assembly with needle roller bearings as described in this claim features innovative improvements in structural design, resulting in numerous significant technical benefits. The high friction problem caused by oilless bearings between rollers and plungers in traditional hydraulic motors is effectively solved. In this solution, needle roller bearings 9 are used as rollers 9, and needle rollers 11 are positioned between the shaft core 13 and the outer ring 10. Rolling friction occurs between the shaft core 13 and the needle roller bearing 9, and also between the outer ring 10 and the needle rollers 11. Compared to traditional sliding friction, the coefficient of friction for rolling friction is significantly reduced, which significantly reduces the frictional torque that the hydraulic motor needs to overcome during startup. According to the principles of mechanical motion, a smaller frictional torque means less energy is required for startup, resulting in a faster startup process and thus greatly improving the startup efficiency of the hydraulic motor.

[0021] From the perspective of overall performance improvement, due to the increased starting efficiency, the hydraulic motor can quickly reach the working state at the initial stage of equipment startup, reducing the preheating time and improving the overall operating efficiency of the equipment. In actual operation, the structural design of the needle roller bearing 9 makes force transmission more uniform and stable. The fixing grooves 14 of the plunger 7 are inserted into both sides of the shaft core 13. Simultaneously, the gap design between the roller cavity 15 on the plunger 7 and the needle roller bearing 9 ensures both flexible rotation of the roller 9 and allows hydraulic oil to enter the gap, providing good lubrication and heat dissipation, effectively reducing component wear during operation and extending the service life of the hydraulic motor. This structural design also optimizes the power output of the hydraulic motor, making the output torque more stable and better adaptable to the power requirements of different working scenarios.

[0022] The plunger 7 is cylindrical with an arc-shaped outer wall. Both ends of the shaft core 13 are also arc-shaped, and the ends of the shaft core 13 are on the same curved surface as the outer wall of the plunger 7. This cylindrical shape and arc-shaped outer wall of the plunger 7, along with the arc-shaped ends of the shaft core 13 and their alignment with the outer wall of the plunger 7, optimizes the hydrodynamic performance of the plunger assembly 6. When hydraulic oil flows within the plunger cavity, the arc-shaped outer wall reduces the flow resistance of the hydraulic oil, resulting in a more uniform pressure distribution and thus improving the efficiency of hydraulic energy conversion to mechanical energy. Simultaneously, the alignment of the shaft core 13 with the outer wall of the plunger 7 increases the stress-bearing area, ensuring a tighter and more stable connection between the shaft core 13 and the plunger 7 during movement. This avoids stress concentration problems caused by structural mismatches, further enhancing the reliability and durability of the assembly.

[0023] The dimensions of the shaft core 13 are the same as those of the fixing groove 14, and the shaft core 13 is fully inserted into the fixing groove 14. This identical size and complete insertion of the shaft core 13 into the fixing groove 14 ensures the precision and robustness of the connection between the shaft core 13 and the plunger 7. Precise dimensional matching effectively reduces the wobble of the shaft core 13 within the fixing groove 14, avoiding additional wear and noise caused by wobble. This robust connection allows the shaft core 13 to stably transmit the movement of the roller 9 to the plunger 7 during hydraulic motor operation, ensuring accurate and efficient power transmission, thereby improving the overall operational stability and reliability of the hydraulic motor.

[0024] A piston ring 16 is provided on the outer wall of the plunger 7. The piston ring 16 effectively prevents the outer wall of the plunger 7 from directly and tightly contacting the inner wall of the plunger cavity, thereby reducing sliding friction. When the plunger 7 reciprocates within the plunger cavity, if the two are in direct contact, the resulting friction will not only consume more energy but may also cause component wear, reducing equipment operating efficiency. The presence of the piston ring 16 creates a gap between the plunger 7 and the plunger cavity, reducing the contact area and significantly lowering the coefficient of friction. This not only improves the energy utilization efficiency of the hydraulic motor and reduces energy loss due to friction but also extends the service life of the plunger 7 and the plunger cavity, reduces equipment maintenance costs, and effectively ensures the stable and efficient operation of the hydraulic motor.

[0025] Hydraulic oil enters the gap. The hydraulic oil enters the gap between the roller 9 and the inner wall of the roller cavity 15, providing good lubrication for the needle roller bearing 9. The formation of the lubricating oil film effectively reduces the coefficient of friction between the components of the needle roller bearing 9, reducing wear. It also carries away the heat generated by friction, playing a role in heat dissipation and cooling, preventing damage to the components due to overheating. Good lubrication and heat dissipation not only improve the working efficiency and service life of the needle roller bearing 9, but also further enhance the overall performance and stability of the hydraulic motor.

[0026] A groove 17 is provided at one end of the shaft core 13, into which a spring pin 8 is inserted. The groove 17 at one end of the shaft core 13, into which the spring pin 8 is inserted, provides precise guidance for the up-and-down movement of the plunger 7 within the plunger cavity. During the operation of the hydraulic motor, the plunger 7 needs to perform reciprocating linear motion within the plunger cavity along a specific trajectory. (Spring pin...)

[0027] The above provides a detailed description of a hydraulic motor using a needle roller bearing plunger assembly, as provided by this utility model. Specific examples have been used to illustrate the principle and implementation of this utility model. The descriptions of the embodiments are merely for the purpose of helping to understand this utility model and its core ideas. It should be noted that those skilled in the art can make various improvements and modifications to this utility model without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. A hydraulic motor employing a plunger assembly with needle bearings, comprising a stator, a rotor assembly, a motor front cover and a motor rear cover, the rotor assembly connected to an output shaft, the rotor assembly comprising a rotor and a plunger assembly, characterized in that The plunger assembly comprises a plunger, a spring pin and a needle bearing, the needle bearing comprises an outer ring and a needle, the needle bearing is a roller, a shaft core is arranged in the center of the needle bearing, the needle is arranged between the shaft core and the outer ring, both sides of the plunger are provided with fixed grooves, both sides of the shaft core are inserted into the fixed grooves, one end of the shaft core is further provided with a spring pin, the plunger is provided with a roller cavity for accommodating the roller, a gap is formed between the roller and the inner wall of the roller cavity, the shaft core and the needle bearing are in rolling friction, and the bearing outer ring and the needle are in rolling friction.

2. A hydraulic motor of a plunger assembly using a needle bearing according to claim 1, wherein The plunger is cylindrical, the outer wall of the plunger is arc-shaped, both ends of the shaft core are arc-shaped, and both ends of the shaft core and the outer wall of the plunger are on the same curved surface.

3. A hydraulic motor of a plunger assembly using a needle bearing according to claim 1, wherein The size of the shaft core is the same as that of the fixed groove, and the shaft core is completely accommodated in the fixed groove.

4. A hydraulic motor of a plunger assembly using a needle bearing according to claim 1, wherein A piston ring is arranged on the outer wall of the plunger.

5. A hydraulic motor using a plunger assembly with needle bearings according to claim 1, wherein Hydraulic oil enters the gap.

6. A hydraulic motor of a plunger assembly using a needle bearing according to claim 1, wherein One end of the shaft core is provided with a sliding groove, and the spring pin is inserted into the sliding groove.

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