WO2017181907A1

WO2017181907A1 - Medium-speed high-torque radial piston hydraulic motor

Info

Publication number: WO2017181907A1
Application number: PCT/CN2017/080515
Authority: WO
Inventors: 叶春浓
Original assignee: 佛山市顺德区中意液压有限公司
Priority date: 2016-04-19
Filing date: 2017-04-14
Publication date: 2017-10-26
Also published as: CN105756850B; CN105756850A

Abstract

A medium-speed high-torque radial piston hydraulic motor, comprising a housing (1), a crankshaft (2), a roller column (3), a bearing sleeve (4), a cylinder cover (5), a telescopic sleeve (6) radially distributed along the bearing sleeve (4), the upper and lower ends thereof respectively abutting an outer spherical face (501) of the cylinder cover (5) and an outer spherical face (402) of the bearing sleeve (4), a retention ring (7) for fully attaching the lower end of the telescopic sleeve (6) to the outer spherical face (402) of the bearing sleeve (4), a suspension rod (8) for fully attaching the upper end of the telescopic sleeve (6) to the outer spherical face (501) of the cylinder cover (5), and a transmission shaft (10), the two ends thereof being connected to the crankshaft (2) and an oil distribution mechanism (9), the roller column (3) being sleeved inside an inner hole (401) of the bearing sleeve (4), and the crank shaft (2) comprising an eccentric shaft section (201). The present radial piston hydraulic motor has the advantages of significantly improving rotation speed and a compact structure.

Description

Medium speed high torque radial piston hydraulic motor

Technical field

The invention relates to the technical field of hydraulic components, in particular to a medium speed large torque radial piston hydraulic motor.

Background technique

The radial piston hydraulic motor is typically configured such that the plunger is radially distributed along the drive shaft, and the plunger movement plane is perpendicular to the drive shaft. The significant advantage is that the displacement is large, the torque is large, and the load can be directly driven, especially suitable for low speed. Torque applications.

However, actual use on the market today indicates that the common radial piston hydraulic motor uses a speed of less than 300 r/min. According to the hydraulic motor industry, 500r/min is classified as a high-speed motor, and less than 500r/min is classified as a low-speed motor. The radial piston hydraulic motor sold on the market today is large. Part of it should be classified as low-speed high-torque radial piston hydraulic motor. High-speed motors above 500r/min are mostly axial piston hydraulic motors with small torque. Generally, the speed reduction link is required to drive the load to start. With the advancement of technology, the market has a strong demand for medium-speed high-torque hydraulic motors with speeds of 300-1000 r/min and corresponding displacements of 4000-200 mL/r, which can be directly loaded with loads.

From the above simple analysis of the hydraulic motor, it can be known that the medium-speed and large-torque direct load-loading can only be a radial piston structure, and all kinds of low-speed and high-torque radial piston hydraulic motors can be improved with the use of the rotating speed. There are various problems that cannot be met, and even if there are individual hydraulic motors that can be called medium-speed and high-torque, there are various defects.

1 and 2 are structural schematic diagrams of a prior art crank-link type low-speed high-torque radial piston hydraulic motor, and the structural diagram thereof can be seen in the product samples of related manufacturers. The housing 1, the front cover 2, the crankshaft 3, the roller 4, the bearing housing 5, the connecting rod 6, the retaining ring 7, the piston 8, the cylinder head 9, and the oil distribution mechanism 10 are included. The crankshaft 3, the roller 4, and the bearing housing 5 form a roller bearing structure, and the connecting rod 6 is rigidly connected to the outer cylindrical surface 501 of the bearing housing 5 through a retaining ring 7 on each side, and the ball head 602 of the connecting rod 6 is disposed on the piston 8 In the ball socket 801, the piston 8 is disposed in the cylindrical inner hole 901 of the cylinder head 9. In operation, the oil distribution mechanism sequentially distributes the hydraulic oil (not shown) to the respective cavities surrounded by the piston 8 and the inner cavity 902 of the cylinder head 9, and the hydraulic oil pushes the piston 8 in the cylindrical inner hole 901 of the cylinder head 9 The lower sliding, downward sliding piston 8 pushes the connecting rod 6 downward, and the connecting rod 6 moves downwardly around the center of the ball 602 thereof in a direction perpendicular to the axis x of the crankshaft 3 and passes through the bearing housing 5, rolling The column 4 pushes the crankshaft 3 to rotate. The crankshaft linkage low-speed high-torque radial piston hydraulic motor is cheap and widely used in low-speed working conditions. It is one of the world's largest low-speed high-torque hydraulic motors, but with the increase of the speed, the structure The hydraulic motor has the following disadvantages:

1. The outer surface 501 of the bearing housing 5 is a cylindrical surface, and the concave surface 603 of the connecting rod 6 matched with the cylindrical surface 501 of the bearing housing 5 is still a cylindrical surface, and the fitting between the cylindrical surfaces cannot be constrained along the axis of the cylinder, that is, the shaft Degree of freedom in the y direction. Therefore, as the working speed is increased, the positioning ability of the connecting rod 6 is poor and the stability is poor.

2. The connecting rod 6 and the retaining ring 7 are completely rigid connections of the mechanical member. There is a gap between the groove 601 of the connecting rod 6 and the inner hole 701 of the retaining ring. As the rotational speed increases, the centrifugal force increases, and the connecting rod 6 and the retaining ring There is a mechanical impact between 7 and noise.

3. As shown in FIG. 2, as the link 6 swings about the center of the ball 602 of the ball 602 in the direction of the axis x perpendicular to the crankshaft 3, the axis m of the link 6 and the axis n of the piston 8 have a periodically varying angle of intersection θ The piston 8 has a periodic lateral force which causes irregular wear of the cylindrical inner hole 901 of the cylinder head 9. After the wear, the circular shape becomes an elliptical shape, as shown in FIG. The higher the pressure, the more severe the elliptical wear.

4. It can be known from the motion law of the above-mentioned connecting rod 6 that the driving force of the connecting rod 6 on the crankshaft 3 has a fluctuation according to the cosine law, that is, the driving force is equal to Fcos θ, wherein F is determined by the diameter of the piston 8 and the hydraulic oil pressure. From this, it can be seen that the output torque of the crankshaft 3 fluctuates.

5. In addition to the above structural defects, the motor of the structural form also has technical defects. Two

steps

301, 302 for constraining the degree of freedom of the roller 4 along the axis y are provided on the crankshaft 3. The distance tolerance between the two

steps

301 and 302 and the surface finish have high requirements, which brings processing. Inconvenience, for the same reason, the

steps

502, 503 of the bearing housing 5 also bring inconvenience to the processing.

Figure 4 is a schematic view showing the structure of a sleeve telescopic pendulum type low-speed high-torque radial piston hydraulic motor of the prior art obtained by the company Calzoni of Italy, Foshan Shunde Zhongyi Hydraulic Co., Ltd., including the housing 1, front Cover 2, crankshaft 3, cylinder 4, piston 5, spring 6, cylinder head 7, spring cover 8, spring seat 9, oil distribution mechanism 10. The crankshaft 3 and the cylinder head 7 are respectively provided with outer

spherical surfaces

301, 701 and a cylinder 4, and the pistons 5 are respectively provided with inner

spherical surfaces

401, 501. The spring 6 passes through the spring seat 9, which respectively abuts the inner spherical surface 401 of the cylinder 4 with the outer spherical surface 301 of the crankshaft 3 and the inner spherical surface 501 of the piston 5 and the outer spherical surface 701 of the cylinder head 7. Cylinder 4 and a piston 5 fitted coaxially, with the axis y, a configuration only along the y axis made with the telescopic sliding axis x and a vertical plane 701 about the spherical center of the spherical head 7 O stretching swinging pivot sleeve structure ₁ . The cylinder head 7, the piston 5, the cylinder 4 and the crankshaft 3 form a sealed cavity. During operation, the hydraulic oil sequentially supplied by the oil distribution mechanism 10 enters the sealed cavity, and the hydraulic oil column enclosed by the cavity directly pushes the crankshaft 3 to rotate. . The crankshaft 3 rotates once, and the cylinder 4 and the piston 5 expand and contract once, and the spring 6 also follows the expansion and contraction once. Compared with the above-mentioned crankshaft link type low speed and high torque radial piston hydraulic motor, the sleeve telescopic pendulum type low speed high torque radial piston hydraulic motor has obvious advantages:

1, only the cylinder 4 along the axis y and the stretching of between 5 and _swinging the telescopic piston axis x and a vertical plane 701 about the spherical center of the spherical head 7 O pivoting movement, the cylinder 4 and the piston 5 remain coaxial, There is no lateral force between the two, which means there is no elliptical wear.

2. The hydraulic oil directly pushes the crankshaft 3 to rotate. The magnitude of the thrust is determined by the diameter of the piston 5 and the hydraulic oil pressure. There is no force caused by the inherent characteristics of the crankshaft linkage low-speed high-torque radial piston hydraulic motor due to the mechanism transformation principle. Torque fluctuations.

However, with the increase of the rotational speed, the prior art sleeve telescopic pendulum type low speed high torque radial piston hydraulic motor shown in FIG. 4 still has the following disadvantages:

1. According to the above analysis, the crankshaft 3 rotates once, and the spring 6 expands and contracts once. The higher the rotational speed, the higher the frequency of expansion and contraction of the spring 6, and the more easily the fatigue fracture occurs. Therefore, the spring 6 becomes one of the bottlenecks for increasing the rotational speed of the motor.

2. With the expansion and contraction of the spring 6, the contact stress between the cylinder 4 and the crankshaft 3, the piston 5 and the cylinder head 7 periodically change. From the knowledge of the contact mechanics, the alternating contact stress is easier to make than the static contact stress. Fatigue damage occurs on the contact surface.

3. A sliding friction pair is formed between the spherical surface 401 of the cylinder and the outer spherical surface 301 of the crankshaft. It is known from the tribological principle that the wear limit of the material is restricted by the PV value between the friction pairs, wherein P is the positive pressure between the friction pairs. V is the relative sliding speed between the friction pairs. As the rotational speed increases, V increases and wear increases. Therefore, friction pair wear is the most serious bottleneck for increasing the rotational speed of the motor.

In view of the shortcomings of the above-mentioned sleeve telescopic pendulum type low-speed high-torque radial piston hydraulic motor, various manufacturers have made various improvements:

The application publication No. CN104329217A published on February 4, 2015 discloses a telescopic swing cylinder type hydraulic motor and an eccentric shaft spherical surface processing method thereof. The invention processes a fine liquid storage hole on the spherical surface of the crankshaft by a process to improve Although its self-lubricating performance can reduce friction and increase the rotational speed to a certain extent, the physical fact of sliding friction between the cylinder and the spherical surface of the crankshaft has not changed, and it is still restricted by the PV value of the friction pair.

The application publication No. CN103014587A, published on Apr. 3, 2013, discloses a method of thermally spraying a molybdenum coating on a crankshaft axial surface by spraying a metal coating on the spherical surface of the crankshaft to increase its self-lubricity and Abrasion resistance, this method achieves good results on large displacement (3600ml/r and above) hydraulic motors, but like the invention method disclosed in CN104329217A above, the physical fact of sliding friction between the cylinder and the crankshaft spherical surface has not changed, still Due to the PV value of the friction pair, it is still not suitable for medium speed conditions.

U.S. Patent No. 5,967,018 discloses a solution, as in Figure 5. A radial expansion sleeve 3 is disposed between the cylinder head 1 and the crankshaft 2. The telescopic sleeve 3 includes an oil cylinder 4. and a piston 5. The cylinder 4 and the piston 5 are each provided with an inner spherical surface, and the cylinder head 1 and the crankshaft 2 are respectively disposed. An outer spherical surface; the spring 6 applies an elastic force to the oil cylinder 4, so that the spherical surface of the oil cylinder 4 is in close contact with the outer spherical surface of the crankshaft 2; the spring 7 applies an elastic force to the piston 5, so that the spherical surface of the piston 5 and the outer spherical surface of the cylinder head 1 are tightly attached; the spring 6 and The spring 7 does not change the compression amount with the rotation of the crankshaft 2, so the pre-tightening force of the contact surface is unchanged, the stress state of the parts related to the contact surface is improved, and the fatigue fracture of the spring and the spherical wear phenomenon are avoided as the rotation speed is increased. . However, the program still has the following disadvantages:

1. The spring 6 and the spring 7 are both disposed at the periphery of the telescopic sleeve 3, which increases the size of the motor, and particularly increases the size of the cylinder head 1.

2. As in the previous scheme, the physical fact of sliding friction between the cylinder 4 and the spherical surface of the crankshaft 2 has not changed, and is still limited by the PV value of the friction pair, and is still unable to perform the medium speed condition.

U.S. Patent No. 7,267,044 B2 is another solution disclosed after U.S. Patent No. 5,676,018, as shown in Figure 6. In this solution, the spring disposed on the outside of the piston is transferred to the inside of the piston, and the spring is pre-tensioned by components such as a hanging rod and a hanging rod ring, thereby reducing the size of the motor, but when the motor is running, the cylinder and the crankshaft are in contact with each other. The friction pair is still a sliding friction pair and is not suitable for medium speed conditions.

Figure 7 is a schematic view of a swing-type high-torque radial piston hydraulic motor produced by Sai Company of Italy, including crankshaft 1, roller 2, bearing sleeve 3, swing cylinder 4, piston 5, retaining ring 6, butterfly The spring 7, the front case 8, the rear case 9, the oil distribution mechanism 10, and the like. The pendulum cylinder 4 is supported by the two

trunnions

401, 402 in the holes of the front casing 8 and the rear casing 9. In operation, the pendulum cylinder 4 swings around the

trunnions

401, 402, and the piston 5 and the pendulum cylinder 4 only perform relative telescopic movement. Therefore, the lateral pressure of the piston 5 on the swing cylinder 4 is eliminated, the friction is reduced, the elliptical wear phenomenon is eliminated, and the mechanical efficiency is improved. The roller bearing structure is adopted between the piston 5 and the crankshaft 1. The sliding friction of the above-mentioned link type and sleeve telescopic pendulum type motor is rolling friction, which greatly reduces friction and heat generation. A butterfly spring 7 is disposed at each end of the bearing sleeve 3, and the butterfly spring 7 applies an elastic force to the retaining ring 6, and fastens the retaining ring 6 to the groove of the piston 5 to prevent the piston 5 from being disengaged from the bearing sleeve 3. The piston 5 is in spherical contact with the bearing sleeve 3, improving the alignment and stability. The motor of the structure has a good application effect in the medium speed field, but still has the following disadvantages:

1. The pendulum cylinder is oscillated around the trunnion supported in the front and rear casings, and the swing center is inside the casing, and the swing radius is small. According to Professor Chen Zhuoru's monograph "Theoretical Design and Calculation of Low-Speed High-Torque Hydraulic Motor", the swing radius is more Small, the greater the motor torque and speed ripple.

2. The trunnion is a cantilever beam structure with bending stress and poor stress characteristics.

3. For the contact stress of the less-cylinder trunnion, the diameter of the trunnion is larger and the weight is larger, which increases the inertia of the pendulum cylinder. The higher the rotational speed, the greater the negative influence.

4. A damping hole is arranged inside the piston, the piston is not completely hollow thin wall structure, and the weight is large, and the disadvantages thereof are the above disadvantages 3.

5. Two cantilever trunnions are arranged on the cylindrical pendulum cylinder. The coaxiality, smoothness and surface hardness of the two trunnions have high requirements, so the processing technology is not good.

6. The spring that provides the spring force to the retaining ring is a butterfly spring. Although it is more compact than the coil spring, there is still room for improvement, and the motor can be made more compact.

U.S. Patent No. 8,206,130 B2 discloses a radial piston hydraulic motor having a high rotational speed capability, the overall structure and working principle of which is similar to that of the above-described Sai cylinder type high torque radial piston hydraulic motor, which is opened on the trunnion. A number of oil grooves for forced lubrication of the trunnion and a lubrication groove on the oil distribution plate, the two measures improved The friction pair lubrication characteristics. However, as shown in the above structure of Fig. 7, the inherent disadvantages of the trunnion structure are not changed, and the oil distribution mechanism does not have an automatic compensation capability.

Summary of the invention

The technical problem to be solved by the present invention is to provide a medium speed high torque radial piston hydraulic motor for the defects of the prior art.

The technical solution of the present invention is realized as follows: a medium-speed high-torque radial piston hydraulic motor, comprising a casing, a crankshaft for outputting external speed and torque, a roller and an inner sleeve of the eccentric shaft section of the crankshaft. In the inner bore of the bearing sleeve, the radial star is uniformly fastened to the cylinder head of the casing, the telescopic sleeve which is radially distributed along the bearing seat and the upper and lower ends respectively abut against the outer spherical surface of the cylinder head and the outer spherical surface of the bearing sleeve The lower end of the telescopic sleeve is always adhered to the spherical retaining ring of the bearing sleeve, the upper end of the telescopic sleeve is always adhered to the hanging rod of the outer spherical surface of the cylinder head, and the transmission ends are respectively connected with the crankshaft and the oil distribution mechanism. axis. The telescopic sleeve comprises a cylinder and a piston, the cylinder and the piston are coaxially engaged, and the axis z always passes through the spherical center O ₁ of the spherical surface outside the cylinder head and the spherical center O ₂ outside the bearing sleeve, when working, cylinder and piston telescoping movement along the z-axis and about the spherical center of the spherical head of the pivot O _1. The crankshaft, the roller and the bearing sleeve form a rolling bearing structure. The utility model further comprises a retaining ring, a retaining ring pressing plate, an elastic rubber ring disposed between the retaining ring and the retaining ring pressing plate, and an elastic retaining ring which is in close contact with the retaining ring pressing plate and is sleeved in the groove of the bearing sleeve, the elastic block The circle fits the spherical surface of the cylinder to the outer surface of the bearing sleeve; and further includes a tray, a self-locking nut, a hanging rod, a hanging rod ring, a butterfly spring, a spring seat, a circlip, the tray, a self-locking nut, and a hanging a rod, a hanging rod ring, a butterfly spring, a spring seat, a circlip ring, the inner spherical surface of the piston and the outer spherical surface of the cylinder head; and an oil distribution mechanism including an oil distribution plate, an oil distribution plate and a floating ring , the butterfly spring, the back cover, the drive shaft hinged at one end to the crankshaft passes through the housing and the other end of the oil distribution plate is hinged with the oil distribution plate. When working, the crankshaft, the drive shaft and the oil distribution plate are synchronously rotated around the axis x forward or reverse Rotating, the butterfly spring with one end and the back cover abutting the other end and the floating ring directly presses the floating ring directly on the oil distribution plate, thereby indirectly pressing the oil distribution plate on the oil distribution plate to perform initial sealing and wear. Compensation function, that is, between the floating ring and the oil distribution plate or the oil distribution plate After the wear between the oil distribution plates, under the elastic force of the butterfly spring, the floating ring and the oil distribution plate, and between the oil distribution plate and the oil distribution plate remain tight. The left and right ends of the bearing sleeve respectively abut against the step surface of the casing and the left end surface of the front cover, that is, the degree of freedom of the bearing sleeve along the axis y is constrained by the step surface and the left end surface, but the bearing sleeve can be Rotating freely around the axis x with the crankshaft.

Further, the cylinder is provided with a groove near the outer diameter of one end of the inner spherical surface, and the diameter A of the groove is slightly smaller than the inner diameter B of the cylinder.

Further, the ratio of the diameter A of the groove to the inner diameter B of the cylinder is approximately equal to 0.8 to 0.85, and the ratio of the size C of the cylinder of the cylinder to the diameter A of the groove is not less than 0.5.

Further, the ratio of the spherical surface dimension C of the cylinder to the diameter A of the groove is 0.7 to 0.8.

Further, the piston is configured as a hollow thin-walled cylindrical structure.

Further, an annular convex step around the axis y is disposed at the left end of the eccentric shaft section of the crankshaft.

Further, the eccentric shaft section of the crankshaft is provided with 2-4 passage relief grooves.

Further, the inner hole of the bearing sleeve is arranged as a light hole without a convex step.

Further, the inner hole of the bearing sleeve is provided with two unloading grooves.

Further, an elastic rubber ring and a groove for placing the elastic rubber ring are disposed between the retaining ring and the retaining ring pressing plate, and the groove may be disposed on the retaining ring or on the retaining ring pressing plate.

Further, the elastic rubber ring disposed between the retaining ring and the retaining ring pressing plate is made of nitrile rubber, and the elastic rubber ring may have a circular, square, star shape or other shape.

Further, the retaining ring is provided with an inner hole, and the retaining ring pressing plate is provided with a boss. The inner hole of the retaining ring is engaged with the boss of the retaining ring pressing plate, and the matching axis is the axis y.

Further, a periphery of the lower end of the cylinder, that is, a periphery of the end opposite to the spherical seat, is provided with a groove, and the retaining ring is fastened to the groove on the outer periphery of the lower end of the cylinder, and is disposed between the retaining ring and the retaining ring pressing plate through the retaining ring. The elastic rubber ring holds the ring pressure plate, and the elastic retaining ring which is tightly attached to the retaining ring pressure plate and is sleeved in the groove of the bearing sleeve adheres the inner spherical surface of the oil cylinder to the outer spherical surface of the bearing sleeve.

Further, the inner hole of the piston is provided with an annular step, and the self-locking nut, the hanging rod, the hanging rod ring, the butterfly spring, the spring seat and the circlip ring which are matched with the thread of the hanging rod through the tray which abuts the annular step The spherical surface of the piston is in close contact with the outer spherical surface of the cylinder head.

Further, the hanging rod and the hanging rod ring are respectively provided with an outer spherical surface and an inner spherical surface, and the two spherical surfaces are opposite to each other for relative sliding.

Further, the hanging rod is provided with 2-4 oil passage holes, and the size and the number of the holes are determined according to the displacement of the motor.

Further, the spherical center O ₁ of the spherical surface outside the cylinder head is disposed outside the cylinder head entity.

Further, the spherical centers of the four parts of the cylinder head, the hanging rod, the hanging rod ring and the piston are concentric.

Further, the oil distribution plate and the oil distribution plate are provided with concentric three-ring sealing tapes on the plane, which are an outer ring sealing tape, a middle ring sealing tape and an inner ring sealing tape, and the outer ring sealing tape is externally Two rows of lubricating oil holes are arranged in the inner stagger, and the number of lubricating oil holes in each row is two or more, and the outer envelope radius of the inner lubricating oil hole is larger than the inner envelope of the outer ring lubricating oil hole The radius of the circle is large, that is, R ₁ &gt _; R ₂ .

Further, the middle ring seal belt is provided with two rows of lubricating oil holes in the outer and outer portions, and the number of the lubricating oil holes in each row is two or more, and the outer circle radius of the inner lubricating oil holes is larger than The radius of the inner envelope circle of the outer ring lubricating oil hole is large, that is, R ₃ > R ₄ .

Further, the inner ring sealing strip is provided with two rows of lubricating oil holes in the outer and outer portions, and the number of the lubricating oil holes in each row is two or more, and the outer circle radius ratio of the inner lubricating oil holes is The radius of the inner envelope circle of the outer ring lubricating oil hole is large, That is, R5>R6.

Compared with the prior art, the present invention has the following advantages and benefits:

1. The invention adopts a telescopic sleeve structure, and the cylinder pistons of the telescopic sleeve are coaxially matched, and the cylinders and pistons of the relatively telescopic movement always coincide with each other, thereby eliminating the relative motion of the connecting rod motor due to the piston and the connecting rod. The axial force has an angle of intersection and a phenomenon of lateral wear and elliptical wear.

2. The hydraulic oil column surrounded by the bearing seat, the oil cylinder, the piston and the cylinder head directly pushes the bearing seat and the crankshaft to rotate, which improves the machine compared with the prior art connecting rod type and the swinging type motor of the Italian Sai company. Efficiency and reliability.

3. The oil cylinder and the piston are thin-walled cylinder structures. Compared with the prior art, the quality is lighter and the motion inertia is smaller, so it is more suitable for medium and high speed working conditions, and at the same time, the processing technology is simpler.

4. Between the cylinder and the bearing seat, the spherical contact between the piston and the cylinder head is better than the cylindrical surface of the connecting rod structure, and the neutrality and stability are better. Compared with the trunnion structure, the force characteristics better.

5. The roller bearing structure between the cylinder and the crankshaft is changed. The sliding friction of the sleeve telescopic pendulum cylinder motor of the Italian Calzoni Company and Foshan Shunde Zhongyi Co., Ltd. is the rolling friction, which greatly reduces the friction and heat generation, but specifically The implementation details are different from the prior art solutions of the Italian Sai company and the crankshaft linkage.

6. The elastic rubber ring is used instead of the butterfly spring to pre-tighten the retaining ring. Compared with the prior art, the axial dimension of the motor is reduced, the motor is more compact, and the rubber ring has the damping effect of absorbing energy and can absorb Positive effects of vibration and noise.

7. The swing center of the telescopic sleeve is disposed outside the cylinder head body to increase the swing radius of the telescopic sleeve, which reduces the motor speed and torque ripple compared with the prior art.

8. There is no relative positional constraint between the crankshaft and the bearing housing in the axial direction. The axial and radial degrees of freedom of the crankshaft are constrained by the two bearings disposed on the housing and the front cover. The axial freedom of the bearing housing is defined by the housing boss. And the left end of the front cover is restrained, so that the convex step of the restraining roller and the bearing seat on the eccentric shaft section of the crankshaft can be removed, and a convex step of the eccentric shaft section of the crankshaft is only temporarily positioned during assembly and disassembly, and can not be functional during operation. The function, dimensional accuracy and surface finish are not required, so the crankshaft is easy to process.

9. The oil distribution plate is provided with a forced oil hole and a compensation spring, which has better lubrication performance and higher reliability.

DRAWINGS

The invention will be further described in detail below with reference to the accompanying drawings.

1 is a schematic view showing the structure of a crankshaft link type low speed high torque radial piston hydraulic motor of the prior art.

Fig. 2 is a cross-sectional view taken along line A-A of Fig. 1;

3 is a schematic view showing the elliptical wear of a crankshaft link type low speed high torque radial piston hydraulic motor.

4 is a schematic structural view of a prior art telescopic swing cylinder type low speed high torque radial piston hydraulic motor.

Figure 5 is a schematic view showing the structure of a solution disclosed in U.S. Patent No. 5,967,018.

Fig. 6 is a schematic view showing the structure of a solution disclosed in U.S. Patent No. 7,267,402 B2.

Fig. 7 is a structural schematic view of a tilting cylinder type high torque hydraulic motor produced by Sai Company of Italy.

Figure 8 is a structural schematic view of a medium speed high torque radial piston hydraulic motor of the present invention.

Figure 9 is a schematic view showing the structure of the cylinder of the present invention.

Figure 10 is a schematic view showing the structure of the hanging rod of the present invention.

Figure 11 is a schematic view showing the structure of the crankshaft of the present invention.

Figure 12 is a partial enlarged view I of Figure 8.

Figure 13 is a schematic view showing the structure of the oil distribution plate of the present invention.

Fig. 14 is a cross-sectional view taken along line A-A of Fig. 13;

Figure 15 is a partial enlarged view II of Figure 13 .

Figure 16 is a schematic view showing the arrangement of the lubricating oil holes of the oil distribution plate of the present invention.

In the picture:

1. Housing 101. Housing step surface

2. Crankshaft 201. Eccentric shaft section 202. Annular convex step 203. Step end surface 204. Unloading groove

3. Roller

4. Bearing sleeve 401. Inner hole 402. Bearing sleeve outer spherical surface

5. Cylinder head 501. Cylinder head outer spherical surface

6. Telescopic sleeve

7. Keep the ring

8. Hanging rod 801. Thread 802. Outer spherical surface 803. Oil hole

9. Oil distribution mechanism

10. Drive shaft

11. Cylinder 1101. Spherical inside the cylinder 1102. Groove

12. Piston 1201. Spherical inner surface of the piston 1202. Annular step

13. Maintain the ring pressure plate

14. Elastic rubber ring

15. The circlip in the groove of the bearing sleeve

16. Pallet

17. Self-locking nut

18. Hanging rod ring 1801. Inner spherical surface

19. Butterfly spring

20. Spring seat

21 circlip

22. Oil distribution board

23. Oil distribution plate 2301. Outer ring sealing tape 2302. Central ring sealing tape 2303. Inner ring sealing tape

2304. Lubricating oil hole 2305. Lubricating oil hole 2306. Lubricating oil hole 2307. Lubricating oil hole 2308. Lubricating oil hole 2308 Lubricating oil hole 2310. Diversion groove 2311. Oil distribution plate peripheral 2312. Lubricating oil hole notch

24. Floating ring

25 oil distribution mechanism butterfly spring

26. Back cover

27. Front cover 2701. Front cover left end

O ₁ . Cylinder head outer spherical core O ₂ . Bearing sleeve outer spherical core

x. Axis y. Axis z. Axis e. Offset.

detailed description

In order to make the technical features, objects and advantages of the present invention more apparent, the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

As shown in FIG. 8, a medium-speed high-torque radial piston hydraulic motor includes a casing 1, a crankshaft 2 for outputting rotational speed and torque, a bearing 29 disposed in the inner hole of the casing 1 and the front cover 27, and an outer casing. The roller 3 and the roller 3 of the eccentric shaft section 201 of the crankshaft 2 are sleeved in the inner hole 401 of the bearing sleeve 4, and the radial star is uniformly fixed to the cylinder head 5 of the casing 1 and radially distributed along the bearing housing 4. And the upper and lower ends respectively a telescopic sleeve 6 which abuts the outer spherical surface 501 of the cylinder head 5 and the outer spherical surface 402 of the bearing sleeve 4, and the lower end of the telescopic sleeve 6 is always in close contact with the retaining ring 7 of the spherical surface 402 outside the bearing sleeve 4, The upper end of the telescopic sleeve 6 is always in close contact with the hanging rod 8 of the outer spherical surface 501 of the cylinder head, and the transmission shaft 10 respectively connected to the left end of the crankshaft 2 and the oil distribution mechanism 9 at both ends.

The telescopic sleeve 6 comprises two parts, a cylinder 11 and a piston 12, the cylinder 11 and the piston 12 are coaxially engaged, the axis is z, and the axis z always passes through the spherical center O _{1 of the} spherical surface 501 outside the cylinder head 5 and the spherical surface of the bearing sleeve 4 The center of the ball O _{2 is} 402. During operation, the cylinder 11 and the piston 12 are telescopically moved along the z-axis and oscillated about the center O ₁ of the spherical surface 501 of the cylinder head 5.

The crankshaft 2, the roller 3 and the bearing sleeve 4 constitute a rolling bearing structure. During operation, the sliding between the oil cylinder 11 and the bearing sleeve 4 is converted into a relative rolling between the bearing sleeve 4 and the crankshaft 2, and the frictional friction is far according to tribology. Far less than the basic principle of sliding friction, the solution greatly improves the friction characteristics of the medium speed high torque radial piston hydraulic motor.

By the retaining ring 7, the retaining ring pressing plate 13, the elastic rubber ring 14 disposed between the retaining ring 7 and the retaining ring pressing plate 13, and the circlip 15 which is in close contact with the retaining ring pressing plate 13 and is ferred in the groove of the bearing sleeve 4 The inner spherical surface 1101 of the oil cylinder 11 is in close contact with the outer spherical surface 402 of the bearing sleeve 4, and the abutting surface serves as a sealing function.

The inner spherical surface 1201 of the piston and the outer spherical surface 501 of the cylinder head are closely adhered by the tray 16, the self-locking nut 17, the hanging rod 8, the hanging rod ring 18, the butterfly spring 19, the spring seat 20, and the elastic retaining ring 21, and the surface is adhered to Sliding seal.

The oil distribution mechanism 9 includes an oil distribution plate 22, an oil distribution plate 23, a floating ring 24, a butterfly spring 25, a rear cover 26, and a transmission shaft 10 hinged at one end to the crankshaft 3 passes through the housing 1 and the other end of the oil distribution plate 22 The oil distribution plate 23 is hinged. When working, the crankshaft 2, the transmission shaft 10, the oil distribution plate 23 synchronously rotate in the forward or reverse direction about the axis x, and the butterfly spring 25 whose one end is opposite to the rear cover 26 and the other end is opposite to the floating ring 24 will The floating ring 24 is directly pressed against the oil distribution plate 23, thereby indirectly pressing the oil distribution plate 23 against the oil distribution plate 22, thereby performing initial sealing and wear compensation, that is, between the floating ring 24 and the oil distribution plate 23 or After the wear between the oil distribution plate 23 and the oil distribution plate 22, under the elastic force of the butterfly spring 25, the floating ring 24 and the oil distribution plate 23, and between the oil distribution plate 23 and the oil distribution plate 22 remain stuck. tight.

The left and right ends of the bearing housing 4 respectively abut against the stepped surface 101 of the housing 1 and the left end surface 2701 of the front cover 27, that is, the degrees of freedom of the bearing housing 4 in the direction of the axis y are the stepped surface 101 and the left end surface 2701 It is constrained, but the bearing block 4 can in turn rotate freely about the axis x together with the crankshaft 2.

During operation, the hydraulic oil is sequentially distributed to the flow path of the casing 1 and the cylinder head 5 through the oil distribution structure 9, and enters a cavity surrounded by the cylinder head 5, the oil cylinder 11, the piston 12, and the spherical seat 4, surrounded by the cavity. The hydraulic oil column generates a thrust to the spherical seat 4, and the thrust acting line always passes through O ₂ . Since O ₂ has an offset e from the axis x of the crankshaft 2, the thrust generates a torque to the crankshaft 2, causing the crankshaft 2 to orbit the axis. x rotation, external output speed and torque, the ball seat 4 revolves around the axis x while revolving around the axis x.

As a more specific technical solution of this embodiment:

As shown in FIG. 9, the cylinder 11 is provided as a hollow thin-walled cylindrical structure, and a groove 1102 is disposed at an outer diameter of the lower end (ie, near the end of the inner spherical surface 1101). To reduce the axial dimension of the motor, the diameter A of the groove 1102 is slightly smaller than the inner diameter B of the cylinder. A/B is approximately equal to 0.8 to 0.85. Considering the mechanical strength of the cylinder 11 and the contact stress of the outer spherical surface 1101 of the cylinder 11 and the outer spherical surface 402 of the bearing housing 4, the size C of the cylinder 11 should not be too small, C/A is not It should be less than 0.5, preferably 0.7 to 0.8. The above-mentioned cylinder 11 is designed to obtain a minimum structural size and reduce the moment of inertia while ensuring the mechanical strength of the material, which is particularly important for increasing the motor speed.

Because the outer spherical surface 802 of the hanging rod 8 is in close contact with the spherical surface 1801 of the hanging rod ring 18, in order to avoid the impact of the hydraulic oil on the hanging rod 8, as shown in FIG. 10, a plurality of oil drain holes 803 are opened in the hanging rod 8, and the oil drain hole 803 is opened. The number and diameter depend on the displacement of the motor.

As shown in Fig. 11, the left end of the eccentric shaft section 201 of the crankshaft 2 is provided with an annular convex step 202 about the axis y for temporary positioning during assembly and disassembly, and does not function as a function during operation. Therefore, the size L precision and the step end surface 203 smoothness are not excessively high, so the crankshaft is easy to process; in order to reduce or eliminate the stress concentration, a plurality of unloading grooves 204 are provided on the eccentric shaft section 201.

As shown in a partially enlarged view of FIG. 12, the retaining ring 7 is fastened to the groove 1102 of the outer diameter of the cylinder 11, and the elastic rubber ring 14 disposed between the retaining ring 7 and the retaining ring pressing plate 13 exerts an elastic force on the retaining ring 7, always The retaining ring 7 is fastened to the groove 1102 of the cylinder 11, so that the inner spherical surface 1101 of the cylinder 11 is always in close contact with the outer spherical surface 402 of the spherical seat 4, and the hydraulic oil facing the hollow inner cavity of the cylinder 11 is sealed. The elastic rubber ring 14 is made of oil-resistant nitrile rubber, and the cross section may be circular, square, star or other shapes. Compared with the prior art butterfly spring design, the elastic rubber ring 14 can be embedded in the groove of the retaining ring pressure plate 13 or the retaining ring 7, which saves installation space and is more compact in size, and the elastic rubber ring also has absorption. The damping of energy can reduce vibration and noise to a certain extent.

Referring to Figures 8, 13, and 14, the oil distribution plate 23 and the oil distribution plate 22 are provided with a concentric outer ring seal band 2301, a middle ring seal band 2302, and an inner ring seal band 2303. The outer ring sealing strip 2301 is internally provided with two rows of lubricating

oil holes

2304 and 2305, and the number of lubricating oil holes per row may be 2, 3, 4... depending on the displacement of the motor and the working condition. The hydraulic oil on the runner 2310 and its periphery 2311 of the oil distribution plate 23 enters each of the lubricating oil holes through the notch 2312 of each of the lubricating oil holes, and the friction pair is forcibly lubricated. The radius of the outer circle of the inner lubricating oil hole 2305 is larger than the radius of the inner enveloping circle of the outer ring lubricating oil hole 2304, that is, R ₁ >R ₂ , and the purpose is to float the ring 22 and the oil distribution plate 23 Lubrication can be obtained on the contact surface of the ring seal band 2301. The method of setting the lubricating oil port on the inner ring sealing strip 2302 and the inner ring sealing strip 2303 and its purpose are the same as the method and purpose of setting the lubricating oil hole on the outer ring sealing strip 2301, and will not be described in detail.

The specific embodiments described above are merely preferred embodiments of the present invention, and equivalent designs made in accordance with the scope of the present invention should be covered by the technology of the present invention.

Claims

A medium-speed high-torque radial piston hydraulic motor comprising a casing (1), a crankshaft (2) for outputting external speed and torque, and a roller (3) sheathed on an eccentric shaft section (201) of the crankshaft (2) The roller (3) is sleeved in the inner hole (401) of the bearing sleeve (4), and the radial star is uniformly fixed to the cylinder head (5) of the casing (1) and along the bearing seat (4). The telescopic sleeve (6) which is distributed to the outer spherical surface (501) of the cylinder head (5) and the outer spherical surface (402) of the bearing sleeve (4), and the lower end of the telescopic sleeve (6) is always tight a retaining ring (7) attached to the spherical surface (402) outside the bearing sleeve (4), and the upper end of the telescopic sleeve (6) is always adhered to the hanging rod (8) of the outer spherical surface (501) of the cylinder head, respectively a drive shaft (10) coupled to the crankshaft (2) and the oil distribution mechanism (9);

The telescopic sleeve (6) comprises a cylinder (11) and a piston (12), the cylinder (11) and the piston (12) are coaxially matched, and the axis (z) is always spherical outside the cylinder head (5) The center of the sphere (O 1 ) of (501) and the center of the sphere (402) outside the bearing sleeve (4) (O 2 ), during operation, the cylinder (11) and the piston (12) telescopically move along the (z) axis and around the cylinder head (5) of the spherical surface (501) of the spherical center (O 1) swing;

The crankshaft (2), the roller (3), and the bearing sleeve (4) constitute a rolling bearing structure;

The utility model further comprises a retaining ring (7), a retaining ring pressing plate (13), an elastic rubber ring (14) disposed between the retaining ring (7) and the retaining ring pressing plate (13), and is closely attached to the retaining ring pressing plate (13). a circlip (15) sleeved in the groove of the bearing sleeve (4), the circlip (15) aligns the spherical surface (1101) of the cylinder (11) with the spherical surface of the bearing sleeve (4) (402 Tightly

The utility model further comprises a tray (16), a self-locking nut (17), a hanging rod (8), a hanging rod ring (18), a butterfly spring (19), a spring seat (20) and a circlip (21), the tray (16), self-locking nut (17), hanging rod (8), hanging rod ring (18), butterfly spring (19), spring seat (20), circlip (21) will be the inner spherical surface of the piston (1201) Close to the outer spherical surface of the cylinder head (501);

Also included is an oil distribution mechanism (9) including an oil distribution plate (22), an oil distribution plate (23), a floating ring (24), a butterfly spring (25), and a back cover (26) The drive shaft (10) hinged at one end to the crankshaft (3) passes through the housing (1) and the other end of the oil distribution plate (22) is hinged to the oil distribution plate (23). When working, the crankshaft (2) and the drive shaft ( 10), the oil distribution plate (23) synchronously rotates in the forward or reverse direction (x), and the butterfly spring (25) which is opposite to the rear cover (26) at one end and the floating ring (24) at the other end will float the ring ( 24) Directly press on the oil distribution plate (23), and indirectly press the oil distribution plate (23) on the oil distribution plate (22) to play the initial sealing and wear compensation, that is, when the floating ring (24) After wear with the oil distribution plate (23) or between the oil distribution plate (23) and the oil distribution plate (22), under the elastic force of the butterfly spring (25), the floating ring (24) and the oil distribution plate ( Between 23), the oil distribution plate (23) and the oil distribution plate (22) remain in close contact;

The left and right ends of the bearing sleeve (4) respectively abut against the gap between the stepped surface (101) of the casing (1) and the left end surface (2701) of the front cover (27), that is, the bearing sleeve (4) along the axis (y) direction The degree of freedom is constrained by the stepped surface (101) and the left end surface (2701), but the bearing sleeve (4) is in turn free to rotate about the shaft (x) together with the crankshaft (2).
The medium speed high torque radial piston hydraulic motor according to claim 1, wherein the oil cylinder (11) is set to medium In the empty thin-walled cylindrical structure, a groove (1102) is disposed on an outer diameter of one end of the cylinder (11) near the inner spherical surface (1101), and the diameter A of the groove (1102) is slightly smaller than the inner diameter B of the cylinder.
The medium speed high torque radial piston hydraulic motor according to claim 2, wherein the ratio of the diameter A of the groove (1102) to the inner diameter B of the cylinder is approximately equal to 0.8 to 0.85, and the cylinder (11) is cut. The ratio of the spherical dimension C to the diameter A of the groove (1102) is not less than 0.5.
The medium speed high torque radial piston hydraulic motor according to claim 3, wherein a ratio of a spherical surface dimension C of said cylinder (11) to a diameter A of said groove (1102) is 0.7 to 0.8.
The medium speed high torque radial piston hydraulic motor according to claim 1, wherein said piston (12) is provided as a hollow thin-walled cylindrical structure.
The medium-speed high-torque radial piston hydraulic motor according to claim 1, characterized in that: the left end of the eccentric shaft section (201) of the crankshaft (2) is provided with an annular convex step (202) around the shaft (y). .
The medium speed high torque radial piston hydraulic motor according to claim 6, wherein the eccentric shaft section (201) of the crankshaft (2) is provided with 2-4 passage relief grooves.
The medium-speed high-torque radial piston hydraulic motor according to claim 1, wherein the inner hole (401) of the bearing sleeve (4) is provided as a light hole without a convex step.
The medium-speed high-torque radial piston hydraulic motor according to claim 8, characterized in that the inner hole (401) of the bearing sleeve (4) is provided with two unloading grooves.
The medium-speed high-torque radial piston hydraulic motor according to claim 1, wherein an elastic rubber ring (14) and an elastic rubber are disposed between the retaining ring (7) and the retaining ring pressing plate (13). The groove of the ring (14) may be disposed on the retaining ring (7) or on the retaining ring pressure plate (13).
The medium-speed high-torque radial piston hydraulic motor according to claim 10, wherein the elastic rubber ring (14) disposed between the retaining ring (7) and the retaining ring pressing plate (13) is made of nitrile rubber. The elastic rubber ring (14) may have a circular, square, star or other cross section.
The medium-speed high-torque radial piston hydraulic motor according to claim 10, wherein the retaining ring (7) is provided with an inner hole, and the retaining ring pressing plate (13) is provided with a boss and a retaining ring (7). The inner hole is engaged with the boss of the retaining ring pressing plate (13), and the matching axis is the axis (y).
The medium-speed high-torque radial piston hydraulic motor according to claim 1, wherein a periphery of a lower end of the cylinder (11), that is, a periphery of an end opposite to the spherical seat (4), is provided with a groove, a retaining ring. (7) Fastened on the groove on the outer periphery of the lower end of the cylinder (11), through the retaining ring (7), the elastic rubber ring (14) disposed between the retaining ring (7) and the retaining ring pressing plate (13), the retaining ring The pressure plate (13), the elastic ring (15) which is in close contact with the retaining ring pressure plate (13) and is sleeved in the groove of the bearing sleeve (4), the spherical surface (1101) and the bearing sleeve (4) of the oil cylinder (11) The outer spherical surface (402) is in close contact.
The medium-speed high-torque radial piston hydraulic motor according to claim 1, wherein the inner hole of the piston (12) is provided with an annular step (1202) through a tray (16) that abuts the annular step (1202). ), self-locking nut (17), hanging rod (8), hanging rod ring (18), butterfly spring (19), spring seat (20), elastic block that cooperate with the thread (801) of the hanging rod (8) The ring (21) abuts the inner spherical surface (1201) of the piston with the outer spherical surface (501) of the cylinder head.
The medium-speed high-torque hydraulic motor according to claim 14, wherein the hanging rod (8) and the hanging rod ring (18) are respectively provided with an outer spherical surface (802) and an inner spherical surface (1801), and two spherical surfaces ( 802) and (1801) can be used to make relative sliding.
The medium-speed high-torque radial piston hydraulic motor according to claim 15, wherein the hanging rod (8) is provided with 2-4 oil passage holes (803), and the size and the number of the holes are determined according to the displacement of the motor. Size depends.
The medium-speed high-torque radial piston hydraulic motor according to claim 1, wherein a spherical core (O 1 ) of the spherical surface (501) outside the cylinder head (5) is disposed on the cylinder head (5) entity The outside.
The medium-speed high-torque radial piston hydraulic motor according to claim 1, characterized in that: the cylinder head (5), the hanging rod (8), the hanging rod ring (18), and the piston (12) are four parts. The spherical centers of the spherical surfaces (501), (802), (1801), and (1201) are concentric.
A medium-speed, high-torque radial piston hydraulic motor according to claim 1, wherein said oil distribution plate (23) and said oil distribution plate (22) are provided with a concentric three-ring sealing tape on a plane , respectively, an outer ring sealing band (2301), a middle ring sealing band (2302), an inner ring sealing band (2303), and the outer ring sealing band (2301) is internally provided with two rows of lubricating oil holes (2304) and (2305), the number of lubricating oil holes per row is 2 or more, and the outer circle radius of the inner lubricating oil hole (2305) is larger than the inner envelope circle of the outer ring lubricating oil hole (2304) The radius is large, ie R 1 >R 2 .
The medium-speed high-torque radial piston hydraulic motor according to claim 19, wherein said central seal band (2302) is internally provided with two rows of lubricating oil holes (2306) and (2307), each of which is interleaved. The number of the lubricating oil holes is two or more, and the outer circle radius of the inner lubricating oil hole (2307) is larger than the inner enveloping circle radius of the outer ring lubricating oil hole (2306), that is, R 3 >R 4 .
The medium-speed high-torque radial piston hydraulic motor according to claim 19, wherein said inner ring seal band (2303) is internally provided with two rows of lubricating oil holes (2308) and (2309). The number of lubricating oil holes per row is two or more, and the outer circle radius of the inner lubricating oil hole (2309) is larger than the inner envelope circle radius of the outer ring lubricating oil hole (2308), that is, R5>R6.