A hydrostatic transmission

Abstract

The utility model provides a kind of hydrostatic transmission device. Including: machine case, swash plate and variable mechanism, variable mechanism can be used to adjust the angle of the swash plate, variable mechanism is between swash plate and operating mechanism;Variable mechanism includes piston element, spring seat, mandrel, limiting piece, first elastic member and second elastic member, the recess structure is equipped in the end of piston element close to locking nut, spring seat is located in recess structure, spring seat can move along mandrel axial direction, limiting piece is fixed in the inner wall of recess structure, first elastic member makes piston element move to the side away from locking nut, the both ends of second elastic member make piston element move to the side close to locking nut.The utility model increases second elastic member in variable mechanism, when hydrostatic transmission device changes from working gear to neutral state, guarantee the mid-position of variable mechanism, eliminate servo valve hysteresis, reduce gear shifting delay time, improve driving experience.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic technology, and in particular to a hydrostatic transmission device. Background Technology

[0002] In existing technologies, hydrostatic transmission devices (such as swashplate axial piston devices) use hydraulic oil to act on a variable piston, allowing the variable piston to move axially within a variable cylinder, which in turn drives the swashplate to oscillate, achieving the continuously variable transmission function of the hydrostatic transmission. However, when the hydrostatic transmission shifts from a working gear to neutral, the piston rod of the variable mechanism exhibits shift lag and cannot quickly return to the neutral position, resulting in a poor overall driving experience. Therefore, it is necessary to provide a hydrostatic transmission device to overcome the aforementioned shortcomings. Utility Model Content

[0003] The purpose of this invention is to provide a hydrostatic transmission device.

[0004] According to this utility model, a hydrostatic transmission device is provided, comprising: a housing, wherein a variable cylinder and a rotary cylinder are formed within the housing; a swashplate, wherein the swashplate is disposed within the rotary cylinder, and the displacement of the rotary cylinder is adjusted by rotating the swashplate; a variable mechanism, wherein the variable mechanism can be used to adjust the angle of the swashplate, and the variable mechanism is located between the swashplate and an operating mechanism; wherein the variable mechanism comprises: a locking nut, wherein the locking nut is disposed at the end of the variable cylinder; a piston element, wherein the piston element is slidably disposed within the variable cylinder, and a groove structure is provided at the end of the piston element near the locking nut; and a spring seat, wherein the spring seat is disposed within the groove structure, and the spring seat comprises a base portion fixed to the piston element, a sleeve portion disposed on the base portion and extending towards the locking nut end, a cover portion disposed at the other end of the sleeve portion, and a cover portion disposed at the other end of the sleeve portion. The body has an opening; a spindle, one end of which is fixed to the locking nut, and the other end of which extends into the cavity inside the sleeve through the opening, and the spring seat can move axially along the spindle; a limiting member, which is fixed to the inner wall of the groove structure; a first elastic member, one end of which abuts against the locking nut, and the other end of which abuts against the cover, causing the piston element to move away from / closer to the locking nut; a second elastic member, one end of which abuts against the limiting member, and the other end of which abuts against the base, causing the piston element to move closer to / away from the locking nut; and a second actuating member, which is disposed on the piston element, and drives the swashplate to deflect through the piston element and the second actuating member.

[0005] Preferably, the limiting member includes an elastic retaining ring that is engaged inside the groove structure and a spring retaining ring that abuts against the elastic retaining ring.

[0006] Preferably, the second elastic element includes a plurality of small springs disposed between the spring retainer and the base portion, the small springs being evenly distributed along the outer periphery of the sleeve portion.

[0007] Preferably, the piston element has closed ends, and the piston element and the inner wall of the variable cylinder form a first hydraulic chamber and a second hydraulic chamber. The piston element also has a valve chamber inside, and a first oil inlet passage connecting the valve chamber and the first hydraulic chamber, and a second oil inlet passage connecting the valve chamber and the second hydraulic chamber are also provided inside the piston element. The valve chamber also has a valve core, and the opening and closing of the first oil inlet passage and the second oil inlet passage are controlled by adjusting the relative position of the valve core and the valve chamber.

[0008] Preferably, the variable mechanism further includes an operating mechanism, which is provided with a first actuating element, which drives the valve core to move along the valve cavity through the piston element.

[0009] Preferably, the operating mechanism is an electro-hydraulic servo valve or a mechanical joystick.

[0010] Preferably, the piston element is provided with an oil supply passage, and the inner surface of the piston element is provided with a first annular oil passage connected to the oil supply passage, a second annular oil passage connected to the first oil inlet passage, and a third annular oil passage connected to the second oil inlet passage. The second annular oil passage and the third annular oil passage are distributed on both sides of the first annular oil passage, and the valve core is provided with a fourth annular oil passage in the circumferential direction.

[0011] In the first position, the fourth annular oil passage connects the first annular oil passage and the second annular oil passage; in the second position, the fourth annular oil passage connects the first annular oil passage and the third annular oil passage.

[0012] Preferably, the valve core is further provided with a main return oil passage in the middle, and the valve core is provided with a first return oil passage and a second return oil passage in the radial direction, and the first return oil passage and the second return oil passage are both connected to the main return oil passage.

[0013] In the first position, the second annular oil passage and the first return oil passage are connected. In the second position, the third annular oil passage and the second return oil passage are connected. In the third position, the second annular oil passage and the first return oil passage, as well as the third annular oil passage and the second return oil passage, are all disconnected.

[0014] Preferably, a reset elastic element is further provided between the valve core and the inner wall of the valve cavity.

[0015] Compared with the prior art, the hydrostatic transmission device provided by this utility model has the following beneficial effects: By adding a small return spring to the variable mechanism, this utility model ensures the neutral position of the variable mechanism when the hydrostatic transmission device changes from the working gear to the neutral state, eliminates servo valve lag, reduces the shifting delay time of the hydrostatic transmission device, and provides better operation and follow-up for the operator, thus improving the driving experience. Attached Figure Description

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0017] Figure 1 This is a schematic diagram of the hydrostatic transmission device in this utility model;

[0018] Figure 2 This is a cross-sectional schematic diagram of the hydrostatic transmission device in this utility model;

[0019] Figure 3 This is a schematic diagram of the AA section of the variable mechanism in this utility model;

[0020] Figure 4 The groove structure in this utility model (i.e. Figure 3 A cross-sectional schematic diagram of region A in the middle;

[0021] Figure 5 This is a schematic diagram of the BB cross-section of the variable mechanism in this utility model;

[0022] Figure 6 This is a schematic diagram of the piston element in this utility model;

[0023] Figure 7 This is a schematic diagram of the CC cross-section of the piston element in this utility model;

[0024] Figure 8 This is a schematic diagram of the DD cross-section of the piston element in this utility model;

[0025] Figure 9 This is a schematic diagram of the EE cross-section of the piston element in this utility model.

[0026] Explanation of reference numerals in the attached drawings: 100, variable chamber; 200, hydraulic chamber; 300, variable mechanism; 1, housing; 11, locking nut; 12, first hydraulic chamber; 13, second hydraulic chamber; 2, piston element; 21, groove structure; 22, valve chamber; 23, valve core; 24, reset elastic element; 25, first oil inlet passage; 26, second oil inlet passage; 27, oil supply passage; 28a, first annular oil passage; 28b, second annular oil passage; 28c, third annular oil passage ; 29. ​​Hole structure; 231. Fourth annular oil passage; 232. Main return oil passage; 233. First return oil passage; 234. Second return oil passage; 3. Spring seat; 31. Base part; 32. Sleeve part; 33. Cover part; 34. Opening part; 4. Mandrel; 5. Limiting component; 51. Elastic retaining ring; 52. Spring retaining ring; 6. First elastic component; 7. Second elastic component; 71. Small spring; 8. Operating mechanism; 81. First actuating component; 9. Second actuating component. Detailed Implementation

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] To keep the drawings concise, only the parts relevant to this invention are shown schematically in each figure, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some figures, only one of the components with the same structure or function is schematically depicted, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0029] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0030] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0031] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the specific implementation methods of this utility model will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of this utility model. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0033] See appendix Figure 1 , 2 This utility model discloses a hydrostatic transmission device, which includes a housing 1, in which a variable cylinder 100 and a rotary cylinder 200 are formed. A swashplate is provided in the rotary cylinder 200, and a variable mechanism 300 is provided in the variable cylinder 100. The output flow of the hydraulic mechanism is adjusted by controlling the angle of the swashplate through the variable mechanism 300, thereby realizing the stepless speed change function of the hydrostatic transmission device.

[0034] See appendix Figures 3 to 9 The variable mechanism 300 includes a housing 1, a piston element 2, a spring seat 3, a spindle 4, a limiting member 5, a first elastic member 6, and a second elastic member 7. The housing 1 forms a variable cylinder 100 above the rotating cavity 200 to accommodate the variable mechanism 300.

[0035] See appendix Figure 3 One end of the variable cylinder 100 is provided with a locking nut 11. The piston element 2 is slidably disposed in the variable cylinder 100. Both ends of the piston element 2 are closed structures. The piston element 2 and the inner sidewall of the variable cylinder 100 form a first hydraulic chamber 12 and a second hydraulic chamber 13. The end of the piston element 2 near the locking nut 11 is provided with a groove structure 21. The spring seat 3 is disposed in the groove structure 21. The limiting member 5 is fixed to the inner wall of the groove structure 21. The spring seat 3 is disposed on the side of the groove structure 21 away from the locking nut 11. The limiting member 5 is disposed on the side of the groove structure 21 near the locking nut 11. The limiting member 5 and the spring seat 3 are separated by a predetermined distance.

[0036] See appendix Figure 4The spring seat 3 includes a base portion 31 fixed to the piston element 2, a sleeve portion 32 disposed on the base portion 31 and extending outward from the piston element 2, a cover portion 33 disposed at the other end of the sleeve portion 32, and an opening portion 34 disposed at the cover portion 33. One end of the spindle 4 is fixed to the locking nut 11, and the other end of the spindle 4 extends into the cavity inside the sleeve portion 32 along the opening portion 34. The spring seat 3 is axially movable along the spindle 4.

[0037] See appendix Figure 4 The limiting member 5 includes an elastic retaining ring 51 that is engaged inside the groove structure 21 and a spring retaining ring 52 that abuts against the elastic retaining ring 51. The limiting member 5 secures the second elastic member 7. Since the gap between the sleeve and the groove structure is limited, and the diameter and pitch of the spring wire in traditional large springs are too large to meet engineering requirements, the second elastic member 7 includes a plurality of small springs 71 disposed between the spring retaining ring 52 and the base portion 31. The small springs 71 are evenly distributed along the outer periphery of the sleeve portion 32.

[0038] See appendix Figure 4 The first elastic member 6 has its two ends abutting against the locking nut 11 and the cover portion 33 respectively, causing the piston element 2 to move away from the locking nut 11; the second elastic member 7 has its two ends abutting against the limiting member 5 and the bottom of the base portion 31 respectively, causing the piston element 2 to move closer to the locking nut 11.

[0039] Of course, those skilled in the art can also adjust the force storage direction of the first elastic element 6 and the second elastic element 7. That is, the first elastic element 6 causes the piston element 2 to move closer to the locking nut 11, and the second elastic element 7 causes the piston element 2 to move away from the locking nut 11.

[0040] See appendix Figure 3 When piston element 2 moves to the left, piston element 2 pushes spring seat 3 to move to the left, compressing the first elastic element 6. When piston element 2 moves to the right, piston element 2 pushes spring retainer ring 52 to move to the right. Spring seat 3 is limited by spindle 4, compressing the second elastic element 7. When in neutral, the spring force of the first elastic element 6 and the second elastic element 7 drives piston element 2 to quickly return to the center position.

[0041] See appendix Figures 5 to 9The piston element 2 is further provided with a valve chamber 22. The piston element 2 is also provided with a first oil inlet passage 25 connecting the valve chamber 22 and the first hydraulic chamber 12, and a second oil inlet passage 26 connecting the valve chamber 22 and the second hydraulic chamber 13. The valve chamber 22 is also provided with a valve core 23. The opening and closing of the first oil inlet passage 25 and the second oil inlet passage 26 are controlled by adjusting the relative position of the valve core 23 and the valve chamber 22.

[0042] See appendix Figure 7 The piston element 2 is provided with an oil supply passage 27. On the inner surface of the piston element 2, there are a first annular oil passage 28a connected to the oil supply passage 27, a second annular oil passage 28b connected to the first oil inlet passage 25, and a third annular oil passage 28c connected to the second oil inlet passage 26. The second annular oil passage 28b and the third annular oil passage 28c are distributed on both sides of the first annular oil passage 28a. The valve core 23 is provided with a fourth annular oil passage 231 circumferentially. The valve core 23 also has a main return oil passage 232 in the middle. The valve core 23 has a first return oil passage 233 and a second return oil passage 234 radially arranged, both of which are connected to the main return oil passage 232.

[0043] See appendix Figure 3 The variable mechanism 300 also includes an operating mechanism 8, which is an electro-hydraulic servo valve, a servo motor, or a mechanical joystick. The operating mechanism 8 is provided with a first actuating element 81, which drives the valve core 23 to move along the valve cavity 22 through the hole structure at the top of the piston element 2 via the first actuating element 81. A reset elastic element 24 is also provided between the valve core 23 and the inner wall of the valve cavity 22 to realize the reset of the valve core 23.

[0044] See appendix Figure 8 The operating mechanism 8 controls the valve core 23 to move to the first position through the first actuating member 81. The fourth annular oil passage 231 connects the first annular oil passage 28a and the second annular oil passage 28b. Hydraulic oil enters the first hydraulic chamber 12. The piston element 2 moves to the left. The piston element 2 is provided with a second actuating member 9. The second actuating member 9 drives the swashplate to deflect to the left. The second annular oil passage 28b and the first return oil passage 233 are connected. The hydraulic oil in the second hydraulic chamber 13 flows back to the rotating chamber 200 in sequence through the second inlet oil passage 26, the third annular oil passage 28c, the valve chamber 22, and the hole structure 29.

[0045] See appendix Figure 9The operating mechanism 8 controls the valve core 23 to move to the second position via the first actuating element 81. The fourth annular oil passage 231 connects the first annular oil passage 28a and the third annular oil passage 28c. Hydraulic oil enters the second hydraulic chamber 13. The piston element 2 moves to the right and drives the swashplate to deflect to the right via the second actuating element 9. The third annular oil passage 28c connects to the second return oil passage 234. The hydraulic oil in the first hydraulic chamber 12 flows back to the cavity of the rotating chamber 200 in sequence through the first inlet oil passage 25, the second annular oil passage 28b, the valve chamber 22, and the hole structure 29.

[0046] The operating mechanism 8 controls the valve core 23 to move to the third position via the first actuating member 81. The fourth annular oil passage 231 is disconnected from the first annular oil passage 28a and the second annular oil passage 28b. The second annular oil passage 28b is also disconnected from the first return oil passage 233, the third annular oil passage 28c and the second return oil passage 234. The spring force of the first elastic member 6 and the second elastic member 7 drives the piston element 2 to quickly return to the neutral position.

[0047] It will be apparent to those skilled in the art that various modifications and variations can be made to the exemplary embodiments of the present invention without departing from the spirit and scope of the present invention. Therefore, it is intended that the present invention cover modifications and variations falling within the scope of the appended claims and their equivalents.

Claims

1. A hydrostatic transmission device, characterized in that, include: A housing, within which a variable cylinder and a rotary cylinder are formed; A swashplate is disposed inside the rotary cylinder, and the displacement of the rotary cylinder is adjusted by rotating the swashplate. A variable mechanism is provided, which can be used to adjust the angle of the swashplate, and the variable mechanism is located between the swashplate and the control mechanism; The variable mechanism includes: A locking nut, which is located at the end of the variable cylinder; A piston element is slidably disposed within the variable cylinder, and a groove structure is provided at the end of the piston element near the locking nut; A spring seat is disposed within the groove structure. The spring seat includes a base portion fixed to the piston element, a sleeve portion disposed on the base portion and extending toward one end of the locking nut, a cover portion disposed at the other end of the sleeve portion, and an opening portion disposed in the cover portion. A mandrel, one end of which is fixed to the locking nut, and the other end of which extends into the cavity inside the sleeve portion along the opening, and the spring seat can move axially along the mandrel; A limiting member, wherein the limiting member is fixedly disposed on the inner wall of the groove structure; A first elastic element, one end of which abuts against the locking nut, and the other end of which abuts against the cover portion, causing the piston element to move away from / closer to the locking nut; The second elastic element has one end abutting against the limiting element and the other end abutting against the base portion, causing the piston element to move towards / away from the locking nut. The second actuating element is disposed on the piston element, and the piston element and the second actuating element drive the swashplate to deflect.

2. The hydrostatic transmission device as described in claim 1, characterized in that, The limiting component includes an elastic retaining ring that is engaged inside the groove structure and a spring retaining ring that abuts against the elastic retaining ring.

3. The hydrostatic transmission device as described in claim 2, characterized in that, The second elastic element includes a plurality of small springs disposed between the spring retainer and the base portion, the small springs being evenly distributed along the outer periphery of the sleeve portion.

4. The hydrostatic transmission device as described in claim 1, characterized in that, The piston element has closed structures at both ends. The piston element and the inner wall of the variable cylinder form a first hydraulic chamber and a second hydraulic chamber. The piston element also has a valve chamber inside. The piston element also has a first oil inlet passage connecting the valve chamber and the first hydraulic chamber, and a second oil inlet passage connecting the valve chamber and the second hydraulic chamber. The valve chamber also has a valve core. The opening and closing of the first oil inlet passage and the second oil inlet passage are controlled by adjusting the relative position of the valve core and the valve chamber.

5. The hydrostatic transmission device as described in claim 4, characterized in that, The operating mechanism is provided with a first actuating element, which drives the valve core to move along the valve cavity by passing through the upper part of the piston element.

6. The hydrostatic transmission device as described in claim 5, characterized in that, The control mechanism is an electro-hydraulic servo valve or a mechanical control lever.

7. The hydrostatic transmission device as described in claim 4, characterized in that, The piston element is provided with an oil supply passage. On the inner surface of the piston element, there is a first annular oil passage connected to the oil supply passage, a second annular oil passage connected to the first oil inlet passage, and a third annular oil passage connected to the second oil inlet passage. The second annular oil passage and the third annular oil passage are distributed on both sides of the first annular oil passage. The valve core is provided with a fourth annular oil passage in the circumferential direction. In the first position, the fourth annular oil passage connects the first annular oil passage and the second annular oil passage; in the second position, the fourth annular oil passage connects the first annular oil passage and the third annular oil passage; and in the third position, the fourth annular oil passage is disconnected from both the first and second annular oil passages.

8. The hydrostatic transmission device as described in claim 7, characterized in that, The valve core is also provided with a main return oil passage in the middle. The valve core is provided with a first return oil passage and a second return oil passage in the radial direction. The first return oil passage and the second return oil passage are both connected to the main return oil passage. In the first position, the second annular oil passage and the first return oil passage are connected. In the second position, the third annular oil passage and the second return oil passage are connected. In the third position, the second annular oil passage and the first return oil passage, as well as the third annular oil passage and the second return oil passage, are all disconnected.

9. The hydrostatic transmission device as described in claim 7, characterized in that, A reset elastic element is also provided between the valve core and the inner wall of the valve cavity.

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