Mechanical check valve structure of transmission shaft

Abstract

The utility model discloses a mechanical check valve structure of a transmission shaft. The mechanical check valve structure is mainly used for rapidly locking the rotating motion of the transmission shaft through the advancing and retreating of a steel ball arranged in the mechanical check valve and the matching effect of the steel ball and a gear. After the transmission shaft is stopped, the movable sleeve quickly slides to the fixed part, and the movable sleeve and the fixed part are connected together through the end face teeth, so that the rotation of the movable sleeve and the transmission shaft is locked. On the contrary, the lock can be released when needed, and the transmission shaft is restored to move; the guide groove for guiding the movable sleeve to slide through the guide part is composed of a left-handed spiral groove and a right-handed spiral groove which are intersected, and when the guide part is located in the guide groove, no matter whether the transmission shaft rotates forwards or reversely to drive the movable sleeve, the movable sleeve can be forced to move in the direction away from the fixed part; the utility model can effectively solve the problem that the transmission shaft cannot be timely braked after stopping driving, and is beneficial to improving the transmission precision.

Description

Technical Field

[0001] The utility model belongs to the technical field of self-locking of a transmission shaft, and in particular relates to a mechanical check valve structure of a transmission shaft. Background Art

[0002] For some rotating mechanisms, in order to prevent the transmission shaft from rotating under the action of external force or inertia after the drive stops, thereby affecting the output of the rotating mechanism or generating a recoil effect on the input of the rotating mechanism, it is necessary to set a self-locking structure that can limit the rotation of the transmission shaft or disengage the transmission. For example, the large double gear structure of the motorcycle engine disclosed in Chinese Patent 2018216020507 improves the large double gear of the motorcycle engine and transforms it into a structure composed of a large gear, a transmission gear and a small gear, and sets a return elastic mechanism and an elastic rotation control mechanism between them; during normal start-up, the small gear is meshed and locked with the transmission gear. After normal start-up, when the electric start fails or the engine suddenly stops during driving, the small gear is disengaged from the transmission gear, and the small gear itself idles on the transmission shaft, and has no driving force on the transmission shaft and other gears on the transmission shaft, so that the main components of the electric start will not be affected by impact, which can effectively protect the electric start mechanism.

[0003] As for the rotating mechanism that accurately adjusts the position of an object through a screw rod, it is necessary to quickly lock the screw rod after stopping the movement to prevent the screw rod from continuing to rotate under the action of external force or inertia, causing the position of the object driven by the screw rod to deviate from the predetermined position; the aforementioned existing scheme only disengages the transmission when the drive stops, and cannot limit the timely rotation of the transmission shaft after the drive stops. Therefore, it is necessary to design a self-locking structure that can lock the rotation of the transmission shaft after the drive stops, so as to improve the transmission accuracy. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of the utility model is to provide a mechanical check valve structure for a transmission shaft, so as to solve the technical problem that the transmission shaft cannot be stopped in time after the driving stops, thereby achieving the effect of rigid controllable self-locking and improving the transmission accuracy.

[0005] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0006] A transmission shaft mechanical check valve structure comprises a transmission shaft, a movable sleeve and a fixed sleeve are sequentially sleeved outwardly on the transmission shaft, the movable sleeve rotates synchronously with the transmission shaft and can slide along the axial direction of the transmission shaft, and the fixed sleeve is fixedly arranged; the fixed sleeve is provided with a fixed portion protruding inwardly, the fixed portion is located on one side of the movable sleeve in the axial direction, and the fixed portion and the movable sleeve are provided with matching end face teeth on the axially opposite surfaces thereof, so as to play a braking function when the end face teeth are meshed, and an elastic member is provided between the fixed sleeve and the movable sleeve, and the elastic member enables the movable sleeve to maintain a tendency to slide toward the fixed portion in the axial direction;

[0007] A ring groove and a plurality of guide grooves evenly distributed in the circumferential direction are provided on the outer circumferential side surface of the movable sleeve. The guide groove is located on the side of the ring groove away from the fixed portion. The guide groove is composed of a left-handed spiral groove and a right-handed spiral groove intersecting each other. The intersection of the left-handed spiral groove and the right-handed spiral groove is naturally connected and transitioned to form a closed end of the guide groove. The left-handed spiral groove and the right-handed spiral groove extend toward the ring groove and away from each other to form an open end of the guide groove. The open end of the guide groove faces the ring groove and is connected to the ring groove.

[0008] The fixed sleeve is provided with a columnar or spherical guide portion protruding inward, which is inserted into the annular groove or the guide groove and can slide relative to the movable sleeve along the path formed by the annular groove and the guide groove; when the guide portion is located at a position where the left-handed spiral groove and the right-handed spiral groove of any guide groove intersect and naturally connect and transition, the end face teeth of the fixed portion and the movable sleeve are meshed.

[0009] Furthermore, the opening ends of two adjacent guide grooves in the circumferential direction are connected.

[0010] Further, a region between the left-handed spiral groove and the right-handed spiral groove of the guide groove is formed as a partition.

[0011] Furthermore, the groove walls of the left-handed spiral groove and the right-handed spiral groove of the guide groove that are adjacent in the circumferential direction are converged and connected at the opening end, and the connection point forms a sharp angle.

[0012] Furthermore, the movable sleeve has a movable abutment protruding outward, and the fixed sleeve has a fixed abutment protruding inward, the fixed abutment and the movable abutment are both located between the fixed sleeve and the movable sleeve, and the fixed abutment is located on the side of the movable abutment away from the fixed portion; the elastic member is a helical compression spring, and the two ends of the helical compression spring are respectively abutted against the fixed abutment and the movable abutment, and the helical compression spring remains in a compressed state.

[0013] Furthermore, the guide portion is located on a side of the helical compression spring away from the movable abutment portion; there are multiple guide portions and they are arranged circumferentially at intervals, and the number of the guide portions does not exceed the guide groove. When the end face teeth of the fixed portion and the movable sleeve are engaged, each guide portion is located at a position where the left-handed spiral groove and the right-handed spiral groove of a corresponding guide groove intersect and naturally connect and transition.

[0014] Furthermore, the guide part is a ball head plunger independent of the fixed sleeve, and the fixed abutment part has a radially penetrating threaded hole, and the guide part is located in the threaded hole and threadedly connected; the inner end of the guide part is connected to a raised hemisphere, and the cross-sections of the annular groove, the left-handed spiral groove and the right-handed spiral groove are all semicircular and the diameter matches the diameter of the hemisphere.

[0015] Furthermore, the fixed abutting portion and the movable abutting portion both extend circumferentially into a ring shape, the movable abutting portion is located at one end of the movable sleeve close to the fixed portion, and the end face teeth of the movable sleeve are arranged on the movable abutting portion.

[0016] Furthermore, the movable sleeve is connected to the transmission shaft for synchronous rotation via a spline or a flat key.

[0017] Furthermore, the fixing portion is annular and the diameter of the inner hole matches the diameter of the transmission shaft.

[0018] Compared with the prior art, the utility model has the following beneficial effects:

[0019] 1. The transmission shaft mechanical check valve structure of the utility model can be applied to a mechanism that needs to quickly lock the rotation of the transmission shaft after the drive stops. After the driving source of the transmission shaft stops inputting torque, the movable sleeve quickly slides toward the fixed part, and the movable sleeve is connected to the fixed part through the end face gear cooperation, thereby locking the rotation of the transmission shaft; it can effectively solve the problem that the transmission shaft cannot be stopped in time after the drive stops, which is beneficial to improving the transmission accuracy.

[0020] 2. In the transmission shaft mechanical check valve structure of the utility model, the guide groove is composed of intersecting left-hand spiral grooves and right-hand spiral grooves. When the guide portion is located in the guide groove, no matter whether the transmission shaft drives the movable sleeve in forward or reverse rotation, the movable sleeve can be forced to move in a direction away from the fixed portion to unlock. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A three-dimensional diagram of a transmission shaft mechanical check valve structure (the transmission shaft is not shown) according to an embodiment;

[0022] Figure 2 It is a front view of the transmission shaft mechanical check valve structure (the transmission shaft is not shown) according to the embodiment;

[0023] Figure 3 for Figure 2 Schematic diagram of the cross section along AA;

[0024] Figure 4 for Figure 1 The structural schematic diagram of the fixed sleeve is hidden;

[0025] Figure 5 It is a side view of the movable sleeve described in the embodiment;

[0026] Among them, there are a movable sleeve 1, a fixed sleeve 2, a fixed part 3, an annular groove 4, a guide groove 5, a guide part 6, a partition part 7, an end face tooth 8, a spiral compression spring 9, a movable abutment part 10, a fixed abutment part 11, and a steel ball 12. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the present utility model clearer, the technical solution in the embodiments of the present utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the present utility model.

[0028] Example:

[0029] See also Figure 1 , Figure 2 and Figure 3 A transmission shaft mechanical check valve structure comprises a transmission shaft (not shown in the figure), a movable sleeve 1 and a fixed sleeve 2 are sequentially sleeved outwardly on the transmission shaft, the movable sleeve 1 rotates synchronously with the transmission shaft and can slide along the axial direction of the transmission shaft, the fixed sleeve 2 is fixedly arranged and movably matched with the movable sleeve 1; the fixed sleeve 2 has an inwardly protruding fixed portion 3, the fixed portion 3 is located on one side of the movable sleeve 1 in the axial direction, and the fixed portion 3 and the movable sleeve 1 are axially opposite. The surfaces are respectively provided with matching end face teeth 8, so as to play a braking function when the two end face teeth 8 are meshed, and an elastic member is provided between the fixed sleeve 2 and the movable sleeve 1, and the elastic member keeps the movable sleeve 1 in a tendency to slide toward the fixed portion 3 in the axial direction;

[0030] The outer circumferential side surface of the movable sleeve 1 is provided with a ring groove 4 and a plurality of guide grooves 5 uniformly distributed in the circumferential direction. The guide groove 5 is located on the side of the ring groove 4 away from the fixed part. The guide groove 5 is composed of a left-handed spiral groove and a right-handed spiral groove intersecting each other. The intersection of the left-handed spiral groove and the right-handed spiral groove is naturally connected and transitioned to form a closed end of the guide groove 5. The left-handed spiral groove and the right-handed spiral groove extend toward the ring groove 4 and away from each other to form an open end of the guide groove 5. The open end of the guide groove 5 faces the ring groove 4 and is connected to the ring groove 4. The fixed sleeve 2 has a column protruding inward. The guide portion 6 is a spherical or ball-shaped guide portion 6, which falls into the annular groove 4 or the guide groove 5 and can slide relative to the movable sleeve 1 along the path formed by the annular groove 4 and the guide groove 5; the groove widths of the annular groove 4, the left-handed spiral groove and the right-handed spiral groove are adapted to the diameter of the guide portion 6, and the groove widths are equal to or slightly larger than the diameter of the guide portion 6; when the guide portion 6 is located at the position where the left-handed spiral groove and the right-handed spiral groove of any guide groove 5 intersect and naturally connect and transition, the end face teeth 8 of the fixed portion 3 and the movable sleeve 1 are meshed, and the movable sleeve 1 and the transmission shaft cannot rotate relative to the fixed sleeve 2, thereby being locked and stopped.

[0031] The transmission shaft mechanical check valve structure of the utility model is that when the transmission shaft starts to rotate and drives the movable sleeve 1 to rotate, the guide groove 5 contacts and transmits force with the fixed guide part 6, driving the movable sleeve 1 away from the fixed part 3, compressing the elastic member, and the end face teeth 8 of the fixed part 3 and the movable sleeve 1 are disengaged, and the guide part 6 further falls into the annular groove 4, and the movable sleeve 1 and the transmission shaft rotate normally; during the normal rotation process, even if the elastic member does work to make the guide part 6 enter the guide groove 5, the guide groove 5 contacts the guide part 6, and the guide part 6 is still driven to fall into the annular groove 4 again; the driving of the transmission shaft After the power source stops inputting torque, the movable sleeve 1 moves toward the fixed part 3 under the elastic force of the elastic member, and the guide part 6 enters the guide groove 5 and falls at the position where the left-handed spiral groove and the right-handed spiral groove of the guide groove 5 intersect and naturally connect and transition, the fixed part 6 and the end face teeth 8 of the movable sleeve 1 engage to lock the transmission shaft again; during manufacturing, the strength of the elastic member affects the timeliness of the locking, and the axial length of the guide groove 5 determines the sliding distance of the movable sleeve 1. The specific process assignment of the relevant parameters can be determined in combination with the mass and inertia of the transmission shaft and the load, the depth of the end face teeth 8, etc.

[0032] The transmission shaft mechanical check valve structure described in the utility model can be applied to mechanisms that need to quickly lock the rotation of the transmission shaft after stopping driving, such as a rotating mechanism that accurately adjusts the position of an object by a screw rod. After stopping driving, the movable sleeve 1 quickly slides toward the fixed part 3, and the movable sleeve 1 is connected to the fixed part 3 through the cooperation of the end face teeth 8, thereby locking the rotation of the movable sleeve 1 and the transmission shaft; the rotation is controlled by the cooperation of the end face teeth 8, which is almost unaffected by the rotation of the movable sleeve 1, and can be directly axially moved and cooperated at any angle. Even if the two end face teeth 8 are not in a state where they can be directly engaged, the angle required for relative rotation is also small, and under the guiding action of the tooth surface, the cooperation can be quickly completed during the movement, which is beneficial to increasing the speed of locking the rotation of the transmission shaft; in addition, the guide groove 5 is composed of intersecting left-handed spiral grooves and right-handed spiral grooves. When the guide part 6 is located in the guide groove 5, no matter whether the transmission shaft drives the movable sleeve 1 in the forward or reverse direction, the movable sleeve 1 can be forced to move in the direction away from the fixed part 3 to unlock.

[0033] See also Figure 5 , the open ends of two adjacent guide grooves 5 in the circumferential direction are connected, that is, the left-handed spiral groove and the right-handed spiral groove of the two adjacent guide grooves 5 have a natural sharp angle transition at the annular groove 4; in this way, the guide portion 6 can enter the guide groove 5 from almost any circumferential position of the annular groove 4, reducing the possibility of the movable sleeve 1 being blocked by the guide portion 6 when axially approaching the fixed portion 3, which is beneficial to increasing the rotation speed of the locking transmission shaft.

[0034] During implementation, the morphology of the guide groove 5 is related to its own size parameters and the size of the tool used for processing. When a larger tool is used, there is no gap between the left-handed spiral groove and the right-handed spiral groove of the guide groove 5, and the left-handed spiral groove and the right-handed spiral groove will partially overlap. At this time, each guide groove 5 has only one connecting opening with the annular groove 4. In addition, it should be ensured that the depth of the middle part of the guide groove 5 in the circumferential direction is consistent to avoid affecting the guiding effect of the guide groove 5 and the guide part 6. This embodiment uses a smaller tool, see Figure 5 , the area between the left-handed spiral groove and the right-handed spiral groove of the guide groove is formed as a partition 7, that is, there is a gap between the left-handed spiral groove and the right-handed spiral groove and the area corresponding to the gap is formed as the partition 7; in this way, each guide groove 5 has two communicating ports with the annular groove 4, which increases the number of communicating ports between the guide groove 5 and the annular groove 4 and reduces the width of a single communicating port. While ensuring that the movable sleeve 1 can be guided to move regardless of forward or reverse rotation, the movable sleeve 1 can quickly disengage from the guide groove 5 again with the rotation during the rotation of the transmission shaft even if the guide portion 6 falls from the annular groove 4 into the guide groove 5, thereby avoiding mislocking and reducing the requirement for the rotation speed of the movable sleeve 1 to keep the two end face teeth 8 disengaged, so that the transmission shaft mechanical check valve structure can be compatible with a rotating mechanism with a lower transmission shaft speed, which is conducive to improving practicality.

[0035] See also Figure 5 The groove walls of the left-handed spiral groove and the right-handed spiral groove of the guide groove 5, which are close to each other in the circumferential direction, are gathered and connected at the open end, and the connection is sharp, that is, the partition 7 is shuttle-shaped in the axial direction; in this way, not only the circumferential width of the end of the partition 7 can be reduced, but also the possibility of the movable sleeve 1 being blocked by the guide part 6 when it is axially close to the fixed part 3 can be reduced, and the guide part 6 can be kept in a state where it can enter the guide groove 5 from almost any circumferential position of the annular groove 4, and each connecting port connecting the guide groove 5 and the annular groove 4 is expanded, which is convenient for guiding the guide part 6 to slide relatively into or out of the guide groove 5, so that the guide part 6 can move more smoothly at the connecting port of the annular groove 4 and the guide groove 5.

[0036] See also Figure 3 and Figure 4 In order to make the guide part 6 move more smoothly in the guide groove 5 and the annular groove 4, reduce shaking and improve stability, the guide part is columnar and the free end is rotatably connected with a steel ball; the cross-sections of the annular groove 4, the left-handed spiral groove and the right-handed spiral groove are all semicircular and the diameters match the diameter of the steel ball 12; specifically, the guide part 6 is a ball head plunger that is independent of the structure of the fixed sleeve 2, and the fixed abutment part 11 has a threaded hole that radially penetrates to the inside and outside of the fixed sleeve 2, and the guide part 6 is located in the threaded hole and is threadedly connected.

[0037] See also Figure 3 and Figure 4In this embodiment, the elastic member adopts a helical compression spring 9, and the specific structure is as follows: the movable sleeve 1 has a movable abutting portion 10 protruding outward, and the fixed sleeve 2 has a fixed abutting portion 11 protruding inward, the fixed abutting portion 11 and the movable abutting portion 10 are both located between the fixed sleeve 2 and the movable sleeve 1, and the fixed abutting portion 11 is located on the side of the movable abutting portion 10 away from the fixed portion; the elastic member is a helical compression spring 9, and the helical compression spring 9 is sleeved outside the movable sleeve 1, and the two ends of the helical compression spring 9 are respectively abutted against the fixed abutting portion 11 and the movable abutting portion 10, and the helical compression spring 9 maintains a compressed state; the guide portion 6 is located on the side of the helical compression spring 9 away from the movable abutting portion 10.

[0038] In this embodiment, the fixed abutment portion 11 and the movable abutment portion 10 are both extended circumferentially into a ring shape, the movable abutment portion 10 is located at one end of the movable sleeve 1 close to the fixed portion 3, and the end face teeth 8 of the movable sleeve 10 are arranged on the movable abutment portion 10; there are multiple guide portions 6 and they are evenly distributed circumferentially; in this way, the radial dimension of the end face teeth 8 can be increased, and the reliability of the locking can be improved. The multiple guide portions 6 make the movable sleeve 1 more evenly stressed during axial movement, making the movement smoother and more stable; the movable sleeve 1 is connected to the transmission shaft for synchronous rotation through a flat key, the fixed portion 3 is annular and the diameter of the inner hole matches the diameter of the transmission shaft, see Figure 3 and Figure 4 The fixing portion 3 is a structural component independent of the fixing sleeve 2 and is threadedly connected in the fixing sleeve 2 .

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit the technical solution. Ordinary technicians in this field should understand that those modifications or equivalent replacements of the technical solution of the utility model without departing from the purpose and scope of the technical solution of the utility model should be included in the scope of the claims of the utility model.

Claims

1. A transmission shaft mechanical check valve structure, characterized in that: The invention comprises a transmission shaft, on which a movable sleeve and a fixed sleeve are sequentially sleeved outwardly, the movable sleeve rotates synchronously with the transmission shaft and can slide along the axial direction of the transmission shaft, and the fixed sleeve is fixedly arranged; the fixed sleeve is provided with a fixed portion protruding inwardly, the fixed portion is located on one side of the movable sleeve in the axial direction, and the axially opposite surfaces of the fixed portion and the movable sleeve are respectively provided with matching end face teeth, so as to play a braking function when the end face teeth are meshed, and an elastic member is provided between the fixed sleeve and the movable sleeve, and the elastic member enables the movable sleeve to maintain a tendency to slide toward the fixed portion in the axial direction; A ring groove and a plurality of guide grooves evenly distributed in the circumferential direction are provided on the outer circumferential side surface of the movable sleeve. The guide groove is located on the side of the ring groove away from the fixed portion. The guide groove is composed of a left-handed spiral groove and a right-handed spiral groove intersecting each other. The intersection of the left-handed spiral groove and the right-handed spiral groove is naturally connected and transitioned to form a closed end of the guide groove. The left-handed spiral groove and the right-handed spiral groove extend toward the ring groove and away from each other to form an open end of the guide groove. The open end of the guide groove faces the ring groove and is connected to the ring groove. The fixed sleeve is provided with a columnar or spherical guide portion protruding inward, which is inserted into the annular groove or the guide groove and can slide relative to the movable sleeve along the path formed by the annular groove and the guide groove; when the guide portion is located at a position where the left-handed spiral groove and the right-handed spiral groove of any guide groove intersect and naturally connect and transition, the end face teeth of the fixed portion and the movable sleeve are meshed.

2. According to claim 1, a transmission shaft mechanical check valve structure is characterized in that: The opening ends of two adjacent guide grooves in the circumferential direction are connected.

3. According to claim 2, a transmission shaft mechanical check valve structure is characterized in that: The area between the left-handed spiral groove and the right-handed spiral groove of the guide groove is formed as a partition.

4. A transmission shaft mechanical check valve structure according to claim 3, characterized in that: The groove walls of the left-handed spiral groove and the right-handed spiral groove of the guide groove, which are close to each other in the circumferential direction, are gathered and connected at the opening end, and the connection point forms a sharp angle.

5. The transmission shaft mechanical check valve structure according to claim 1, characterized in that: The movable sleeve is provided with a movable abutting portion protruding outward, and the fixed sleeve is provided with a fixed abutting portion protruding inward. Both the fixed abutting portion and the movable abutting portion are located between the fixed sleeve and the movable sleeve, and the fixed abutting portion is located on the side of the movable abutting portion away from the fixed portion. The elastic member is a helical compression spring, and the two ends of the helical compression spring are respectively abutted against the fixed abutting portion and the movable abutting portion, and the helical compression spring remains in a compressed state.

6. A transmission shaft mechanical check valve structure according to claim 5, characterized in that: The guide portion is located on the side of the spiral compression spring away from the movable abutment portion; there are multiple guide portions and they are arranged circumferentially at intervals, and the number of the guide portions does not exceed the guide groove. When the end face teeth of the fixed portion and the movable sleeve are engaged, each guide portion is located at a position where the left-handed spiral groove and the right-handed spiral groove of a corresponding guide groove intersect and naturally connect and transition.

7. The transmission shaft mechanical check valve structure according to claim 5, characterized in that: The guide part is a ball head plunger independent of the fixed sleeve, and a radially penetrating threaded hole is provided in the fixed abutment part. The guide part is located in the threaded hole and is threadedly connected; the inner end of the guide part is connected to a raised hemisphere, and the cross-sections of the annular groove, the left-handed spiral groove and the right-handed spiral groove are all semicircular and the diameter matches the diameter of the hemisphere.

8. The transmission shaft mechanical check valve structure according to claim 5, characterized in that: The fixed abutting portion and the movable abutting portion both extend circumferentially into a ring shape. The movable abutting portion is located at one end of the movable sleeve close to the fixed portion, and the end face teeth of the movable sleeve are arranged on the movable abutting portion.

9. The transmission shaft mechanical check valve structure according to claim 1, characterized in that: The movable sleeve is connected to the transmission shaft for synchronous rotation via a spline or a flat key.

10. The transmission shaft mechanical check valve structure according to claim 1, characterized in that: The fixing portion is annular and the diameter of the inner hole matches the diameter of the transmission shaft.

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