A speed selection mechanism for a propeller governor

Abstract

The present invention discloses a speed selection mechanism for a propeller governor. The upper part of the speed selection stop assembly is sleeved between the speed selection handle and the upper part of the variable diameter screw shaft; a return torsion spring is sleeved on the outer end of the large cylinder at the upper end of the upper housing assembly; the thinner part in the middle and lower part of the variable diameter screw shaft is press-fitted into the inner hole of the upper spring seat; a lower spring seat is arranged on the upper end surface of the valve core; the thicker lower end of the variable diameter screw shaft is located below the bottom surface of the insert piece, and the spring fixed on the upper and lower spring seats is sleeved on the variable diameter screw shaft; the valve core is installed in the valve sleeve, and a bearing with the hook end of the centrifugal block abutted against the convex platform on its bottom surface is assembled with a clearance on the valve core at the lower end surface of the valve cap; a shoulder is arranged on the outer circle of the valve core, and oil grooves I and II are arranged on the outer circle of the valve core above and below the shoulder; an inlet high-pressure oil port, an outlet high-pressure oil port communicating with the oil groove I and an oil return port communicating with the oil groove II are arranged on the valve sleeve. When the propeller of the present invention is used, the rotational speed can be steplessly adjusted within a certain range, and reliable operation can be ensured at the selected required propeller rotational speed.

Description

Technical Field

[0001] The present invention relates to a speed selection mechanism for a propeller governor. Background Art

[0002] The higher the rotational speed of a propeller, the greater the thrust generated. When an aircraft takes off, a large thrust is required, while when the aircraft is cruising and flying horizontally, a smaller thrust is needed. Existing propeller governors maintain a constant balanced rotational speed by balancing the centrifugal force of a counterweight with the spring force, and there is only one balanced rotational speed. Whether during takeoff or cruising and horizontal flight, it is always the same rotational speed and cannot be selected. This leads to the situation that if the balanced rotational speed is set higher when the takeoff task can be completed, the takeoff task can be completed more smoothly and efficiently, and the engine is not easily damaged. However, during cruising and horizontal flight, a large amount of fuel is still wasted, and the fuel consumption during flight is very high. If the balanced rotational speed is set lower, fuel is saved during cruising and horizontal flight, but although the aircraft can complete the takeoff task, a large amount of fuel needs to be burned to generate greater power, so not only is fuel wasted, but the engine is also easily damaged. Therefore, it is necessary to select a suitable balanced rotational speed according to the actual situation of the aircraft. However, no matter what, as long as the balanced rotational speed can meet the takeoff requirements, a large amount of fuel will be wasted during cruising and horizontal flight. Therefore, there is an urgent need to study a propeller governor with speed selection and adjustable and controllable balanced rotational speed to ensure that the thrust of the propeller is large when the aircraft takes off and small when the aircraft is cruising and flying horizontally. The flight of an aircraft is ensured by adjusting the rotational speed of the propeller and the blade angle. The propeller has only one high-efficiency blade angle, and the working efficiency of the propeller is relatively low in other blade angle states. For a constant-speed propeller, in order to keep the rotational speed unchanged under the condition of changing flight conditions, the blade angle needs to be changed to absorb the engine power, which results in a relatively low working efficiency of the propeller. In order to always maintain the working efficiency of the propeller at a high level, there is also an urgent need to study a propeller governor with speed selection and adjustable and controllable balanced rotational speed, so that the blade angle always remains at the position of the high-efficiency blade angle. Summary of the Invention

[0003] The object of the present invention is to solve the above problems existing in the prior art, and provide a speed selection mechanism for a propeller governor with a relatively simple structure, convenient installation and disassembly, capable of speed selection and adjustable and controllable balanced rotational speed. The rotational speed of the propeller using this speed selection mechanism can be steplessly adjusted within a certain range, and it can ensure reliable operation at the selected required rotational speed of the propeller.

[0004] To achieve the above object, the technical solution of the present invention is: A speed selection mechanism for a propeller governor, comprising upper and lower housing assemblies, a bottom plate, a speed selection handle, a speed selection stop assembly, a return torsion spring, a maximum speed stop, a feathering stop, a variable diameter screw shaft, upper and lower spring seats, a spring, a bearing, a centrifugal counterweight assembly, a valve sleeve, a valve core valve cap assembly, and a insert piece located inside the cavity of the upper and lower housing assemblies; one end of the speed selection handle has a spline hole, and the other end has a connection structure with the propeller rod; the upper part of the speed selection stop assembly is sleeved between the spline hole of the speed selection handle and the upper part of the variable diameter screw shaft, its external spline is connected to the internal spline of the speed selection handle, its internal spline is connected to the external spline of the upper part of the variable diameter screw shaft, and a limiting flange is provided thereon; the maximum speed stop and the feathering stop are respectively fixed on two small cylinders on the upper end face of the upper housing assembly; a return torsion spring with the upper end fixed on the speed selection stop assembly and the lower end fixed on one of the small cylinders is sleeved on the outer end of the large cylinder at the upper end of the upper housing assembly; the limiting flange of the speed selection stop assembly rotates between the maximum speed stop and the feathering stop; the middle and upper part of the variable diameter screw shaft is sleeved and thread-sealedly connected in a threaded hole opened in the large cylinder at the upper end of the upper housing assembly, and the thinner middle and lower part is press-fitted into the inner hole of the upper spring seat; the valve core valve cap assembly includes a valve core and a valve cap integrated with the upper end of the valve core, a lower spring seat is integrally provided on the outer circle of the upper end face of the valve core, a groove is provided on the inner circle of the lower spring seat, and the insert piece is placed in the groove and key-connected to the key groove on the inner circle of the lower spring seat; the lower end part of the variable diameter screw shaft is sleeved in the insert piece with a slight clearance, and the thickened lower end is located below the insert piece, and the spring fixed on the upper and lower spring seats is sleeved on the variable diameter screw shaft; the valve core of the valve core valve cap assembly is installed in the valve sleeve, and a bearing with a bottom convex platform is assembled with a clearance on the valve core at the lower end face of the valve cap; the centrifugal counterweight assembly including centrifugal blocks is located inside the upper end cavity of the lower housing assembly, its lower end is sleeved and clamped on the outer circle of the upper end part of the valve sleeve through a spline, and the hook end of its centrifugal block abuts against the bottom convex platform of the bearing; the valve sleeve is assembled with a slight clearance in the installation hole of the lower housing assembly, and its lower end has a connection mechanism with the engine; a shoulder is provided on the outer circle of the valve core, and oil grooves I and II are provided on the outer circle of the valve core above and below the shoulder; an inlet high-pressure oil port, an outlet high-pressure oil port communicating with oil groove I and an oil return port communicating with oil groove II are provided on the valve sleeve; when the propeller operates normally at the selected equilibrium speed, the shoulder blocks the outlet high-pressure oil port on the valve sleeve; when the propeller speed becomes smaller than the selected equilibrium speed, the shoulder is at the lower end of the outlet high-pressure oil port, and the outlet high-pressure oil port communicates with the inlet high-pressure oil port; when the propeller speed becomes larger than the selected equilibrium speed, the shoulder is at the upper end of the outlet high-pressure oil port, and the outlet high-pressure oil port communicates with the oil return port.

[0005] Further preferably, the circumferential wall at one end of the speed selection handle with an internal spline hole is disconnected, a through hole is opened on one of the two end walls of the disconnected circumferential wall, a threaded hole is opened on the other, and the two are fixed together by a socket head cap screw I with a hole and a light spring washer I. This structure is easy to install and disassemble.

[0006] Further preferably, the circumferential wall of the speed selection stop assembly is disconnected. One of the two end walls of the disconnected circumferential wall is provided with a through hole, and the other is provided with a threaded hole. The two are fixed together by a perforated spherical head screw II and a light spring washer II. This structure is easy to install and disassemble.

[0007] Further preferably, the centrifugal counterweight assembly includes a support, two centrifugal blocks distributed correspondingly, and a spiral retaining ring; the lower end of the support is sleeved with a spline and clamped on the outer circle of the upper end of the valve sleeve; the two centrifugal blocks are respectively assembled on the support with a clearance by a shaft and a bearing. A spiral retaining ring is clamped and fixed on the outer wall of the upper end of the support. The two ends of the shaft are abutted against the inner end wall of the spiral retaining ring; the hook end abutted against the bottom convex platform of the bearing is provided with an arc surface. The presence of the spiral retaining ring makes the shaft not easy to escape, and the structure has high reliability. The arc surface reduces the friction of the bottom convex platform of the bearing and increases the service life.

[0008] The speed selection handle of the present invention is manipulated by the propeller rod on the aircraft, the position of the variable diameter screw shaft is changed, and then the compression amount of the spring is changed, so that the propeller can be selected to work at different balanced speeds. The governor is driven to rotate by the transmission mechanism of the engine. At this time, the elastic force of the spring and the axial component force generated by the rotation of the centrifugal blocks of the centrifugal counterweight assembly acting on the valve core and valve cap assembly reach equilibrium. The shoulder of the valve core just blocks the lubricating oil passage leading to the propeller cavity, so that it works at a balanced speed. When the governor exceeds this balanced speed, the centrifugal blocks swing upward, overcoming the elastic force of the spring, and lifting the valve core and valve cap assembly. The high-pressure oil port and the oil return port are communicated, so that the high-pressure oil in the propeller cavity is diverted to the low-pressure oil tank, the propeller pitch becomes larger, the load increases, and the propeller speed decreases until the valve core and valve cap assembly descends, so that the elastic force of the spring and the axial component force of the centrifugal force reach equilibrium, and the speed returns to the selected balanced speed. The shoulder of the valve core blocks the lubricating oil passage leading to the propeller cavity again. When the governor is lower than this balanced speed, the elastic force of the spring overcomes the axial component force of the centrifugal force of the centrifugal blocks, causing the valve core and valve cap assembly to descend. The high-pressure oil outlet and the high-pressure oil inlet are communicated, and the high-pressure oil enters the propeller cavity, making the propeller pitch smaller, the load smaller, and the propeller speed increase until the valve core and valve cap assembly rise, so that the elastic force of the spring and the axial component force of the centrifugal force reach equilibrium, and the speed returns to the selected balanced speed. The shoulder of the valve core blocks the oil passage leading to the propeller cavity again.

[0009] In summary, the structure of the present invention is relatively simple, easy to install and disassemble, and has the functions of speed selection and adjustable and controllable balanced speed. The propeller speed using the present invention can be steplessly adjusted within a certain range, and it can ensure reliable operation at the selected required propeller speed, making the flight of the aircraft safer and more reliable. Description of the Drawings

[0010] Figure 1 It is a schematic installation structure diagram of the present invention when the governor is at the balanced speed;

[0011] Figure 2 Schematic diagram of the installation structure of the present invention when the governor gear pump is not rotating at a high speed;

[0012] Figure 3 Schematic diagram of the installation structure of the present invention when the governor gear pump is not rotating at a low speed;

[0013] Figure 4 Top view of the governor for installing the present invention;

[0014] Figure 5 Top view of the centrifugal counterweight assembly in the present invention. Detailed implementation manners

[0015] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0016] As Figures 1 to 5As shown in the figure, this embodiment includes upper and lower housing assemblies 1 and 9, a bottom plate 16, a speed selection handle 3, a speed selection stop assembly 5, a return torsion spring 2, a maximum speed stop 14, a feathering stop 15, a stepped screw shaft 4, upper and lower spring seats 13 and 17, a spring 6, a bearing 7, a centrifugal counterweight assembly 8, a valve sleeve 10, a valve core valve cap assembly 11, and a tab 12 located inside the cavities of the upper and lower housing assemblies 1, 9, and the bottom plate 16. One end of the speed selection handle 3 has a spline hole, and the other end has a connection structure for connecting to the propeller rod. Preferably, the circumferential wall of the end of the speed selection handle 3 with an internal spline hole is disconnected, with a through hole opened on one of the two end walls of the disconnected circumferential wall and a threaded hole opened on the other. The two are fixed together by a slotted round head screw I 28 and a light spring washer I 27. The upper part of the speed selection stop assembly 5 is sleeved between the spline hole of the speed selection handle 3 and the upper part of the stepped screw shaft 4. Its external spline is connected to the internal spline of the speed selection handle 5, and its internal spline is connected to the external spline of the upper part of the stepped screw shaft 4. A limiting flange is provided thereon. Preferably, the circumferential wall of the speed selection stop assembly 5 is disconnected, with a through hole opened on one of the two end walls of the disconnected circumferential wall and a threaded hole opened on the other. The two are fixed together by a slotted round head screw II 29 and a light spring washer II 30. The maximum speed stop 14 and the feathering stop 15 are respectively fixed on two small cylinders on the upper end face of the upper housing assembly; a return torsion spring 2 with its upper end fixed to the speed selection stop assembly 5 and its lower end fixed to one of the small cylinders is sleeved outside the large cylinder at the upper end of the upper housing assembly 1. The limiting flange of the speed selection stop assembly 5 rotates between the maximum speed stop 14 and the feathering stop 15. The middle and upper part of the stepped screw shaft 4 is sleeved and hermetically connected by a trapezoidal thread to the threaded hole opened in the large cylinder at the upper end of the upper housing assembly 1, and the thinner middle and lower part is press-fitted into the inner hole of the upper spring seat 13. The valve core valve cap assembly 11 includes a valve core 19 and a valve cap 18 integrally formed with the upper end of the valve core 19. An integral lower spring seat 17 is provided on the outer circle of the upper end face of the valve core 19. There is a groove on the inner circle of the lower spring seat 17, and the tab 12 is placed in the groove and key-connected to the key groove on the inner circle of the lower spring seat 17. The lower end of the valve sleeve 10 has a spline for connecting to the engine output shaft. The lower end part of the stepped screw shaft 4 is sleeved in the tab 12 with a slight clearance, and the lower end with a thicker diameter is located below the tab 12. The spring 6 fixed to the upper and lower spring seats 13 and 17 is sleeved on the stepped screw shaft 4. The valve core 19 of the valve core valve cap assembly is installed in the valve sleeve 10, and a bearing 7 with a bottom convex platform is installed on the valve core 19 at the lower end face of the valve cap 18 with a clearance. The centrifugal counterweight assembly 8 including centrifugal blocks is located inside the upper end cavity of the lower housing assembly 9. Its lower end is sleeved and clamped on the outer circle of the upper end part of the valve sleeve 10 through a spline, and the hook end of its centrifugal block abuts against the bottom convex platform of the bearing 7.Preferably, the centrifugal counterweight assembly includes a support 32, two correspondingly distributed centrifugal blocks 33 and a spiral retaining ring 31; the lower end of the support 32 is sleeved with a spline and clamped on the outer circle of the upper end of the valve sleeve 10; the two centrifugal blocks 33 are respectively assembled on the support 32 with a clearance by a shaft 35, a bearing 36 and a gasket 34, and a spiral retaining ring 31 is clamped and fixed on the outer wall of the upper end of the support 32, and both ends of the shaft 35 are abutted against the inner end wall of the spiral retaining ring 31; the hook end abutted against the bottom boss of the bearing 7 is provided with an arc surface. The valve sleeve 10 is assembled in the mounting hole of the lower housing assembly 9 with a slight clearance, and its lower end is connected to the engine by splines. A shoulder 20 is provided on the outer circle of the valve core 19, and oil grooves I 22 and oil grooves II 24 are provided on the outer circle of the valve core 19 above and below the shoulder 20. The valve sleeve 10 is provided with an inlet high-pressure oil port 26 communicating with the oil groove I 22, an outlet high-pressure oil port 23 and an oil return port 25 communicating with the oil groove II 24. When the propeller operates normally at the selected balance speed, the shoulder 20 blocks the outlet high-pressure oil port 23 on the valve sleeve 10; when the propeller speed is smaller than the selected balance speed, the shoulder 20 is at the lower end of the outlet high-pressure oil port 23, and the outlet high-pressure oil port 23 communicates with the inlet high-pressure oil port 26, and the propeller enters high-pressure oil and the speed increases until it reaches the selected balance speed and operates normally, and the shoulder 20 blocks the outlet high-pressure oil port 23 on the valve sleeve 10. When the propeller speed is larger than the selected balance speed, the shoulder 20 is at the upper end of the outlet high-pressure oil port 23, and the outlet high-pressure oil port 23 communicates with the oil return port 25, and the propeller returns oil and the speed decreases until it reaches the selected balance speed and operates normally, and the shoulder 20 blocks the outlet high-pressure oil port 23 on the valve sleeve 10. 21 is an inlet high-pressure oil hole in the lower housing assembly 9 communicating with the inlet high-pressure oil port 26.

[0017] Certainly, the present invention has many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make corresponding changes and deformations according to the present invention, but these corresponding changes and deformations should all belong to the improvement of equivalent technologies and fall within the protection scope of the claims of the present invention.

Claims

1. A speed selection mechanism for a propeller governor, characterized in that: It includes upper and lower housing assemblies, a bottom plate, a speed selection handle, a speed selection stop assembly, a return torsion spring, a maximum speed stop, a feathering stop, a stepped screw shaft, upper and lower spring seats, a spring, a bearing, a centrifugal counterweight assembly, a valve sleeve, a valve core valve cap assembly and an insert piece located in the inner cavity of the upper and lower housing assemblies; one end of the speed selection handle has a spline hole, and the other end has a connection structure with the propeller rod; the upper part of the speed selection stop assembly is sleeved between the spline hole of the speed selection handle and the upper part of the stepped screw shaft, its external spline is connected with the internal spline of the speed selection handle, its internal spline is connected with the external spline of the upper part of the stepped screw shaft, and a limiting flange is arranged on it; the maximum speed stop and the feathering stop are respectively fixed on two small cylinders on the upper end face of the upper housing assembly; a return torsion spring with the upper end fixed on the speed selection stop assembly and the lower end fixed on one of the small cylinders is sleeved on the outer end of the large cylinder at the upper end of the upper housing assembly; the limiting flange of the speed selection stop assembly rotates between the maximum speed stop and the feathering stop; the middle and upper part of the stepped screw shaft is sleeved and thread-sealed in the threaded hole opened in the large cylinder at the upper end of the upper housing assembly, and the thinner middle and lower part is press-fitted in the inner hole of the upper spring seat; the valve core valve cap assembly includes a valve core and a valve cap integrated with the upper end of the valve core, a lower spring seat is integrally arranged on the outer circle of the upper end face of the valve core, a groove is arranged on the inner circle of the lower spring seat, and the insert piece is placed in the groove and connected with the key groove on the inner circle of the lower spring seat; the lower end part of the stepped screw shaft is sleeved in the insert piece with a slight clearance, and the thickened lower end is located below the insert piece, and the spring fixed on the upper and lower spring seats is sleeved on the stepped screw shaft; the valve core of the valve core valve cap assembly is installed in the valve sleeve, and a bearing with a bottom convex platform is assembled on the valve core at the lower end face of the valve cap with a clearance; the centrifugal counterweight assembly including centrifugal blocks is located in the upper inner cavity of the lower housing assembly, its lower end is sleeved and clamped on the outer circle of the upper end part of the valve sleeve through a spline, and the hook end of its centrifugal block abuts against the bottom convex platform of the bearing; the valve sleeve is assembled in the installation hole of the lower housing assembly with a slight clearance, and its lower end has a connection mechanism with the engine; a shoulder is arranged on the outer circle of the valve core, and oil grooves I and II are arranged on the outer circle of the valve core above and below the shoulder; an inlet high-pressure oil port, an outlet high-pressure oil port communicating with oil groove I and an oil return port communicating with oil groove II are arranged on the valve sleeve; when the propeller is operating normally at the selected balanced speed, the shoulder blocks the outlet high-pressure oil port on the valve sleeve; when the propeller speed becomes smaller than the selected balanced speed, the shoulder is at the lower end of the outlet high-pressure oil port, and the outlet high-pressure oil port communicates with the inlet high-pressure oil port; when the propeller speed becomes larger than the selected balanced speed, the shoulder is at the upper end of the outlet high-pressure oil port, and the outlet high-pressure oil port communicates with the oil return port; The circumferential wall of the speed selection stop assembly is disconnected, one of the two end walls of the disconnected circumferential wall is provided with a through hole, and the other is provided with a threaded hole, and the two are fixed together by a stud with a perforated spherical head II and a light spring washer II; The centrifugal counterweight assembly includes a support, two correspondingly distributed centrifugal blocks and a spiral retaining ring; the lower end of the support is sleeved with a spline and clamped on the outer circle of the upper end of the valve sleeve; the two centrifugal blocks are respectively assembled on the support with a clearance between the shaft and the bearing, and a spiral retaining ring is clamped and fixed on the outer wall of the upper end of the support, and both ends of the shaft are abutted against the inner end wall of the spiral retaining ring; the hook end abutted against the bottom convex platform of the bearing is provided with an arc surface.

2. The speed selection mechanism of the propeller governor according to claim 1, characterized in that: The circumferential wall at one end of the speed selection handle with an internal spline hole is disconnected, a through hole is opened on one of the two end walls of the disconnected circumferential wall, a threaded hole is opened on the other, and the two are fixed together by a stud with a perforated spherical head Ⅰ and a light spring washer Ⅰ.

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