A speed measuring generator for environment-resistant aircraft engines

Abstract

The present invention provides an environment-resistant tachometer generator for aircraft engines, which solves the problem that existing tachometer generators fail to take into account strength, temperature resistance, corrosion resistance and sealing. The tachometer generator includes a front housing, a rotor, a stator, a rear housing, a locking nut, a connecting nut, a ball, a sealing plug, a connector, a shaft end nut, an end sleeve, a sealing assembly, a sealing ring, a sealing gasket, a rear cover, and a baffle. The tachometer generator of the present invention has the advantages of high reliability, good sealing, strong corrosion resistance, a wide application temperature range, and stable output signals, and can be extended to aerospace, weapons, ships, and other equipment with similar needs.

Description

Technical Field

[0001] The invention belongs to the technical field of tachometer generators and relates to a tachometer generator for an environment-resistant aircraft engine. Background Art

[0002] A tachometer generator is a device that converts the speed of a rotating part to be measured into an electrical signal output, and the speed of the measured part is known by monitoring the electrical signal. The tachometer generator used to monitor the speed of aircraft engines has an extremely harsh working environment. The existing tachometer generators fail to take into account strength, temperature resistance, corrosion resistance and sealing. To address this problem, a tachometer generator that can stably monitor the speed of aircraft engines for a long time in harsh environments is now provided. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a tachometer generator capable of stably monitoring the rotation speed of an aircraft engine for a long time in a harsh environment.

[0004] In order to achieve the above-mentioned object, the present invention adopts the following technical scheme: an environment-resistant aircraft engine tachometer generator, the tachometer generator comprising a front housing, a rotor, a stator, a rear housing, a locking nut, a connecting nut, a ball, a sealing plug, a connector, a shaft end nut, an end sleeve, a sealing assembly, a sealing gasket, a rear cover, and a baffle;

[0005] The front housing and the rear housing are fixed by screws, and the stator is placed in a cavity formed after the front housing and the rear housing are installed; the rotor is axially placed in the stator, and the rotor includes a connecting rod, a shaft, a magnetic steel, and a limit ring, the magnetic steel is die-cast on the shaft by die-casting, the connecting rod is axially placed inside the shaft, an annular groove is provided at the tail end of the connecting rod, and the limit ring is installed in the annular groove;

[0006] The front and rear ends of the shaft are supported by the first bearing and the second bearing placed in the bearing chambers of the front housing and the rear housing respectively. An end sleeve is installed on the outer periphery of the front end of the front housing by means of a thread, a connecting nut is installed on the outer periphery of the end sleeve, and a plurality of balls are filled between the connecting nut and the end sleeve. A baffle cover is sleeved on the outer periphery of the shaft at the front end of the first bearing, and a sealing assembly is installed on the outer periphery of the baffle cover. The sealing assembly is fixed to the front end of the first bearing through a locking nut, and the baffle cover and the first bearing are locked on the shaft at the front end of the baffle cover through the shaft end nut, thereby fixing the shaft axially. The sealing gasket is pressed onto the rear housing by the rear cover, and the sealing plug is interference fit in the cavity after the rear housing and the connector are installed.

[0007] Furthermore, a sealing ring is installed on the butt joint surface between the front shell and the rear shell, and the front shell and the rear shell clamp and fix the sealing ring.

[0008] Furthermore, the sealing assembly includes a sealing cover, multiple sealing sheets, and a retaining spring. The multiple sealing sheets are fixed and compressed in the sealing cover by the retaining spring, and the multiple sealing sheets are sleeved in parallel on the outer periphery of the blocking cover. The sealing sheets are made of polytetrafluoroethylene material.

[0009] Furthermore, the sealing pad and the sealing plug are both made of heat-resistant and oil-resistant rubber material.

[0010] Furthermore, the sealing ring is made of heat-resistant and oil-resistant rubber material.

[0011] Furthermore, the connecting rod includes a small diameter section cylinder and a large diameter section cylinder, the step between the small diameter section cylinder and the large diameter section cylinder is a first smooth transition step, a connector for docking with the rotating end of the engine is provided at the front end of the small diameter section cylinder, four axially symmetrical rectangular sections are cut from the outer circumference of the large diameter section cylinder along the tail end to the front end, the axial length of the rectangular section is smaller than the axial length of the large diameter section cylinder, and the annular groove is located at the tail end of the large diameter section cylinder after the section is cut.

[0012] Furthermore, the shaft comprises a first cylindrical segment, a second cylindrical segment, a third cylindrical segment and a fourth cylindrical segment which are axially connected in sequence and integrally formed, wherein the outer diameters of the first cylindrical segment, the second cylindrical segment and the third cylindrical segment increase in sequence, the outer diameter of the fourth cylindrical segment is smaller than the outer diameter of the third cylindrical segment, and an inner square hole is provided in the fourth cylindrical segment, and at the same time, a cylindrical inner hole is provided inside the shaft from the front end of the inner square hole to the front end face of the first cylindrical segment of the shaft, and a second smooth transition step is provided between the end end face of the cylindrical inner hole and the front end face of the inner square hole; two spherical protrusions are provided on the outer periphery of the second cylindrical segment at intervals, and two planes are symmetrically provided on each spherical protrusion.

[0013] Furthermore, four grooves are evenly distributed on the outer circumferential surface of the first cylindrical segment, and the boss end of the shaft end nut is pressed and falls into the four grooves for locking.

[0014] Furthermore, four inclined slots are provided in the axial direction of the outer periphery of the magnetic steel, and the magnetic steel is subjected to four-level saturation magnetization.

[0015] Furthermore, the lead-out end of the stator lead-out wire passes through the sealing plug and is connected to the contact body of the connector, and the lead-out wire is fixed to the protrusion of the rear housing by a wire pressing piece, and the winding of the stator adopts high-temperature special enameled wire.

[0016] Compared with the prior art, the present invention has the following beneficial effects: the present invention designs multiple sealing structures, and the sealing gaskets, sealing plugs, and sealing rings are all made of heat-resistant and oil-resistant rubber materials, which can effectively prevent dust and oil. The front shell and the rear shell of the tachometer generator are both machined, and the outer surfaces are spray-painted. Such treatment can ensure that the two shells have high strength, strong corrosion resistance and beautiful appearance. The rotor magnetic steel structure is integrally die-cast on the shaft, and four inclined slots are provided in the axial direction of the outer periphery of the magnetic steel, and the permanent magnet is magnetized by four-level saturation. This structure has high reliability and can effectively reduce the cogging torque, so that the output voltage and frequency signal of the tachometer generator are stable. The stator winding uses high-temperature special enameled wire, which can withstand a high temperature of up to 250°C, and is provided with a wire pressing piece to fix the lead wire, which can ensure that the lead wire does not shake inside the tachometer generator. All threaded connections are glued to ensure reliable connection when the tachometer generator is running.

[0017] The tachometer generator of the present invention has the advantages of high reliability, good sealing, strong corrosion resistance, wide application temperature range and stable output signal, and can be extended to aerospace, weapons, ships and other equipment with similar requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the present invention;

[0019] Figure 2 It is a schematic structural diagram of the rotor of the present invention;

[0020] Figure 3 It is a schematic diagram of the rotor coupling rod structure;

[0021] Figure 4 is a schematic diagram of the shaft structure of the rotor;

[0022] Figure 5 It is a schematic diagram of the overall appearance of the rotor;

[0023] Figure 6 It is a schematic diagram of the connection between the coupling rod and the shaft;

[0024] Figure 7 is a schematic diagram of the structure of the sealing assembly;

[0025] Figure 8 It is a schematic diagram of the overall external structure of the present invention;

[0026] In the figure: 1-front housing; 2-rotor; 2-1-coupling rod; 2-1-1-small diameter section cylinder; 2-1-2-large diameter section cylinder; 2-1-2-1-rectangular section; 2-1-2-2-annular groove; 2-1-3-first smooth transition step; 2-1-4-connector; 2-2-shaft; 2-2-1-first cylindrical section; 2-2-2-second cylindrical section; 2-2-3-third cylindrical section; 2-2-4-fourth cylindrical section; 2-2-4-1-inner square hole; 2-2-5-spherical protrusion; 2 -2-5-1-plane; 2-2-6-cylindrical inner hole; 2-3-magnet; 2-3-1-bevel groove; 2-4-limit ring; 3-stator; 4-rear housing; 5-locking nut; 6-connecting nut; 7-ball; 8-sealing plug; 9-connector; 10-shaft end nut; 11-end sleeve; 12-sealing assembly; 12-1-sealing cover; 12-2-sealing plate; 12-3-circlip; 13-sealing ring; 14-sealing gasket; 15-rear cover; 16-blocking cover; 17-wire pressing plate; 18-first bearing; 19-second bearing. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Example

[0029] Reference Figure 1 and Figure 8 , an environment-resistant aircraft engine tachometer generator, the tachometer generator comprises a front housing 1, a rotor 2, a stator 3, a rear housing 4, a locking nut 5, a connecting nut 6, a ball 7, a sealing plug 8, a connector 9, a shaft end nut 10, an end sleeve 11, a sealing assembly 12, a sealing gasket 14, a rear cover 15, and a baffle 16;

[0030] The front housing 1 and the rear housing 4 are fixed by screws, and the stator 3 is placed in a cavity formed after the front housing 1 and the rear housing 4 are installed; the rotor 2 is axially placed in the stator 3, and the rotor 2 includes a connecting rod 2-1, a shaft 2-2, a magnetic steel 2-3, and a limit ring 2-4. The magnetic steel 2-3 is die-cast on the shaft 2-2 by die-casting. The connecting rod 2-1 is axially placed inside the shaft 2-2, and an annular groove 2-1-2-2 is provided at the tail end of the connecting rod 2-1, and the limit ring 2-4 is installed in the annular groove 2-1-2-2;

[0031] The front and rear ends of the shaft 2-2 are supported by a first bearing 18 and a second bearing 19 respectively placed in the bearing chambers of the front housing 1 and the rear housing 4. An end sleeve 11 is installed on the outer periphery of the front end of the front housing 1 by a threaded manner, and a connecting nut 6 is installed on the outer periphery of the end sleeve 11. A plurality of balls 7 are filled between the connecting nut 6 and the end sleeve 11. A baffle 16 is sleeved on the outer periphery of the shaft 2-2 at the front end of the first bearing 18, and a sealing assembly 12 is installed on the outer periphery of the baffle 16. The sealing assembly 12 is fixed to the front end of the first bearing 18 through a locking nut 5. The baffle 16 and the first bearing 18 are locked on the shaft 2-2 at the front end of the baffle 16 through the shaft end nut 10, thereby axially fixing the shaft 2-2. The sealing gasket 14 is pressed onto the rear housing 4 by the rear cover 15, and the sealing plug 8 is interference fit in the cavity after the rear housing 4 and the connector 9 are installed.

[0032] A sealing ring 13 is installed on the butt joint surface between the front housing 1 and the rear housing 4 , and the front housing 1 and the rear housing 4 clamp and fix the sealing ring 13 .

[0033] Reference Figure 7 The sealing assembly 12 includes a sealing cover 12-1, a plurality of sealing sheets 12-2, and a retaining spring 12-3. The plurality of sealing sheets 12-2 are fixed and compressed in the sealing cover 12-1 by the retaining spring 12-3, and the plurality of sealing sheets 12-2 are parallelly mounted on the outer periphery of the blocking cover 16.

[0034] The sealing sheet 12 - 2 is made of polytetrafluoroethylene material.

[0035] The sealing pad 14 and the sealing plug 8 are both made of heat-resistant and oil-resistant rubber materials.

[0036] The sealing ring 13 is made of heat-resistant and oil-resistant rubber material.

[0037] Reference Figure 2-Figure 4 The connecting rod 2-1 comprises a small diameter section cylinder 2-1-1 and a large diameter section cylinder 2-1-2, the step between the small diameter section cylinder 2-1-1 and the large diameter section cylinder 2-1-2 is a first smooth transition step 2-1-3, a connector 2-1-4 for docking with the rotating end of the engine is provided at the front end of the small diameter section cylinder 2-1-1, four axially symmetrical rectangular sections 2-1-2-1 are cut from the rear end to the front end of the outer circumference of the large diameter section cylinder 2-1-2, the axial length of the rectangular section 2-1-2-1 is smaller than the axial length of the large diameter section cylinder 2-1-2, and the annular groove 2-1-2-2 is located at the rear end of the large diameter section cylinder 2-1-2 after the section is cut.

[0038] The shaft 2-2 comprises a first cylindrical segment 2-2-1, a second cylindrical segment 2-2-2, a third cylindrical segment 2-2-3 and a fourth cylindrical segment 2-2-4 which are axially connected in sequence and integrally formed, wherein the outer diameters of the first cylindrical segment 2-2-1, the second cylindrical segment 2-2-2 and the third cylindrical segment 2-2-3 increase in sequence, the third cylindrical segment 2-2-3 is a shaft shoulder, the outer diameter of the fourth cylindrical segment 2-2-4 is smaller than the outer diameter of the third cylindrical segment 2-2-3, and an inner four-piece is provided in the fourth cylindrical segment 2-2-4. Square hole 2-2-4-1, and at the same time, a cylindrical inner hole 2-2-6 is provided inside the shaft from the front end face of the inner square hole 2-2-4-1 to the front end face of the first cylindrical section 2-2-1 of the shaft, and a second smooth transition step 2-2-4-2 is provided between the end face of the cylindrical inner hole 2-2-6 and the front end face of the inner square hole 2-2-4-1; two spherical protrusions 2-2-5 are provided at intervals on the outer periphery of the second cylindrical section 2-2-2, and two planes 2-2-5-1 are symmetrically provided on each spherical protrusion 2-2-5. When the coupling rod is placed inside the shaft, the large diameter section cylinder 1-2 of the coupling rod is placed in the inner square hole 2-4-1 of the fourth cylindrical section 2-4 of the shaft, and the large diameter section cylinder 1-2 with a rectangular cross section 1-5 is placed in the inner square hole 2-4-1 of the shaft 2, and the step surface of the first smooth transition step 2-7 fits with the step surface of the second smooth transition step 2-7. At this time, there is a gap between the rectangular cross section 1-5 and the inner square hole 2-4-1, and the gap between each rectangular cross section 1-5 and the inner square hole 2-4-1 is 0.02mm-0.05mm.

[0039] Four grooves 2-2-1-1 are evenly distributed on the outer circumference of the first cylindrical segment 2-2-1, and the boss end of the shaft end nut 10 is pressed and falls into the four grooves 2-2-1-1 to be locked.

[0040] The coupling rod 2-1 is made of high-hardness stainless steel material with good wear resistance, which can ensure long-term effective operation under the condition of docking with external rotating parts.

[0041] Reference Figure 5 Four inclined grooves 2-3-1 are provided in the axial direction of the outer periphery of the magnetic steel 2-3, and the magnetic steel 2-3 is subjected to four-level saturation magnetization.

[0042] The lead-out end of the lead-out wire of the stator 3 passes through the sealing plug 8 and is connected to the contact body of the connector 9 , and the lead-out wire is fixed to the protrusion of the rear housing 4 by a wire pressing piece 17 .

[0043] The stator 3 includes a stator core and a winding, and the winding enameled wire adopts a high-temperature special enameled wire.

[0044] The front housing 1 and the rear housing 4 are both machined, and their outer surfaces are spray-painted.

[0045] All threaded connections in the tachometer generator are coated with thread locking glue.

[0046] The connector 2-1-4 of the connecting rod 2-1 of the tachometer generator rotor of the present invention is connected to the rotating end of the engine and drives the rotor 2 to rotate to generate a magnetic field. The stator 3 generates an induced electromotive force through the induced magnetic field, and outputs voltage and frequency signals to the outside through the connector 9. The output voltage and frequency signals are monitored to measure the engine speed.

[0047] The tachometer generator of the present invention is provided with multiple sealing structures. The sealing gasket, sealing plug and sealing ring are all made of heat-resistant and oil-resistant rubber materials. The sealing sheet is made of polytetrafluoroethylene material, which can effectively prevent dust and oil. The front shell and the rear shell of the tachometer generator are both machined, and the outer surfaces are spray-painted. Such treatment can ensure that the two shells have high strength, strong corrosion resistance and beautiful appearance. The stator winding uses high-temperature special enameled wire, which can withstand a maximum temperature of 250°C, and is provided with a wire pressing piece to fix the lead wire, which can ensure that the lead wire does not shake inside the tachometer generator.

[0048] The magnetic steel of the present invention is a permanent magnetic material that is die-casted with the shaft as a whole by die-casting. Such a structure improves production efficiency and reduces material consumption. Four inclined grooves are provided on the periphery of the magnetic steel, and four-level saturation magnetization is adopted for the magnetic steel. Such a structure has high reliability and can effectively reduce the cogging torque, so that the output voltage and frequency signal of the tachometer generator are stable. In addition, two spherical protrusions 2-5 with a planar structure are provided on the shaft, and the magnetic steel is die-casted on the outside of the two spherical protrusions 2-5. Such a structure can effectively prevent the problem of circumferential and axial movement of the magnetic steel under severe vibration conditions.

[0049] In addition, the connecting rod 1 is designed as a slender rod structure, which has good toughness and is connected to the shaft 2 with a small gap. Figure 6 , (the gap between each rectangular section 1-5 and the inner square hole 2-4-1 is 0.02mm-0.05mm, and the gap value can be adjusted between 0.02mm-0.05mm according to the actual range of circumferential movement of the end of the connecting rod). This connection method can ensure that the connecting rod rotates synchronously with the shaft, and can ensure that the connecting rod moves at a small angle in the circumferential direction with the axis as the center, overcoming the problem of high coaxiality requirements when docking with external rigid rotating parts, and can effectively prevent the problem of the connecting rod breaking due to stress concentration when docking with external rotating parts. The limit ring 4 is a circular ring formed by bending stainless steel wire, which is stuck in the annular groove 1-6, and the large diameter section cylinder 1-2 with the rectangular section 1-5 is placed in the inner square hole 2-4-1 of the shaft 2. The step structure in which the first smooth transition step 2-7 and the step surface of the second smooth transition step 2-7 fit together play an axial limiting role for the connecting rod 1.

[0050] The tachometer generator of the present invention has the advantages of high reliability, good sealing, strong corrosion resistance, wide application temperature range and stable output signal, and can be extended to aerospace, weapons, ships and other equipment with similar requirements.

[0051] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An environmentally resistant aircraft engine tachometer generator, characterized in that: The tachometer generator comprises a front housing, a rotor, a stator, a rear housing, a locking nut, a connecting nut, a ball, a sealing plug, a connector, a shaft end nut, an end sleeve, a sealing assembly, a sealing gasket, a rear cover and a baffle; The front housing and the rear housing are fixed by screws, and the stator is placed in a cavity formed after the front housing and the rear housing are installed; the rotor is axially placed in the stator, and the rotor includes a connecting rod, a shaft, a magnetic steel and a limit ring, the magnetic steel is die-cast on the shaft by die-casting, the connecting rod is axially placed inside the shaft, an annular groove is provided at the tail end of the connecting rod, and the limit ring is installed in the annular groove; The front and rear ends of the shaft are supported by the first bearing and the second bearing placed in the bearing chambers of the front housing and the rear housing respectively. An end sleeve is installed on the outer periphery of the front end of the front housing by means of a thread, a connecting nut is installed on the outer periphery of the end sleeve, and a plurality of balls are filled between the connecting nut and the end sleeve. A baffle cover is sleeved on the outer periphery of the shaft at the front end of the first bearing, and a sealing assembly is installed on the outer periphery of the baffle cover. The sealing assembly is fixed to the front end of the first bearing by a locking nut, and the baffle cover and the first bearing are locked by a shaft end nut on the shaft at the front end of the baffle cover, thereby fixing the shaft axially. The sealing gasket is pressed on the rear housing by the rear cover, and the sealing plug is interference fit in the cavity after the rear housing and the connector are installed. A sealing ring is installed on the butt joint surface of the front shell and the rear shell, and the front shell and the rear shell clamp and fix the sealing ring; The connecting rod includes a small diameter section cylinder and a large diameter section cylinder, the step between the small diameter section cylinder and the large diameter section cylinder is a first smooth transition step, a connector for docking with the rotating end of the engine is provided at the front end of the small diameter section cylinder, four axially symmetrical rectangular sections are cut from the rear end to the front end of the outer circumference of the large diameter section cylinder, the axial length of the rectangular section is smaller than the axial length of the large diameter section cylinder, and the annular groove is located at the rear end of the large diameter section cylinder after the rectangular sections are cut.

2. The environment-resistant aircraft engine tachometer generator according to claim 1, characterized in that: The sealing assembly comprises a sealing cover, a plurality of sealing sheets and a retaining spring. The plurality of sealing sheets are fixed and pressed in the sealing cover by the retaining spring. The plurality of sealing sheets are sleeved in parallel on the outer periphery of the blocking cover. The sealing sheets are made of polytetrafluoroethylene material.

3. The environment-resistant aircraft engine tachometer generator according to claim 1, characterized in that: The sealing pad and the sealing plug are both made of heat-resistant and oil-resistant rubber material.

4. The environment-resistant aircraft engine tachometer generator according to claim 1, characterized in that: The sealing ring is made of heat-resistant and oil-resistant rubber material.

5. The environment-resistant aircraft engine tachometer generator according to claim 1, characterized in that: The shaft comprises a first cylindrical segment, a second cylindrical segment, a third cylindrical segment and a fourth cylindrical segment which are axially connected in sequence and integrally formed, wherein the outer diameters of the first cylindrical segment, the second cylindrical segment and the third cylindrical segment increase in sequence, the outer diameter of the fourth cylindrical segment is smaller than the outer diameter of the third cylindrical segment, and an inner square hole is provided in the fourth cylindrical segment, and a cylindrical inner hole is provided inside the shaft from the front end of the inner square hole to the front end face of the first cylindrical segment of the shaft, and a second smooth transition step is provided between the end face of the cylindrical inner hole and the front end face of the inner square hole; two spherical protrusions are provided at intervals on the outer periphery of the second cylindrical segment, and two planes are symmetrically provided on each spherical protrusion.

6. The environment-resistant aircraft engine tachometer generator according to claim 5, characterized in that: Four grooves are evenly distributed on the outer circumferential surface of the first cylindrical segment.

7. The environment-resistant aircraft engine tachometer generator according to claim 1, characterized in that: Four oblique slots are arranged in the axial direction of the outer periphery of the magnetic steel, and the magnetic steel is subjected to four-level saturation magnetization.

8. The environment-resistant aircraft engine tachometer generator according to claim 1, characterized in that: The lead-out end of the lead-out wire of the stator passes through the sealing plug and is connected to the contact body of the connector, and the lead-out wire is fixed to the protrusion of the rear shell body by a wire pressing piece. The winding of the stator adopts high-temperature special enameled wire.

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