Patent Application
20090185939
1. Field of the Invention
The present invention relates to a constructing technique for a trochoid pump applicable in a fuel injection pump, in a fuel injection device of a diesel engine.
2. Related Art
Conventionally, there are well-known trochoid pumps as forms of pumps. For example, as described in JP 2002-98065, a trochoid pump, which is applicable as a fuel injection pump in a fuel injection device of a diesel engine, is disclosed. The diesel engine needs to pressurize fuels at high pressure and inject them so as to delivery them into the air compressed at high pressure in a combustion chamber. The fuel injection device assumes pressurizing and sending fuels. The fuel injection device includes the fuel injection pump that pressurizes fuels at high pressure and sends them into injection nozzles, as well as injection nozzles that inject fuels into cylinders.
The prior art on a trochoid pump 200 will be described with reference to
A drive gear 207 as a bevel gear is annealed and fixed into, or pressed into one end of a driving shaft 203. The other end of the driving shaft 203 is penetrated into the central portion of the inner rotor 201 and supported in the cap 205. A rotational direction of the inner rotor 201 is regulated by a drive pin 218.
A camshaft 209 is driven via the gear by a crankshaft (not shown) and it vertically moves a plunger (not shown) by rotating a cam (not shown) formed on the camshaft 209 and rotates the drive gear 208. In this regard, the camshaft 209 drives the driving shaft 203 via the bevel gear composed of the drive gears 207, 208.
Due to the above-mentioned construction, as the inner rotor 201 is driven by the camshaft 209, the outer rotor 202 is rotated. Because the centers of the inner rotor 201 and the outer rotor 202 are decentered and the numbers of teeth of the inner rotor 201 are one less than them of the outer rotor 202, the fuel oil is interposed between the rotors 201 and 202 and is delivered from a inlet port (not shown) to a outlet port (not shown).
Due to the above-mentioned construction of the trochoid pump 200, the driving shaft 203 is regulated by the cap 205 and the drive gear 208 in a thrust direction (in a direction of arrow in
However, when the drive gear 208 as the bevel gear is abraded, the driving shaft 203 is offset in the thrust direction, thereby increasing a backlash (a gap when the gears are meshed with). The more the backlash increases, the more the abrasion of the drive gears 207 and 208 increase, thereby shortening the life cycle of a product.
The problem so as to be solved is to prevent the offset of the driving shaft to the thrust direction in the trochoid pump.
The problem so as to be solved by the present invention is as mentioned above. Next, the means of solving the problem will be described.
The present invention comprises a trochoid pump, comprising a driving shaft, wherein a drive gear comprising of a bevel gear is fixed on one end thereof and a inner rotor is penetrated onto the other end thereof, an outer rotor, the center of which is decentered to the inner rotor, wherein both rotors are covered with the cap and the casing, a first regulatory structure, wherein the driving shaft or a means of control fixed on the driving shaft regulates an one-way movement to the casing, a second regulatory structure, wherein an end face of the other side of the driving shaft is engaged with one end of the cap and regulates the other way movement of the cap, wherein the thrust of the driving shaft is axially regulated by the first regulatory structure and by the second regulatory structure.
In the present invention, one part of the driving shaft is a different diameter shaft which is larger than the diameter of the driving shaft, and the first regulatory structure is constructed to join the end face of the different diameter shaft with that of the inner rotor.
In the present invention, a double-sided portion is provided on the different diameter shaft, a joint is disposed on the inner rotor, wherein it is fixed with the double-sided portion, and the inner rotor is driven by the different diameter shaft.
In the present invention, a specially shaped drive pin, which a tetrahedral shape is provided on both sides thereof and a joint, which the tetrahedral shape is fixed on to the inner rotor, wherein the first regulatory structure is constructed to join one side of the tetrahedral shape with one side of the joint, and the inner rotor is driven by the tetrahedral shape.
The present invention shows the following effects.
In the present invention, because a position of the thrust direction of the driving shaft is determined, an increase in the abrasion of the drive gear can be prevented when the drive gear is abraded. The movable scope of the driving shaft can be adjusted by single piece of the trochoid pump, thereby improving the operability of the trochoid pump.
In the present invention, the effect can be realized with a simple construction that one part of the driving shaft is different from other portion of it in diameter.
In the present invention, the rotational direction of the inner rotor can be regulated toward the driving shaft without the conventional drive pin, thereby reducing the number of components of the trochoid pump.
In the present invention, the conventional drive pin has two functions by fabricating it, thereby reducing the number of components of the trochoid pump. The thrust direction of the driving shaft and the rotational direction of the inner rotor are regulated by the proximal contacts thereof, thereby advancing the regulatory accuracy and increasing the durability due to the reduction in the abrasion of the contact portions.
Next, embodiments of the present invention will be described.
A distributor type pump 250 that a trochoid pump of the present invention is applicable will be briefly described with reference to
A camshaft 209, which is rotatably supported on the lower side of the in the distributor type pump 250, is transversely situated. A cam 212 is fixed on the camshaft 209 and a plunger 260 is provided on the upper side of the cam 212. Due to the above construction, the cam 212 and the camshaft 209 are integrally rotatable, and the plunger 260 is vertically movable by rotating the cam 212. A fuel gallery 265 is formed in a housing of the distributor type pump 250.
A distribution shaft 270 is provided parallel to the plunger 260 on the side of the plunger 260, and a driving shaft 203 is connected to the lower side of the distribution shaft 270. The driving shaft 203 is drivingly connected to the camshaft 209 via bevel gears 207 and 208, thereby driving the distribution shaft 270. A trochoid pump 200 is coaxially disposed onto the driving shaft 203 and is driven by the driving shaft 203.
Due to the above construction of the distributor type pump 250, fuels in a fuel tank 291 are pressurized and sent into the fuel gallery 265 through a fuel tubing 292 by the trochoid pump 200 and a feed pump 290. The pressurized fuels are sent into the distribution shaft 270 as the plunger 260 is upwardly moved, and they are further sent in a distribution chase (not shown) provided on the distribution shaft 270. Finally, the fuels are supplied with delivery valves 293 of the respective cylinders. The pressurized fuels supplied with the delivery valves 293 are sent into a injection nozzle 294 and injected from thence.
Next, the trochoid pump 200 according to the present invention will be briefly described with reference to
The trochoid pump 200 is constituted so that the inner rotor 201 and the outer rotor 202 are embedded with a pump aperture 223 of the casing 206. The inner rotor 201 is rotatably driven by the driving shaft 203. The outer rotor 202 meshed with the inner rotor 201 is rotated in the same direction with the inner rotor 201.
Due to the above construction, a plurality of pump chambers formed between the inner rotor 201 and the outer rotor 202 are movable so as to change the volumes thereof. A fuel oil is inlet from a inlet port 220 formed so that the volumes of the pump chambers are gradually increased, and the fuel oil s are discharged from the outlet port 221 formed so that the volumes of the pump chambers are gradually decreased
The present invention comprises a trochoid pump, wherein a driving shaft, which a drive gear comprising of a bevel gear is fixed on one end thereof and a inner rotor is penetrated onto the other end thereof, an outer rotor, which is decentered to the inner rotor, and wherein both rotors are covered with the cap and the casing, the thrust of the driving shaft is axially regulated by a first regulatory structure, that the driving shaft itself or a means of control fixed on the driving shaft regulates an one-way movement to the casing and by a second regulatory structure, that an end face on the other side of the driving shaft regulates the other way movement of the cap resulting from the joining with one side of the cap.
In this regard, embodiments 1 to 11 according to the trochoid pumps of the present invention will be described below, mainly with pattern cross-sectional diagrams (
Hereinafter, with respect to the thrust directions of the driving shafts 13 to 113, the sides of the removable caps 15 to 115 (the observers' left side) are defined as the front sides, and the sides of the drive gears 17 to 117 (the observers' right side) are defined as the rear sides. In other words, with regard to
As the first embodiment of the present invention, a trochoid pump 10 will be described with reference to the pattern cross-sectional diagram as shown in
The driving shaft 13 is constituted as the different diameter shaft 13X so that the diameter from the end of the front side to the midstream thereof is larger than that of the driving shaft 13. In this regard, the portion, which the diameter of the driving shaft 13 is changed, is defined as a stepped section 13 R. In addition, the drive pin 18 is inserted into the midstream of the driving shaft 13 perpendicular to the direction of the shaft center, and engagement portions (not shown), which engage with both ends of the drive pin 18, are formed on the inner surface of the front side of the inner rotor 11.
When the above-mentioned driving shaft 13 is covered with the casing 16 and the cap 15, the end face 13b on the rear side of the stepped section 13 R is engaged with the end face 13a on the front side of the inner rotor 11, thereby consisting of the first regulatory structure. The end face 13a on the front side of the driving shaft 13 is engaged with the inner end face 15a of the cap 15, thereby consisting of the second structure.
Due to the above construction, the end face 13a on the front side of the driving shaft 13 is engaged with the inner end face 15a of the cap 15 toward the front side of the thrust direction of the driving shaft 13, thereby consisting of the second regulatory structure. The end face 13b on the rear side of the stepped section 13 R is engaged with the end face 11b on the front side of the inner rotor 11, thereby consisting of the first regulatory structure. In other words, the driving shaft 13 is regulated in the thrust direction.
In the embodiment, one portion of the driving shaft 13 is composed of the simple construction as the different diameter shaft 13X, so that the position in the thrust direction of the driving shaft 13 is determined. Thus, even if the drive gear 17 is abraded, the offset of the driving shaft 13 remains unchanged, thereby preventing the increase in the abrasion of the drive gear 17. In addition, the movable scope of the driving shaft 13 can be adjusted by the single piece of the trochoid pump 10, thereby advancing the operability of the trochoid pump 10.
As the second embodiment of the present invention, a trochoid pump 20 will be described with reference to the pattern cross-sectional diagram as shown in
Moreover, as shown is
When the above-mentioned driving shaft 23 is disposed on the inner rotor 21, the end face 23a on the front side of the driving shaft 23 is engaged with the inner end face 25a of the cap 25, and the end face 23b on the rear side of the stepped section 23 R is engaged with the end face 21b on the rear side of the joint 21G in the inner rotor 21. The dihedral portion 23c of the driving shaft 23 is engaged with the notch 21c on the joint 21G in the inner rotor 21, thereby transmitting the revolution drive to it.
Due to the above construction, the end face 23a on the front side of the driving shaft 23 is engaged with the inner end face 25a of the cap 25 toward the front side of the thrust direction, thereby consisting of the second regulatory structure. In addition, the end face 23b on the rear side of the stepped section 23 R is engaged with the end face 21b on the front side of the joint 21G in the inner rotor 21 toward the rear side of the thrust direction, thereby consisting of the first regulatory structure. In other words, the driving shaft 23 is regulated in the thrust direction.
Moreover, as the dihedral portion 23c of the driving shaft 23 is fixed on the joint 21G, the inner rotor 21 is regulated toward the driving shaft 23 in the rotational direction thereof, thereby transmitting the revolution drive to it.
In the embodiment, one portion of the driving shaft 23 is composed of the simple construction as the different diameter shaft 23X, so that the position in the thrust direction of the driving shaft 23 is determined. Thus, even if the drive gear 27 is abraded, the offset of the driving shaft 23 remains unchanged, thereby preventing the increase in the abrasion of the drive gear 27. In addition, the movable scope of the driving shaft 23 can be adjusted by the single piece of the trochoid pump 20, thereby advancing the operability of the trochoid pump 20.
In the embodiment, the rotational direction of the inner rotor 21 toward the driving shaft 23 is regulated by forming the dihedral portion 23c on the driving shaft 23 without the conventional drive pin, thereby reducing the number of components of the trochoid pump 20.
As the third embodiment of the present invention, a trochoid pump 30 will be described with reference to the pattern cross-sectional diagram as shown in
In the embodiment, one portion of the driving shaft 33 is composed of the simple construction as the different diameter shaft 33X that is removable by the bolt 34, so that the position in the thrust direction of the driving shaft 33 is determined. Thus, even if the drive gear 37 is abraded, the offset of the driving shaft 33 remains unchanged, thereby preventing the increase in the abrasion of the drive gear 37. In addition, the movable scope of the driving shaft 33 can be adjusted by the single piece of the trochoid pump 30, thereby advancing the operability of the trochoid pump 30.
In the embodiment, also, the rotational direction of the inner rotor 31 toward the driving shaft 33 is regulated by forming the dihedral portion 33c on the driving shaft 33 without the conventional drive pin, thereby reducing the number of components of the trochoid pump 30.
Moreover, as the different diameter shaft 33X is removable by the bolt 34, without the stepped processes on the shaft as the first and second embodiments, the workability can be improved, thereby reducing the number of the fabrication processes. In this regard, as the different diameter shaft 33X is removable by the bolt 34, the trochoid pump 30 can be easily decomposable, even if the drive gear 37 is fixed with expansion fit etc., thereby advancing the maintenance performance.
As the forth embodiment of the present invention, a trochoid pump 40 will be described with reference to the pattern cross-sectional diagram as shown in
With reference to
When the above-mentioned driving shaft 43 is covered with the casing 46 and the cap 45, the end face 43a on the front side of the driving shaft 43 is engaged with the inner end face 45a of the cap 45.
Due to the above construction, the end face 43a on the front side of the driving shaft 43 is engaged with the inner end face 45a of the cap 45 toward the front side of the thrust direction, thereby consisting of the second regulatory structure. The end face 44b on the rear side of the horseshoe piece 44 is engaged with the end face 41b on the front side of the inner rotor 41 toward the rear side of the thrust direction, thereby consisting of the first regulatory structure. In other words, the driving shaft 43 is regulated in the thrust direction.
In the embodiment, the driving shaft 43 is composed of the simple construction as the horseshoe piece 44, so that the position in the thrust direction of the driving shaft 43 is determined. Thus, even if the drive gear 47 is abraded, the offset of the driving shaft 43 remains unchanged, thereby preventing the increase in the abrasion of the drive gear 47. In addition, the movable scope of the driving shaft 43 can be adjusted by the single piece of the trochoid pump 40, thereby advancing the operability of the trochoid pump 40.
In the embodiment, also, as the horseshoe piece 44 is provided on the driving shaft 43, without the stepped processes on the shaft as the first and second embodiments, the workability can be improved, thereby reducing the number of the fabrication processes.
Moreover, as the horseshoe piece 44 is removable, the trochoid pump 40 can be easily decomposable, thereby advancing the maintenance performance. At the same time, the trochoid pump 40 is easily manufacturable, thereby reducing the number of the fabrication processes.
As the fifth embodiment of the present invention, a trochoid pump 50 will be described with reference to the pattern cross-sectional diagram as shown in
In the driving shaft 53, a chase is furrowed around the front side of the inner rotor 51 and into which a horseshoe piece 54 is fixturable therein. A dihedral portion 54c is provided on the outer circumference of the horseshoe piece 54
In addition, as shown in
As shown in
When the above-mentioned driving shaft 53 is covered with the casing 56 and the cap 55, the end face 53a on the front side of the driving shaft 53 is engaged with the inner end face 55a of the cap 55, and the end face 55b on the rear side of the horseshoe piece 54 is engaged with the end face 54b on the front side of the joint 51G on the inner rotor 51.
Due to the above construction, the end face 53a on the front side of the driving shaft 53 is engaged with the inner end face 55a of the cap 55 toward the front side of the thrust direction, thereby consisting of the second regulatory structure. The end face 54b on the rear side of the horseshoe piece 54 is regulated by the end face 51b on the front side of the joint 51G on the inner rotor 51 toward the rear side of the thrust direction, thereby consisting of the first regulatory structure. In other words, the driving shaft 53 is regulated in the thrust direction.
The horseshoe piece 54 is fixed onto the joint 51G, so that the rotational direction of the inner rotor 51 is regulated by the driving shaft 53 and the inner rotor 51 can be rotatably driven.
In the embodiment, the driving shaft 53 is composed of the simple construction as the horseshoe piece 54, so that the position in the thrust direction of the driving shaft 53 is determined. Thus, even if the drive gear 57 is abraded, the offset of the driving shaft 53 remains unchanged, thereby preventing the increase in the abrasion of the drive gear 57. In addition, the movable scope of the driving shaft 53 can be adjusted by the single piece of the trochoid pump 50, thereby advancing the operability of the trochoid pump 50.
In the embodiment, also, the rotational direction of the inner rotor 51 toward the driving shaft 53 is regulated by the dihedral portion 54c equipped with the horseshoe piece 54, without the conventional drive pin, thereby reducing the number of components of the trochoid pump 50.
Moreover, the cap 55 is removed and the driving shaft 53 is slided by the thickness of the cap 55 so as to remove the horseshoe piece 54, so that the trochoid pump 50 is easily decomposable, thereby improving the maintenance performance of it.
As the sixth embodiment of the present invention, a trochoid pump 60 will be described with reference to the pattern cross-sectional diagram as shown in
As shown in
As shown in
As shown in
Due to the above-mentioned construction, the end face 63a on the front side of the driving shaft 63 is engaged with the inner end face 65a of the cap 65 toward the front side of the thrust direction, thereby consisting of the second regulatory structure. The dihedral portion 64b on the rear side of the tetrahedral shaped portion 64G of the specially shaped drive pin 64 is regulated by the end face 61b on the front side of the joint 61G toward the rear side of the thrust direction, thereby consisting of the first regulatory structure. In other words, the driving shaft 63 is regulated in the thrust direction.
The tetrahedral shaped portion 64G of the specially shaped drive pin 64 is fixed onto the joint 61G, so that the rotational direction of the inner rotor 61 is regulated by the driving shaft 63.
In the embodiment, the driving shaft 63 is composed of the simple construction as the specially shaped drive pin 64, so that the position in the thrust direction of the driving shaft 63 is determined. Thus, even if the drive gear 67 is abraded, the offset of the driving shaft 63 remains unchanged, thereby preventing the increase in the abrasion of the drive gear 67. In addition, the movable scope of the driving shaft 63 can be adjusted by the single piece of the trochoid pump 60, thereby advancing the operability of the trochoid pump 60.
In the embodiment, also, the rotational direction and the thrust direction of the inner rotor 61 toward the driving shaft 63 is regulated by fabricating the conventional drive pin, thereby providing two functions and reducing the number of components of the trochoid pump 60.
Moreover, the positions in the thrust direction and the rotational direction are adjusted by the shape of the tetrahedral shaped portion 64G of the specially shaped drive pin 64, thereby enhancing the accuracy of the positioning.
Further, because the specially shaped drive pin 64 of the embodiment is tetrahedrally in contact with the inner rotor 61, while the conventional drive pin is tangentially in contact with the engagement portion of the inner rotor, thereby creating more contact areas, decreasing the abrasion of the specially shaped drive pin 64 and the inner rotor 61, as well as improving the durability of them.
As the seventh embodiment of the present invention, a trochoid pump 70 will be described with reference to the pattern cross-sectional diagram as shown in
As shown in
Due to the above construction, the end face 73a on the front side of the driving shaft 73 is engaged with the inner end face 75a of the cap 75 toward the front side of the thrust direction, thereby consisting of the second regulatory structure. Also, the end face 73b on the rear side of the driving shaft 73 is regulated by the inner end face 78b of the cover 78 toward the rear side of the thrust direction, thereby consisting of the first regulatory structure. In other words, the driving shaft 73 is regulated in the thrust direction.
In the embodiment, the cover 78 is equipped with the trochoid pump 70, so that the position in the thrust direction of the driving shaft 73 is determined.
Thus, even if the drive gear 77 is abraded, the offset of the driving shaft 73 remains unchanged, thereby preventing the increase in the abrasion of the drive gear 77. In addition, the movable scope of the driving shaft 73 can be adjusted by the single piece of the trochoid pump 70, thereby advancing the operability of the trochoid pump 70.
As the eighth embodiment of the present invention, a trochoid pump 80 will be described with reference to the pattern cross-sectional diagram as shown in
As shown in
Due to the above-mentioned construction, the end face 83a on the front side of the driving shaft 83 is engaged with the inner end face 85a of the cap 85 toward the front side of the thrust direction, thereby consisting of the second regulatory structure. Also, the end face 83b on the rear side of the driving shaft 83 is regulated by the end face 89b of the adjusting bolt 89 toward the rear side of the thrust direction, thereby consisting of the first regulatory structure. In other words, the driving shaft 83 is regulated in the thrust direction.
In the embodiment, the cover 88 and the adjusting bolt 89 are equipped with the trochoid pump 80, so that the position in the thrust direction of the driving shaft 83 is determined. Thus, even if the drive gear 87 is abraded, the offset of the driving shaft 83 remains unchanged, thereby preventing the increase in the abrasion of the drive gear 87. In addition, the movable scope of the driving shaft 83 can be adjusted by the single piece of the trochoid pump 80, thereby advancing the operability of the trochoid pump 80.
As the ninth embodiment of the present invention, a trochoid pump 90 will be described with reference to the pattern cross-sectional diagram as shown in
Also, the trochoid pump 90 includes a cover 98 that covers with a drive gear 97. As in the case of the eighth embodiment, the cover 98 has a notch in a portion which contacts with a drive gear (not shown) that transmits the driving of the drive gear 97. Further, at the substantially central portion of the cover 98, a thrust washer 99 is provided toward the front side of the thrust direction of the driving shaft 93. In other words, the thrust washer 99 is interposed between the cover 98 and the driving shaft 93.
Due to the above-mentioned construction, the end face 93a on the front side of the driving shaft 93 is engaged with the inner end face of the cap 95 toward the front side of the thrust direction, thereby consisting of the second regulatory structure. Also, the end face 93b on the rear side of the driving shaft 93 is regulated via the bounce of the thrust washer 99 toward the rear side of the thrust direction, thereby consisting of the first regulatory structure. In other words, the driving shaft 93 is regulated in the thrust direction.
In the embodiment, the cover 98 and the thrust washer 99 are equipped with the trochoid pump 90, so that the position in the thrust direction of the driving shaft 93 is determined. Thus, even if the drive gear 97 is abraded, the offset of the driving shaft 93 remains unchanged, thereby preventing the increase in the abrasion of the drive gear 97. In addition, the movable scope of the driving shaft 93 can be adjusted by the single piece of the trochoid pump 90, thereby advancing the operability of the trochoid pump 90.
As the tenth embodiment of the present invention, a trochoid pump 100 will be described with reference to the pattern cross-sectional diagram as shown in
An adjusting bolt 108 is provided onto the cap 105 toward the rear side of the thrust direction of the driving shaft 103. In this regard, the adjusting bolt 108, which is facing with the driving shaft 103, is provided onto the cap 105.
Due to the above-mentioned construction, the offset of the end face 103a on the front side of the driving shaft 103 is adjusted and regulated by the end face 108a of the adjusting bolt 108 toward the front side of the thrust direction. In other words, the driving shaft 103 is regulated in the thrust direction.
In the embodiment, the adjusting bolt 108 is provided onto the cap 105 of the trochoid pump 100, so that the movable scope of the driving shaft 103, with the driving shaft 103 attached to the fuel injection device, can be adjusted from the outside of the device. Accordingly, even if a drive gear 107 is abraded and is offset in the thrust direction, the increase in the abrasion of the drive gear 107 can be prevented by being adjusted the movable scope of the driving shaft 103.
As the eleventh embodiment of the present invention, a trochoid pump 110 will be described with reference to the pattern cross-sectional diagram as shown in
Also, an adjusting bolt 118 is provided via a thrust washer 119 onto the cap 115 toward the front side of the thrust direction of the driving shaft 113 covered with the cap 115. In other words, the thrust washer 119 is interposed between the adjusting bolt 118 and the driving shaft 113.
Due to the above-mentioned construction, in the driving shaft 113, the end face 113a on the front side of the driving shaft 113 is regulated via the bounce of the thrust washer 119 by the end face 118a of the adjusting bolt 118 toward the rear side of the thrust direction. In other words, the driving shaft 113 is regulated in the thrust direction.
In the embodiment, the adjusting bolt 118 is provided via the thrust washer 119 onto the cap 115 of the trochoid pump 110, so that the movable scope of the driving shaft 103 can be adjusted. Accordingly, the increase in the abrasion of the drive gear 107 can be prevented by being adjusted the movable scope of the driving shaft 113, even if a drive gear 107 is abraded and the driving shaft 113 is offset in the thrust direction.
The offset of the driving shaft 103 in the thrust direction can be minimized by the elastic force of the thrust washer 119 while the trochoid pump 110 is driven, thereby reducing the abrasion of the drive gear 117.
The present invention can be available in the trochoid pump of the diesel engine.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-130782 | May 2006 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2007/059204 | 4/27/2007 | WO | 00 | 2/18/2009 |
