JP4048601B2 - Hydraulic gear pump or motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hydraulic gear pump or motor having a suction port that opens to the front surface of a front cover.
[0002]
[Prior art]
There is known a hydraulic gear pump or motor that is connected to another rotary engine such as a piston pump and has a suction port that is opened in front of the cover for the purpose of sharing the suction port with such a piston pump.
[0003]
[Problems to be solved by the invention]
However, in this type of gear pump or motor, lubrication by the working fluid may be insufficient at the bearing portion and the connecting portion with other rotary engines, which may cause wear and the like. Hindered improvement in performance and efficiency. For example, a cylindrical bush that is conventionally used in the bearing section is a structure that lubricates by flowing hydraulic fluid into a minute gap formed between the gear shaft and the lubrication performance is further improved. I couldn't let you. In addition, since there is no further flow path for circulating the inflowing hydraulic fluid, the lubricating hydraulic fluid has a solid gear shaft, for example, near the gear shaft end surface on the side opposite to the front cover. In some cases, the oil stays at a high temperature and deteriorates quickly, which adversely affects lubrication.
[0004]
On the other hand, the hydraulic fluid has not been introduced in the connection portion in the related art, and air is accumulated, and fretting wear may be caused in the connection portion.
[0005]
[Means for Solving the Problems]
In order to eliminate such points, the present invention provides a groove in the bush to facilitate the flow of hydraulic fluid between the inner surface of the bush and the outer surface of the gear shaft. The first object is to improve the lubricity and increase the allowable bearing load by providing a hydraulic fluid circulation path for forcibly circulating the hydraulic fluid. A second object is to reduce wear such as fretting in the connecting portion by flowing the working fluid into the connecting portion with another rotating engine.
[0006]
That is, the gear pump according to the invention of claim 1 has a suction port that opens to the front surface of the front cover and uses a ring-shaped bush for the bearing of the gear shaft in order to achieve the first object. a is, together with the provision of the grooves on the inner surface of the bush, by using the groove to form a working fluid circulation path for hydraulic fluid leaking from the gear side is returned to the suction port through the bushing inside Further, the portion where the groove is provided is set on the opposite side of the portion receiving the radial load from the gear shaft .
[0007]
In such a case, since the groove is provided in the bush, the lubricating oil is reliably supplied to the gap between the bush and the gear shaft, and the lubricity is improved. As a result, the allowable bearing load is also increased. In addition, since the hydraulic fluid circulation path using this groove finally communicates with the suction port having a negative pressure, the lubricating hydraulic fluid is forcibly circulated and does not stay. Therefore, not only can the deterioration of the hydraulic fluid be delayed, but also the circulating hydraulic fluid can be made to dissipate heat. In addition, since the portion where the groove is provided is set on the opposite side of the portion receiving the radial load from the gear shaft, the shaft support capability of the bush can be prevented from being reduced.
[0008]
As a gear pump motor in which the effect by such a configuration becomes remarkable, a gear pump motor having a solid gear shaft can be cited. This is because the hydraulic fluid is likely to stay in the vicinity of the end surface of the gear shaft in such a conventional configuration. More specifically, the effect is remarkable when applied to a multiple type of two or more series in which it is difficult to provide a through hole in the gear shaft because the gear shafts are coupled by a spline or the like.
[0009]
As a specific embodiment of the hydraulic fluid circulation path, a bearing hole that supports the gear shaft on the side opposite to the front cover in the drive gear via a bush, and a gear shaft on the side opposite to the front cover in a corresponding driven gear via the bush. A first communication channel that communicates with the bearing hole to be supported is provided, a shaft through hole is provided along the axis of the driven gear, and the bearing hole that supports the gear shaft on the front cover side of the driven gear through the bush is used as the suction port. A second communication channel that communicates is provided, and a part of the hydraulic fluid that leaks from the side of the gear is configured to return to the suction port through the bush, the first communication channel, the shaft through hole, and the second communication channel. Things.
[0010]
On the other hand, the gear pump or motor according to the invention of claim 2 has a suction port that opens to the front surface of the front cover in order to achieve the second object, and includes a drive shaft and another rotating engine. In order to connect, the connecting portion provided in the front cover is provided with a lubrication flow path for communicating the suction port by eliminating a part of the wall between the bearing hole and the suction port. .
[0011]
If this is the case, the hydraulic fluid is forcibly supplied to the connecting portion, which has conventionally been lubricated without any lubrication, using the negative pressure of the suction port as in the first aspect of the invention. Thus, it is possible to effectively prevent lubrication and wear such as fretting at the connecting portion.
[0012]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
1, 2, and 3 show a gear pump 100 of the present embodiment, and are a front view, a side sectional view, and a rear view, respectively. The gear pump 100 is of a double type that uses oil as a hydraulic fluid, and includes a first pump motor unit 1 including a first drive gear 11 and a first driven gear 12, a second drive gear 21, and a second drive gear 21. A second pump motor unit 2 configured by a second driven gear 22 that meshes with the drive gear 21 and a casing 3 that accommodates the drive gears 11 and 12 and the driven gears 21 and 22 and rotatably supports them are provided. The casing 3 includes a front cover 31, a rear body 32, and a main body 33 disposed between the front cover 31 and the rear body 32.
[0013]
The first drive gear 11 has a solid gear shaft 111 and is formed with a spline groove sp1 for connection with another rotating engine at one end 11a disposed on the front cover 31 side. Further, a spline groove sp2 for connecting to the second drive gear 21 is formed in the other end portion 11b. The first driven gear 12 meshes with the first drive gear 11, and a through hole 53 is penetrated along the axis of the gear shaft 121. The second drive gear 21 is spline-coupled to the other end portion 11 b of the first drive gear 11 at one end portion 21 a of the gear shaft 211 and interlocks with the first drive gear 11. Thus, a through hole 213 is formed in the gear shaft 211 along the axis. The second driven gear 22 meshes with the second drive gear 21, and the gear shaft 221 has a through hole 52 extending along the axis.
[0014]
The front cover 31 is provided with bearing holes 311 and 312 for rotatably supporting one end portions 11a and 12a of the gear shafts 111 and 121 of the first drive gear 11 and the first driven gear 12 via the bushes 4, respectively. is there. Of these, the bearing hole 311 corresponding to the first drive gear 11 is also opened in the front surface 31a of the front cover 31, and the spline groove sp1 formed in the one end portion 11a of the gear shaft 111 is exposed to the outside. Yes. Furthermore, a hydraulic oil suction port 6 common to the first pump motor unit 1 and the second pump motor unit 2 is opened in the front surface 31 a of the front cover 31.
[0015]
The main body 33 accommodates the gear portions 112 and 122 of the first drive gear 11 and the first driven gear 12 and performs a pump motor action, and the main body 33 has a bottom surface of the gear housing chamber 331. Bearing holes 332 and 333 that penetrate through the rear surface 33b and rotatably support the other end portions 11b and 12b of the gear shafts 111 and 121 in the first drive gear 11 and the first driven gear 12 through the bush 4 are provided. It has been. These bearing holes 332 and 333 support the one end portions 21a and 22a of the gear shafts 211 and 221 in the second drive gear 21 and the second driven gear 22 in the latter half portion so as to be rotatable via the bush 4 as described above. .
[0016]
The rear body 32 accommodates the gear portions 212 and 222 of the second drive gear 21 and the second driven gear 22, and a second gear housing chamber 321 for performing a pump motor action, and a bottom surface 32 a of the second gear housing chamber 321. Bearing holes 322 and 323 are provided through the bush 4 for rotatably supporting the other end portions 21b and 22b of the gear shafts 211 and 221 in the second drive gear 21 and the second driven gear 22, respectively. .
[0017]
In addition, the code | symbol 7 in FIG. 2 has shown the side plate, and the code | symbol 71 has shown the known gasket formed in 3 character shape.
In this embodiment, as shown in FIG. 4, a groove 41 is provided on the inner surface 4 a of the bush 4, and the hydraulic fluid leaking from the side surface of the gear portion passes through the bush 4 by using the groove 41. A hydraulic fluid circulation path 5 for returning to the suction port 6 is formed.
[0018]
As shown in FIGS. 4 and 5, the groove 41 is located on the inner surface 4a of each bush 4 on the opposite side of the portion receiving the radial load from the gear shafts 111, 121, 211, and 221 and still has the gasket. 71 is provided in a portion where the opening end face does not contact. Further, in the present embodiment, the depth of the groove 41 is set so that the thickness of the bush 4 in the portion where the groove 41 is provided does not greatly change from the thickness of the portion where the bush 4 is not provided.
[0019]
As shown in FIG. 2, the hydraulic fluid circulation path 5 includes a first communication channel 51 that communicates the bearing hole 322 provided in the rear body 32 and the bearing hole 323, and the first and second driven gears 12 and 22. Each of the through holes 53 and 52 formed in the front cover 31 and a bearing hole 312 for supporting the gear shaft 121 of the first driven gear 12 provided in the front cover 31 are at least composed of a second communication channel 54 communicating with the suction port 6. I am doing so. As shown in FIGS. 2, 4, and 6, the first communication channel 51 is provided on the side groove 511 provided on the inner surface of each of the bearing holes 322 and 323 and the bottom surface 32 a of the second gear housing chamber 321. And the end surface groove 512 that allows the open end portions of the side surface groove 511 to the bottom surface 32a to communicate with each other.
[0020]
In the gear pump 100 of the present embodiment configured as described above, the operation of the hydraulic fluid related to bearing lubrication will be described below. For example, while the gear pump 100 performs pumping and the gears 11, 12, 21, and 22 are rotating, the working fluid leaks through the side plates 7 and the like, and the leaked working fluid Lubrication is performed between the bush 4 and the gear shafts 111, 121, 211, and 221. At this time, since the grooves 41 are provided in the bushes 4, the lubricating oil is reliably supplied to the gaps between the bushes 4 and the gear shafts 111, 121, 211, and 221 to improve the lubricity. As a result, the allowable bearing load is also increased. Moreover, since this groove | channel 4a is provided in the part which does not contribute to support of the gear shafts 111, 121, 211, and 221, the shaft support capability by the bush 4 is prevented from reducing.
[0021]
On the other hand, the hydraulic oil that has passed through the bush 4 pivotally supporting the second drive gear 21 and the bush 11 pivoting the other end portion 11 b of the gear shaft 111 of the first drive gear 11 is transferred to the gear shaft 111 of the first drive gear 11. Is solid, most of them pass through the spline coupling portion and the like as indicated by arrows A and B in FIG. 7 and flow into the bearing hole 322 that pivotally supports the other end portion 21b of the gear shaft 211. The bearing hole 322 is provided with the first communication channel 51 that communicates with the other bearing hole 323, so that the hydraulic oil flows into the other bearing hole 323 through the first communication channel 51. Inflow (shown by arrow C in the figure), and further passes through the through hole 52 of the gear shaft 221, the through hole 53 of the gear shaft 122, and the second communication channel 54, as shown by the arrow D from here. It will return to the suction port 6 which is not shown in figure. Of course, the hydraulic oil that has passed through the bush 4 other than the above also returns to the suction port 6 through a route indicated by arrows E, F, G, etc. in the figure. As described above, since the negative pressure is generated in the suction port 6, the lubricating hydraulic oil is forcibly circulated without stagnation. Therefore, not only can the hydraulic oil be allowed to dissipate heat, but also its deterioration can be delayed.
[0022]
As described above, according to this embodiment, it is possible to favorably lubricate and circulate the hydraulic fluid, so that not only the allowable bearing load of the bush 4 increases but also contributes to the improvement of the durability of the product. Will be able to.
On the other hand, in this embodiment, as shown in FIGS. 8 and 9, the rear surface PPb of the piston pump PP, which is another hydraulic rotary engine, and the front cover front surface 31a are brought into close contact with each other so that the suction port 6 is shared and the shafts are shared. It is configured so that it can be connected.
[0023]
The connecting portion 8 between the shafts includes an end portion 11a of the gear shaft 111 having the spline groove sp1 and an end portion PPa of the drive shaft PP1 of the piston pump PP similarly having the spline groove sp3 in the spline grooves sp1 and sp3. It is connected through a coupling 81 to be fitted. Thus, the coupling 81 is positioned by a collar-shaped attachment spigot 82 fitted into the bearing hole 311 from the front side of the front cover 31.
[0024]
In this embodiment, as shown in FIG. 10, a lubrication flow path 9 is provided to connect the bearing hole 311 and the suction port 6, and hydraulic oil flows from the suction port 6 into the connecting portion 8. is doing. Specifically, the lubricating flow path 6 is formed by lacking a part of the wall between the bearing hole 311 and the suction port 6.
If this is the case, hydraulic oil can be forcibly supplied to the connecting portion 8, which has conventionally been lubricated without any lubrication, using the negative pressure of the suction port 6. Thus, it is possible to effectively prevent lubrication in the connecting portion 8 and wear such as fretting.
[0025]
In addition, this invention is not limited to the Example demonstrated above. For example, the gear pump to be applied is not limited to two, but a single pump or three or more may be used. Also, a plurality of grooves may be provided in one bush, and the hydraulic fluid circulation path using these grooves is not limited to the embodiment. The lubrication flow path may be configured so that the hydraulic oil flows into the connecting portion. Furthermore, both the hydraulic fluid circulation path and the lubrication flow path need not be provided in the same gear pump, and only one of them may be provided as necessary. Of course, it goes without saying that the same effect can be obtained by applying the present invention to a gear motor.
[0026]
In addition, the present invention is not limited to the illustrated examples described above, and various modifications can be made without departing from the spirit of the present invention.
[0027]
【The invention's effect】
Since the gear pump or motor according to the present invention is configured as described above, it is possible to improve efficiency and durability.
In particular, according to the first aspect of the present invention, the groove provided in the bushing reliably supplies the lubricating oil to the gap between the bushing and the gear shaft, thereby improving the lubricity. As a result, the allowable bearing load is also increased. Furthermore, since the hydraulic fluid circulation path using this groove finally communicates with the suction port that has a negative pressure, the lubricating hydraulic fluid is forcibly circulated and does not stay. Therefore, not only can the deterioration of the hydraulic fluid be delayed, but also the circulating hydraulic fluid can be made to dissipate heat. In addition, since the portion where the groove is provided is set on the opposite side of the portion receiving the radial load from the gear shaft, the shaft support capability of the bush can be prevented from being reduced.
[0028]
Further, according to the invention according to claim 2, since the lubrication flow path for communicating the suction port is provided in the connecting portion provided in the front cover in order to connect the drive shaft and the other rotary engine, It has become possible to forcibly supply hydraulic fluid to this connecting part, which has conventionally been lubricated without any lubrication, using the negative pressure of the suction port, improving the lubricity at the connecting part. Wear such as fretting can be effectively prevented.
[Brief description of the drawings]
FIG. 1 is a front view of a gear pump motor according to an embodiment of the present invention.
FIG. 2 is a side sectional view of a gear pump motor in the same embodiment.
FIG. 3 is a rear view of the gear pump motor in the embodiment.
4 is a cross-sectional view taken along line XX in FIG.
FIG. 5 is a front view showing a bush of the same embodiment.
FIG. 6 is a partial perspective view mainly showing a rear body in the embodiment.
FIG. 7 is a route explanatory diagram showing a circulation route of hydraulic fluid according to the embodiment.
FIG. 8 is an overall side view showing a state where a piston pump is attached in the same embodiment.
FIG. 9 is a partial side sectional view showing a connecting portion in the same embodiment.
10 is a partial cross-sectional view taken along line YY in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 100 ... Hydraulic gear pump or motor 111, 121, 211, 221 ... Gear shaft 31 ... Front cover 31a ... Front cover front surface 4 ... Bush 4a ... Inner surface 41 ... Groove 5 ... Hydraulic fluid circulation path 6 ... Suction port 8 ... Connection part 9 ... Lubrication channel

Claims (2)

Has a suction port that opens to the front cover front, a liquid圧歯car pumps utilizing bushing cylindrical the bearing of the gear shaft, is provided with the grooves on the inner surface of the bush, using groove A portion for forming a working fluid circulation path for the working fluid leaking from the side surface of the gear to return to the suction port through each bush, and further providing a portion for receiving the radial load from the gear shaft. A hydraulic gear pump characterized by being set on the opposite side of the above. A hydraulic gear pump or motor having a suction port that opens to the front surface of the front cover, wherein a lubrication flow path for flowing hydraulic fluid from the suction port into a connecting portion between the drive shaft and another rotary engine is formed in a bearing hole. Hydraulic gear pump or motor provided by the lack of a part of the wall between the suction port and the suction port.

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