JPH07332254A - Two-throw gear pump or motor - Google Patents

Abstract

PURPOSE:To reduce the size of the whole of a system and improve recovery of energy by a method wherein pressure liquid delivered from two gear mechanisms for driving a pump is joined and fed to the actuator side and pressure liquid fed from the actuator side to the gear mechanisms is fed to only one gear mechanism by a check valve. CONSTITUTION:The flow passage L6 of the gear mechanism P2 of a two-throw gear pump TP and the flow passage L5 of the gear mechanism PI are intercoupled through a check valve CV. The check valve CV causes the flow of delivery oil from a flow passage L6 to only the L5 side. Thus, the gear mechanisms P1 and P2 are rotated in the direction of an arrow mark and when pump function is provided, delivery oil from the gear mechanism P2 flows through the check valve CV to a flow passage 5 after the flow of it through a flow passage 6 and is joined with delivery oil in the flow passage 5 and fed through a flow passage L7 to an actuator 23. Reversely, pressure oil of the actuator 23 during recovery of energy is fed to only the gear mechanism P1 through the working of the check valve CV.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dual gear pump or motor which can be used in various fluid equipment (hydraulic equipment) fields.

[0002]

2. Description of the Related Art A pump or motor (a fluid machine that functions as a pump that outputs a high-pressure liquid when rotational power is applied, and conversely functions as a motor when the high-pressure liquid is input) used in the field of fluid equipment is Although there are piston type and vane type, gear type pumps or motors which are the simplest, easy to process and economical are especially used as fluid machinery for driving cargo handling machines. For example, a high-pressure gear pump is commonly used in a battery forklift that lifts and lowers luggage.

In the case of this battery forklift, however, the gear pump that has been operated for lifting the load is operated as a hydraulic motor when descending, and therefore the gear pump driving electric motor is driven as a generator to recover the position energy. Being tried. In this energy recovery system, the discharge side of the gear pump is connected to a single-acting actuator for a forklift via a hydraulic circuit, and when lowering the load, the pressure from the actuator (cylinder) is pressed into the gear pump. become. Then, the gear pump driving electric motor is driven as a generator to recover energy. In this case, in order for the gear pump driving electric motor to function as a generator, it is necessary that the tooth tips are rotationally driven in the same direction when the electric motor drives the gear pump. Therefore, the hydraulic circuit is switched during energy recovery so that the gear pump is always driven to rotate in the same direction.

On the other hand, there are also dual gear pumps or motors in which two pairs of the same gear mechanism are installed and synchronously rotated to output pressure oil from each pump mechanism. Further, these double gear pumps or motors are also used as fluid devices for driving cargo handling machines.

[0005]

However, in such an energy recovery type gear pump or motor, the entire system is complicated and the size becomes large. In particular, as described above, since the gear pump needs to be driven to rotate in the same direction at the time of energy recovery, a valve mechanism for switching the hydraulic circuit is installed, which is complicated and large in size. Further, since the same gear mechanism is used by switching between the pump and the motor, there is a problem that it is difficult to obtain a rotation speed required as a generator because the capacities are the same, and it is difficult to sufficiently recover energy.

The present invention provides a twin gear pump or motor that solves the above problems.

[0007]

In a dual gear pump or motor provided by the present invention, two pairs of gear mechanisms meshing with each other are arranged in front of and behind an integral casing having an intermediate partition wall, and the front and rear gear mechanisms are mounted on the partition wall. In a dual type gear pump or motor in which a bearing for supporting the gear shaft of is provided so that both gear mechanisms rotate synchronously, a connecting path that connects the respective flow passage ports of both gear mechanisms to the intermediate partition is provided. It is formed and a check valve is installed in this connecting passage.

[0008]

According to the dual gear pump or motor provided by the present invention, the pressure liquids discharged from both gear mechanisms are combined and supplied to the actuator side. However, when the pressure liquid is supplied from the actuator side to the gear mechanism, The check valve supplies power to only one gear mechanism. For example, when the gear pump driving electric motor is driven as a generator to recover energy, the generator is driven to rotate at high speed. Further, since the check valve is installed in the intermediate partition wall, it is possible to avoid making the gear mechanism large.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in the drawings. The structure of the double gear pump or the motor TP provided by the present invention is as shown in the drawing. In particular, FIGS. 1 to 3 are cross-sectional views showing the structure of a dual gear pump or motor provided by the present invention, FIG. 1 being a vertical cross section, and FIG.
II-II sectional view of FIG. 3, and FIG. 3 shows a III-III sectional view of FIG. As is clear from these figures, the respective gear mechanisms P1 and P2 consist of a pair of gears 4 and 7 that mesh with each other and a pair of gears 8 and 9 that mesh with each other. 1 and housing 2
It is installed in a casing composed of the rear cover 3. That is, the housing 2 is formed with an intermediate partition wall 2W which divides the two gear mechanisms into an intermediate portion. The first gear mechanism P1 is housed in the chamber formed by the step portion on the left side of the partition wall 2W and the front cover 1, and is formed by the step portion on the right side of the partition wall 2W and the rear cover 3. The second gear mechanism P2 is housed in the room. Reference numeral 12 is a fixing bolt for integrally fixing the front cover 1, the housing 2 and the rear cover 3.

The gear 4 is integrally formed with the input / output shaft 4 and is supported by the bearing 5 and the bush 6 with respect to the casing. The gear 7 is also integrally formed with the shaft by the bush 6 with respect to the casing. It is supported. On the other hand,
The gear 8 is supported on the casing by a bush 6 on the same axis as the gear 4, but the shaft end of the gear 4 is screwed and fixed to the gear 8. Therefore, the gear 8 is driven to rotate synchronously with the gear 4. However, the gear 9 is the gear 7.
It is supported by a bush 6 on the same axis as the casing, but is formed separately from the gear 7, and both gear 7 and gear 9 are driven by gear 4 and gear 8 separately.

As is apparent from the figure, the gear mechanism P
The tooth width of 1 is larger than that of the gear mechanism P2.
The discharge capacity per rotation is different. 4G, 7G, 8G, 9
G indicates a tooth. Also, in FIG. 1, 10 and 11
Is a side plate that is permanently installed as a high-voltage gear, and both side plates 10 and 11
Have different configurations as described later. The gears 7 and 9 have hollow shafts 7K and 9K at their support shafts, and communicate with the right empty space 3K. The empty portion 3K communicates with a low pressure region of a check valve CV described later. Therefore, the oil leakage from each tooth root of the gear is introduced from the hollow portions 7K and 9K to the low pressure region of the check valve CV through the empty portion 3K.

Although the flow passage port of the gear mechanism P1 is not shown in FIG. 1, the flow passage ports 13 and 14 are provided in the housing 2 as shown in FIGS. When the gear mechanism P1 operates as a pump, the flow path port 13 serves as an inflow port and the flow path port 14 serves as a discharge port. The gear mechanism P
Although the flow path port 2 is not shown, the flow path indicated by L3 in FIG. 3 corresponds to the discharge port when operating as a pump. That is, in FIG. 3, the gear mechanism P2
Channel L6 of the gear mechanism P1 and the channel L6 of the gear mechanism P1
5 is connected to form a connecting path. A check valve CV is installed in this connecting path. The check valve CV is one in which the ball valve element 15 in the retainer 17 is biased by the spring 18 against the valve seat 16, and blocks the flow from the flow path L5 to the flow path L6. Therefore, when the gear mechanisms P1 and P2 function as pumps, only the discharge oil from the gear mechanism P2 flows in the flow path L5, and the pump discharges of both gear mechanisms P1 and P2 join together. Reference numeral 19 is a spring retainer screwed into the retainer 17, and a circulation portion is formed. This spring retainer 1
As shown in FIG. 2, 9 has a dent on the upper surface, which can be rotated from the outside to adjust the elastic force of the spring 18.

The structure of this double gear pump or motor TP is schematically shown in FIG. Figure 6
Double gear pump or motor TP and actuator 23
And a hydraulic circuit connecting the oil tank 24 is shown. The hydraulic circuits L1, L2, and L7 are shown by a two-dot chain line because hydraulic circuits are arranged in parallel in addition to those shown in the drawing, and they are omitted. That is, when both gear mechanisms P1 and P2 rotate in the arrow direction and function as a pump, the pressure oil is supplied to the actuator 23 side, and the actuator 23 is projected from the cylinder 22. When both gear mechanisms P1 are supplied with pressure oil from the actuator 23 side for energy recovery, the rotation of the gear mechanism P1 is supplied by a circuit (not shown) so as to rotate in the arrow direction. In this case, both gear mechanisms P1, P
The total amount of oil having a capacity of 2 is supplied, and the gear mechanism P1 (the electric motor 20 functioning as a generator) is rotationally driven at high speed. A hydraulic circuit is configured so that the gear mechanism P2 is not supplied with pressure oil and is not rotationally driven during the energy recovery. In this way, when the driving electric motor 20 of the gear pump P1 is driven as a generator, electric power is collected in the power supply unit 21.

Further, in the present invention, as is clear from the above description, both the flow passage ports 13 and 14 of the gear mechanism P1 are in the high pressure region, but the gear mechanism P2 always functions as a pump, so the high pressure region is It is fixed. Therefore,
The side plate 10 and the side plate 11 of each gear mechanism have different configurations. Since the high pressure region of the side plate 11 is fixed, FIG. 5 (A)
As shown in (B), it is a fixed position type in the high pressure region, and the concave portion 1 in the high pressure region
1K is installed. (A) is the figure which looked at the side plate which contacts the gearwheel, (C) is the figure which looked at the side plate of this invention from the side which contacts the casing. The other side plate 10 has both flow passage ports 1
Since both 3 and 14 are in the high pressure range, the structure is adapted to this. That is, the side plate 10 is as shown in FIG. 4A is a view of the side plate that is in contact with the gear, FIG. 4B is a vertical cross-sectional view of the center of FIG. 4A, and FIG. 4C is a casing of the side plate of the present invention. It is the figure seen from the side which touches.

As shown in these figures, the side plate 10 has a gourd shape as in the conventional case, but it is new in that both the gourd shapes have a perfect circle shape except for the gear meshing portion. . The side plates cover the entire area around the addendum on the axial side surfaces of the meshing gears. In addition, a flow portion that penetrates from the gear side to the counter gear side is formed in the center portion of the side plate 10 on the non-meshing side. The flow portion 10H is specifically crescent-shaped in order to simplify processing and to smoothly introduce the hydraulic pressure from the gear side. This crescent-shaped through hole 10H
A notch 10K is formed on the side surface of the gear at the portion where the hole is formed so that high-pressure oil between the teeth can be smoothly guided by the crescent-shaped through hole 10H. On the other hand, on the surface (C) that immediately joins the anti-gear surface to the casing, a groove surrounding the gear shaft including the crescent-shaped through hole 10H is formed, and the groove has a rectangular cross section as shown in FIG. The sealing member 26 is fitted in, and the sealing member 25 having an L-shaped cross section is fitted in the groove 10M. The outer peripheral end (outer diameter) of the seal member 25 having an L-shaped cross section fitted in the groove 10M is formed so as to coincide with the outer peripheral end (outer diameter) of the crescent-shaped through hole 10H, whereby the crescent-shaped through hole is formed. Therefore, the hydraulic pressure from the gear side does not enter the outer peripheral end surface of the seal member 25 or the surface joined to the casing. With such a configuration, even if both the flow path ports 13 and 14 are in the high pressure region, the low pressure region and the high pressure region can be reliably sealed.

The gear pump or motor provided by the present invention is as described above, but is not limited to the above and illustrated examples and includes some modified examples. For example, in the above description, a hydraulic device is taken as an example of the fluid device, but a special water other than oil may be used as the fluid to be used, and the fluid is not limited to oil. Further, the connection mechanism of the gear 4 and the gear 8 is a screw connection, but may be a spline connection and is not limited to the illustrated example. The configuration of the check valve is not limited to the ball valve shape, for example. It is not limited to the crescent shape of the flow portion of the side plate, and may have a plurality of circular holes. The double gear pump or motor of the present invention,
Although it is effective for energy recovery, it goes without saying that it can also be used for other normal applications, that is, for driving normal hydraulic actuators. The tooth width of the gear mechanism P1 may be the same as that of the gear mechanism P2. The present invention covers all these modifications.

The double gear pump or the motor provided by the present invention is as described above, and is summarized as follows.

1) Two pairs of gear mechanisms meshing with each other are arranged in front of and behind an integral casing having an intermediate partition wall, and the partition walls are provided with bearings for supporting the gear shafts of the front and rear gear mechanisms,
In a double gear pump or motor in which both gear mechanisms rotate synchronously, a connecting passage that connects the respective flow passage openings of the two gear mechanisms corresponding to each other is formed in the intermediate partition wall, and a check valve is provided in this connecting passage. Installed double gear pump or motor.

2) Two pairs of gear mechanisms meshing with each other are arranged before and after an integral casing having an intermediate partition wall, and the partition walls are provided with bearings for supporting the gear shafts of the front and rear gear mechanisms,
In a double gear pump or motor in which both gear mechanisms rotate synchronously, a connecting passage that connects the respective flow passage openings of the two gear mechanisms corresponding to each other is formed in the intermediate partition wall, and a check valve is provided in this connecting passage. The dual gear, which is installed and has a side plate having a seal that does not short-circuit high and low pressures in the gear mechanism communicating with the outlet side of the check valve regardless of which of both flow passage ports is in the high pressure region. Pump or motor.

3) Two pairs of gear mechanisms meshing with each other are arranged before and after an integral casing having an intermediate partition wall, and the partition walls are provided with bearings for supporting the gear shafts of the front and rear gear mechanisms,
In a double gear pump or motor in which both gear mechanisms rotate synchronously, a connecting passage that connects the respective flow passage openings of the two gear mechanisms corresponding to each other is formed in the intermediate partition wall, and a check valve is provided in this connecting passage. The gear mechanism, which is installed and communicates with the outlet side of the check valve, is provided with a side plate having a seal that does not short-circuit high and low pressures even when both of the flow path ports are in the high pressure region, and the liquid mixed from the root of the tooth is provided. Is configured so as to be guided to a low pressure region that communicates with the outlet side of the check valve.

[0021]

Since the double gear pump or motor provided by the present invention is as described above, the entire gear pump or motor can be made compact. Further, when used as a hydraulic device for recovering potential energy, a dual gear pump or motor with high recovery effect is provided.

[Brief description of drawings]

FIG. 1 is a sectional view showing a dual gear pump or motor according to the present invention.

FIG. 2 is a sectional view showing a dual gear pump or motor according to the present invention.

FIG. 3 is a sectional view showing a double gear pump or a motor according to the present invention.

FIG. 4 is a view showing a side plate of a double gear pump or a motor according to the present invention.

FIG. 5 is a view showing a side plate of a double gear pump or a motor according to the present invention.

FIG. 6 is a diagram showing a system of hydraulic equipment using the present invention.

[Explanation of symbols]

 1 ... Front cover 2 ... Housing 2W ... Intermediate partition wall 3 ... Rear cover 4,7,8,9 ... Gear 10,11 ... Side plate 13,14 ... Flow passage port 15 ... Ball valve body 16 ... Valve seat 20 ... Electric motor 21 ... Power supply unit 22 ... Cylinder 23 ... Actuator 25, 26 ... Seal member CV ... Check valve

Claims (1)

[Claims] 1. A pair of gear mechanisms meshing with each other are arranged in front of and behind an integral casing having an intermediate partition wall, and the partition walls are provided with bearings for supporting the gear shafts of the front and rear gear mechanisms, so that both gear mechanisms rotate synchronously. In the double-type gear pump or motor configured as described above, the intermediate partition is formed with a connecting passage connecting the corresponding flow passage openings of both gear mechanisms, and a check valve is installed in the connecting passage. Double gear pump or motor.