JP2006132683A - Hydraulic drive unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic drive unit for solving problems on the vibration, noises and lives of a hydraulic pump and an electric motor for driving it. <P>SOLUTION: The hydraulic drive unit 10 comprises the hydraulic pump 1 provided on a body block 8 at the side of the electric motor N and various kinds of valves 4, 5, 6A, 6B, 7 provided at other sites than the installation site of the hydraulic pump 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hydraulic pump that includes an electric motor and pumps hydraulic oil in both forward and reverse directions, a hydraulic actuator that operates by the hydraulic oil, and an operation check valve that controls the forward and reverse bidirectional flow of hydraulic oil between the two. The present invention relates to a hydraulic drive unit that includes a tank for storing hydraulic oil, a switching valve for controlling a forward / reverse bidirectional flow between the tank and the hydraulic pump, and the like, and independently applies a driving force by hydraulic pressure to a driven body.

  A hydraulic drive unit that easily provides hydraulic drive force as long as there is a power supply without using hydraulic piping is used, for example, for lifting and lowering work equipment with respect to the cultivated ground of special agricultural vehicles. The above application fields are expected and expanded.

  FIG. 2 is a hydraulic circuit diagram showing a basic configuration of the hydraulic drive unit.

  The hydraulic drive unit OU pumps the hydraulic oil in both forward and reverse directions by the forward / reverse rotating motor M in order to give the driven body W a hydraulic drive force independently while circulating the hydraulic oil in a closed system. A hydraulic pump OP, a hydraulic actuator OA (here, a hydraulic cylinder) that operates by the hydraulic oil and generates the driving force, a tank OT that stores hydraulic oil in a closed space, and between the hydraulic pump OP and the hydraulic actuator OA The operation check valve OC for controlling the forward / reverse bidirectional flow of the hydraulic oil and the switching valve OI for controlling the forward / reverse bidirectional hydraulic oil flow between the hydraulic pump OP and the tank OT are provided as basic components. Yes.

  The operating check valve OC basically pilots the hydraulic pressure to the check valve OCa to a pair of check valves OCa that allow only the flow of hydraulic oil from the hydraulic pump OP to the hydraulic actuator OA. And a pair of pilot lines OCb.

  The pair of check valves OCa includes a pipe line connecting one port of the hydraulic pump OP and the bottom side oil chamber OAa of the hydraulic actuator OA, the other port of the hydraulic pump OP and the rod side oil chamber OAb of the hydraulic actuator OA. And a pipe line connecting the two.

  The switching valve OI switches and connects between the tank OT and any pipe line between the hydraulic pump OP and the bottom side oil chamber OAa and the rod side oil chamber OAb of the hydraulic actuator OA.

  In the following description, the left side in the figure, such as the check valve OCa arranged in a pair of left and right, the one on the bottom side and the right side as the hydraulic oil entering and leaving the bottom side oil chamber OAa of the hydraulic actuator OA, The rod-side oil chamber OAb may be referred to as the rod side as it relates to the hydraulic oil entering and leaving the rod-side oil chamber OAb. Similarly, in the port of the hydraulic pump OP, the left side may be referred to as the bottom side and the right side may be referred to as the rod side.

  With such a configuration, according to the hydraulic drive unit OU, in a state where the hydraulic pump OP is stopped, the operation check valve OC allows any one of the bottom side oil chamber OAa and the rod side oil chamber OAb of the hydraulic actuator OA. The hydraulic oil is prevented from flowing out from the side, and the current stationary state of the hydraulic actuator OA is maintained against a predetermined external force.

  When the hydraulic pump OP rotates to discharge hydraulic oil to the bottom port, the hydraulic oil is supplied from the hydraulic pump OP to the bottom oil chamber OAa through the bottom check valve OCa, and at the same time, the bottom pilot line OCb The hydraulic oil that pushes and opens the rod side check valve OCa by the hydraulic pressure, allows the hydraulic oil to flow from the rod side oil chamber OAb to the hydraulic pump OP, and circulates clockwise between the hydraulic pump OP and the hydraulic actuator OA. And a driving force in the extending direction is generated in the hydraulic actuator OA.

  At this time, considering the case where the hydraulic actuator OA is a hydraulic cylinder as illustrated, the rod-side oil chamber OAb is compared to the amount of hydraulic oil flowing into the bottom-side oil chamber OAa with respect to the movement amount of the piston of the hydraulic cylinder. The amount of hydraulic oil flowing out from the piston is reduced by the amount of the rod of this piston, but the switching valve OI is pushed by the hydraulic oil on the bottom side of higher hydraulic pressure so that the switching valve OI is connected between the pipe line to the rod side oil chamber OAb and the tank OT. It switches so that they may be connected to each other, and a shortage of hydraulic oil is supplied from the tank OT.

  On the other hand, when the hydraulic pump OP rotates so as to discharge the hydraulic oil to the rod side port, the reverse flow of the hydraulic oil occurs, and a driving force in the contracting direction is generated in the hydraulic actuator OA, and the bottom side oil is generated. The hydraulic fluid flowing into the hydraulic pump OP from the chamber OAa becomes redundant, but the excess hydraulic fluid is connected to the tank OT and the pipe line to the bottom side oil chamber OAa by the action of the switching valve OI opposite to the above. , It is returned to the tank OT.

  Note that the amount of hydraulic oil in the sealed tank OT increases or decreases depending on the position of the piston of the hydraulic cylinder that is the hydraulic actuator OA, and the gas pressure sealed in the tank OT varies. Therefore, the fluctuation of the gas pressure does not affect the operation of the hydraulic drive unit OU.

  Thus, the function of the hydraulic drive unit OU is exhibited and maintained while using the hydraulic actuator OA which is a closed system and has a difference in the amount of hydraulic oil entering and exiting due to its operation.

  The hydraulic drive unit OU includes the following additional elements in addition to the basic components described above.

  In the pipelines between the bottom side oil chamber OAa of the hydraulic actuator OA, the rod side oil chamber OAb and the respective check valves OCa of the operating check valve OC, hydraulic oil from the respective oil chambers OAa, OAb to the check valve OCa is provided. Slow return valves SR for restricting only the flow are provided respectively.

  The slow return valve SR is for preventing hunting that occurs when an external force is generated from the driven body W during operation of the hydraulic pump OP.

  From the pipelines between the slow return valves SR and the check valves OCa, pipelines provided with relief valves RV1 respectively branch to the tank OT. Similarly, from the pipe line between the hydraulic pump OP and the check valve OCa on the bottom side and the rod side, pipe lines each provided with a relief valve RV2 branch to the tank OT.

  These relief valves RV1 and RV2 allow excess hydraulic oil to escape to the tank OT when an abnormal pressure occurs in the branch source pipe.

  Furthermore, from the pipe line between the rod side and bottom side slow return valve SR and the check valve OCa, the pipe line provided with the emergency manual valve MV branches to the tank OT, and the hydraulic pump OP is powered. When the emergency manual valve MV is used, the hydraulic actuator OA can be manually operated by releasing the pipelines of the bottom side oil chamber OAa and the rod side oil chamber OAb of the hydraulic actuator OA to the tank OT. I am doing so.

  With such a configuration, this hydraulic drive unit OU achieves its basic functions well, and even if an abnormal situation occurs, it does not lead to damage of the unit OU, thus ensuring safety and reliability. Accident avoidance is ensured.

  FIGS. 3A and 3B conceptually show the hydraulic drive unit OU with particular attention to its component arrangement. FIG. 3A is an overall arrangement view, and FIG. 3B is an internal view excluding the hydraulic cylinder portion of FIG. FIG. 5C is a layout view in which the configuration is viewed from the side, and FIG. 5C is a layout view in which the position of FIG.

  The hydraulic drive unit OU includes an electric motor M on one side of a main body block MB which is a structure housing the above-described various valves OC, OI and the like and a hydraulic pump OP, and a tank OT opposite to the electric motor M. On the side, a hydraulic cylinder 0A as a hydraulic actuator is installed on the side (this direction is called “lateral direction”) orthogonal to the installation direction of the electric motor M and the tank 0T (this is called “vertical direction”). It has a structure.

  Here, as shown in FIGS. 3B and 3C, in this main body block MB, the pump OP is connected to the switching valve OI directly intervening between the tank OT and the hydraulic valve in FIG. The relief valve RV2 for the pipe line is interposed between the tank OT and the tank OT as close to the vertical direction as possible. As a result, the other operation check valve OC and the pipe line to the hydraulic cylinder OA The slow return valve SR and the like are provided on the electric motor M side in the vertical direction from the hydraulic pump OP.

  In FIG. 3 (c), reference numeral OA indicates that there is a hydraulic cylinder in the back position that has penetrated this figure, and a pipe line to the hydraulic cylinder exists here. The relief valve RV1 for the pipe line between the operation check valve OC and the hydraulic cylinder OA is located on the tank OT side in the vertical direction as compared with the pump OP. Because there is.

  The hydraulic pump OP is provided at such a position on the hydraulic pipe line in which the length of the pipe line between the hydraulic pump OP and the tank OT storing the hydraulic oil that is a suction target is shortened as much as possible to improve the suction. It is based on common technical knowledge. In addition, by doing so, there is also an aspect that the pipeline configuration is simplified.

  However, if the hydraulic pump OP is arranged at such a position, the motor output shaft (pump drive shaft) Oz must be long from the motor M to the operating position of the pump OP, and the vibration and noise caused thereby. This has an effect on the life of electric motors and hydraulic pumps.

In addition, as other specific conventional examples of the hydraulic drive unit, there are those described in Patent Document 1 and Patent Document 2, but in both cases, the position of the hydraulic pump is closer to the tank, It did not solve the above problem.
Japanese Patent No. 2824659 (FIG. 1) Japanese Patent Laying-Open No. 2003-172307 (FIG. 1)

  An object of the present invention is to provide a hydraulic drive unit that solves the problems of vibration, noise, and life of a hydraulic pump and an electric motor that drives the hydraulic pump.

The hydraulic drive unit of the present invention includes a hydraulic pump that pumps hydraulic oil in both forward and reverse directions, an electric motor that drives the hydraulic pump, a tank that stores the hydraulic oil, a hydraulic actuator that is operated by the hydraulic oil, and the hydraulic pressures thereof. A hydraulic drive unit that includes various valves that control the flow of hydraulic oil in both the forward and reverse directions between the pump, tank, and hydraulic actuator, and that independently applies a hydraulic drive force to the driven body by the operation of the hydraulic actuator. There,
The electric motor is provided on one side, the tank is provided on a side opposite to the electric motor, and the actuator is provided on a side orthogonal to the installation direction of the electric motor and the tank. The hydraulic pump is provided on the motor side, and the various valves are provided in addition to the installation location of the hydraulic pump.

  In the hydraulic drive unit of the present invention, since the hydraulic pump is provided on the electric motor side of the main body block, the output shaft of the electric motor (pump drive shaft) becomes shorter, and the vibration and noise of this shaft become smaller, The degree of shaft fatigue due to shaft runout is reduced, vibration and noise can be reduced, shaft life can be extended, and problems with vibration, noise and life of electric motors and hydraulic pumps can be solved.

  Embodiments (examples) of the present invention will be described below with reference to the drawings.

  FIG. 1 conceptually shows an example of a hydraulic drive unit OU according to the present invention, particularly focusing on its component arrangement, (a) is an overall arrangement view, and (b) is a hydraulic cylinder portion of (a). FIG. 5C is a layout diagram in which the internal configuration excluding the symbol is viewed from the side, and FIG.

  The hydraulic drive unit 10 requires a driving force by hydraulic pressure independently and easily. For example, the hydraulic drive unit 10 is used for raising and lowering work equipment with respect to the cultivated ground of an agricultural special vehicle.

  The configuration includes a hydraulic pump 1 having an electric motor M that pumps hydraulic oil in both forward and reverse directions, a hydraulic cylinder 2 as a hydraulic actuator that is operated by the hydraulic oil and generates a driving force to the driven body W, and is closed. A tank 3 that stores hydraulic oil in the space, an operation check valve 4 that controls the forward / reverse bidirectional flow of hydraulic oil between the hydraulic pump 1 and the hydraulic cylinder 2, and a positive flow between the hydraulic pump 1 and the tank 3. It comprises a switching valve 5 that controls the flow of hydraulic fluid in the opposite direction, two types of relief valves 6A and 6B, a slow return valve 7, and a main body block 8 that houses these hydraulic pumps 1, valves 4, 5, and the like. Basically.

  The basic functions and interrelationships of these hydraulic pump 1, hydraulic cylinder 2, tank 3, operation check valve 4, switching valve 5, relief valves 6A and 6B, and slow return valve 7 are the same as those of hydraulic drive unit OU in FIG. Since the hydraulic pump OP, the hydraulic actuator OA, the tank OT, the operation check valve OC, the switching valve OI, the relief valves RV1 and RV2, and the slow return valve SR are the same as those of the hydraulic pump OP, the redundant description is omitted.

  Further, although the emergency manual valve MV shown in the hydraulic circuit diagram of FIG. 2 is not shown here, it is assumed that this is provided as necessary.

  The hydraulic drive unit 10 is characterized by the arrangement of the components constituting it, and an electric motor M is installed on one side of the main body block 8, and a tank 3 is installed on the opposite side. M, a hydraulic cylinder 2 is installed on the side (this direction is called “lateral direction”) orthogonal to the installation direction of the tank 3 (this is called “vertical direction”). 8, the hydraulic pump 1 is installed on the electric motor M side, and the above-described valves 4, 5, 6 A, 6 B, 7, and the like are installed at portions other than the installation site of the hydraulic pump 1. And

  Even in such an arrangement, as can be seen from a comparison between FIG. 1B and FIG. 3C and FIG. 3B and FIG. As with the hydraulic drive unit OU in FIGS. 2 and 3, it is possible to supply hydraulically driven force independently to the driven body while being a closed system, and to improve safety, reliability, and accident avoidance. Secured.

  In addition, in this hydraulic drive unit, as shown in FIG. 1B, the output shaft (pump drive shaft) 1z of the motor is shorter, and as a result, the vibration and noise of this shaft 1z are reduced. To reduce the degree of shaft fatigue due to shaft runout, reduce vibration and noise, extend the life of the shaft 1z, and solve problems of vibration, noise and life of the electric motor M and hydraulic pump 1 Can do.

  The arrangement of the valves such as the operation check valve 4 and the switching valve 5 shown in FIG. 1B is an example, and these valves 4 except for the restriction that the pump 1 is provided on the lightning motor M side. The arrangement of 5... Is not limited to the series arrangement of this example.

  Further, in this hydraulic drive unit 10, the hydraulic cylinder 2 is installed in the main body block 8 so that the vertical direction, which is the installation direction of the electric motor M and the tank 3, and the axial direction of the hydraulic cylinder 2 are parallel. .

  With such an installation, the area occupied by the unit 10 on the surface in FIG. 1A can be reduced compared to the case where the hydraulic cylinder 2 is installed in the lateral direction perpendicular to the vertical direction. It is suitable as a hydraulic drive unit where space is limited and compactness is required.

  Further, in the hydraulic drive unit, there is a severe condition that the problem of durability and vibration must be solved while accommodating related parts as compactly as possible in a space limited by a closed system. Under such severe conditions, the company has also solved the problems of durability and vibration.

  The problem that the pump 1 is further away from the tank 3 by the amount closer to the electric motor M can be solved by enlarging the pipe line between the pump 1 and the tank 3. On the other hand, according to the present invention, the pipe length between the various valves 4, 5, etc. is also reduced.

  Further, as shown in FIG. 1 (a), the hydraulic cylinder 2 is also in a vertical direction parallel to the vertical direction, which is the installation direction of the electric motor M and the tank 3 with respect to the main body block 8, and the hydraulic cylinder 2 is substantially the same. The main body block 8 is installed near the center of the axial length.

  That is, both ends in the longitudinal direction of the hydraulic cylinder 2 are installed so as to extend to both the electric motor M side and the tank 3 side in the vertical direction with respect to the electric motor M and the tank 3 installed in the main body block 8. As much as possible, the unit 10 is arranged so as not to protrude in the longitudinal direction.

  On the other hand, for example, when it is installed in the main body block 8 so as to extend toward the tank 3 side on the bottom side of the hydraulic cylinder 2, the electric motor M is disposed on the electric motor M side with respect to the vertical direction of the main body block 8. The bulge is produced only on the tank 3 side by the entire length of the hydraulic cylinder 2, and although it is composed of the same parts, its surrounding dimensions are increased, which is contrary to compactness.

  That is, as shown in FIG. 1A, the installation in the main body block 8 near the center of the axial length of the hydraulic cylinder 2 greatly contributes to the compactness of the unit 10.

  Further, the hydraulic drive unit of the present invention can independently be used in any industrial field where compaction is required by giving a driven force by hydraulic pressure to the driven body.

An example of the hydraulic drive unit OU of the present invention is conceptually shown with particular attention to its component arrangement, (a) an overall arrangement view, and (b) an internal configuration excluding the hydraulic cylinder portion of (a). (C) is a layout diagram expressing the position (b) viewed from the top side in a hydraulic circuit form. Hydraulic circuit diagram showing the basic configuration of the hydraulic drive unit FIG. 2 conceptually shows the hydraulic drive unit OU of FIG. 2 with particular attention paid to its component arrangement, (a) is an overall arrangement view, and (b) is an internal configuration excluding the hydraulic cylinder portion of (a). (C) is a layout diagram expressing the position (b) viewed from the top side in a hydraulic circuit form.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydraulic pump 2 Hydraulic actuator 3 Tank 4 Operate check valve 5 Switching valve 6A, 6B Relief valve 7 Slow return valve 8 Body block M Electric motor 10 Hydraulic drive unit

Claims (3)

Hydraulic pump that pumps hydraulic oil in both forward and reverse directions, electric motor that drives this hydraulic pump, tank that stores this hydraulic oil, hydraulic actuator that operates with this hydraulic oil, and between these hydraulic pump, tank, and hydraulic actuator A hydraulic drive unit comprising various valves for controlling the flow of hydraulic oil in both forward and reverse directions, and independently applying a hydraulic drive force to the driven body by the operation of the hydraulic actuator;
The electric motor is provided on one side, the tank is provided on the side opposite to the electric motor, and the actuator is provided on a side perpendicular to the installation direction of the electric motor and the tank.
The hydraulic drive unit according to claim 1, wherein the hydraulic pump is provided on the electric motor side of the main body block, and the various valves are provided at a place other than the installation location of the hydraulic pump.   The actuator is a hydraulic cylinder, and the cylinder shaft thereof is installed in the main body block so as to be parallel to the arrangement direction of the electric motor, the main body block, and the tank. Item 1. The hydraulic drive unit according to Item 1.   3. The hydraulic drive unit according to claim 2, wherein the hydraulic cylinders arranged in parallel with the electric motor, the main body block, and the tank are arranged so as not to protrude in the parallel direction as a whole.

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