US-12618224-B2 - Electric work machine

Abstract

A hydraulic excavator as an electric work machine includes: an electric motor; a battery unit that stores electric power for driving the electric motor; a hydraulic oil tank that contains hydraulic oil, and a hydraulic pump that is driven by the electric motor and connected to the hydraulic oil tank. The electric motor, the hydraulic pump, and the hydraulic oil tank are arranged below the battery unit on a machine body frame, and are arranged side by side in a lateral direction of the machine body frame.

Inventors

• Hiroyuki Muraoka
• Mitsuyuki Hatanaka

Assignees

• Yanmar Holdings Co., Ltd.

Dates

Publication Date

20260505

Application Date

20231013

Priority Date

20221020

Claims (10)

1. 1 . An electric work machine comprising: an electric motor; a battery unit that stores electric power for driving the electric motor; a hydraulic oil tank that contains hydraulic oil; and a hydraulic pump that is driven by the electric motor and is connected to the hydraulic oil tank, wherein the electric motor, the hydraulic pump, and the hydraulic oil tank are arranged below the battery unit on a machine body frame and are arranged side by side in a lateral direction of the machine body frame.
2. 2 . The electric work machine according to claim 1 , wherein the electric motor is arranged on a first side of the machine body frame and the hydraulic oil tank is arranged on a second side, in the lateral direction on the machine body frame.
3. 3 . The electric work machine according to claim 2 , wherein the hydraulic pump is arranged between the electric motor and the hydraulic oil tank.
4. 4 . The electric work machine according to claim 2 , further comprising: an engine room that contains the battery unit; and a fan that generates a flow of wind in the engine room, wherein the fan is arranged between the battery unit and a rear wall of the engine room.
5. 5 . The electric work machine according to claim 4 , wherein the fan is arranged on the second side in the lateral direction in the engine room.
6. 6 . The electric work machine according to claim 5 , wherein a first opening is provided at a position facing the fan in the rear wall of the engine room, and a second opening is provided in a side wall connected to the rear wall of the engine room and located on the first side in the lateral direction with respect to the rear wall.
7. 7 . The electric work machine according to claim 6 , wherein the fan includes a first fan and a second fan arranged side by side in a vertical direction in the engine room.
8. 8 . The electric work machine according to claim 7 , wherein an oil cooler for cooling the hydraulic oil is arranged between the fan and the first opening.
9. 9 . The electric work machine according to claim 8 , wherein the oil cooler is arranged between the first fan and the first opening, wherein the first fan is located at an upper part and above the second fan in the vertical direction.
10. 10 . The electric work machine according to claim 5 , further comprising electrical equipment arranged toward the first side relative to the fan in the lateral direction.

Description

CROSS-REFERENCE This application claims foreign priority of JP2022-168257 filed Oct. 20, 2022, the disclosures of which are hereby incorporated by reference in their entirety. TECHNICAL FIELD The present invention relates to an electric work machine. BACKGROUND ART Conventionally, an electric work machine including an electric motor and a hydraulic pump has been proposed. For example, Patent Document 1 discloses an electric work machine in which an electric motor and a hydraulic pump are arranged below a battery unit that supplies electric power to the electric motor. PRIOR ART DOCUMENT Patent Document Patent Document 1: Japanese Unexamined Patent Application Publication No. 2022-97079 SUMMARY OF INVENTION Technical Problem The hydraulic pump is driven by the electric motor and pumps hydraulic oil to a hydraulic actuator. The hydraulic oil is contained in a hydraulic oil tank. In a configuration of Patent Document 1, the hydraulic oil tank is arranged on a side of the battery unit. Therefore, there is room for improvement in achieving a layout suitable for a small-sized electric work machine, i.e., a compact layout including the hydraulic oil tank and the battery unit. In particular, even when the battery unit is increased in size in order to increase a capacity of the battery unit in a small-sized electric work machine, it is necessary to secure a space for arranging the hydraulic oil tank separately from the battery unit in the configuration of Patent Document 1. For this reason, it is more difficult to achieve the compact layout, and it may become difficult to increase the capacity of the battery unit. In addition, when the electric motor and the hydraulic pump are driven, heat is generated, and the hydraulic oil flowing through the hydraulic actuator also reaches a high temperature and therefore, the hydraulic oil tank that contains the hydraulic oil also reaches a high temperature. In order to ensure cooling performance of the electric motor, the hydraulic pump, and the hydraulic oil tank, it is desirable to achieve a layout which also takes into consideration cooling efficiency in cooling these components. The present invention has been made in order to solve the above problems, and an object of the present invention is to provide an electric work machine that has a compact layout and facilitates an increase in capacity of a battery unit while also taking into consideration the cooling efficiency in cooling an electric motor, a hydraulic pump, and a hydraulic oil tank. Solution to Problem An electric work machine according to one aspect of the present invention includes an electric motor, a battery unit that stores electric power for driving the electric motor, a hydraulic oil tank that contains hydraulic oil, and a hydraulic pump that is driven by the electric motor and is connected to the hydraulic oil tank, where the electric motor, the hydraulic pump, and the hydraulic oil tank are arranged below the battery unit on a machine body frame and are arranged side by side in a lateral direction of the machine body frame. Advantageous Effects of Invention It is possible to achieve an electric work machine that has a compact layout and facilitates an increase in capacity of the battery unit while also taking into consideration cooling efficiency when cooling the electric motor, the hydraulic pump, and the hydraulic oil tank. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a side view illustrating a schematic configuration of a hydraulic excavator provided as an example of an electric work machine according to one embodiment of the present invention. FIG. 2 is a rear view of the above-mentioned hydraulic excavator. FIG. 3 is a block diagram schematically illustrating a configuration of an electric system and a hydraulic system of the above-mentioned hydraulic excavator. FIG. 4 is a plan view illustrating an internal configuration of an engine room of the above-mentioned hydraulic excavator. FIG. 5 is a perspective view of an inside of the above-mentioned engine room when viewed obliquely from a rear upper side. FIG. 6 is a perspective view of an inside of the above-mentioned engine room when viewed obliquely from a rear lower side. DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described as follows with reference to the drawings. 1. Electric Work Machine FIG. 1 is a side view illustrating a schematic configuration of a hydraulic excavator (electric excavator) 1 provided as an example of an electric work machine according to the present embodiment. FIG. 2 is a rear view of the hydraulic excavator 1. The hydraulic excavator 1 includes a lower traveling body 2, a work machine 3, and an upper turning body 4. Here, in this embodiment, each direction is defined as follows. A forward direction is a direction in which an operator (manipulator, driver) seated on a driver seat 41a of the upper turning body 4 faces front, and a backward direction is a direction opposite to the forward direction. Th