Electric motor unit for an industrial truck

Abstract

Electric motor unit for an industrial truck with an electric motor (10) which has an end face with a motor output shaft (12), with a power connection (32, 34) for supplying the electric motor (10), with a control connection (36) for controlling the electric motor (10) and with a hood (20) which is attached to an end face (16) of the electric motor (10) opposite the motor output shaft (12), characterized in that the hood (20) has at least one circuit board (40) which has a plurality of plug contacts (48, 50) for contacting the electric motor (10).

Description

[0001] The present invention relates to an electric motor unit for an industrial truck. Electrically powered industrial trucks are preferably equipped with direct current or three-phase motors as electric motors. The electric motor can be designed as a drive motor and / or as a steering motor for the industrial truck. Other components and parts on an industrial truck can also be powered by an electric motor.

[0002] The electric motor unit has an electric motor with a motor output shaft on one end. Furthermore, the electric motor unit is equipped with a power connection for supplying the electric motor. The electric motor unit also has a control connection for controlling the electric motor. Furthermore, the electric motor unit is equipped with a cover mounted on the end of the electric motor opposite the motor output shaft. Typically, the electric motor has a cylindrical housing with the motor output shaft on one end and a cover on the opposite end.

[0003] The assembly of such an electric motor unit has two aspects: First, the electric motor unit itself must be manufactured, and second, it must be installed in the industrial truck. In addition to installing the electric motor unit in the industrial truck, another step involves connecting the electrical phases to the electric motor. The pole order must be observed here. Furthermore, the electric motor's sensor signal wires must also be connected correctly.

[0004] The invention is based on the object of providing an electric motor unit for an industrial truck which can be easily assembled and connected using simple means.

[0005] According to the invention, the object is achieved by an electric motor unit for an industrial truck having the features of claim 1. Advantageous embodiments form the subject matter of the dependent claims.

[0006] The electric motor unit according to the invention is provided and intended to be installed in an industrial truck. The electric motor unit has an electric motor which is equipped with a motor output shaft on one end face. Power connections for supplying the electric motor are also provided. Furthermore, a control connection for controlling the electric motor, for example with regard to speed and / or torque, is provided. In addition, a cover is provided which is attached as a housing to the end face of the electric motor opposite the motor output shaft. According to the invention, the cover has at least one circuit board which has a plurality of plug contacts for contacting the electric motor. The plug contacts provided on the at least one circuit board serve to contact the electric motor by placing the cover with the at least one circuit board onto the electric motor.In addition to contacting the phases of the electric motor, the at least one circuit board can also establish contact with sensor signal lines, such as a temperature and / or speed sensor. Such a plug-in connection has a number of advantages: Firstly, it can be quickly mounted on the motor and thus offers simple and secure connection technology for the electric motor. In addition, the plug-in contacts provide protection against reverse polarity. Preferably, the plug-in contacts of the at least one circuit board are designed such that they can be plugged onto the electric motor along a longitudinal direction of the latter. This means that when the cover is attached and placed on the electric motor, the plug-in contacts of the circuit board are also directly connected. This results in a wireless connection of the electric motor to its power supply. Preferably, the cover is placed on the electric motor in the longitudinal direction of the electric motor with its shaft direction.

[0007] In a preferred embodiment, the first circuit board also has a control connection for the control signals. The control signals are used to control the electric motor, for example, with regard to its speed or torque.

[0008] In a preferred embodiment, the hood has a second circuit board that carries the power connection for the direct current from the battery. The direct current preferably originates from a battery carried on the industrial truck, the direct current from which is converted, for example, on the second circuit board for the electric motor. The first and second circuit boards are preferably arranged parallel and spaced from one another in the hood. Both circuit boards preferably have a central opening in extension of the shaft of the electric motor. The central opening makes it possible to directly access a shaft connection of the electric motor with a tool. The hood preferably also has a corresponding opening, which is preferably closable and through which a steering function is possible for servicing in the event of a steering failure. The electric motor can be mechanically adjusted via the shaft connection without the need for complex disassembly of the hood and its circuit board.

[0009] Preferably, two circuit boards are provided, with the second circuit board being equipped with power electronics that converts the applied direct current for the electric motor, for example, into three-phase current. Sleeves extending in the longitudinal direction are preferably provided for the power transmission between the first and second circuit boards, which transmit the current between the circuit boards.

[0010] The plug contacts on the first circuit board preferably interact with connectors on the electric motor. The plug contact and the connector have a contact tongue for each electrical contact and mechanically preloaded contact elements that rest against the tongue. The connector can establish electrical contact with the electric motor to supply it with power, and signals and measurement results can also be exchanged with the electric motor via the connector.

[0011] In addition to the above variant with two boards, where a control board and a power board are provided, these can also be combined on a single board. In this configuration, there is a common board that carries the plug contacts and / or the power electronics.

[0012] A preferred embodiment of the electric motor unit according to the invention is illustrated by the following figures. Fig. 1 shows a partial sectional view of the electric motor unit, Fig. 2 shows a perspective view of an entire electric motor unit, Fig. 3 shows an exploded view of the electric motor unit with the hood removed and Fig. 4 shows the connectors in detail from Fig. 1.

[0013] Fig. Figure 1 shows an electric motor 10 with its motor output shaft 12. The electric motor 10, with its housing, has a substantially cylindrical shape, with two end faces 14, 16, which form the end surfaces of the cylinder. The motor output shaft 12 extends along the cylinder axis 18, via which the industrial truck can be driven with an intermediate gear. A hood 20 is mounted on the end face 16 of the electric motor 10. The hood 20 is connected to the cylinder via three longitudinally extending bores 22a, b, c (see Fig. 2) is attached to the electric motor 10. The hood 20 has an edge 24 that projects laterally beyond the electric motor 10 and serves as a positioning aid for the hood 20. The hood 20 has a central opening 26 that can be closed with a cover 28. A shaft section 30 of the electric motor 10 is accessible through the central opening 26, with which the motor can be mechanically rotated even without electrical current. The opening 26 is closed by the cover 28 and thus protected from dust and moisture. The hood 20 has two poles 32 and 34 on its upper side, via which the battery carried on the vehicle can be connected for power supply.

[0014] A protruding connector 36 is provided on the side of the hood 10. A corresponding counterpart of the connector can be connected to the connector 36 and secured to the connector 36 via a locking mechanism 38. Control data for the electric motor 10 can be applied via the connector 36. Data from the electric motor 10, such as temperature values or actual speeds, can also be read out and forwarded to a higher-level control system in the industrial truck.

[0015] Within the hood 20 is a first circuit board 40, arranged parallel to a second circuit board 42. The first and second circuit boards have central openings that coincide with the central opening 26 of the hood 20. The second circuit board 42 is attached to the inside of the hood 20, for example, using a thermally conductive foil. The first circuit board 40 is attached to the second circuit board 42. The current sleeves 44 also serve for attachment; they connect the circuit boards to one another and conduct the current.

[0016] Not shown in Fig. 1 is the power electronics provided on the second circuit board 42, which converts the direct current applied to poles 32 and 34 into three-phase current. Alternatively, a direct current motor can also be provided. The first circuit board 40 has a connector 46 that interacts with a plug contact 48 of the electric motor 10.

[0017] Fig. Figure 4 shows the structure in detail: The plug contact 48 is arranged on the electric motor and surrounded by a connector housing 49. The plug contact 48 consists of a longitudinally extending metallic tongue that forms the electrical contact of the electric motor. A pair of contact elements 50 that are prestressed against one another are provided on the first circuit board 40. When the cover is placed inside the contact housing 49, the contact elements 50 are pressed onto the plug contact 48 with its metallic tongue. In this way, an electrical connection is established within the contact housing 49 between the first circuit board 40 and the plug contact 48 of the electric motor. In addition to the plug contacts for the three-phase current phases UVW, other contacts can also be provided, such as a contact 52 for transmitting the motor temperature and / or the speed.

[0018] The particular advantage of using plug contact 48 is that the electrical contact is established when the hood is placed on the electric motor and is connected in a way that protects against polarity reversal.

[0019] As in Fig. 3, the electrical contacts 54 of the lateral control connection 36 are also attached to the first circuit board 40. Clearly visible in Fig. 3 also the sleeves 44 U, V, W, via which the three-phase current of the second circuit board 42 is transmitted to the first circuit board 40.

Claims

[1] Electric motor unit for an industrial truck with an electric motor (10) having a front end with a motor output shaft (12), with a power connection (32, 34) for supplying the electric motor (10), with a control connection (36) for controlling the electric motor (10) and with a hood (20) which is mounted on a front end (16) of the electric motor (10) opposite the motor output shaft (12), characterized by that the hood (20) has at least one circuit board (40) which has a plurality of plug contacts (48, 50) for contacting the electric motor (10). [2] Electric motor unit according to claim 1, characterized by that the plug contacts of the at least one circuit board (40) are designed such that they can be plugged along a longitudinal direction of the electric motor (10). [3] Electric motor unit according to claim 2, characterized by that the longitudinal direction of the electric motor (10) corresponds to a shaft direction of the motor output shaft (12). [4] Electric motor unit according to one of claims 1 to 3, characterized by that the at least one circuit board (40) carries the control connection (36) for the applied control signals. [5] Electric motor unit according to one of claims 1 to 4, characterized by that the hood (20) has a second circuit board (42) which carries a power connection (32, 34) for the direct current. [6] Electric motor unit according to claim 5, characterized by that in the hood (20) the first and second circuit boards (40, 42) are arranged parallel and spaced from one another and both have a central opening in extension of the motor output shaft (12) of the electric motor. [7] Electric motor unit according to claim 5 or 6, characterized by that the second circuit board (42) carries power electronics which convert the applied direct current into power for the electric motor (10). [8] Electric motor unit according to one of claims 5 to 7, characterized bythat sleeves (44) extending in the longitudinal direction are provided between the first and the second circuit board (40, 42) for current transmission. [9] Electric motor unit according to one of claims 1 to 4, characterized by that exactly one circuit board carries the power electronics that converts the applied direct current for the electric motor. [10] Electric motor unit according to claim 9, characterized by that exactly one board has a power connection for the applied direct current. [11] Electric motor unit according to one of claims 1 to 8, characterized by that the plug contacts (48) on the at least one circuit board interact with plug connectors (49, 50) on the electric motor, wherein the plug contact (48) and plug connector (49, 50) have a contact tongue and mechanically prestressed contact elements (50) for each electrical contact, which contact tongue rests against the contact tongue.

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