Balancing system for a rotating spindle (3) of a machine tool (1); the balancing system has a rotating part comprising a balancing head (7) with at least one balancing mass (8) and at least one electric motor (9) which is adapted to regulate the position of the balancing mass; the rotating part also includes a vibration sensor (10) and a control system (11) with at least one hardware (12) and at least one software (13) executed by the hardware; the balancing system also includes a two-way contactless communication system (14) which establishes communication between the rotating control system and a fixed processing and control electronics (15) connected to a machine tool control unit (20). The software of the control system features: a management application (19) which performs all the management of the balancing head and the vibration sensor during normal operation, and a service application (18) which, when the control system is powered after a suspension of the power supply, automatically starts up and starts the management application or, if a software update is required, overwrites the existing version of the management application with a new version.

A sander includes a housing, an electric motor, a fan assembly, an eccentric element, a base plate assembly including a base plate, a support for supporting the eccentric element. The support includes a first end surface and a second end surface opposite to each other, and the second end surface is disposed on a side of the support facing the lower surface relative to the first end surface. The sander further includes a counterweight connected to the eccentric element. The ratio of the distance from the centroid of the counterweight to the lower surface of the base plate to the distance from the first end surface of the support to the lower surface of the base plate is greater than or equal to 0.1 and less than or equal to 0.5.

An adjustable stroke mechanism has a housing with a central axis and a wall enclosing a cavity. At least one counterweight is movably disposed within the cavity. A mounting assembly is disposed within the cavity. The mounting assembly has a workpiece attachment mechanism. A stroke adjustor couples the at least one counterweight with the mounting assembly. The stroke adjustor enables the counterweight and mounting assembly to move with respect to one another such that a distance between the counterweight and the mounting assembly is variably adjusted which, in turn, variably adjusts a stroke radius of the workpiece attachment mechanism with respect to the central axis of the housing.

A machine tool having a drivetrain, which includes a tool shaft rotatably mounted on a drive support by means of a bearing assembly and a tool holder arranged on the tool shaft, wherein the tool shaft is rotationally drivable by a drive motor of the machine tool around a rotational axis, and wherein a balancing device is arranged on the tool shaft, which includes a guide body having at least one orbital path extending around the rotational axis and at least one balancing body movably mounted in the orbital path.

An automatic adjustable stroke device for a random orbital machine has a housing with a central axis and a wall defining a cavity. A counterbalance shaft assembly is rotatably disposed at least partially within the cavity. A shaft portion of the counterweight shaft assemblies aligned with the central axis. A mounting assembly is disposed at least partially within the cavity. The mounting assembly has a workpiece attachment mechanism. A stroke adjuster couples the counterweight shaft with the mounting assembly. The stroke adjuster enables the mounting assembly to adjust its stroke upon rotation of counterweight shaft. The mounting assembly variably adjusts a stroke radius of the workpiece attachment mechanism with respect to the central axis of the housing. The stroke adjuster has a gear automatically adjusting the mounting assembly stroke.

An electric grinding machine tool comprises a grip body, a grinding disc and a battery, the grip body is arranged with a tool shaft connected with the grinding disc, a driving component capable of rotating the tool shaft when receiving power, and a circuit board electrically connected with the driving component and the battery, and the grip body has a battery mount exposed to an outer surface. The board surface of the circuit board is not perpendicular to the tool shaft, the circuit board and the battery mount are respectively positioned on opposite sides of the tool shaft, and a line passes through the circuit board, the battery mount, and the tool shaft. By changing the position of the circuit board, the height of the grip body is reduced, so that the gravity center of the grip body is reduced to improve stability of a grinding operation.

Provided is a balancing device for a rotating body including at least one unbalance detector to measure the unbalance of the rotating body; two balancing masses to be handled along a handling circumference so as to cancel the unbalance; a position sensor to detect the mutual position of the balancing masses; and a motor to independently handle each of the balancing masses as a function of their mutual position and unbalance.

A pole sander is provided including an elongate body having a longitudinal axis, and a sanding head attached via a pivot mechanism to a first end of the elongate body. The sanding head includes a hood including a plate and a sidewall to form a chamber, an output spindle projecting through the hood into the chamber, and an electric motor mounted on the hood and configured to rotatably drive the output spindle about a rotational axis. The pivot mechanism allows the sanding head to pivot around a pivot axis that intersects the sanding head forward of at least one of a centre of gravity of the sanding head or the rotational axis of the output spindle relative to the elongate body when the longitudinal axis of the elongate body is located parallel to the plane of the plate.

The invention relates to a machine tool system (1) comprising a machine tool (2) comprising a spindle (3) that can be rotatably driven for machining workpieces, with a plurality of tools each clamped in chucks (5), in the form of so-called tool heads (4), that can be coupled to the spindle (3), and a balancing device (8) for balancing the tool heads (4), the machine tool system (1) comprising a data memory (11) in which the balancing protocol associated with each system-associated tool head (4) is stored, and a controller (12) that reads balancing data from the balancing protocol, for a tool head (4) coupled to the spindle (3), and compares it with at least one parameter of the machining for which said tool head (4) is provided, or with at least one general balancing parameter, the machine tool system (1) preferably being designed such that it rejects a tool head (4) when there is no available balancing data for said tool head (4).

The invention discloses an eccentric mechanism, comprising an eccentric block assembly and a weight structure and a heat dissipating component. The weight structure is used to balance the eccentric block assembly when rotating, so that the shaft passage one and the shaft passage two provided on the eccentric block are located on the same axis when the eccentric block assembly is rotated. And the heat dissipating component is connected with the eccentric block assembly, and is provided with an fan structure comprising a plurality of fan blade structures driven by a drive mechanism, wherein the heat dissipating component rotates synchronously with a working part, to dissipate heat for structural units.

There is also provided a power tool, comprising a housing mechanism, a driving mechanism, an output mechanism and a working component, the output mechanism comprising an output shaft and the eccentric mechanism described above, the output shaft has one end connected to the driving mechanism, the eccentric mechanism passing the rotating shaft and the working parts are connected. The power tool is provided with a heat dissipating mechanism to dissipate heat from the power tool, especially for working parts such as a grinding head and a polishing head, thereby greatly improving the service life of the tool and better protecting the product such as the surface medium of the automobile. The surface of the product is smoother.