Abstract: A sprocket wheel, which is an example of the machine component, includes a base made of a first metal, and an overlay disposed in contact with the base to cover at least a part of a surface of the base. The overlay includes a matrix made of a second metal, and hard particles dispersed in the matrix. The overlay includes a protrusion that protrudes toward the base in a region including the interface between the overlay and the base.

Abstract: A dimmable lighting system may replace a bi-level lighting system without having to modify or supplement the existing wiring between a bi-level control unit and one or more light fixtures. The dimmable lighting system may include a dimming controller that may be configured to replace a bi-level control unit in situ (i.e., e.g., in a wall-mounted dual-gang switch box). The dimmable lighting system may also include a dimming driver that may be coupled to the dimming controller via the existing wiring of the bi-level lighting system. The dimming controller may output to the dimming driver a 0-10 volt DC dimming signal referenced to an AC utility voltage. In response, a dimmable lighting device coupled to the dimming driver may output light over a wide range of dimming light levels. Methods of replacing a bi-level lighting system with a dimmable lighting system are also provided, as are other aspects.

Abstract: A method for assembling a helically geared first sprocket, particularly a worm gear and a second sprocket arranged on an axis, particularly a worm, to form a transmission, particularly a worm drive, in which the first sprocket is positioned coaxially in reference to an axis of assembly of the first sprocket, aligned at a 90° position in reference to the axis via an assembly device.

Abstract: Methods of forming a drill bit or boring tool having a cutting edge that includes a pair of generally smooth curvilinear shaped portions that are positioned near the radial outer portions of the cutting edge and connected to one another by a pair of generally linear portions that traverse a longitudinal centerline of the tool.

Abstract: Components of a pocket-sprung-mattress sub-assembly having individual metal springs retained within a matrix of fabric pockets are separated. A rotatable tearing drum 405 is driven by a drive motor 406. Tearing devices 407 are arranged to pull metal springs from a pocket-sprung-mattress sub-assembly during the rotation of the tearing drum 405. A feeding assembly 408 compressors an end portion of the mattress sub-assembly and moves this end portion continually to bring an end of the mattress sub-assembly into contact with the rotating tearing devices 407.

Abstract: Provided are methods and systems for aligning multiple parts using simultaneous scanning of features of different parts and using feature-based coordinate systems for determining relative positions of these. Specifically, a feature-based coordinate system may be constructed using one or more critical dimensions between features of different parts. The scanner may be specifically positioned to capture each of these critical dimensions precisely. The feature-based coordinate system is used to compare the critical dimensions to specified ranges. The position of at least one part may be adjusted based on results of this comparison using, for example, a robotic manipulator. The process may be repeated until all critical dimensions are within their specified ranges. In some embodiments, multiple sets of features from different parts are used such that each set uses its own feature-based coordinate system. The part adjustment may be performed based on the collective output from these multiple sets.

Abstract: A nozzle station installation device capable of installing multiple nozzle stations, which hold multiple suction nozzles that are used in an electronic component mounting machine, in a nozzle cleaning device or the like, is provided. The nozzle station installation device is provided with multiple reference bases, and intermediate bases that are provided to be attachable and detachable on each of the multiple reference bases and on which multiple nozzle stations are capable of being placed, positioning sections which position intermediate bases are provided at a common position on the multiple reference bases, a positioning and fixing device that positions and fixes each of the multiple nozzle stations to be attachable and detachable is provided on each of the multiple intermediate bases, and 2D codes are disposed in a fixed positional relationship with the positioning sections in each of the multiple nozzle stations.

Abstract: A workpiece clamping device able to perform a set-up changing operation for clamping members depending on the kind of a workpiece to be processed, at a low cost, by a simple method. The workpiece clamping device includes a bracket, a movable part which is movable with respect to the bracket, a clamping member to be attached to and detached from the bracket or the movable part, to clamp a workpiece, and a detachable device for detachably coupling the bracket or the movable part to the clamping member.

Abstract: A system and method for using a robotic arm and a part gripping jaw to tend a CNC machine. A robotic arm picks up a part gripping jaw and used the jaw to grip a part, and moves the part into a vise in the CAN machine. The part gripping jaw has features which the vise engages, and secures the part in the part gripping jaw for processing in the CNC machine. The system and method includes a novel racking system, robotic end of arm tool, jaw grippers and vise system. The jaw grippers that hold the part are moved from the rack system, with the part to be processed, by the robot, to the vise where the vise uses the jaw grippers to secure the part for processing. After the part is processed, the robot removes the part from the vise with the jaw grippers and stores the part back into the rack system using the jaw grippers.

Abstract: A counterbalance system employs one or more springs to support a large motor drill on an upper horizontal work surface, for example on the tops of drill jigs or bushings. The counterbalance system supports the drill above the work surface where the counterbalance system can slide across the work surface to selectively position the drill over a drill bushing through which a drilling operation is to be performed. A user of the drill supported on the counterbalance system can then push downwardly on the drill to compress the spring and perform a drilling operation. On removal of the downward directed force exerted by the user of the drill, the spring pushes the drill upwardly to disengage the drill from the work surface. The user of the counterbalance system can then slide the counterbalance system and the drill across the top of the work surface.

Abstract: Systems and methods for configuring a power tool. One system includes a power tool communication system that includes an external device and a power tool. The external device includes a user interface configured to receive a first selection to enable a feature of a power tool, and receive a second selection of a threshold of a motor characteristic of the power tool. The power tool includes a motor within a housing. The power tool receives the selected feature and the selected threshold from the external device. The power tool includes a sensor configured to monitor the motor characteristic of the motor. The power tool further includes an electronic processor that controls the motor to operate according to the selected feature and adjusts an operating parameter of the motor when the motor characteristic is determined to cross the selected threshold.

Abstract: A cable bushing fitting machine includes: a fitting region; a mandrel disposed at said fitting region, said mandrel being hollow to receive a cable therethrough; a first rotatably mounted stripping jaw arranged in the fitting region; a second rotatably mounted stripping jaw arranged in the fitting region; a drive configured to mount cable bushings onto cable by successively disposing respective ones of the cable bushings onto the mandrel, feeding the cable through the mandrel, and executing a relative movement between the mandrel and the first and second rotatably mounted stripping jaws to locate the respective cable bushings onto the cable; a camera directed toward the fitting region to capture images of the respective cable bushings located on the cable; and at least the first rotatably mounted stripping jaw having a rotation axis, the first stripping jaw rotation axis being laterally offset from an optical axis of said camera by a distance sufficient to permit the camera unimpeded views of cable bushings i

Abstract: A method for smoothing and/or polishing slabs of stone or stone-like material suitable for being implemented with a machine comprising: a support bench (16) for a slab to be machined; and at least one machining station (14). The machining station comprises two bridge support structures (20, 22) arranged transversely astride the support bench (16). A spindle-carrying beam (24), in suitable for being moved above the bridge structures in a transverse direction, is provided on the bridge support structures (20, 22). At least one spindle-carrying structure (34), suitable for being rotated about its own vertical axis (32), is provided on the spindle-carrying beam (24). Each spindle-carrying structure (34) is provided with two motorized spindles (38A, 38B), the ends of which are provided with machining heads (42A, 42B) arranged spaced apart and opposite each other with respect to the vertical axis (32) of the spindle-carrying structure (34) and comprising machining tools (44A, 44B).

Abstract: A polishing apparatus polishes a periphery of a substrate by bringing a polishing tool into sliding contact with the substrate. The polishing apparatus includes a substrate-holding mechanism configured to hold a substrate and rotate the substrate, a polishing mechanism configured to press a polishing tool against a periphery of the substrate so as to polish the periphery, and a periphery-supporting mechanism configured to support the periphery of the substrate by a fluid. The periphery-supporting mechanism is configured to support a surface of the substrate from an opposite side or the same side of the periphery of the substrate.

Abstract: A method for dispensing solid compound pastes for surface treatment to a machining tool comprises the steps of providing a solid compound paste for surface treatment that contains abrasives, softening at least a partial amount of the solid compound paste by supplying thermal energy, feeding the softened solid compound paste to a dosing device by means of a conveyor device that is adapted for abrasive media, and applying the softened solid compound paste to a machining tool by means of the dosing device.

Abstract: The invention simulates polishing amount taking into account pressure concentration that occurs in the vicinity of the edge of a substrate when a small-diameter buffing pad overhangs the substrate to be buffed. One embodiment of the invention provides a method for simulating polishing amount in a case where a polishing pad of a smaller size than a substrate is used to buff the substrate. The method includes measuring distributions of pressure that is applied from the polishing pad to the substrate according to each overhang amount of the polishing pad relative to the substrate by using a pressure sensor, and correcting the pressure that is used in the polishing amount simulation in accordance with the overhang amounts and the measured pressure distributions.

Abstract: A method for polishing a germanium wafer having a surface composed of germanium, including: adding aqueous hydrogen peroxide to a first polishing slurry of an aqueous alkaline solution containing colloidal silica to make a second polishing slurry, and polishing the surface of the germanium wafer by using the second polishing slurry; wherein the aqueous hydrogen peroxide is added to the first polishing slurry in a concentration such that 30 wt % aqueous hydrogen peroxide is added in a volume of more than 0 vol % and 0.1 vol % or less based on the volume of the first polishing slurry, and the polishing is performed by using the second polishing slurry. A method for polishing a germanium wafer that can make the surface roughness of a polished Ge surface be sufficiently small, and can sufficiently suppress generation of interface defects such as voids and blisters when used for a wafer to be bonded.

Abstract: Provided is a composition for polishing a titanium alloy material, which enables polishing of a titanium alloy material at a high polishing speed and can provide a polished titanium alloy material having excellent surface smoothness and having a highly glossy surface after polishing. The composition for polishing a titanium alloy material is a composition that is intended for polishing a titanium alloy material and comprises a compound having a function of dissolving at least one metal element other than titanium, which exists at a content of more than 0.5% by mass with respect to the total mass of the titanium alloy material, at a higher degree of solubility than that of titanium; and abrasive grains.

Abstract: A chemical mechanical polishing conditioner comprises a substrate and at least one abrasive unit. The abrasive unit is provided on the substrate, and the abrasive unit comprises a supporting layer, an abrasive layer and a stress-relief layer. The supporting layer is provided with a working face far away from the substrate and a non-working face opposite to the working face. The abrasive layer is provided on the working face of the supporting layer, and the abrasive layer is a first diamond-plated film formed by chemical vapor deposition method. The first diamond-plated film is provided with a plurality of abrasive tips. The stress-relief layer is provided on the non-working face of the supporting layer, and the stress-relief layer is a second diamond-plated film formed by chemical vapor deposition method. A thermal stress-relieving effect may be exerted by the stress-relief layer, so as to reduce warpage or deformation of the supporting layer.

Abstract: The invention concerns a tool for machining of materials, specifically a grinding tool, which has a substantially rotationally symmetrical shape with respect to a rotation axis (R), the tool comprising an outer shell centred about the rotation axis and defining an internal space therein, wherein at least a part of a surface of the outer shell is provided with an abrasive coating or component, wherein the outer shell encases an internal skeleton structure in the internal space, the internal skeleton being integral with the outer shell and defining void volumes in the internal space thereby establishing material and void volumes of the internal space, and wherein the material to void ratio M/V is distributed substantially identically along each radius (r) centred around the rotation axis (R) and its corresponding symmetrical radius (r?). The invention also concerns a method for producing such tool.

Abstract: Disclosed herein is a clamping apparatus that includes an upper jaw structure having a hinge end and a clamp end, a lower jaw structure having a hinge end and a clamp end, and a hinge located at the hinge ends of the upper and lower jaw structures, the hinge providing for rotation of upper jaw structure with respect to the lower jaw structure. The clamping apparatus includes an elongated element threadably attached to the first and second upper jaw structures between the hinge end and the clamp end of each of the first and second upper jaw structures, wherein rotation of the elongated element in a first direction causes the clamp end of the upper jaw structure to move closer to the clamp end of the lower jaw structure. The elongated element includes an end configured to receive a tool configured to facilitate the rotation of the elongated element.

Abstract: A spring clamp for assembly fixturing includes a retainer that limits a minimum distance between jaws of the spring clamp when the spring clamp is in a relaxed state.

Abstract: A system for supporting a workpiece is disclosed, wherein several heads with a suction cup define an engaging and supporting surface that is at least partially shaped like the workpiece. Each each head with suction cup is coupled by a bail joint with a first movable element of a vertical linear actuator and is couplable by a removable fitting with a fork carried by a second movable element that rotates around a rotation axis that is coaxial with the axis of the linear actuator. The second movable element carries an abutment, spaced from the center of the ball joint against which the suction cup head abuts and moved by the linear actuator to perform the adjustment of the orientation thereof around the ball joint.

Abstract: A power tool has a handle, a tool body, a rotator, a first working unit, and a second working unit. The handle has a handle body, a mounting ring rotatably mounted around the handle body, and a switch mounted on the mounting ring and inserted into the handle body. The tool body is mounted on the handle. The rotator is mounted in the tool body, and has a first driving end and a second driving end. The first working unit is mounted in the tool body, and is mounted around and engaged with the rotator. The second working unit is mounted in the tool body, and is mounted around and engaged with the rotator.

Abstract: The present invention relates to the field of combination rotary tools, more in particular in the combination of screwdrivers and drills. In particular, the invention relates to a sleeve member having a hollow portion adapted to embrace a drill, and comprising a bolt- or screw-fitting unit. More in particular, in the context of the present invention said sleeve member is provided with a built-in mechanism for torque limitation.

Abstract: An impact rotary tool includes: an impact mechanism that applies stroke impact to an output shaft by an output from a motor; a stroke detector that detects a stroke by the impact mechanism; a controller that stops rotation of the motor based on the detection result by the stroke detector; and a voltage detector that detects a voltage in the stroke detector. The controller determines whether the stroke detector has an abnormality based on the voltage detected by the voltage detector while the motor is not rotating. An informing unit informs a user that an abnormality is occurring when the controller determines an abnormality in the stroke detector.

Abstract: A tool is disclosed for installing a roller tappet in a bore of the cylinder head of an internal combustion engine. The tool includes an elongated body and a connection head arranged at one end of the elongated body and configured to be at least in part inserted into an opening of the roller tappet. The tool further includes at least one reversible constraining element of the connection head to the roller tappet.

Abstract: A nail guiding device of a nailer includes a guiding portion for guiding the nails along a straight path. The nailer has a reception recess with which a guiding member is pivotably connected. A guiding plate includes two grooves defined along two sides thereof. The strike plate and nails are slidably moved along the guiding plate between the two grooves. The guiding plate has first and second slots. The guiding member has a pivot pivotably inserted in the reception recess, a first guiding portion, a first rail, a second rail parallel to the first rail and a second guiding portion. The guiding member has a resilient arm connected thereto which contacts an inside of the body of the nailer. The first and second rails swing through the first and second slots so as to guide the nails to be ejected along a straight path.

Abstract: A fastener driving tool is provided with a plunger, an impact spring, a motor, a drive mechanism, a motor drive control unit, a position detection unit, and a timer unit. The drive mechanism moves the plunger from a stop position to top dead center by rotation of the motor. The impact spring moves the plunger in a driving direction. The position detection unit detects that the plunger has reached a predetermined position by the rotation of the motor, and the timer unit measures time therebetween. The motor drive control unit, after power supply to the motor is cut off, performs a stop control for stopping the motor at the predetermined stop position based on the time measured by the timer unit.

Abstract: A tool holder system with first and second spindles, a locking ring slideably mounted on the first spindle, a first biasing mechanism biasing the locking ring towards an indentation position where the locking ring surrounds an indentation on the first spindle, and a moveable locking element mounted on the second spindle, the locking element being engageable to the indentation. The first spindle can be unlocked from the second spindle by sliding the locking ring away from the indentation position against the biasing force of the biasing mechanism and towards the second spindle. Such action moves the locking element to disengage from the indentation.

Abstract: One feature pertains to cutters that include a first lever, a second lever having a bottom edge, and a cutting lever having a top edge. A first member rotatably couples the first lever to the second lever, a second member couples the cutting lever to the first lever and/or the second lever, where the second member provides a pivot for the cutting lever to rotate relative to the second lever. A means for rotating the cutting lever relative to the second lever to move the top edge toward or away from the bottom edge when the first lever's first end is moved relative to the second lever's first end is provided, where the first lever, the second lever, and the cutting lever are arranged in a side-by-side configuration such that each has a longitudinal axis that is parallel to each other when the cutters are in a closed position.

Abstract: A toothbrush with a push-back replaceable brush head includes a handle portion, a handle front section moveable inserted into the handle portion and having a supporting platform, a push mechanism including a push plate and a locking plate stacked together and penetrating through the handle front section, the push plate and the locking plate secured onto the handle portion; a brush head replaceably installed on the supporting platform, another end of the locking plate locked onto the brush head and the handle front section; wherein the handle front section is pushed toward the handle portion to allow the locking plate, the handle front section and the brush head to release from locking while the push plate pushes the brush head away from the supporting platform. Therefore, the release of locking and disengagement of the brush head can be achieved at the same time to facilitate operations of the toothbrush.

Abstract: I claim an applicator component retainer for quickly detaching and attaching disposable components comprising of paint brush heads, paint roller covers, dusting feathers, dusting cloths, cleaning cloths, chemical wipes and sandpaper onto a hand tool applicator shaft, said applicator component retainer comprises: an elongated hollow member, a slot, and at least one recessed member, whereby said slot is positioned along the entire length of said elongated hollow member and whereby said slot creates an opening all the way from the outside to the inside of said elongated hollow member, and whereby recessed member extends from the elongated hollow member and whereby said recessed member is recessed away from the top of the slot forming material at a smaller height below the slot.

Abstract: A tool arm mount couples a tool arm to an aerial work platform. The tool arm mount includes a first mounting hook that hangs on a first rail of the aerial work platform and a second mounting hook that hangs on a second rail of the aerial work platform. The first mounting hook defines a first channel in which the first rail is received, and the second mounting hook defines a second channel in which the second rail is received. The first and second mounting hooks are coupled to a spine of the tool arm mount. The tool arm mount also includes a first lock that locks the first mounting hook to the first rail.

Abstract: A drill press includes a main housing, a base coupled to the main housing, and a drill unit supported by the main housing for relative movement therewith. The base includes a bore formed in a top surface and a magnet to create a magnetic field for magnetically latching the base to a workpiece. The drill press further includes a holding force detection assembly having a plug and a sensor coupled to the plug to detect the magnetic field within the base. The holding force detection assembly is received within the bore formed in the top surface of the base.

Abstract: An access and storage system including a storage component configured to store items therein or thereon in an associated storage position, wherein the storage component is configured to provide a user direct manual access to the items in the storage positions. The system further includes a sensor system configured to track at least one of the user's removal of an item from the associated storage position or replacement of an item to the associated storage position and an identification system for identifying the user. The system also has an authorization database operatively coupled to the identification system for tracking which of the items a particular identified user is authorized to access.

Abstract: A multi-position storage system including a first housing, and a second housing. The second housing is connected to the first housing. The second housing is capable of being moved from a first position with respect to the first housing to a second position with respect to the first housing.

Abstract: A device comprising a tower covered by a shell, the tower having a base with a first axis of movement around a first joint, a first arm connected to the tower via a second joint along a second axis of movement, a second arm connected to the first arm at a proximal end of the second arm via a third joint defining a third axis of movement, the second arm having an end effector interface configured to hold a variety of end effectors usable for different applications, the end effectors being exchangeable allowing the device to perform digital fabrication and desktop manufacturing, an autolevelling function configured to sense a height of a work surface, and a training function allowing a user to teach either arm to perform or repeat specific actions and/or collaborate with the other arm to achieve a common assembly or fabrication task.

Abstract: The invention concerns a device forming a robotic finger comprising a base (100) forming a palm, at least one knuckle (500, 700, 900) articulated on the base (100) about two separate joints (200, 400) non-parallel to each other, at least two actuators (110, 120, 130, 140) and cable-linking means (112, 122) respectively linking the two actuators (110, 120) to drive elements of said two joints (200, 400), characterised in that the device comprises guide means (150, 151, 152) designed to guide the cables involved in the control of each joint (400, 600, 800) located after the first joint (200) on the base (100), in a common plane passing through the axis (202) of said first joint (200).

Abstract: An industrial robot includes an actuator and a driver. The actuator serves to provide power inside so as to create a predetermined motional form. The driver serves to drive an internal power source of the actuator to output power. The driver is adjacently and fixedly connected with one end of the actuator. A power unit is disposed in the actuator for generating power. The power unit has an output shaft. The actuator has a transmission unit for transmitting the power to make an operation unit move in the predetermined motional form. The transmission unit has a transmission shaft. The output shaft and the transmission shaft are coaxially and integrally formed.

Abstract: There is provided a remote control system including a controlled device and a remote device. The controlled device has a light source and moves according to a control signal from the remote device. The remote device is adapted to be operated by a user and includes an image sensor. The remote device determines a moving direction of the controlled device according to an imaging position of the light source in the image captured by the image sensor and a pointing position of the user, and outputs the control signal.

Abstract: A method includes a first step of vertically moving the arm or the pins from a reference position in one direction by a predetermined distance, a second step of moving the arm in a horizontal direction, a third step of vertically moving the arm or the pins moved in the one direction in the other direction by a distance equal to or greater than the predetermined distance, a fourth step of detecting a horizontal position of the substrate held by the arm with respect to the arm. The steps are repeated. Whenever the processes are performed, the reference position in the first step is shifted in the one direction by the predetermined distance, and a vertical position of the arm or the pins which is obtained when the horizontal position of the substrate detected in the fourth step is deviated from a preset position is taught as the delivery position.

Abstract: Modular components form a robotic assembly. the mod-components include modules and tools, each have a set of functions and capabilities, are rapidly configured-reconfigured to function cooperatively, creating a configurable robotic assemblage. Each mod-component incorporates a standardized connector mating with any other standardized connector in an interchangeable manner providing mechanical stability, power, and signals therebetween. Each mod-component incorporates a processor, data storage for mod-component identity, status, and programmable functionality, and for responding to commands. Storage is reprogrammed while the robot is operational, altering both commands and responses. After interconnection, inter-module power and communication are established and each modular component identifies itself and its functionality, thereby providing “plug and play” configuration.

Abstract: A method for energy Management in a robotic device includes providing a base station for mating with the robotic device, determining a quantity of energy stored in an, energy storage unit of the robotic device, and performing a predetermined task based at least in part on the quantity of energy stored. Also disclosed are systems for emitting avoidance signals to prevent inadvertent contact between the robot and the base station, and systems for emitting homing signals to allow the robotic device to accurately dock with the base station.

Abstract: A robot calibrating apparatus calibrating a command value for a robot body 2 whose position and orientation is controlled based on the command value, includes an operating unit configured to calculate a calibrating function of calibrating the command value, based on the difference between an ideal position and orientation of the robot body 2 and an actual position and orientation of the robot body 2. The ideal position and orientation is operated based on a command value RHTcom for calibration used during calibration or on a control result value which is a result of control according to the command value. The actual position and orientation is operated based on a measurement value RHT?meas for calibration acquired by a camera 3 arranged at a prescribed relative position and orientation with respect to the robot body 2 during the robot body 2 being controlled according to the command value for calibration.

Abstract: A method of operating a robot includes electronically receiving images and augmenting the images by overlaying a representation of the robot on the images. The robot representation includes user-selectable portions. The method includes electronically displaying the augmented images and receiving an indication of a selection of at least one user-selectable portion of the robot representation. The method also includes electronically displaying an intent to command the selected at least one user-selectable portion of the robot representation, receiving an input representative of a user interaction with at least one user-selectable portion, and issuing a command to the robot based on the user interaction.

Abstract: An automated lumber handling method for transferring various size boards from multiples board storage stations to a common board-receiving area uses a trolley that carries at least two board pickers that can operate independently. The method provides several operating modes. In a first mode, a first board picker retrieves single boards from various stations, while a second board picker is inactive. In a second mode, two board pickers retrieve two individual boards from a single station. In a third mode, one board picker retrieves one size board from a first station, and s second board picker retrieves a different size board from a second station. The two different boards can be released simultaneously at the board-receiving area. In some examples, the lumber at each station is laser scanned to determine the number of boards at each station, and a worker is notified if a station needs to be restocked.

Abstract: An end effector for a robotic arm is disclosed. The end effector includes a grasping apparatus having a gripping member and an appendage extending from the gripping member forming a channel between the griping member and the appendage. The channel is configured to receive at least a portion of an article, such as a latch for a container, to be manipulated by the end effector.

Abstract: A robot assembly having an exchangeable application device is provided. The application device is connected and exchangeable via an intermediate flange, with the respective construction lengths of the application device and the intermediate flange being matched to each other as a pair such that an exchange of the application device together with the associated and individually matched intermediate flange maintains the tool center point.

Abstract: A robot includes a joint and a drive mechanism disposed in the joint. A reducer includes an output shaft and a fixed portion. A first seal seals a gap between the output shaft and the fixed portion. A first cover is fixed to the fixed portion and covers an outer surface of the fixed portion. An intermediate portion is fixed to an output-side portion of the output shaft. A second cover is fixed to an output-side portion of the intermediate portion and covers an outer surface and an output-side edge of the first cover. A second seal seals a gap between the first cover and the intermediate portion. A groove extends approximately over a circumference of the outer surface of the first cover.