114results about How to "Even weight distribution" patented technology

A modular conference table may be expanded from an assembly of two identical end sections by adding one or more extension sections with all configurations utilizing the same connection assemblies. The two and three module tables use the same single center leg. The use of structural connecting blocks at the joints between the extension section and each of the end sections obviates the need for additional supporting legs.

The invention discloses a three-axis simulation flight simulator executing mechanism. The mechanism includes a roll platform, a pitch platform, a yaw platform, and a base platform. The roll platform includes a front cabin, a rear cabin, a roll motor, a roll reducer, a roll sprocket pair minor sprocket, a roll cylindrical bore self-aligning roller bearing, and a large-diameter rubber roller pivotalbearing inner ring. The pitch platform includes a pivotal bearing outer ring, a U-shaped frame, a roll sprocket pair large sprocket, a roll bearing seat, a pitch sprocket pair large sprocket, a pitchright shaft, a pitch cylindrical bore self-aligning roller bearing, and a pitch left shaft. The yaw platform includes a U-shaped bracket, a pitch bearing seat, a pitch motor, a pitch reducer, a pitchsprocket pair minor sprocket and a yaw bearing seat. The base platform includes a base, a base bracket, a large-diameter pivotal bearing, a yaw motor, a yaw reducer, an open internal gear meshing pair small gear, and support feet. The mechanism of the invention can simulate that a single person operates an aircraft to perform three degrees of freedom of roll, pitch and yaw movements to realize asimulated flight function.

A pet bed comprising a one-piece body including a base having a top surface, a wall structure, and a recessed space. The one-piece body is molded from a polyurethane visco-elastic foam material having a thermal response characteristic. The top surface is provided with a complex, three-dimensional surface contour having a concave contour component. The wall structure cooperates with the top surface to form and define a “nesting cradle”. The recessed space is provided to receive and retain any of a number of accessory, complementary, or otherwise desirable items. The solid, one-piece molded construction decreases production costs and increases product durability and longevity over prior art multi-piece pet beds, and the memory foam material and complex surface contouring work to avoid pressure points and provide even weight distribution, thereby minimizing loss of circulation and resulting numbness and resulting in more restful sleep.

The invention discloses a four-wheel-drive bow-type steering multipurpose tractor which comprises a rear frame and a front frame, wherein the rear frame is provided with a diesel engine, a gear box, a transfer box, a braking hub, a power output reduction box, a rear axle and travelling wheels; the front frame is provided with a turning device, a front axle and travelling wheels; a driving belt wheel of the diesel engine is connected with a driven belt wheel of the gear box; an output shaft of the gear box is connected with an input shaft of the transfer box; the two ends of an output shaft of the transfer box are connected with differential mechanisms; the braking hub is mounted at a middle shaft of the transfer box; the driven belt wheel is internally provided with a clutch, and connected with a transmission shaft I; the other end of the transmission shaft I is connected with the power output reduction box; one end of a rear power output shaft achieves rear power output; a driving chain wheel is mounted at the other end of the rear power output shaft, and connected with a driven chain wheel at one end of a transmission shaft II; a small driving chain wheel at the other end of the transmission shaft II is connected with a small driven chain wheel on a transmission shaft III of the turning device; and a front power output shaft of the turning device is connected with matching machines and tools to achieve front power output. The four-wheel-drive bow-type steering multipurpose tractor is provided with multiple power output ports, and is flexible in steering and wide in application scope.

A protective cover for an animal's extremity, that: is soft or comfortable to the animals hoof, foot or pads; is adjustable for fit; can protect or cover the length of the animal's leg; is durable; and easy to put on and take off; is easily cleaned and re-useable; and can reduce the wear or tear upon a bandage, splint or cast reducing the need for re-bandaging, splinting or casting. The device employs a stable and moldable base with an open ended piece of durable material, called a shell, which is fashioned into a tapered tube that is opened up on the side so as to allow the animal's foot or hoof to be inserted. The tapered tube wraps and closes around the horse's lower leg by use of several elastic straps sewn horizontally onto the exterior of the tapered tube material. The sizing of the protective covering allows the tube to be closed over most sized bandages, wraps or casts placed upon the injured animal and means for closing the tube from dirt or other items that might damage or degrade a bandage, wrap, splint or cast placed upon the animal's leg. Inserted or attached to the top of the moldable base is a soft neoprene pad that is resilient and provides a barrier from the ground with bottom of the horse's hoof This barrier is waterproof yet breathable and beneficial for the horse in that the horse's hoof is protected from contact with the ground yet the pliable nature allows for a more even distribution of weight to be applied on the animal's limbs.

The invention relates to an electric razor with a housing (1) and a shaving head (4). The shaving head (4) is coupled to the housing (1) by means of at least one first elastic element (6, 31) and has at least one first shaving element (5). The electric razor also has an electric motor (2) for generating an oscillating movement of the shaving head (4) and a diverging oscillating movement of at least one second shaving element (13). The electric motor (2) has two drive components (7, 8), and a first drive component (7) can be actuated in an oscillating manner relative to a second drive component (8). One of the drive components (7) is connected to the at least one second shaving element (13). The at least one second shaving element (13), or a drive part (12, 14) connected thereto, has an elastic connection to the shaving head (4). The electric motor (2) is arranged in the housing (1).

The invention relates to a horizontal band sawing machine which comprises a portal frame, a driving saw wheel, a driven saw wheel, a saw wheel supporting seat, a tension mechanism, a band saw driving motor and a lifting transmission mechanism. A main location rotating shaft is arranged at the center of the driving saw wheel, and an auxiliary location rotating shaft is arranged at the center of the driven saw wheel. The saw wheel supporting seat is arranged on the front side of the portal frame in a vertical sliding mode and in transmission connection with the lifting transmission mechanism. The saw wheel supporting seat comprises a front beam and a back beam, and an open groove is retained between the two beams. The driven saw wheel is located in one end of the open groove of the saw wheel supporting seat, and a driving piece drives the driven saw wheel to move along the beams through a push rod and a fork arm. The driving saw wheel is located in the other end of the open groove of the saw wheel supporting seat, and two ends of the main location rotating shaft of the driving saw wheel are respectively connected with the front beam and the back beam of the saw wheel supporting seat in a supporting mode. The horizontal band sawing machine has the advantages of being compact in structure, small in size, small in operation noise, long in service life, balanced in stress and the like.

The invention discloses an airborne camera structure which is a camera mounted out of a manned aircraft or unmanned aircraft cabin. The airborne camera structure comprises a lens protection screen (1), a lens protection screen front sealing ring (2), a lens protection screen rear sealing ring (3), a lining ring (4), a compression nut (5), a front cover (6), a camera assembly fixing frame (7), a camera assembly (8), a function board (9), a sealing connector (10), a sealing connector sealing ring (11), a rear cover sealing ring (12), a rear cover (13), vertical posts (14), a cover shell (15), nitrogen (16) and a front cover sealing ring (17). The airborne camera structure is sealed by a shell, the nitrogen is filled in the shell for protection, the lens protection screen is automatically heated and defrosted and related structure and material selection is carried out, so an environment adaption demand for employing the camera out of the aircraft cabin is satisfied.

The invention discloses a trailer hydraulic road core machine. The core machine comprises a core machine main body and water tank [4] arranged on a trailer car body [16] and a hydraulic power unit; and a hydrocylinder [13] is fixed above each fixed stay [24] and on the car body, and each fixed stay [24] is fixed on the piston rod [23] of the corresponding hydrocylinder. The core machine is driven by a hydraulic motor [14] and an oil pump [2] is driven by a gasoline engine [12]. The height of the fixed stays is automatically adjusted through the hydraulic mode; the entire car body has low center of gravity, uniform weight distribution, good stability and stable and reliable working performance; and full-automatic hydraulic coring can be realized, the use is convenient and labor-saving, and the operation is easy and convenient.

The invention relates to the field of clamps, in particular to an oil tank rotation clamp. The oil tank rotation clamp comprises a drive frame clamped at the first end of an oil tank, and a driven frame clamped at the second end of the oil tank. The drive frame is provided with a drive shaft and a drive device driving the drive shaft to rotate. The second end of the drive shaft and the first end of the oil tank are connected together. The driven frame is provided with a driven shaft, the first end of the driven shaft is connected with the second end of the oil tank, and the driven shaft is connected to a balance weight device. The oil tank rotation clamp has the beneficial effects that through cooperation of the drive frame and the driven frame, the oil tank is clamped; then the drive device is utilized for conveniently adjusting the position of the oil tank, the oil tank is rotated, and accordingly welding, paint spraying and other operation are conducted; and through the balance weight device, the weight of the oil tank can be distributed more evenly, and accordingly the problem that during oil tank rotation, centrifugal force is generated due to uneven mass distribution of the oil tank, and vibration and instability of the oil tank are caused is solved.

The invention discloses a biped robot capable of conducting wheeled motion and a working method thereof. The biped robot comprises a top mounting plate, the left side and the right side of the bottomof the top mounting plate are connected with a first foot sole plate and a second foot sole plate for walking through three steering engines correspondingly, and the left-front side and the right-front side of the top mounting plate are connected with a first wheel and a second wheel through a first steering engine and an eighth steering engine correspondingly. The biped robot has the characteristics of simple structure and large wheel diameter size, can quickly roll on the flat terrain, and has high terrain adaptability; and the robot can also be switched into a foot-type robot in a biped form, can realize a walking mode similar to lower limbs of a human body, can adapt to the rugged and complex terrain environment, is simple and reasonable in overall structure and easy to deform, and canbe widely applied to occasions of production and life.

The invention discloses a rotor circuit double-ended excitation type hybrid excitation electrical machine comprising a housing. A stator composed of an armature core and an armature winding and a rotor composed of an N-pole magnet yoke, an N-pole shoe, an S-pole magnet yoke, an S-pole shoe, a permanent magnet magnetized in a tangential manner and a spindle are installed in the housing. Two ends in the axial direction are provided with an electric excitation device respectively. The main pole air-gap magnetic field of the electrical machine is generated by the permanent magnet and electric excitation devices collectively, brushless electric excitation can be realized through the excitation devices, so smooth adjustment can be performed on the main pole air-gap magnetic field in a certain range, when the electrical machine is used in an electromotor, the magnetic field is adjusted to make the electrical machine comprise a wide constant power region to realize weak magnetism speed raising, when the electrical machine is used as a generator, the voltage adjustment requirement can be satisfied through the design of structure parameters, compared with the prior art, advantages of short axial magnetic circuit, the magnetism-collected structure type permanent magnet, large air-gap magnetic field and high efficiency can be realized; additionally, the axial structure is symmetrical, the rotor weight is distributed evenly in the axial direction, stresses on left and right bearings are consistent; a magnetic bridge is located at the axial end, and the assembly is convenient.

A handheld dust collector comprises a dust collector body with a built-in vacuum generator, a dust collecting cup and a battery pack. An air outlet is formed in the dust collector body. The dust collector is characterized in that the dust collecting cup is detachably arranged at the front end of the dust collector body, the dust collecting cup and the vacuum generator are coaxially and transversely arranged front and back, and a handle part is downwards formed at the rear end of the dust collector body; the battery pack is fixedly arranged in the handle part or the battery pack is detachably inserted into the handle part; the handle part and the battery pack are connected and fixed through buckling. The dust collector is more compact in structural design, more reasonable in layout, less inair volume loss and large in wind power, the operation is convenient, labor is saved, and the dust collector is convenient to store and the carry and very convenient to use.

The invention discloses a wet and dry dual-purpose dust collector capable of improving corner cleaning capacity. The dust collector comprises: a floor brush component, wherein the floor brush component comprises a main shell, a clear water tank and a rolling brush; a negative pressure suction hole which is formed in the main shell, wherein the rotating rolling brush shifts sewage and garbage rolls to the negative pressure suction hole; a water conveying pipeline which is communicated with a flow dividing assembly and is arranged at the bottom of the clear water tank, wherein the flow dividing assembly is provided with a plurality of nozzles, and a water pump conveys water in the clear water tank into the flow dividing assembly through the water conveying pipeline and sprays the water onto the rolling brush through the nozzles; a machine body part which comprises a main machine body, a sewage tank and an air extractor; and a negative pressure pipeline which is hermetically communicated between the interior of the sewage tank and the negative pressure suction hole, wherein the air extractor works and generates negative pressure to suck sewage and garbage at the negative pressure suction hole into the sewage tank through the negative pressure pipeline. The clear water tank is arranged on the floor brush component, the labor intensity of a user is reduced, the rolling brush is detachably arranged at the front end of the main shell, and the corner cleaning capacity is greatly improved.

The invention discloses rope unwinding equipment with fire-extinguishing and rescue functions. The rope unwinding equipment comprises a box body; a steel wire rope is arranged in a fixing frame; a sliding block is mounted at the bottom end of a sliding rail; one side of the sliding block is connected with an electric pushing rod; the end, away from a servo motor, of a rotating shaft is connected with a driving roller; a driven roller is arranged in the box body; the two ends of the driven roller are connected with rope winding barrels correspondingly; and the output end of a telescopic cylinder is connected with a limiting block. The arranged electric pushing rod pushes the sliding block to move back and forth on the sliding rail, thus the steel wire rope is evenly wound, the space utilization rate of the rope winding barrels is increased, meanwhile, the weight of the rope winding barrels is evenly distributed, and the service life of parts is prolonged; and the arranged telescopic cylinder upwards jacks the limiting block, thus a convex block on the driven roller and a clamping groove in the limiting block are clamped to lock the driven roller, and the situation that during rope unwinding, the rope winding barrels continuously rotate to fall down is avoided.

The invention relates to a rice transplanter. The rice transplanter comprises a body, wherein a rice seedling rack is arranged on the body and comprises a base, a turntable, a support and a rotating shaft; the turntable is installed on the base; the lower end of the support is fixed on the turntable; the upper end of the rotating shaft and the upper end of the support are fixed; the rotating shaft penetrates through the center of the support; the lower end of the rotating shaft and the turntable are fixed; the support is a polygon prism; a plurality of trays are fixed on each side of the support; rice seedling plates are fixed on the trays and are respectively rectangular structures formed by two transverse boards and two baffles; a plurality of wheel devices are arranged in the rice seedling plates and comprise wheel shafts and wheels; the two ends of the wheel shafts are respectively fixed on the two transverse boards; the wheels are arranged on the wheel shafts in a sleeving manner and can rotate. The rice transplanter has the obvious effects that the rice transplanter is reasonable in structural design and takes full advantage of space; meanwhile, the weights of the rice seedlings are uniformly distributed, so that the rice seedling rack can not be damaged and users have fewer concerns during driving; the rice seedlings are convenient to take and can not be damaged, thus ensuring the rice seedlings to be transplanted smoothly.

The invention discloses an ayssalpelagic energy collection and electricity generation device. The ayssalpelagic energy collection and electricity generation device is characterized in that the upper end of a frame is sequentially provided with seven groups of transmission shafts, the transmission shafts are arranged on an impeller support at the upper end of the frame in parallel in a bilateral symmetry mode from front to back, the middle portion of the frame is provided with a main power driving shaft, the back end of the frame is provided with a back power driving shaft, and the back side of the main power driving shaft is provided with a generator. According to the ayssalpelagic energy collection and electricity generation device, an electricity generation device is arranged on the sea surface, seven groups of buoyancy tanks are respectively fixed on the frame in a welded mode through connecting plates, and an impact impeller and the buoyancy tanks are ingeniously arranged on the frame, the weight distribution of the frame can be balanced and the stability performance of the device is improved, besides, the impact of waves can be flexibly and effectively absorbed and utilized, and the impeller is driven to rotate to do work.

The invention discloses a novel spinning pen. The spinning pen comprises a pen holder, a spinning part, a sealing assembly and a balancing assembly. The pen holder comprises a ringlike part and two casing rods, wherein the casing rods are symmetrically distributed at the two sides of the ringlike part. The casing rods are identical in size and shape. An included angle exists between the central axis of the ringlike part and the central axis of each casing rod. One end of each casing rod is opened. The casing rods are used for containing a refill. A cavity is formed in the axis direction of the ringlike part and used for mounting the spinning part therein. The sealing assembly comprises a first sealing part and a second sealing part. The first sealing part is connected with the spinning part and seals one end of the cavity, and the second sealing part seals the other end of the cavity and is connected with the first sealing part. The balancing assembly is mounted on the outer side walls of the casing rods in a sleeving manner. According to the novel spinning pen, the spinning part is matched with the sealing assembly, the sealing assembly is controlled through fingers, so that the spinning part is made to spin, and thus spinning of the pen holder is achieved; and the spinning pen is stable in integral structure, good in balance degree and capable of spinning for a long time.

The invention provides a communicating cabin for a C-shaped liquid tank liquefied gas carrier. The communicating cabin comprises a left communicating cabin body used for communicating a left top edgeballast tank with a left bottom edge ballast tank, and a right communicating cabin body used for communicating a right top edge ballast tank with a right bottom edge ballast tank. The left communicating cabin and the right communicating cabin are oppositely arranged on the left board side and the right board side; the front ends and the rear ends of the left communicating cabin and the right communicating cabin are located in two adjacent cargo cabins correspondingly and are symmetrical about a transverse bulkhead between the two adjacent cargo cabins. The vertical distances s from the front ends and the rear ends of the left communicating cabin and the right communicating cabin to the transverse bulkhead both meet the requirement that the ship cabin breaking stability is improved while the utilization rate of the cabin capacity of the cargo cabins is guaranteed.

The invention discloses a pressurizing and inter-cooling integration device used for a V type engine. The device comprises a pressurizing device and an intercooler, and further comprises a bottom support, a cooling piping waterway is mounted in the pressurizing device and the intercooler, the bottom of the pressurizing device fixedly communicates with an air inlet cavity and an air outlet cavity,the intercooler is mounted between the air inlet cavity and the air outlet cavity, a compression air outlet of the pressurizing device is connected with the air inlet cavity, the air inlet cavity is connected with the inner side of the intercooler, the outer side of the intercooler is connected with the air outlet cavity, the air outlet cavity communicates with an air inlet pipe of the engine, thepressurizing device, the intercooler, a lubricating module of the intercooler and the cooling piping waterway form an independent whole module, parts of an engine body are reduced, the structure is compact, supporting is reliable, whole dismounting and mounting are achieved, and a generator set is efficient and convenient to maintain and repair.

The invention discloses a production system and production method of a high-air-permeability composite non-woven fabric. The production system comprises a supporting table, wherein a material conveying mechanism is fixedly arranged on one side of the top end of the supporting table, an air supply mechanism is fixedly arranged on the other side of the top end of the supporting table, the edge side of the bottom end of the supporting table is fixedly connected to the edge side of the top end of a bottom plate, and one end of one side of the supporting table is fixedly connected to one end of a crawling ladder. According to the production system, a cloth spraying mechanism is matched with a wind shielding mechanism, an angle of a wind shielding cover can be adjusted, the cloth spraying mechanism can be protected and prevented from being influenced by wind power, a receiving mechanism matches an air draft mechanism, vertical movement of an air draft cover can be guaranteed, then a distance between a conveying net belt and the air draft cover is changed, therefore suction force borne by the surface of the conveying net belt is changed, under the cooperation of the wind shielding mechanism and the air draft mechanism, fibers sprayed by the cloth spraying mechanism can be more uniformly distributed on the conveying net belt, so that the gram weight distribution of the non-woven fabric is more uniform, and the quality of the non-woven fabric is ensured.

The invention discloses a heavy double side pass soil preparation machine and relates to a soil preparation machine of the agricultural machines; the heavy double side pass soil preparation machine improves the working ability of the soil preparation machine, solves the problem of incomplete balance of the weight division of the soil preparation machine and comprises a frame, a main transmission case, a left stubble-cleaning cutter shaft gear box and a right stubble-cleaning cutter shaft gear box, a left rotary tillage cutter shaft gear box and a right rotary tillage cutter shaft gear box, a left stubble-cleaning cutter shaft assembly and a right stubble-cleaning cutter shaft assembly and a left rotary tillage cutter shaft assembly and a right rotary tillage cutter shaft assembly, wherein,the left stubble-cleaning cutter shaft gear box and the left rotary tillage cutter shaft gear box are both arranged on the outer wall of a left side plate, the right stubble-cleaning cutter shaft gear box and the right rotary tillage cutter shaft gear box are both arranged on the outer wall of a right side plate, the left stubble-cleaning cutter shaft assembly and the right stubble-cleaning cutter shaft assembly are coaxial, and the left rotary tillage cutter shaft assembly and the right rotary tillage cutter shaft assembly are coaxial. As the four gear boxes are symmetrically arranged on theleft, the right, the front and the back, the soil preparation machine is balance in any direction, has balance weight division and improves the working stability of the soil preparation machine greatly; the soil preparation machine lengthens the rotary tillage cutter shaft and the stubble-cleaning cutter shaft one time, thus increasing the working ability and the efficiency one time.

The invention discloses a double-end double-drive double-horizontal-shaft mixer which comprises a mixing drum, two mixing shafts, mixing arms, mixing blades, four driving motors and four transmission assemblies, wherein the two driving motors are arranged on a side wall of the left end of the driving motor; the other two driving motors are arranged on a side wall of the right end of the mixing drum; the two transmission assemblies are arranged at the left end of the mixing drum; the other two transmission assemblies are arranged at the right end of the mixing drum; the two transmission assemblies located at the left end of the mixing drum are connected by a coupler; the two transmission assemblies located at the right end of the mixing drum are connected by a coupler; and each end of each mixing shaft is connected with one driving motor by one transmission assembly and driven by the driving motor. The configuration power of a single mixing driving motor is reduced, the structural sizes and weights of the driving motors are decreased, the transmission assemblies are convenient to arrange, and the overall structure of the mixer is more reasonable and stable.

The invention relates to the technical field of bicycles, and discloses a shaft transmission structure of a variable-speed bicycle. The structure comprises a frame, a rear transmission gear and a front transmission gear, and at least two groups of gears are arranged on each of the rear transmission gear and the front transmission gear. According to the shaft transmission structure of the variable-speed bicycle, during assembling, the rear transmission shaft sleeve and the front transmission shaft sleeve can move respectively, the motor is meshed with the rear transmission gear and the front transmission gear in sequence without interference, the requirement on the matching precision is greatly reduced, production and assembly difficulties are reduced, ordinary people can also assemble andsimply maintain, and it is convenient to be widely applied; when the gear on one side is excessively abraded, only the abraded gear needs to be replaced, the whole gear does not need to be replaced, the use cost is reduced, the middle shaft and the rear shaft can change the speed, multi-stage speed changing is achieved through the simple structure, weight distribution is uniform, the structure islight, riding is relatively easy, and the speed changing structure is simple, convenient to maintain and high in reliability.

The invention discloses a novel suspension system for a tracked mobile robot and belongs to the fields of the robot technology and automation. The novel suspension system solves the problem that according to a traditional tracked vehicle suspension system, the contact area between a vehicle and the ground is small, and therefore the traction provided by the ground for a robot is limited. The novel suspension system comprises a front swing arm power output suspension, a rear driving wheel suspension and a middle bogie wheel suspension, wherein the middle bogie wheel suspension is located between a track of the tracked mobile robot and the bottom of a vehicle body. The front swing arm power output suspension comprises a first spring, a first bearing, a first hinge and a first fixed rod. The middle bogie wheel suspension is composed of a plurality of bogie wheels and a plurality of spring damping systems, and the weight of a machine body is evenly shared by the multiple groups of bogie wheels; each group of bogie wheels comprises two bogie wheels connected through a hinge, and the spring and damping structure can be realized conveniently by grouping the bogie wheels. The novel suspension system is specifically applied to the tracked robot.

The invention discloses an automotive plate and a production method thereof. The plate is made of non-woven fabrics formed by mixing polylactic acid fibers with natural fibers, the strength of the polylactic acid fibers is higher than 1.4CN / dtex, the strength of the natural fibers is higher than 3.0CN / dtex, and the three-point bending strength of the plate is higher than 0.04N / 50mm / g / m<2>. The automotive plate has the advantages of high strength, fine dimensional stability, no environmental pollution and simple processing technology.

The present invention relates to a nozzle of a cleaner. A nozzle of a cleaner according to the present invention comprises: a nozzle body having suction passages for suctioning air; a first rotary cleaning part and a second rotary cleaning part which are arranged spaced apart from each other in the left and right directions below the nozzle body, and each of which is provided with a rotary plate to which a rag can be attached; a first driving device which is disposed on one side of the suction passage, among the suction passages, extending in the front-rear direction, and which is provided with a first driving motor for driving the first rotary cleaning part; a second driving device which is disposed on the other side of the suction passage, among the suction passages, extending in the front-rear direction, and which is provided with a second driving motor for driving the second rotary cleaning part; a water tank which is detachably mounted to the upper side of the nozzle body and stores water to be supplied to each of the rotary cleaning parts; a first detection part for detecting the rotation speed of the first driving motor; a second detection part for detecting the rotation speed of the second driving motor; and a control unit which receives an input of the rotation speeds of the first and second driving motors as detected by the first and second detection parts, and controls the rotation speeds of the first and second driving motors.