The invention discloses a variable transmission ratio rack gear shaping force prediction method. The method comprises the following steps of S1, establishing a cutter gear tooth model, discretizing the cutter gear tooth model, and meanwhile, establishing a machined rack model in a workpiece coordinate system; S2, calculating a polar angle and a polar diameter from the discrete point of the rack tothe center of slotting cutters; S3, the discrete points are screened out to serve as cut points, and the number of all the screened discrete points is the size a of the cutting area; S4, judging thevertical position relation between the discrete points of all the slotting cutters and the machined surface of the machined rack; S5, screening out the discrete points at the same position on the machined surface of the machined rack, and the number of all the screened discrete points is the size b of the contact length; and S6, substituting the cutting area a and the cutting contact length b intothe metal cutting force model to finish the prediction calculation of the gear shaping force of the variable transmission ratio rack in each direction. The method provides a novel accurate calculation method for the cutting area and the cutting contact length, and accurate prediction of the gear shaping force of the variable transmission ratio rack is achieved.

Variable transmission ratio rack gear shaping force prediction method

Provided is a non-circular face gear transmission mechanism for intersecting shafts The transmission mechanism comprises a small cylindrical gear and a non-circular face gear, wherein the small cylindrical gear is non-orthogonal to the rotation axis of the non-circular face gear In the engagement process, the pitch cylinder of the small cylindrical gear is kept tangent to the pitch cone of the non-circular face gear, and the tangent line is a pitch cone bus of the non-circular face gear The pitch curve of the non-circular face gear is a curve wound around the pitch cone face of the non-circular face gear, and the projection of the non-circular face gear pitch curve on the pitch cone bottom face is a non-circular curve about the axis of the pitch cone According to the transmission mechanism, the transmission mechanism formed by engagement of the pair of gears achieves the speed-reduction-variable-speed composite transmission effect which only can be achieved by at least two pairs ofgears of a traditional intersecting shaft transmission mechanism under the non-orthogonal condition, the transmission structure is simplified to the maximum extent, a transmission chain is shortened,transmission parts are reduced, the transmission efficiency and precision are improved, and the non-circular face gear transmission mechanism is particularly suitable for occasions with any intersecting shaft structure, space limitation and speed-reduction-variable-speed composite transmission requirements

Non-circular face gear transmission mechanism for intersecting shafts

The invention discloses a fast predicating method of the each-tooth cutting area of circular corner milling. The fast predicating method comprises the following steps: a, establishing a rectangular coordinate system by taking the circle center at the circular bead of the design contour line of a to-be-processed component as the origin of coordinates; b, establishing the S1 equation of the design contour line of the to-be-processed component, the S2 equation of the workblank contour line of the to-be-processed component, and the S0 equation of the axis movement contour line of a milling cutter;c, at moment t, solving the coordinate pi0 of the milling cutter circle center point in the coordinate system; d, solving the intersection point pi1 of the outer contour circle of the milling cutterand the design contour line of the to-be-processed component; e, solving the intersection point pi2 of the outer contour circle of the milling cutter and the workblank contour line of the to-be-processed component; f, solving the included angle formed by the connecting line of pi0 and pi2 and the connecting line of pi0 and pi1; and g, according to the known milling cutter radius r, the each-toothfeeding ft of the milling cutter and the included angle phit obtained in the step f, solving the each-tooth cutting area At of the milling cutter at the moment t. According to the fast predicating method, the limitation of the each-tooth cutting area solving method to circular bead processing during the milling machining process in the prior art is overcome to realize fast predication of each-tooth cutting area of circular corner milling.

Fast predicating method of each-tooth cutting area of circular corner milling

The invention relates to a method for predicting cutting force of non-cylindrical gear slotting machining. The method comprises the following steps of: calculating the contact area when the non-cylindrical gear and the slotting cutter are processed, and uniformly distributing enough data points in the contact area; and solving the coordinate transformation matrix according to the position relationof the non-cylindrical gear and the slotting cutter to be processed; transforming the points on the isometric curve family into points in the slotting cutter coordinate system through the coordinatetransformation matrix; in each cutting step of the slotting cutter, discriminating the coordinate transformation points to select the points of the workpiece in the slotting cutter; distributing a sufficient number of data points on the tooth top circle and the left and the right involute of the slotting cutter; in each cutting step, distinguishing the contact points between the shaping cutter andthe workpiece, and screening out the contact points between the slotting cutter and the workpiece; and obtaining the size of the cutting force based on the formula of the unit cutting force. The method can accurately predict the cutting force of the non-cylindrical gear slotting machining, and has the advantages of high calculation accuracy, high calculation efficiency and the like.

Method for predicting cutting force of non-cylindrical gear slotting machining

The invention relates to a method for predicting cutting force of cylindrical gear slotting, which comprises the following steps: calculating the area of a circular ring in the contact area of a cylindrical gear and a slotting cutter during machining, and uniformly distributing enough data points in the circular ring; according to the position relation between the cylindrical gear and slotting cutter, solving a coordinate transformation matrix; judging the points after coordinate transformation, selecting the points in the gear shaping cutter according to the size of the pole diameter and thepole angle at the gear tooth position of the gear shaping cutter; distributing enough data points equidistantly on the tooth tip circle and involute of the gear shaping cutter; in each step of gear shaping cutter cutting, judging the point of contact between the gear shaping cutter and a workpiece, and selecting the point of contact between the gear shaping cutter and the workpiece according to the distance between equidistant points distributed on the gear shaping cutter tooth profile and the workpiece center; and determining the magnitude of the cutting force by the formula based on the unitcutting force. The invention can accurately predict the cutting force of cylindrical gear shaping, and has the advantages of high calculation precision and high calculation efficiency.

Han Xinghui

Papers

Method for predicting cutting force of non-cylindrical gear slotting machining

Method for predicting cutting force of cylindrical gear slotting